Movement disorders and normal aging
Identifieur interne : 000016 ( Istex/Corpus ); précédent : 000015; suivant : 000017Movement disorders and normal aging
Auteurs : Padma R. Mahant ; Mark A. StacySource :
- Neurologic Clinics [ 0733-8619 ] ; 2001.
Url:
DOI: 10.1016/S0733-8619(05)70034-7
Links to Exploration step
ISTEX:F5189D93C275183A1E0C46319EA89B601DD445C0Le document en format XML
<record><TEI wicri:istexFullTextTei="biblStruct"><teiHeader><fileDesc><titleStmt><title>Movement disorders and normal aging</title><author><name sortKey="Mahant, Padma R" sort="Mahant, Padma R" uniqKey="Mahant P" first="Padma R." last="Mahant">Padma R. Mahant</name><affiliation><mods:affiliation>From the Movement Disorders, Muhammad Ali Parkinson Research Center at Barrow Neurological Institute, Phoenix, Arizona</mods:affiliation></affiliation></author><author><name sortKey="Stacy, Mark A" sort="Stacy, Mark A" uniqKey="Stacy M" first="Mark A." last="Stacy">Mark A. Stacy</name><affiliation><mods:affiliation>From the Movement Disorders, Muhammad Ali Parkinson Research Center at Barrow Neurological Institute, Phoenix, Arizona</mods:affiliation></affiliation></author></titleStmt><publicationStmt><idno type="wicri:source">ISTEX</idno><idno type="RBID">ISTEX:F5189D93C275183A1E0C46319EA89B601DD445C0</idno><date when="2001" year="2001">2001</date><idno type="doi">10.1016/S0733-8619(05)70034-7</idno><idno type="url">https://api.istex.fr/document/F5189D93C275183A1E0C46319EA89B601DD445C0/fulltext/pdf</idno><idno type="wicri:Area/Istex/Corpus">000016</idno><idno type="wicri:explorRef" wicri:stream="Istex" wicri:step="Corpus" wicri:corpus="ISTEX">000016</idno></publicationStmt><sourceDesc><biblStruct><analytic><title level="a">Movement disorders and normal aging</title><author><name sortKey="Mahant, Padma R" sort="Mahant, Padma R" uniqKey="Mahant P" first="Padma R." last="Mahant">Padma R. Mahant</name><affiliation><mods:affiliation>From the Movement Disorders, Muhammad Ali Parkinson Research Center at Barrow Neurological Institute, Phoenix, Arizona</mods:affiliation></affiliation></author><author><name sortKey="Stacy, Mark A" sort="Stacy, Mark A" uniqKey="Stacy M" first="Mark A." last="Stacy">Mark A. Stacy</name><affiliation><mods:affiliation>From the Movement Disorders, Muhammad Ali Parkinson Research Center at Barrow Neurological Institute, Phoenix, Arizona</mods:affiliation></affiliation></author></analytic><monogr></monogr><series><title level="j">Neurologic Clinics</title><title level="j" type="abbrev">NCL</title><idno type="ISSN">0733-8619</idno><imprint><publisher>ELSEVIER</publisher><date type="published" when="2001">2001</date><biblScope unit="volume">19</biblScope><biblScope unit="issue">3</biblScope><biblScope unit="page" from="553">553</biblScope><biblScope unit="page" to="563">563</biblScope></imprint><idno type="ISSN">0733-8619</idno></series><idno type="istex">F5189D93C275183A1E0C46319EA89B601DD445C0</idno><idno type="DOI">10.1016/S0733-8619(05)70034-7</idno><idno type="PII">S0733-8619(05)70034-7</idno></biblStruct></sourceDesc><seriesStmt><idno type="ISSN">0733-8619</idno></seriesStmt></fileDesc><profileDesc><textClass></textClass><langUsage><language ident="en">en</language></langUsage></profileDesc></teiHeader></TEI><istex><corpusName>elsevier</corpusName><author><json:item><name>Padma R. Mahant MD</name><affiliations><json:string>From the Movement Disorders, Muhammad Ali Parkinson Research Center at Barrow Neurological Institute, Phoenix, Arizona</json:string></affiliations></json:item><json:item><name>Mark A. Stacy MD</name><affiliations><json:string>From the Movement Disorders, Muhammad Ali Parkinson Research Center at Barrow Neurological Institute, Phoenix, Arizona</json:string></affiliations></json:item></author><language><json:string>eng</json:string></language><originalGenre><json:string>N/A</json:string></originalGenre><qualityIndicators><score>4.803</score><pdfVersion>1.3</pdfVersion><pdfPageSize>432 x 648 pts</pdfPageSize><refBibsNative>true</refBibsNative><keywordCount>0</keywordCount><abstractCharCount>0</abstractCharCount><pdfWordCount>4791</pdfWordCount><pdfCharCount>30094</pdfCharCount><pdfPageCount>11</pdfPageCount><abstractWordCount>1</abstractWordCount></qualityIndicators><title>Movement disorders and normal aging</title><pii><json:string>S0733-8619(05)70034-7</json:string></pii><genre><json:string>other</json:string></genre><host><volume>19</volume><pii><json:string>S0733-8619(05)X7003-7</json:string></pii><pages><last>563</last><first>553</first></pages><issn><json:string>0733-8619</json:string></issn><issue>3</issue><genre><json:string>journal</json:string></genre><language><json:string>unknown</json:string></language><title>Neurologic Clinics</title><publicationDate>2001</publicationDate></host><categories><wos><json:string>science</json:string><json:string>neurosciences</json:string><json:string>clinical neurology</json:string></wos><scienceMetrix><json:string>health sciences</json:string><json:string>clinical medicine</json:string><json:string>neurology & neurosurgery</json:string></scienceMetrix></categories><publicationDate>2001</publicationDate><copyrightDate>2001</copyrightDate><doi><json:string>10.1016/S0733-8619(05)70034-7</json:string></doi><id>F5189D93C275183A1E0C46319EA89B601DD445C0</id><score>0.15656045</score><fulltext><json:item><extension>pdf</extension><original>true</original><mimetype>application/pdf</mimetype><uri>https://api.istex.fr/document/F5189D93C275183A1E0C46319EA89B601DD445C0/fulltext/pdf</uri></json:item><json:item><extension>zip</extension><original>false</original><mimetype>application/zip</mimetype><uri>https://api.istex.fr/document/F5189D93C275183A1E0C46319EA89B601DD445C0/fulltext/zip</uri></json:item><istex:fulltextTEI uri="https://api.istex.fr/document/F5189D93C275183A1E0C46319EA89B601DD445C0/fulltext/tei"><teiHeader><fileDesc><titleStmt><title level="a">Movement disorders and normal aging</title></titleStmt><publicationStmt><authority>ISTEX</authority><publisher>ELSEVIER</publisher><availability><p>©2001 W. B. Saunders Company</p></availability><date>2001</date></publicationStmt><notesStmt><note>Address reprint requests to, Mark A. Stacy, MD, Muhammad Ali Parkinson Research Center, 500 W. Thomas Avenue, Suite 700, Phoenix, AZ 85013</note><note type="content">Section title: Movement Disorders and Normal Aging</note></notesStmt><sourceDesc><biblStruct type="inbook"><analytic><title level="a">Movement disorders and normal aging</title><author xml:id="author-1"><persName><forename type="first">Padma R.</forename><surname>Mahant</surname></persName><roleName type="degree">MD</roleName><affiliation>From the Movement Disorders, Muhammad Ali Parkinson Research Center at Barrow Neurological Institute, Phoenix, Arizona</affiliation></author><author xml:id="author-2"><persName><forename type="first">Mark A.</forename><surname>Stacy</surname></persName><roleName type="degree">MD</roleName><affiliation>From the Movement Disorders, Muhammad Ali Parkinson Research Center at Barrow Neurological Institute, Phoenix, Arizona</affiliation></author></analytic><monogr><title level="j">Neurologic Clinics</title><title level="j" type="abbrev">NCL</title><idno type="pISSN">0733-8619</idno><idno type="PII">S0733-8619(05)X7003-7</idno><imprint><publisher>ELSEVIER</publisher><date type="published" when="2001"></date><biblScope unit="volume">19</biblScope><biblScope unit="issue">3</biblScope><biblScope unit="page" from="553">553</biblScope><biblScope unit="page" to="563">563</biblScope></imprint></monogr><idno type="istex">F5189D93C275183A1E0C46319EA89B601DD445C0</idno><idno type="DOI">10.1016/S0733-8619(05)70034-7</idno><idno type="PII">S0733-8619(05)70034-7</idno></biblStruct></sourceDesc></fileDesc><profileDesc><creation><date>2001</date></creation><langUsage><language ident="en">en</language></langUsage></profileDesc><revisionDesc><change when="2001">Published</change></revisionDesc></teiHeader></istex:fulltextTEI><json:item><extension>txt</extension><original>false</original><mimetype>text/plain</mimetype><uri>https://api.istex.fr/document/F5189D93C275183A1E0C46319EA89B601DD445C0/fulltext/txt</uri></json:item></fulltext><metadata><istex:metadataXml wicri:clean="Elsevier doc found" wicri:toSee="Elsevier, no converted or simple article"><istex:xmlDeclaration>version="1.0" encoding="UTF-8"</istex:xmlDeclaration><istex:docType PUBLIC="-//ES//DTD journal article DTD version 5.0.1//EN//XML" URI="art501.dtd" name="istex:docType"></istex:docType><istex:document><article> <item-info> <jid>NCL</jid> <aid>70034</aid> <ce:pii>S0733-8619(05)70034-7</ce:pii><ce:doi>10.1016/S0733-8619(05)70034-7</ce:doi> <ce:copyright type="other" year="2001">W. B. Saunders Company</ce:copyright> </item-info> <head> <ce:article-footnote> <ce:note-para>Address reprint requests to, Mark A. Stacy, MD, Muhammad Ali Parkinson Research Center, 500 W. Thomas Avenue, Suite 700, Phoenix, AZ 85013</ce:note-para> </ce:article-footnote> <ce:dochead> <ce:textfn>Movement Disorders and Normal Aging</ce:textfn> </ce:dochead> <ce:title>Movement disorders and normal aging</ce:title> <ce:author-group> <ce:author> <ce:given-name>Padma R.</ce:given-name> <ce:surname>Mahant</ce:surname> <ce:degrees>MD</ce:degrees> </ce:author> <ce:author> <ce:given-name>Mark A.</ce:given-name> <ce:surname>Stacy</ce:surname> <ce:degrees>MD</ce:degrees> </ce:author> <ce:affiliation> <ce:textfn>From the Movement Disorders, Muhammad Ali Parkinson Research Center at Barrow Neurological Institute, Phoenix, Arizona</ce:textfn> </ce:affiliation> </ce:author-group> </head> <body> <ce:sections> <ce:para>Movement disorders are particularly prevalent in the elderly. Disorders of gait and mobility are second only to cognitive impairment as the most frequent neurologic effects of aging.<ce:cross-ref refid="bib40"><ce:sup>40</ce:sup></ce:cross-ref> In 1998, there were 34.4 million Americans over the age of 65,<ce:cross-ref refid="bib80"><ce:sup>80</ce:sup></ce:cross-ref> and the United States Census Bureau projects that by the middle of the century the population of persons 65 years and over will reach 80 million.<ce:cross-ref refid="bib79"><ce:sup>79</ce:sup></ce:cross-ref> In addition, the rate of elderly population growth is more rapid in developing countries than in developed countries.<ce:cross-ref refid="bib79"><ce:sup>79</ce:sup></ce:cross-ref></ce:para> <ce:para>As the proportion of Americans over the age of 65 increases from one in eight to one in five by 2030,<ce:cross-ref refid="bib79"><ce:sup>79</ce:sup></ce:cross-ref> it is important for clinicians to be able to recognize the effects of normal aging. Furthermore, it is essential to distinguish age–related changes from diseases that accompany aging. The influence of normal aging on the evaluation of major hypokinetic and hyperkinetic movement disorders, including Parkinson's disease (PD) and essential tremor (ET), will be discussed.</ce:para> <ce:section id="cesec1"> <ce:section-title>The Basis of Motor Impairment in Normal Aging</ce:section-title> <ce:para>Age–related anatomic and pathologic changes in older adults consist of loss of volume in cerebral hemispheres, diminution of brain weight, gyral atrophy, ventricular dilatation, and decreased cortical thickness.<ce:cross-refs refid="bib12 bib67 bib76"><ce:sup>12,67,76</ce:sup></ce:cross-refs> Shrinkage of large neurons predominates, resulting in an increase in small neurons and glia, particularly in the midfrontal and superior temporal cortices.<ce:cross-ref refid="bib76"><ce:sup>76</ce:sup></ce:cross-ref> Cerebellar atrophy has been demonstrated in normal aging as well.<ce:cross-ref refid="bib35"><ce:sup>35</ce:sup></ce:cross-ref> Regional cerebral blood flow, measured by Xenon CT scanning, declines in the elderly, particularly in the prefrontal, parietal, inferior temporal, frontotemporal regions, as well as the subcortical gray matter of the thalamus, putamen, and caudate.<ce:cross-ref refid="bib47"><ce:sup>47</ce:sup></ce:cross-ref> This decline may reflect a higher prevalence of arteriosclerotic changes in the elderly, or age–related declines in metabolic demands of the brain.<ce:cross-ref refid="bib47"><ce:sup>47</ce:sup></ce:cross-ref> FDG–PET has been used to explore metabolic topography of normal aging, and frontal, specifically premotor cortex, hypometabolism has been demonstrated.<ce:cross-ref refid="bib49"><ce:sup>49</ce:sup></ce:cross-ref></ce:para> <ce:para>Anatomic and pathologic changes that affect dopaminergic function have been widely studied in PD and normal aging. In both instances, the width of the substantia nigra pars compacta, as measured by MRI, is directly associated with motor function.<ce:cross-ref refid="bib59"><ce:sup>59</ce:sup></ce:cross-ref> In normal aging, this decline is correlated with poor performance on motor tasks; in PD patients, the reduction in substentia nigra pars compacta width is associated with poor motor performance and higher UPDRS motor scores.<ce:cross-ref refid="bib59"><ce:sup>59</ce:sup></ce:cross-ref> Furthermore, autopsy review has demonstrated an age–related loss of neurons in the zona compacta of the substantia nigra of approximately 6% per year.<ce:cross-ref refid="bib46"><ce:sup>46</ce:sup></ce:cross-ref> The pathologic changes in normal aging and PD, although similar, should not be considered equivalent; Kish et al have estimated that the 80%–90% striatal dopamine loss necessary to develop parkinsonism would not occur in an individual with normal age–related dopamine decline until the age of 110, far beyond the current average life expectancy.<ce:cross-ref refid="bib32"><ce:sup>32</ce:sup></ce:cross-ref> In addition, the pattern of dopamine loss observed in the putamen and caudate is uniform in normal aging, while putamenal loss is more severe in PD.<ce:cross-ref refid="bib32"><ce:sup>32</ce:sup></ce:cross-ref> Although the mechanism of cell loss in normal aging is unknown, apoptosis, with nuclear and cytoplasmic shrinkage and aggregation of neuromelanin, similar to the cell death observed in PD, has been demonstrated.<ce:cross-ref refid="bib78"><ce:sup>78</ce:sup></ce:cross-ref></ce:para> <ce:para>Neurochemical alterations specifically affecting dopaminergic function are also known to occur with aging. Severe loss of striatal tyrosine hydroxylase, the rate-controlling enzyme in the synthesis of dopamine, as well as dopamine transporters, vesicular monoamine transporters, and D2 receptors have been demonstrated.<ce:cross-refs refid="bib13 bib46 bib58"><ce:sup>13,46,58</ce:sup></ce:cross-refs> Monoamine oxidase (MAO) has been shown to be consistently elevated in the frontal cortex, striatum, globus pallidus, and substantia nigra pars compacta in normal elderly subjects.<ce:cross-refs refid="bib13 bib72"><ce:sup>13,72</ce:sup></ce:cross-refs> Increased MAO may hasten degradation of dopamine and norepinephrine to produce elevated concentrations of monoamine catabolites reported in the cerebrospinal fluid of elderly patients.<ce:cross-ref refid="bib72"><ce:sup>72</ce:sup></ce:cross-ref></ce:para> </ce:section> <ce:section id="cesec2"> <ce:section-title>Clinical Manifestations of Normal Aging</ce:section-title> <ce:para>The neurochemical, neuroanatomic, and neuropathologic changes that occur in normal aging impart gradual declines in cognition, motor function, sensation, coordination, balance, and ambulation. The aggregation of these changes, which are further magnified by impaired integration of these systems, results in the picture of declining mobility in the elderly.</ce:para> <ce:para>Frontal lobe dysfunction has been postulated to explain the decline in visuospatial perception, information processing, and reaction speed associated with both aging and PD.<ce:cross-refs refid="bib5 bib10 bib11 bib20 bib48 bib49 bib56 bib63 bib67"><ce:sup>5,10,11,20,48,49,56,63,67</ce:sup></ce:cross-refs> Fozard et al studied reaction times to auditory stimuli as part of the Baltimore Longitudinal Study of Aging, and found that reaction time increases at a rate of 0.5–1.6 milliseconds (ms) per year, starting at age 20. In this paradigm the mean simple reaction time of 225 ms in the second decade increases to 273 ms by the eighth decade.<ce:cross-ref refid="bib17"><ce:sup>17</ce:sup></ce:cross-ref> Simple reaction times in PD patients are significantly slower than reaction times in healthy controls. Wang et al have estimated a slowing of 34% in PD patients compared with healthy controls.<ce:cross-ref refid="bib82"><ce:sup>82</ce:sup></ce:cross-ref> Slower simple reaction times in PD patients have been linked to difficulty with preprogramming of motor responses, and the premotor, supplementary cortex has been implicated in this deficit.<ce:cross-ref refid="bib7"><ce:sup>7</ce:sup></ce:cross-ref></ce:para> <ce:para>Oculomotor dysfunction, in particular vertical gaze palsy, is seen in several movement disorders, including PD and progressive supranuclear palsy.<ce:cross-ref refid="bib61"><ce:sup>61</ce:sup></ce:cross-ref> Kaye et al used standardized criteria for testing eye movements to find significant declines in upgaze, pursuit, and saccadic function with aging.<ce:cross-ref refid="bib30"><ce:sup>30</ce:sup></ce:cross-ref> The average limitation in upgaze of 5.9% in otherwise normal subjects ages 65 to 74 increased to 64.7% in those over 84 years.<ce:cross-ref refid="bib30"><ce:sup>30</ce:sup></ce:cross-ref> Others have reported vertical gaze impairment in approximately 30% of individuals in the eighth decade of life.<ce:cross-ref refid="bib29"><ce:sup>29</ce:sup></ce:cross-ref></ce:para> <ce:para>Motor examination often reveals muscle atrophy, increased tone, reduced power, and declining motor speed in the elderly population. In addition, musculoskeletal abnormalities in the elderly may result in focal pain and mechanical restriction of movement, which may be mistaken for bradykinesia.<ce:cross-refs refid="bib50 bib61"><ce:sup>50,61</ce:sup></ce:cross-refs> A community population study by Bennet et al revealed lower extremity rigidity in approximately 45% of individuals over the age of 85.<ce:cross-ref refid="bib4"><ce:sup>4</ce:sup></ce:cross-ref> The increased tone generally takes the form of paratonic rigidity, which is described as progressively increased or irregular resistance to passive movement.<ce:cross-ref refid="bib61"><ce:sup>61</ce:sup></ce:cross-ref> Potvin et al have demonstrated a decrease in power from 21% to 45% in arms and legs when comparing subjects ages 20 to 80.<ce:cross-ref refid="bib57"><ce:sup>57</ce:sup></ce:cross-ref> Hand and foot speeds also declined from ages 20 to 80, as demonstrated by hand tapping and step tracking movement.<ce:cross-ref refid="bib57"><ce:sup>57</ce:sup></ce:cross-ref> Testing of coordination tasks in this same population revealed a 14%–27% decline in performance on various coordination tests, such as inter-finger manipulation, finger grasping and progressive arm tracking.<ce:cross-ref refid="bib57"><ce:sup>57</ce:sup></ce:cross-ref> Additionally, testing of simulated activities of daily living revealed an average loss in function of 30% from ages 20 to 80.<ce:cross-ref refid="bib57"><ce:sup>57</ce:sup></ce:cross-ref> These activities included managing small and large buttons, manipulating safety pins, zipping garments, tying bows, rotating pegs, handwriting speed, and cutting with a knife.<ce:cross-ref refid="bib57"><ce:sup>57</ce:sup></ce:cross-ref> Similar complaints are noted by patients with PD.</ce:para> <ce:para>Electromyographic studies in the elderly have revealed increases in amplitude, duration, and complexity of motor unit action potentials, indicative of increasing motor unit size; this may reflect age–related denervation with compensatory reinnervation, loss of anterior horn motor cells, or degeneration of anterior spinal roots or peripheral motor nerves.<ce:cross-ref refid="bib24"><ce:sup>24</ce:sup></ce:cross-ref> Furthermore, decreased motor unit firing rates have been described, suggesting age–related changes in upper motor neuron function or central drive.<ce:cross-ref refid="bib24"><ce:sup>24</ce:sup></ce:cross-ref> Motor control laboratories have reported decreased end–point accuracy in the upper limbs with increased trajectory variability in elderly subjects aged 68 to 95 for arm movements during the acceleration and deceleration phases of movement. These changes were attributed to altered motor neuron population or abnormal control of antagonist muscle activity.<ce:cross-ref refid="bib11"><ce:sup>11</ce:sup></ce:cross-ref></ce:para> <ce:para>Sensory examination of the elderly often reveals impairment in primary sensory modalities, such as vibration and proprioception, stereognosis, and two-point discrimination.<ce:cross-refs refid="bib8 bib30 bib52 bib57 bib81"><ce:sup>8,30,52,57,81</ce:sup></ce:cross-refs> Potvin et al have reported a 64%, 86%, and 97% decline in vibratory sensation at the wrist, ankle, and great toe, respectively, when comparing elderly subjects with young controls.<ce:cross-ref refid="bib57"><ce:sup>57</ce:sup></ce:cross-ref> Cole evaluated tests of two–point discrimination which revealed an inability of elderly subjects (ages 71–92 years) to perceive two points at separation distances less than 2.0 mm, whereas none of the control group (ages 17–32 years) required distances of separation greater than 2.0 mm.<ce:cross-ref refid="bib8"><ce:sup>8</ce:sup></ce:cross-ref> Grip forces in the elderly group were, on average, over twice as large as the control group, suggesting that impaired sensory discrimination may lead to increased grip forces and limited dexterity.<ce:cross-ref refid="bib8"><ce:sup>8</ce:sup></ce:cross-ref></ce:para> <ce:para>Balance and postural control are accomplished through the integration of intact somatosensory systems, vestibular input, central postural reflexes, and motor output. Sensory ataxia results from decline in proprioception and vibratory sensation, frequently observed in the elderly. Vestibular and visual function are special senses necessary for postural control that also decline with age.<ce:cross-refs refid="bib45 bib54"><ce:sup>45,54</ce:sup></ce:cross-refs> Under test conditions where somatosensory input is limited, older persons lose their balance much more frequently than younger persons.<ce:cross-refs refid="bib15 bib43 bib84"><ce:sup>15,43,84</ce:sup></ce:cross-refs></ce:para> <ce:para>Sway results from alternating agonist and antagonist muscle activity in the legs and trunk and is required for maintenance of upright stance. Although changes in the activity of these muscles are usually imperceptible, sway is exaggerated in the normal elderly person, resulting in postural instability.<ce:cross-refs refid="bib43 bib53 bib84"><ce:sup>43,53,84</ce:sup></ce:cross-refs> Studies have suggested the elderly have disordered coordination of postural reflexes with voluntary sway.<ce:cross-refs refid="bib15 bib74 bib85"><ce:sup>15,74,85</ce:sup></ce:cross-refs> Stelmach et al studied age–related changes in functional relationships between postural reflexes and voluntary movement through electromyography and found that older adults (ages 61–78) had slower, less reliable postural reflexes that were less responsive to the demands of voluntary movement.<ce:cross-ref refid="bib74"><ce:sup>74</ce:sup></ce:cross-ref> These investigators also found that functional muscles were less likely to be activated at the same time on the right and left sides, and older adults displayed less inhibition of inappropriate muscle activity.<ce:cross-ref refid="bib74"><ce:sup>74</ce:sup></ce:cross-ref> To complicate this picture, anteroposterior displacement, a measure of the functional base of support, decreases by about 33% from the third to the eighth decades;<ce:cross-ref refid="bib31"><ce:sup>31</ce:sup></ce:cross-ref> and is further reduced in patients with PD.<ce:cross-ref refid="bib66"><ce:sup>66</ce:sup></ce:cross-ref></ce:para> <ce:para>Ambulation requires integration of intact sensory, motor, cerebellar, and higher cortical pathways. Differentiation between gait disorders caused by disease and gait changes related to age is important, as a treatable cause may be found in approximately 25% of cases.<ce:cross-ref refid="bib75"><ce:sup>75</ce:sup></ce:cross-ref> The diagnosis of treatable causes is made possible through detailed musculoskeletal, sensory, motor, and reflex examinations. One community study revealed musculoskeletal causes as more common than neurologic causes of gait impairment in the elderly,<ce:cross-ref refid="bib42"><ce:sup>42</ce:sup></ce:cross-ref> and skeletal surveys reveal evidence of osteoarthritis in up to 85% of the population beyond 74 years.<ce:cross-ref refid="bib50"><ce:sup>50</ce:sup></ce:cross-ref> Age–related factors contributing to impaired ambulation include decreased speed and stride length and one common denominators in gait disturbances of various neurologic etiologies.<ce:cross-ref refid="bib15"><ce:sup>15</ce:sup></ce:cross-ref> Some investigators suggest these changes to be a function of increased joint stiffness, decreased proximal muscle strength, energy conservation strategies, or increased “double support time,” defined as the amount of time during a stride when both feet have contact with the ground, which can serve to improve balance.<ce:cross-refs refid="bib1 bib14 bib15 bib75"><ce:sup>1,14,15,75</ce:sup></ce:cross-refs> Speed decline is approximately 1.6% per year after age 63 in subjects free of orthopedic, cardiopulmonary, neurologic, or cognitive problems.<ce:cross-ref refid="bib22"><ce:sup>22</ce:sup></ce:cross-ref> Walking speed is a crucial factor in crossing intersections safely. Howie and Rubinstein found that 27% of 592 older adult pedestrians were unable to reach the opposite curb in the usual amount of time allowed for pedestrians crossing an intersection.<ce:cross-ref refid="bib25"><ce:sup>25</ce:sup></ce:cross-ref></ce:para> <ce:para>Senile gait disorder is traditionally described as a gait disorder associated with aging, unrelated to systemic or neurologic disease, but some have suggested that senile gait disorder might represent the preclinical phase of a slowly evolving neurologic disorder. A number of reports have linked cognitive decline,<ce:cross-ref refid="bib86"><ce:sup>86</ce:sup></ce:cross-ref> extra-pyramidal dysfunction,<ce:cross-ref refid="bib9"><ce:sup>9</ce:sup></ce:cross-ref> musculoskeletal abnormalities,<ce:cross-ref refid="bib73"><ce:sup>73</ce:sup></ce:cross-ref> or ventriculomegaly<ce:cross-ref refid="bib37"><ce:sup>37</ce:sup></ce:cross-ref> to this condition. Clinically, senile gait disorder is characterized by the gradual development of a broad-based gait with small steps, diminished arm swing, stooped posture, flexion at hips and knees, difficulty with turning and initiating steps, or tendency toward falling.<ce:cross-ref refid="bib9"><ce:sup>9</ce:sup></ce:cross-ref> Patients with senile gait disorder walk less than half as fast as healthy older adults, with shorter stride lengths, an increased percent of stride in double support, and abnormal foot-floor contact and clearance.<ce:cross-ref refid="bib6"><ce:sup>6</ce:sup></ce:cross-ref> Although gait impairment is common in the elderly, it should be emphasized that it is not an inevitable result of aging,<ce:cross-ref refid="bib6"><ce:sup>6</ce:sup></ce:cross-ref> and it has been repeatedly demonstrated that exercise or an active lifestyle can result in significant gait improvement.<ce:cross-refs refid="bib3 bib16 bib23 bib44 bib65 bib86"><ce:sup>3,16,23,44,65,86</ce:sup></ce:cross-refs></ce:para> </ce:section> <ce:section id="cesec3"> <ce:section-title>Hypokinetic Movement Disorders and Normal Aging</ce:section-title> <ce:para>PD affects approximately 1% of the general population over 60 years of age, and 1.5 million Americans. Although some signs of PD, such as bradykinesia, rigidity, and postural instability, may be seen with normal aging, the degree of impairment is much greater in PD patients. Other factors that differentiate normal aging from PD include absence of rest tremor, symmetric neurologic findings, and lack of response to dopaminergic therapy.<ce:cross-refs refid="bib51 bib55 bib61"><ce:sup>51,55,61</ce:sup></ce:cross-refs></ce:para> <ce:para>In an effort to estimate the prevalence of parkinsonian signs in the elderly, Bennett et al studied 467 normal elderly residents over the age of 65 in a Boston community by structured neurologic examination.<ce:cross-ref refid="bib4"><ce:sup>4</ce:sup></ce:cross-ref> The study revealed several age-specific trends for bradykinesia, rigidity, and gait disturbance. The prevalence of bradykinesia, represented in this study by paucity of movements of the face and extremities and slow finger taps, was estimated at 30.1% for individuals aged 85 and older. Lower extremity rigidity was present in 43.3%–46.3% of individuals over age 85. Gait disturbance, reflected by reduced arm swing, shuffling gait, and prolonged turning, also increased with age. Shuffling gait was observed in 6.4% of individuals in the 65–74 age group, and 29.7% of individuals in the 85 and older age group. Furthermore, the presence of two or more of these categories—criteria used in the diagnosis of early PD—also increased with age: 14.9% in the 65 to 74 age group, 29.5% in the 75 to 84 age group, and 52.4% in the age group over 85.<ce:cross-ref refid="bib4"><ce:sup>4</ce:sup></ce:cross-ref></ce:para> <ce:para>Age has been described as a significant risk factor in the development of parkinsonian signs, and age may also have a significant influence on the course of PD. PD is primarily a disease of older individuals, with the mean age of onset in the seventh decade, although rarely it may begin during the third or fourth decade of life.<ce:cross-ref refid="bib68"><ce:sup>68</ce:sup></ce:cross-ref> Zetusky et al noted that patients with tremor had an earlier age of onset and a more benign course.<ce:cross-ref refid="bib87"><ce:sup>87</ce:sup></ce:cross-ref> Earlier age of onset is more often associated with motor fluctuations and dystonia, and later age of onset of PD correlates with gait disturbance, postural instability, dementia, and increased susceptibility to adverse effects of PD medications.<ce:cross-refs refid="bib19 bib39 bib68 bib87"><ce:sup>19,39,68,87</ce:sup></ce:cross-refs></ce:para> </ce:section> <ce:section id="cesec4"> <ce:section-title>Hyperkinetic Movement Disorders in Normal Aging</ce:section-title> <ce:para>Hyperkinetic disorders include tremor, chorea, myoclonus, tics and stereotypies. Tremor is defined as a regular, rhythmical oscillatory movement resulting from alternating contraction of agonist and antagonist muscle groups. Essential tremor (ET) is estimated to affect five million individuals in the United States, and increases dramatically with age.<ce:cross-refs refid="bib34 bib61"><ce:sup>34,61</ce:sup></ce:cross-refs> Rajput et al retrospectively studied ET in Rochester, Minnesota and found the following age–specific annual incidence rates per 100,000: 72.6 between the ages of 60 and 69, 105.8 between the ages of 70 and 79, and 135.7 in those over 80 years of age.<ce:cross-ref refid="bib60"><ce:sup>60</ce:sup></ce:cross-ref> Prevalence rates of ET were studied in a Finnish population, and rates increased from 6.84% in ages 60–69, to 12.6% in ages 70–79.<ce:cross-ref refid="bib62"><ce:sup>62</ce:sup></ce:cross-ref> Although essential tremor is commonly mistaken as a feature of “old age,” a strong family history and more recently identified genetic markers suggest that ET has a genetic basis and is not simply the product of normal aging.<ce:cross-ref refid="bib34"><ce:sup>34</ce:sup></ce:cross-ref></ce:para> <ce:para>Several effects of aging have been identified in patients with ET, most notably a slow progression over many years, with an increase in amplitude or a spread to involve other body parts than those involved at the onset of tremor.<ce:cross-ref refid="bib36"><ce:sup>36</ce:sup></ce:cross-ref> Others report lower–frequency tremor, less hand involvement and less associated dystonia in older subjects compared with younger subjects,<ce:cross-ref refid="bib41"><ce:sup>41</ce:sup></ce:cross-ref> and increased difficulty with tandem walking.<ce:cross-ref refid="bib26"><ce:sup>26</ce:sup></ce:cross-ref> Jankovic et al studied the longevity and frequency of familial tremor in relatives of patients with ET, PD, and healthy controls, and found that parents with tremor lived 9.2 years on average longer than those without tremor.<ce:cross-ref refid="bib28"><ce:sup>28</ce:sup></ce:cross-ref></ce:para> <ce:para>Chorea is an irregular, rapid series of movements that flow from one body part to another, without a predictable pattern, and is most often seen in patients with Huntington's disease (HD). Senile chorea is rare and slowly progressive, with generalized symmetric choreiform movements usually beginning in the face or upper limbs, in the absence of other movement disorders, dementia, family history, or neuroleptic exposure. Senile chorea and sporadic, late–onset Huntington's disease (HD) may be clinically indistinguishable. One prospective multicenter study revealed a diagnosis of sporadic, late–onset HD in three of six patients who met clinical criteria for senile chorea; in these patients, abnormal expansions of CAG repeats (IT15) on chromosome 4 were in the lower limits of abnormality (38–40 triplets), perhaps explaining the mild clinical symptoms in these patients.<ce:cross-ref refid="bib18"><ce:sup>18</ce:sup></ce:cross-ref></ce:para> <ce:para>Tardive dyskinesia represents a wide variety of involuntary movement, including chorea, dystonia, akathisia, stereotypies, myoclonus and tremor, that result from exposure to dopamine receptor blocking agents, such as phenothiazines or anti-emetic drugs.<ce:cross-ref refid="bib71"><ce:sup>71</ce:sup></ce:cross-ref> The overall prevalence rate of tardive dyskinesia among individuals exposed to these agents is approximately 13.9 %.<ce:cross-ref refid="bib21"><ce:sup>21</ce:sup></ce:cross-ref> There are reports that 64% of psychiatric patients over the age of 70, compared with 14.8% of patients in the third to fifth decades of life are affected.<ce:cross-ref refid="bib69"><ce:sup>69</ce:sup></ce:cross-ref> Loss of D<ce:inf>2</ce:inf> receptors in the neostriatum has been associated with this iatrogenic movement disorder,<ce:cross-ref refid="bib13"><ce:sup>13</ce:sup></ce:cross-ref> although little is known about the exact pathophysiology.</ce:para> <ce:para>The most common manifestation of tardive dyskinesia is stereotypy, or rhythmic involuntary movements.<ce:cross-ref refid="bib70"><ce:sup>70</ce:sup></ce:cross-ref> In a review of 100 consecutive patients with tardive dyskinesia, Stacy et al found that 78% of patients manifested stereotypies, with 61 patients demonstrating “classic” orofacial movements.<ce:cross-ref refid="bib70"><ce:sup>70</ce:sup></ce:cross-ref> These orofacial stereotypies are indistinguishable from spontaneous oral–lingual–buccal dyskinesias, which occur in the absence of exposure to neuroleptics.<ce:cross-ref refid="bib83"><ce:sup>83</ce:sup></ce:cross-ref> Klawans and Barr studied the incidence of spontaneous lingual–facial–buccal dyskinesias and found a 6.8% overall incidence between the ages of 60 and 79; this incidence, similar to tardive dyskinesia, increases with age.<ce:cross-ref refid="bib33"><ce:sup>33</ce:sup></ce:cross-ref> Koller studied 75 consecutive edentulous patients, not previously exposed to neuroleptics, in a Veterans Administration dental clinic, and found that 16% of edentulous patients had orofacial dyskinesia.<ce:cross-ref refid="bib38"><ce:sup>38</ce:sup></ce:cross-ref> Ill fitting or no dentures, were thought to be a risk factor for patients with orofacial dyskinesias.<ce:cross-ref refid="bib38"><ce:sup>38</ce:sup></ce:cross-ref></ce:para> <ce:para>The similarities between spontaneous choreiform movements of senile chorea and tardive stereotypy suggest exposure to dopamine receptor blocking agents may hasten the “release” of primitive motor circuits with advancing age. Primitive reflexes, or “release” phenomena, resulting from impaired cerebral inhibition of lower centers, are common in neurodegenerative disorders.<ce:cross-ref refid="bib61"><ce:sup>61</ce:sup></ce:cross-ref> Moreover, several studies have revealed increased primitive reflexes, such as snout, grasp, and palmomental reflexes, in the normal elderly population.<ce:cross-refs refid="bib27 bib30 bib52"><ce:sup>27,30,52</ce:sup></ce:cross-refs> Prevalence rates in one study for the snout reflex were 33% in the 65–74 age group, compared with 73% in the 85+ age group; prevalence rates for the grasp reflex were 27% in the 65–74 age group, compared with 67% in the 85+ age group.<ce:cross-ref refid="bib52"><ce:sup>52</ce:sup></ce:cross-ref> The incidence of the palmomental reflex in another study was 20% in the fifth decade compared with 60% in the ninth decade.<ce:cross-ref refid="bib27"><ce:sup>27</ce:sup></ce:cross-ref></ce:para> <ce:para>Other hyperkinetic disorders that occur with increased frequency in the elderly population include dystonia, hemiballismus, myoclonus, and periodic limb movements of sleep. Most adult-onset focal dystonias have onset in the fourth to sixth decades; the onset of blepharospasm is generally in the sixth decade.<ce:cross-ref refid="bib77"><ce:sup>77</ce:sup></ce:cross-ref> Hemiballismus most often occurs in the setting of stroke, which is a common disorder of aging.<ce:cross-ref refid="bib61"><ce:sup>61</ce:sup></ce:cross-ref> Myoclonus may occur in the setting of metabolic derangements and certain neurodegenerative disorders that have increased frequency with age, such as Alzheimer's disease, Creuzfeldt–Jakob disease, or corticobasal degeneration.<ce:cross-ref refid="bib61"><ce:sup>61</ce:sup></ce:cross-ref> High prevalence rates for periodic leg movements of sleep (PLMS) are seen in the general population over the age of 65. In one community study, 427 individuals, ages 65 and over, were evaluated for signs of PLMS, with 45% demonstrating highly suggestive symptoms.</ce:para> </ce:section> <ce:section id="cesec5"> <ce:section-title>Summary</ce:section-title> <ce:para>Normal aging is associated with a variety of changes in the nervous system, many of which manifest as motor impairment. While every effort should be made to determine possible treatable causes for motor decline or involuntary movements in the normal elderly individual, treatment most often will be of a conservative nature, and should include physical therapy or occupational therapy. It should be emphasized that significant neurologic deterioration is not an inevitable aspect of aging. Recent articles and studies have focused on differentiating “successful” aging from “usual”aging.<ce:cross-refs refid="bib30 bib52 bib64"><ce:sup>30,52,64</ce:sup></ce:cross-refs> The challenge for future studies will be to determine those factors that lead to successful aging, thereby allowing clinicians to educate patients on how to achieve optimal health in their later years.</ce:para> </ce:section> </ce:sections> </body> <tail> <ce:bibliography> <ce:section-title>References</ce:section-title> <ce:bibliography-sec> <ce:bib-reference id="bib1"> <ce:label>1</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>N.B.</ce:given-name> <ce:surname>Alexander</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Gait disorders in older adults</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>J Am Geriatr Soc</sb:maintitle> </sb:title> <sb:volume-nr>44</sb:volume-nr> </sb:series> <sb:date>1996</sb:date> </sb:issue> <sb:pages> <sb:first-page>434</sb:first-page> <sb:last-page>451</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib2"> <ce:label>2</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>S.</ce:given-name> <ce:surname>Ancoli–Israel</ce:surname> </sb:author> <sb:author> <ce:given-name>D.F.</ce:given-name> <ce:surname>Kripke</ce:surname> </sb:author> <sb:author> <ce:given-name>M.R.</ce:given-name> <ce:surname>Klauber</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Periodic limb movements in sleep in community–dwelling elderly</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Sleep</sb:maintitle> </sb:title> <sb:volume-nr>14</sb:volume-nr> </sb:series> <sb:date>1991</sb:date> </sb:issue> <sb:pages> <sb:first-page>496</sb:first-page> <sb:last-page>500</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib3"> <ce:label>3</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>M.J.</ce:given-name> <ce:surname>Bendall</ce:surname> </sb:author> <sb:author> <ce:given-name>E.J.</ce:given-name> <ce:surname>Bassey</ce:surname> </sb:author> <sb:author> <ce:given-name>M.B.</ce:given-name> <ce:surname>Pearson</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Factors affecting walking speed of elderly people</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Age Ageing</sb:maintitle> </sb:title> <sb:volume-nr>18</sb:volume-nr> </sb:series> <sb:date>1989</sb:date> </sb:issue> <sb:pages> <sb:first-page>327</sb:first-page> <sb:last-page>332</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib4"> <ce:label>4</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>D.A.</ce:given-name> <ce:surname>Bennet</ce:surname> </sb:author> <sb:author> <ce:given-name>L.A.</ce:given-name> <ce:surname>Beckett</ce:surname> </sb:author> <sb:author> <ce:given-name>A.M.</ce:given-name> <ce:surname>Murray</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Prevalence of parkinsonian signs and associated mortality in a community population of older people</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>N Engl J Med</sb:maintitle> </sb:title> <sb:volume-nr>334</sb:volume-nr> </sb:series> <sb:date>1996</sb:date> </sb:issue> <sb:pages> <sb:first-page>71</sb:first-page> <sb:last-page>76</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib5"> <ce:label>5</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>A.L.</ce:given-name> <ce:surname>Benton</ce:surname> </sb:author> <sb:author> <ce:given-name>P.J.</ce:given-name> <ce:surname>Eslinger</ce:surname> </sb:author> <sb:author> <ce:given-name>A.R.</ce:given-name> <ce:surname>Damasio</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Normative observations on neuropsychological test performances in old age</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>J Clin Neuropsychol</sb:maintitle> </sb:title> <sb:volume-nr>3</sb:volume-nr> </sb:series> <sb:date>1981</sb:date> </sb:issue> <sb:pages> <sb:first-page>33</sb:first-page> <sb:last-page>42</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib6"> <ce:label>6</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>B.R.</ce:given-name> <ce:surname>Bloem</ce:surname> </sb:author> <sb:author> <ce:given-name>J.</ce:given-name> <ce:surname>Haan</ce:surname> </sb:author> <sb:author> <ce:given-name>A.M.</ce:given-name> <ce:surname>Lagaay</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Investigation of gait in elderly subjects over 88 years of age</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>J Geriatr Psychiatry Neurol</sb:maintitle> </sb:title> <sb:volume-nr>5</sb:volume-nr> </sb:series> <sb:date>1992</sb:date> </sb:issue> <sb:pages> <sb:first-page>78</sb:first-page> <sb:last-page>84</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib7"> <ce:label>7</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>K.</ce:given-name> <ce:surname>Botzel</ce:surname> </sb:author> <sb:author> <ce:given-name>M.</ce:given-name> <ce:surname>Mayer</ce:surname> </sb:author> <sb:author> <ce:given-name>W.H.</ce:given-name> <ce:surname>Oertel</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Frontal and parietal premovement slow brain potentials in Parkinson's disease and aging</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Mov Disord</sb:maintitle> </sb:title> <sb:volume-nr>10</sb:volume-nr> </sb:series> <sb:date>1995</sb:date> </sb:issue> <sb:pages> <sb:first-page>85</sb:first-page> <sb:last-page>91</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib8"> <ce:label>8</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>K.J.</ce:given-name> <ce:surname>Cole</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Grasp force control in older adults</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>J Mot Behav</sb:maintitle> </sb:title> <sb:volume-nr>23</sb:volume-nr> </sb:series> <sb:date>1991</sb:date> </sb:issue> <sb:pages> <sb:first-page>251</sb:first-page> <sb:last-page>258</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib9"> <ce:label>9</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>M.</ce:given-name> <ce:surname>Critchley</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Senile disorders of gait</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Geriatrics</sb:maintitle> </sb:title> <sb:volume-nr>3</sb:volume-nr> </sb:series> <sb:date>1948</sb:date> </sb:issue> <sb:pages> <sb:first-page>364</sb:first-page> <sb:last-page>370</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib10"> <ce:label>10</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>W.L.</ce:given-name> <ce:surname>Danziger</ce:surname> </sb:author> <sb:author> <ce:given-name>T.A.</ce:given-name> <ce:surname>Salthouse</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Age and the perception of incomplete figures</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Exp Aging Res</sb:maintitle> </sb:title> <sb:volume-nr>4</sb:volume-nr> </sb:series> <sb:date>1978</sb:date> </sb:issue> <sb:pages> <sb:first-page>67</sb:first-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib11"> <ce:label>11</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>W.G.</ce:given-name> <ce:surname>Darling</ce:surname> </sb:author> <sb:author> <ce:given-name>J.D.</ce:given-name> <ce:surname>Cooke</ce:surname> </sb:author> <sb:author> <ce:given-name>S.H.</ce:given-name> <ce:surname>Brown</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Control of simple arm movements in elderly humans</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Neurobiol Aging</sb:maintitle> </sb:title> <sb:volume-nr>10</sb:volume-nr> </sb:series> <sb:date>1989</sb:date> </sb:issue> <sb:pages> <sb:first-page>149</sb:first-page> <sb:last-page>157</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib12"> <ce:label>12</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>P.C.</ce:given-name> <ce:surname>Davis</ce:surname> </sb:author> <sb:author> <ce:given-name>S.S.</ce:given-name> <ce:surname>Mirra</ce:surname> </sb:author> <sb:author> <ce:given-name>N.</ce:given-name> <ce:surname>Alazraki</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>The brain in older persons with and without dementia: Findings on MR, PET, and SPECT Images</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>AJR</sb:maintitle> </sb:title> <sb:volume-nr>162</sb:volume-nr> </sb:series> <sb:date>1994</sb:date> </sb:issue> <sb:pages> <sb:first-page>1267</sb:first-page> <sb:last-page>1278</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib13"> <ce:label>13</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>S.T.</ce:given-name> <ce:surname>DeKosky</ce:surname> </sb:author> <sb:author> <ce:given-name>A.M.</ce:given-name> <ce:surname>Palmer</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Neurochemistry of Aging</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:edited-book> <sb:editors> <sb:editor> <ce:given-name>M.L.</ce:given-name> <ce:surname>Albert</ce:surname> </sb:editor> <sb:editor> <ce:given-name>J.E.</ce:given-name> <ce:surname>Knoefel</ce:surname> </sb:editor> </sb:editors> <sb:title> <sb:maintitle>Clinical Neurology of Aging</sb:maintitle> </sb:title> <sb:edition>ed 2</sb:edition> <sb:date>1994</sb:date> <sb:publisher> <sb:name>Oxford University Press</sb:name> <sb:location>New York</sb:location> </sb:publisher> </sb:edited-book> <sb:pages> <sb:first-page>79</sb:first-page> <sb:last-page>101</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib14"> <ce:label>14</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>R.J.</ce:given-name> <ce:surname>Elble</ce:surname> </sb:author> <sb:author> <ce:given-name>L.</ce:given-name> <ce:surname>Hughes</ce:surname> </sb:author> <sb:author> <ce:given-name>C.</ce:given-name> <ce:surname>Higgins</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>The syndrome of senile gait</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>J Neurol</sb:maintitle> </sb:title> <sb:volume-nr>239</sb:volume-nr> </sb:series> <sb:date>1992</sb:date> </sb:issue> <sb:pages> <sb:first-page>71</sb:first-page> <sb:last-page>75</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib15"> <ce:label>15</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>R.J.</ce:given-name> <ce:surname>Elble</ce:surname> </sb:author> <sb:author> <ce:given-name>S.S.</ce:given-name> <ce:surname>Thomas</ce:surname> </sb:author> <sb:author> <ce:given-name>C.</ce:given-name> <ce:surname>Higgins</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Stride–dependent changes in gait of older people</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>J Neurol</sb:maintitle> </sb:title> <sb:volume-nr>238</sb:volume-nr> </sb:series> <sb:date>1991</sb:date> </sb:issue> <sb:pages> <sb:first-page>1</sb:first-page> <sb:last-page>5</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib16"> <ce:label>16</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>M.A.</ce:given-name> <ce:surname>Fiatarone</ce:surname> </sb:author> <sb:author> <ce:given-name>E.F.</ce:given-name> <ce:surname>O'Neill</ce:surname> </sb:author> <sb:author> <ce:given-name>N.D.</ce:given-name> <ce:surname>Ryan</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Exercise training and nutritional supplementation for physical frailty in very elderly people</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>N Engl J Med</sb:maintitle> </sb:title> <sb:volume-nr>330</sb:volume-nr> </sb:series> <sb:date>1994</sb:date> </sb:issue> <sb:pages> <sb:first-page>1769</sb:first-page> <sb:last-page>1775</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib17"> <ce:label>17</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>J.L.</ce:given-name> <ce:surname>Fozard</ce:surname> </sb:author> <sb:author> <ce:given-name>M.</ce:given-name> <ce:surname>Vercruyssen</ce:surname> </sb:author> <sb:author> <ce:given-name>S.L.</ce:given-name> <ce:surname>Reynolds</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Age differences and changes in reaction time: The Baltimore longitudinal study on aging</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>J Gerontol</sb:maintitle> </sb:title> <sb:volume-nr>49</sb:volume-nr> </sb:series> <sb:date>1994</sb:date> </sb:issue> <sb:pages> <sb:first-page>P179</sb:first-page> <sb:last-page>P189</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib18"> <ce:label>18</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>P.J.</ce:given-name> <ce:surname>Garcia Ruiz</ce:surname> </sb:author> <sb:author> <ce:given-name>E.</ce:given-name> <ce:surname>Gomez–Tortosa</ce:surname> </sb:author> <sb:author> <ce:given-name>A.</ce:given-name> <ce:surname>del Barrio</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Senile chorea: a multicenter prospective study</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Acta Neurol Scand</sb:maintitle> </sb:title> <sb:volume-nr>95</sb:volume-nr> </sb:series> <sb:date>1997</sb:date> </sb:issue> <sb:pages> <sb:first-page>180</sb:first-page> <sb:last-page>183</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib19"> <ce:label>19</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>W.R.</ce:given-name> <ce:surname>Gibb</ce:surname> </sb:author> <sb:author> <ce:given-name>A.J.</ce:given-name> <ce:surname>Lees</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>A comparison of clinical and pathological features of young- and old-onset Parkinson's disease</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Neurology</sb:maintitle> </sb:title> <sb:volume-nr>38</sb:volume-nr> </sb:series> <sb:date>1988</sb:date> </sb:issue> <sb:pages> <sb:first-page>1402</sb:first-page> <sb:last-page>1406</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib20"> <ce:label>20</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>M.D.</ce:given-name> <ce:surname>Giraudo</ce:surname> </sb:author> <sb:author> <ce:given-name>D.</ce:given-name> <ce:surname>Gayraud</ce:surname> </sb:author> <sb:author> <ce:given-name>M.</ce:given-name> <ce:surname>Habib</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Visuospatial ability of Parkinsonians and elderly adults in location memory tasks</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Brain Cogn</sb:maintitle> </sb:title> <sb:volume-nr>34</sb:volume-nr> </sb:series> <sb:date>1997</sb:date> </sb:issue> <sb:pages> <sb:first-page>259</sb:first-page> <sb:last-page>273</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib21"> <ce:label>21</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>C.G.</ce:given-name> <ce:surname>Goetz</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Tardive dyskinesia</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:edited-book> <sb:editors> <sb:editor> <ce:given-name>R.L.</ce:given-name> <ce:surname>Watts</ce:surname> </sb:editor> <sb:editor> <ce:given-name>W.C.</ce:given-name> <ce:surname>Koller</ce:surname> </sb:editor> </sb:editors> <sb:title> <sb:maintitle>Movement Disorders: Neurologic Principles and Practice.</sb:maintitle> </sb:title> <sb:date>1997</sb:date> <sb:publisher> <sb:name>McGraw–Hill</sb:name> <sb:location>New York</sb:location> </sb:publisher> </sb:edited-book> <sb:pages> <sb:first-page>519</sb:first-page> <sb:last-page>526</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib22"> <ce:label>22</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>J.E.</ce:given-name> <ce:surname>Himann</ce:surname> </sb:author> <sb:author> <ce:given-name>D.A.</ce:given-name> <ce:surname>Cunningham</ce:surname> </sb:author> <sb:author> <ce:given-name>P.A.</ce:given-name> <ce:surname>Rechnitzer</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Age–related changes in speed of walking</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Med Sci Sports Exerc</sb:maintitle> </sb:title> <sb:volume-nr>20</sb:volume-nr> </sb:series> <sb:date>1988</sb:date> </sb:issue> <sb:pages> <sb:first-page>161</sb:first-page> <sb:last-page>166</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib23"> <ce:label>23</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>D.R.</ce:given-name> <ce:surname>Hopkins</ce:surname> </sb:author> <sb:author> <ce:given-name>B.</ce:given-name> <ce:surname>Murrah</ce:surname> </sb:author> <sb:author> <ce:given-name>W.K.</ce:given-name> <ce:surname>Hoeger</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Effect of low–impact aerobic dance on the functional fitness of elderly women</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Gerontologist</sb:maintitle> </sb:title> <sb:volume-nr>30</sb:volume-nr> </sb:series> <sb:date>1990</sb:date> </sb:issue> <sb:pages> <sb:first-page>189</sb:first-page> <sb:last-page>192</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib24"> <ce:label>24</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>J.E.</ce:given-name> <ce:surname>Howard</ce:surname> </sb:author> <sb:author> <ce:given-name>K.C.</ce:given-name> <ce:surname>McGill</ce:surname> </sb:author> <sb:author> <ce:given-name>L.J.</ce:given-name> <ce:surname>Dorfman</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Age effects on properties of motor unit action potentials: ADEMG analysis</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Ann Neurol</sb:maintitle> </sb:title> <sb:volume-nr>24</sb:volume-nr> </sb:series> <sb:date>1988</sb:date> </sb:issue> <sb:pages> <sb:first-page>207</sb:first-page> <sb:last-page>213</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib25"> <ce:label>25</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>R.E.</ce:given-name> <ce:surname>Howie</ce:surname> </sb:author> <sb:author> <ce:given-name>L.Z.</ce:given-name> <ce:surname>Rubinstein</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Are older pedestrians allowed enough time to cross intersections safely?</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>J Am Geriatr Soc</sb:maintitle> </sb:title> <sb:volume-nr>42</sb:volume-nr> </sb:series> <sb:date>1994</sb:date> </sb:issue> <sb:pages> <sb:first-page>241</sb:first-page> <sb:last-page>244</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib26"> <ce:label>26</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>J.P.</ce:given-name> <ce:surname>Hubble</ce:surname> </sb:author> <sb:author> <ce:given-name>K.L.</ce:given-name> <ce:surname>Busenbark</ce:surname> </sb:author> <sb:author> <ce:given-name>R.</ce:given-name> <ce:surname>Pahwa</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Clinical expression of essential tremor: effects of gender and age</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Mov Disord</sb:maintitle> </sb:title> <sb:volume-nr>12</sb:volume-nr> </sb:series> <sb:date>1997</sb:date> </sb:issue> <sb:pages> <sb:first-page>969</sb:first-page> <sb:last-page>972</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib27"> <ce:label>27</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>L.</ce:given-name> <ce:surname>Jacobs</ce:surname> </sb:author> <sb:author> <ce:given-name>M.D.</ce:given-name> <ce:surname>Gossman</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Three primitive reflexes in normal adults</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Neurology</sb:maintitle> </sb:title> <sb:volume-nr>30</sb:volume-nr> </sb:series> <sb:date>1980</sb:date> </sb:issue> <sb:pages> <sb:first-page>184</sb:first-page> <sb:last-page>188</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib28"> <ce:label>28</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>J.</ce:given-name> <ce:surname>Jankovic</ce:surname> </sb:author> <sb:author> <ce:given-name>J.</ce:given-name> <ce:surname>Beach</ce:surname> </sb:author> <sb:author> <ce:given-name>K.</ce:given-name> <ce:surname>Schwartz</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Tremor and longevity in relatives of patients with Parkinson's disease, essential tremor, and control subjects</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Neurology</sb:maintitle> </sb:title> <sb:volume-nr>45</sb:volume-nr> </sb:series> <sb:date>1995</sb:date> </sb:issue> <sb:pages> <sb:first-page>645</sb:first-page> <sb:last-page>648</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib29"> <ce:label>29</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>L.R.</ce:given-name> <ce:surname>Jenkyn</ce:surname> </sb:author> <sb:author> <ce:given-name>A.G.</ce:given-name> <ce:surname>Reeves</ce:surname> </sb:author> <sb:author> <ce:given-name>T.</ce:given-name> <ce:surname>Warren</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Neurologic signs in senescence</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Arch Neurol</sb:maintitle> </sb:title> <sb:volume-nr>42</sb:volume-nr> </sb:series> <sb:date>1985</sb:date> </sb:issue> <sb:pages> <sb:first-page>1154</sb:first-page> <sb:last-page>1157</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib30"> <ce:label>30</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>J.A.</ce:given-name> <ce:surname>Kaye</ce:surname> </sb:author> <sb:author> <ce:given-name>B.S.</ce:given-name> <ce:surname>Oken</ce:surname> </sb:author> <sb:author> <ce:given-name>D.B.</ce:given-name> <ce:surname>Howieson</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Neurologic evaluation of the optimally healthy oldest old</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Arch Neurol</sb:maintitle> </sb:title> <sb:volume-nr>51</sb:volume-nr> </sb:series> <sb:date>1994</sb:date> </sb:issue> <sb:pages> <sb:first-page>1205</sb:first-page> <sb:last-page>1211</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib31"> <ce:label>31</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>M.B.</ce:given-name> <ce:surname>King</ce:surname> </sb:author> <sb:author> <ce:given-name>J.O.</ce:given-name> <ce:surname>Judge</ce:surname> </sb:author> <sb:author> <ce:given-name>L.</ce:given-name> <ce:surname>Wolfson</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Functional base of support decreases with age</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>J Gerontol Med Sci</sb:maintitle> </sb:title> <sb:volume-nr>48</sb:volume-nr> </sb:series> <sb:date>1994</sb:date> </sb:issue> <sb:pages> <sb:first-page>M258</sb:first-page> <sb:last-page>M263</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib32"> <ce:label>32</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>S.J.</ce:given-name> <ce:surname>Kish</ce:surname> </sb:author> <sb:author> <ce:given-name>K.</ce:given-name> <ce:surname>Shannak</ce:surname> </sb:author> <sb:author> <ce:given-name>A.</ce:given-name> <ce:surname>Rajput</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Aging produces a specific pattern of striatal dopamine loss: Implications for the etiology of idiopathic Parkinson's disease</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>J Neurochem</sb:maintitle> </sb:title> <sb:volume-nr>58</sb:volume-nr> </sb:series> <sb:date>1992</sb:date> </sb:issue> <sb:pages> <sb:first-page>642</sb:first-page> <sb:last-page>648</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib33"> <ce:label>33</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>H.L.</ce:given-name> <ce:surname>Klawans</ce:surname> </sb:author> <sb:author> <ce:given-name>A.</ce:given-name> <ce:surname>Barr</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Prevalence of spontaneous lingual-facial-buccal dyskinesias in the elderly</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Neurology</sb:maintitle> </sb:title> <sb:volume-nr>32</sb:volume-nr> </sb:series> <sb:date>1982</sb:date> </sb:issue> <sb:pages> <sb:first-page>558</sb:first-page> <sb:last-page>559</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib34"> <ce:label>34</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>W.C.</ce:given-name> <ce:surname>Koller</ce:surname> </sb:author> <sb:author> <ce:given-name>K.L.</ce:given-name> <ce:surname>Busenbark</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Essential tremor</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:edited-book> <sb:editors> <sb:editor> <ce:given-name>R.L.</ce:given-name> <ce:surname>Watts</ce:surname> </sb:editor> <sb:editor> <ce:given-name>W.C.</ce:given-name> <ce:surname>Koller</ce:surname> </sb:editor> </sb:editors> <sb:title> <sb:maintitle>Movement Disorders: Neurologic Principles and Practice.</sb:maintitle> </sb:title> <sb:date>1997</sb:date> <sb:publisher> <sb:name>McGraw-Hill</sb:name> <sb:location>New York</sb:location> </sb:publisher> </sb:edited-book> <sb:pages> <sb:first-page>365</sb:first-page> <sb:last-page>385</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib35"> <ce:label>35</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>W.C.</ce:given-name> <ce:surname>Koller</ce:surname> </sb:author> <sb:author> <ce:given-name>S.L.</ce:given-name> <ce:surname>Glatt</ce:surname> </sb:author> <sb:author> <ce:given-name>J.H.</ce:given-name> <ce:surname>Fox</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Cerebellar atrophy: Relationship to aging and cerebral atrophy</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Neurology</sb:maintitle> </sb:title> <sb:volume-nr>31</sb:volume-nr> </sb:series> <sb:date>1981</sb:date> </sb:issue> <sb:pages> <sb:first-page>1486</sb:first-page> <sb:last-page>1488</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib36"> <ce:label>36</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>W.C.</ce:given-name> <ce:surname>Koller</ce:surname> </sb:author> <sb:author> <ce:given-name>S.J.</ce:given-name> <ce:surname>Huber</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Tremor disorders of aging: Diagnosis and management</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Geriatrics</sb:maintitle> </sb:title> <sb:volume-nr>44</sb:volume-nr> </sb:series> <sb:date>1989</sb:date> </sb:issue> <sb:pages> <sb:first-page>33</sb:first-page> <sb:last-page>41</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib37"> <ce:label>37</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>W.C.</ce:given-name> <ce:surname>Koller</ce:surname> </sb:author> <sb:author> <ce:given-name>R.S.</ce:given-name> <ce:surname>Wilson</ce:surname> </sb:author> <sb:author> <ce:given-name>S.L.</ce:given-name> <ce:surname>Glatt</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Senile gait: Correlation with computed tomographic scans</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Ann Neurol</sb:maintitle> </sb:title> <sb:volume-nr>13</sb:volume-nr> </sb:series> <sb:date>1983</sb:date> </sb:issue> <sb:pages> <sb:first-page>343</sb:first-page> <sb:last-page>344</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib38"> <ce:label>38</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>W.C.</ce:given-name> <ce:surname>Koller</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Edentulous orodyskinesia</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Ann Neurol</sb:maintitle> </sb:title> <sb:volume-nr>13</sb:volume-nr> </sb:series> <sb:date>1983</sb:date> </sb:issue> <sb:pages> <sb:first-page>97</sb:first-page> <sb:last-page>99</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib39"> <ce:label>39</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>V.</ce:given-name> <ce:surname>Kostic</ce:surname> </sb:author> <sb:author> <ce:given-name>S.</ce:given-name> <ce:surname>Przedborski</ce:surname> </sb:author> <sb:author> <ce:given-name>E.</ce:given-name> <ce:surname>Flaster</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Early development of levodopa–induced dyskinesias and response fluctuations in young–onset Parkinson's disease</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Neurology</sb:maintitle> </sb:title> <sb:volume-nr>41</sb:volume-nr> </sb:series> <sb:date>1991</sb:date> </sb:issue> <sb:pages> <sb:first-page>202</sb:first-page> <sb:last-page>205</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib40"> <ce:label>40</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>D.D.</ce:given-name> <ce:surname>Larish</ce:surname> </sb:author> <sb:author> <ce:given-name>P.E.</ce:given-name> <ce:surname>Martin</ce:surname> </sb:author> <sb:author> <ce:given-name>M.</ce:given-name> <ce:surname>Nungiole</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Characteristic patterns of gait in the healthy old</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Ann NY Acad Sci</sb:maintitle> </sb:title> <sb:volume-nr>515</sb:volume-nr> </sb:series> <sb:date>1988</sb:date> </sb:issue> <sb:pages> <sb:first-page>18</sb:first-page> <sb:last-page>32</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib41"> <ce:label>41</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>J.S.</ce:given-name> <ce:surname>Lou</ce:surname> </sb:author> <sb:author> <ce:given-name>J.</ce:given-name> <ce:surname>Jankovic</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Essential tremor: Clinical correlates in 350 patients</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Neurology</sb:maintitle> </sb:title> <sb:volume-nr>41</sb:volume-nr> </sb:series> <sb:date>1991</sb:date> </sb:issue> <sb:pages> <sb:first-page>234</sb:first-page> <sb:last-page>238</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib42"> <ce:label>42</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>B.</ce:given-name> <ce:surname>Lundgren–Lindquist</ce:surname> </sb:author> <sb:author> <ce:given-name>A.</ce:given-name> <ce:surname>Aniansson</ce:surname> </sb:author> <sb:author> <ce:given-name>A.</ce:given-name> <ce:surname>Rundgren</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Functional studies in 79–year–olds. III. Walking performance and climbing capacity</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Scand J Rehabil Med</sb:maintitle> </sb:title> <sb:volume-nr>15</sb:volume-nr> </sb:series> <sb:date>1983</sb:date> </sb:issue> <sb:pages> <sb:first-page>125</sb:first-page> <sb:last-page>131</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib43"> <ce:label>43</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>B.E.</ce:given-name> <ce:surname>Maki</ce:surname> </sb:author> <sb:author> <ce:given-name>P.J.</ce:given-name> <ce:surname>Holliday</ce:surname> </sb:author> <sb:author> <ce:given-name>G.R.</ce:given-name> <ce:surname>Fernie</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Aging and postural control: A comparison of spontaneous and induced–sway balance tests</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>J Am Geriatr Soc</sb:maintitle> </sb:title> <sb:volume-nr>38</sb:volume-nr> </sb:series> <sb:date>1990</sb:date> </sb:issue> <sb:pages> <sb:first-page>1</sb:first-page> <sb:last-page>9</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib44"> <ce:label>44</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>P.E.</ce:given-name> <ce:surname>Martin</ce:surname> </sb:author> <sb:author> <ce:given-name>D.E.</ce:given-name> <ce:surname>Rothstein</ce:surname> </sb:author> <sb:author> <ce:given-name>D.D.</ce:given-name> <ce:surname>Larish</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Effects of age and physical activity status on the speed-aerobic demand relationship of walking</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>J Appl Physiol</sb:maintitle> </sb:title> <sb:volume-nr>73</sb:volume-nr> </sb:series> <sb:date>1992</sb:date> </sb:issue> <sb:pages> <sb:first-page>200</sb:first-page> <sb:last-page>206</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib45"> <ce:label>45</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>I.C.</ce:given-name> <ce:surname>Matjucha</ce:surname> </sb:author> <sb:author> <ce:given-name>B.</ce:given-name> <ce:surname>Katz</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Neuro–ophthalmology of aging</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:edited-book> <sb:editors> <sb:editor> <ce:given-name>M.L.</ce:given-name> <ce:surname>Albert</ce:surname> </sb:editor> <sb:editor> <ce:given-name>J.E.</ce:given-name> <ce:surname>Knoefel</ce:surname> </sb:editor> </sb:editors> <sb:title> <sb:maintitle>Clinical Neurology of Aging</sb:maintitle> </sb:title> <sb:edition>ed 2</sb:edition> <sb:date>1994</sb:date> <sb:publisher> <sb:name>Oxford University Press</sb:name> <sb:location>New York</sb:location> </sb:publisher> </sb:edited-book> <sb:pages> <sb:first-page>421</sb:first-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib46"> <ce:label>46</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>P.L.</ce:given-name> <ce:surname>McGeer</ce:surname> </sb:author> <sb:author> <ce:given-name>E.G.</ce:given-name> <ce:surname>McGeer</ce:surname> </sb:author> <sb:author> <ce:given-name>J.S.</ce:given-name> <ce:surname>Suzuki</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Aging and extrapyramidal function</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Arch Neurol</sb:maintitle> </sb:title> <sb:volume-nr>34</sb:volume-nr> </sb:series> <sb:date>1977</sb:date> </sb:issue> <sb:pages> <sb:first-page>33</sb:first-page> <sb:last-page>35</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib47"> <ce:label>47</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>E.</ce:given-name> <ce:surname>Melamed</ce:surname> </sb:author> <sb:author> <ce:given-name>S.</ce:given-name> <ce:surname>Lavy</ce:surname> </sb:author> <sb:author> <ce:given-name>S.</ce:given-name> <ce:surname>Bentin</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Reduction in regional cerebral blood flow during normal aging in men</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Stroke</sb:maintitle> </sb:title> <sb:volume-nr>11</sb:volume-nr> </sb:series> <sb:date>1980</sb:date> </sb:issue> <sb:pages> <sb:first-page>31</sb:first-page> <sb:last-page>35</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib48"> <ce:label>48</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>R.</ce:given-name> <ce:surname>Mielke</ce:surname> </sb:author> <sb:author> <ce:given-name>J.</ce:given-name> <ce:surname>Kessler</ce:surname> </sb:author> <sb:author> <ce:given-name>B.</ce:given-name> <ce:surname>Szelies</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Normal and pathologic aging—findings of positron–emission tomography</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>J Neural Transm</sb:maintitle> </sb:title> <sb:volume-nr>105</sb:volume-nr> </sb:series> <sb:date>1998</sb:date> </sb:issue> <sb:pages> <sb:first-page>821</sb:first-page> <sb:last-page>837</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib49"> <ce:label>49</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>J.R.</ce:given-name> <ce:surname>Moeller</ce:surname> </sb:author> <sb:author> <ce:given-name>T.</ce:given-name> <ce:surname>Ishikawa</ce:surname> </sb:author> <sb:author> <ce:given-name>V.</ce:given-name> <ce:surname>Dhawan</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>The metabolic topography of normal aging</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>J Cereb Blood Flow Metab</sb:maintitle> </sb:title> <sb:volume-nr>16</sb:volume-nr> </sb:series> <sb:date>1996</sb:date> </sb:issue> <sb:pages> <sb:first-page>385</sb:first-page> <sb:last-page>398</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib50"> <ce:label>50</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>R.W.</ce:given-name> <ce:surname>Moskowitz</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Clinical and laboratory findings in osteoarthritis</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:edited-book> <sb:editors> <sb:editor> <ce:given-name>D.J.</ce:given-name> <ce:surname>McCarty</ce:surname> </sb:editor> </sb:editors> <sb:title> <sb:maintitle>Arthritis and allied conditions</sb:maintitle> </sb:title> <sb:edition>ed 11</sb:edition> <sb:date>1989</sb:date> <sb:publisher> <sb:name>Lea & Febiger</sb:name> <sb:location>Philadelphia</sb:location> </sb:publisher> </sb:edited-book> <sb:pages> <sb:first-page>1605</sb:first-page> <sb:last-page>1630</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib51"> <ce:label>51</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>R.P.</ce:given-name> <ce:surname>Newman</ce:surname> </sb:author> <sb:author> <ce:given-name>P.A.</ce:given-name> <ce:surname>LeWitt</ce:surname> </sb:author> <sb:author> <ce:given-name>M.</ce:given-name> <ce:surname>Jaffe</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Motor function in the normal aging population: Treatment with levodopa</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Neurology</sb:maintitle> </sb:title> <sb:volume-nr>35</sb:volume-nr> </sb:series> <sb:date>1985</sb:date> </sb:issue> <sb:pages> <sb:first-page>571</sb:first-page> <sb:last-page>573</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib52"> <ce:label>52</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>G.</ce:given-name> <ce:surname>Odenheimer</ce:surname> </sb:author> <sb:author> <ce:given-name>H.H.</ce:given-name> <ce:surname>Funkenstein</ce:surname> </sb:author> <sb:author> <ce:given-name>L.</ce:given-name> <ce:surname>Beckett</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Comparison of neurologic changes in “successfully aging” persons vs. the total aging population</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Arch Neurol</sb:maintitle> </sb:title> <sb:volume-nr>51</sb:volume-nr> </sb:series> <sb:date>1994</sb:date> </sb:issue> <sb:pages> <sb:first-page>573</sb:first-page> <sb:last-page>580</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib53"> <ce:label>53</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>P.W.</ce:given-name> <ce:surname>Overstall</ce:surname> </sb:author> <sb:author> <ce:given-name>A.N.</ce:given-name> <ce:surname>Exton-Smith</ce:surname> </sb:author> <sb:author> <ce:given-name>F.J.</ce:given-name> <ce:surname>Imms</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Falls in the elderly related to postural imbalance</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>BMJ</sb:maintitle> </sb:title> <sb:volume-nr>1</sb:volume-nr> </sb:series> <sb:date>1977</sb:date> </sb:issue> <sb:pages> <sb:first-page>261</sb:first-page> <sb:last-page>264</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib54"> <ce:label>54</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>S.W.</ce:given-name> <ce:surname>Parker</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Dizziness in the elderly</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:edited-book> <sb:editors> <sb:editor> <ce:given-name>M.L.</ce:given-name> <ce:surname>Albert</ce:surname> </sb:editor> <sb:editor> <ce:given-name>J.E.</ce:given-name> <ce:surname>Knoefel</ce:surname> </sb:editor> </sb:editors> <sb:title> <sb:maintitle>Clinical Neurology of Aging</sb:maintitle> </sb:title> <sb:edition>ed 2</sb:edition> <sb:date>1994</sb:date> <sb:publisher> <sb:name>Oxford University Press</sb:name> <sb:location>New York</sb:location> </sb:publisher> </sb:edited-book> <sb:pages> <sb:first-page>569</sb:first-page> <sb:last-page>579</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib55"> <ce:label>55</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>J.G.</ce:given-name> <ce:surname>Phillips</ce:surname> </sb:author> <sb:author> <ce:given-name>T.</ce:given-name> <ce:surname>Schiffter</ce:surname> </sb:author> <sb:author> <ce:given-name>M.E.</ce:given-name> <ce:surname>Nicholls</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Does old age or Parkinson's disease cause bradyphrenia?</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>J Gerontol</sb:maintitle> </sb:title> <sb:volume-nr>54A</sb:volume-nr> </sb:series> <sb:date>1999</sb:date> </sb:issue> <sb:pages> <sb:first-page>M404</sb:first-page> <sb:last-page>M409</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib56"> <ce:label>56</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>D.J.</ce:given-name> <ce:surname>Plude</ce:surname> </sb:author> <sb:author> <ce:given-name>W.P.</ce:given-name> <ce:surname>Milberg</ce:surname> </sb:author> <sb:author> <ce:given-name>J.</ce:given-name> <ce:surname>Cerella</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Age differences in depicting and perceiving tridimensionality in simple line drawings</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Exp Aging Res</sb:maintitle> </sb:title> <sb:volume-nr>12</sb:volume-nr> </sb:series> <sb:date>1986</sb:date> </sb:issue> <sb:pages> <sb:first-page>221</sb:first-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib57"> <ce:label>57</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>A.R.</ce:given-name> <ce:surname>Potvin</ce:surname> </sb:author> <sb:author> <ce:given-name>K.</ce:given-name> <ce:surname>Syndulko</ce:surname> </sb:author> <sb:author> <ce:given-name>W.W.</ce:given-name> <ce:surname>Tourtellotte</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Human neurologic function and the aging process</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>J Am Geriatr Soc</sb:maintitle> </sb:title> <sb:volume-nr>28</sb:volume-nr> </sb:series> <sb:date>1980</sb:date> </sb:issue> <sb:pages> <sb:first-page>1</sb:first-page> <sb:last-page>9</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib58"> <ce:label>58</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>S.N.</ce:given-name> <ce:surname>Pradhan</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Central neurotransmitters and aging</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Life Sci</sb:maintitle> </sb:title> <sb:volume-nr>26</sb:volume-nr> </sb:series> <sb:date>1980</sb:date> </sb:issue> <sb:pages> <sb:first-page>1643</sb:first-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib59"> <ce:label>59</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>J.</ce:given-name> <ce:surname>Pujol</ce:surname> </sb:author> <sb:author> <ce:given-name>C.</ce:given-name> <ce:surname>Junque</ce:surname> </sb:author> <sb:author> <ce:given-name>P.</ce:given-name> <ce:surname>Vendrell</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Reduction of the substantia nigra width and motor decline in aging and Parkinson's disease</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Arch Neurol</sb:maintitle> </sb:title> <sb:volume-nr>49</sb:volume-nr> </sb:series> <sb:date>1992</sb:date> </sb:issue> <sb:pages> <sb:first-page>1119</sb:first-page> <sb:last-page>1122</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib60"> <ce:label>60</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>A.H.</ce:given-name> <ce:surname>Rajput</ce:surname> </sb:author> <sb:author> <ce:given-name>K.P.</ce:given-name> <ce:surname>Offord</ce:surname> </sb:author> <sb:author> <ce:given-name>C.M.</ce:given-name> <ce:surname>Beard</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Essential tremor in Rochester, MN: A 45–year study</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>J Neurol Neurosurg Psychiatry</sb:maintitle> </sb:title> <sb:volume-nr>47</sb:volume-nr> </sb:series> <sb:date>1984</sb:date> </sb:issue> <sb:pages> <sb:first-page>466</sb:first-page> <sb:last-page>470</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib61"> <ce:label>61</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>A.H.</ce:given-name> <ce:surname>Rajput</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Movement disorders and aging</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:edited-book> <sb:editors> <sb:editor> <ce:given-name>R.L.</ce:given-name> <ce:surname>Watts</ce:surname> </sb:editor> <sb:editor> <ce:given-name>W.C.</ce:given-name> <ce:surname>Koller</ce:surname> </sb:editor> </sb:editors> <sb:title> <sb:maintitle>Movement Disorders: Neurologic Principles and Practice.</sb:maintitle> </sb:title> <sb:date>1997</sb:date> <sb:publisher> <sb:name>McGraw–Hill</sb:name> <sb:location>New York</sb:location> </sb:publisher> </sb:edited-book> <sb:pages> <sb:first-page>673</sb:first-page> <sb:last-page>686</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib62"> <ce:label>62</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>I.</ce:given-name> <ce:surname>Rautakorpi</ce:surname> </sb:author> <sb:author> <ce:given-name>J.</ce:given-name> <ce:surname>Takala</ce:surname> </sb:author> <sb:author> <ce:given-name>R.J.</ce:given-name> <ce:surname>Marttila</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Essential tremor in a Finnish population</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Acta Neurol Scand</sb:maintitle> </sb:title> <sb:volume-nr>66</sb:volume-nr> </sb:series> <sb:date>1982</sb:date> </sb:issue> <sb:pages> <sb:first-page>58</sb:first-page> <sb:last-page>67</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib63"> <ce:label>63</ce:label> <ce:other-ref> <ce:textref>Romero DH, Selmach GE. Motor function in neurodegenerative disease and aging <ce:italic>In</ce:italic> Boller F, Grafman J. Handbook of Neuropsychology. New York, Elsevier Science, in press</ce:textref> </ce:other-ref> </ce:bib-reference> <ce:bib-reference id="bib64"> <ce:label>64</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>J.W.</ce:given-name> <ce:surname>Rowe</ce:surname> </sb:author> <sb:author> <ce:given-name>R.L.</ce:given-name> <ce:surname>Kahn</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Human aging: Usual and successful</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Science</sb:maintitle> </sb:title> <sb:volume-nr>237</sb:volume-nr> </sb:series> <sb:date>1987</sb:date> </sb:issue> <sb:pages> <sb:first-page>143</sb:first-page> <sb:last-page>149</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib65"> <ce:label>65</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>L.R.</ce:given-name> <ce:surname>Sauvage</ce:surname> </sb:author> <sb:author> <ce:given-name>B.M.</ce:given-name> <ce:surname>Myklebust</ce:surname> </sb:author> <sb:author> <ce:given-name>J.</ce:given-name> <ce:surname>Crow–Pan</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>A clinical trial of strengthening and aerobic exercise to improve gait and balance in elderly male nursing home residents</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Am J Phys Med Rehabil</sb:maintitle> </sb:title> <sb:volume-nr>71</sb:volume-nr> </sb:series> <sb:date>1992</sb:date> </sb:issue> <sb:pages> <sb:first-page>333</sb:first-page> <sb:last-page>342</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib66"> <ce:label>66</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>M.</ce:given-name> <ce:surname>Schieppati</ce:surname> </sb:author> <sb:author> <ce:given-name>M.</ce:given-name> <ce:surname>Hugon</ce:surname> </sb:author> <sb:author> <ce:given-name>M.</ce:given-name> <ce:surname>Grasso</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>The limits of equilibrium in young and elderly normal subjects and in Parkinsonians</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Electroencephalogr Clin Neurophysiol</sb:maintitle> </sb:title> <sb:volume-nr>93</sb:volume-nr> </sb:series> <sb:date>1994</sb:date> </sb:issue> <sb:pages> <sb:first-page>286</sb:first-page> <sb:last-page>298</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib67"> <ce:label>67</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>D.</ce:given-name> <ce:surname>Schretlen</ce:surname> </sb:author> <sb:author> <ce:given-name>G.D.</ce:given-name> <ce:surname>Pearlson</ce:surname> </sb:author> <sb:author> <ce:given-name>J.C.</ce:given-name> <ce:surname>Anthony</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Elucidating the contributions of processing speed, executive ability, and frontal lobe volume to normal age–related differences in fluid intelligence</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>J Int Neuropsychol Soc</sb:maintitle> </sb:title> <sb:volume-nr>6</sb:volume-nr> </sb:series> <sb:date>2000</sb:date> </sb:issue> <sb:pages> <sb:first-page>52</sb:first-page> <sb:last-page>61</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib68"> <ce:label>68</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>H.</ce:given-name> <ce:surname>Shale</ce:surname> </sb:author> <sb:author> <ce:given-name>S.</ce:given-name> <ce:surname>Fahn</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Parkinson's disease in the elderly patient</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:edited-book> <sb:editors> <sb:editor> <ce:given-name>M.L.</ce:given-name> <ce:surname>Albert</ce:surname> </sb:editor> <sb:editor> <ce:given-name>J.E.</ce:given-name> <ce:surname>Knoefel</ce:surname> </sb:editor> </sb:editors> <sb:title> <sb:maintitle>Clinical Neurology of Aging</sb:maintitle> </sb:title> <sb:edition>ed 2</sb:edition> <sb:date>1994</sb:date> <sb:publisher> <sb:name>Oxford University Press</sb:name> <sb:location>New York</sb:location> </sb:publisher> </sb:edited-book> <sb:pages> <sb:first-page>493</sb:first-page> <sb:last-page>501</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib69"> <ce:label>69</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>J.M.</ce:given-name> <ce:surname>Smith</ce:surname> </sb:author> <sb:author> <ce:given-name>L.T.</ce:given-name> <ce:surname>Kucharski</ce:surname> </sb:author> <sb:author> <ce:given-name>C.</ce:given-name> <ce:surname>Eblen</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>An assessment of tardive dyskinesia in schizophrenic outpatients</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Psychopharmacology</sb:maintitle> </sb:title> <sb:volume-nr>64</sb:volume-nr> </sb:series> <sb:date>1979</sb:date> </sb:issue> <sb:pages> <sb:first-page>99</sb:first-page> <sb:last-page>104</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib70"> <ce:label>70</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>M.</ce:given-name> <ce:surname>Stacy</ce:surname> </sb:author> <sb:author> <ce:given-name>F.</ce:given-name> <ce:surname>Cardoso</ce:surname> </sb:author> <sb:author> <ce:given-name>J.</ce:given-name> <ce:surname>Jankovic</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Tardive stereotypy and other movement disorders in tardive dyskinesias</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Neurology</sb:maintitle> </sb:title> <sb:volume-nr>43</sb:volume-nr> </sb:series> <sb:date>1993</sb:date> </sb:issue> <sb:pages> <sb:first-page>937</sb:first-page> <sb:last-page>941</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib71"> <ce:label>71</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>M.</ce:given-name> <ce:surname>Stacy</ce:surname> </sb:author> <sb:author> <ce:given-name>J.</ce:given-name> <ce:surname>Jankovic</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Tardive dyskinesia</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Curr Opin Neurol Neurosurg</sb:maintitle> </sb:title> <sb:volume-nr>4</sb:volume-nr> </sb:series> <sb:date>1991</sb:date> </sb:issue> <sb:pages> <sb:first-page>343</sb:first-page> <sb:last-page>349</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib72"> <ce:label>72</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>S.M.</ce:given-name> <ce:surname>Stahl</ce:surname> </sb:author> <sb:author> <ce:given-name>K.F.</ce:given-name> <ce:surname>Faull</ce:surname> </sb:author> <sb:author> <ce:given-name>J.D.</ce:given-name> <ce:surname>Barchas</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>CSF monoamine metabolites in movement disorders and normal aging</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Arch Neurol</sb:maintitle> </sb:title> <sb:volume-nr>42</sb:volume-nr> </sb:series> <sb:date>1985</sb:date> </sb:issue> <sb:pages> <sb:first-page>166</sb:first-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib73"> <ce:label>73</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>F.U.</ce:given-name> <ce:surname>Steinberg</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Gait disorders in old age</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Geriatrics</sb:maintitle> </sb:title> <sb:volume-nr>21</sb:volume-nr> </sb:series> <sb:date>1966</sb:date> </sb:issue> <sb:pages> <sb:first-page>134</sb:first-page> <sb:last-page>143</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib74"> <ce:label>74</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>G.E.</ce:given-name> <ce:surname>Stelmach</ce:surname> </sb:author> <sb:author> <ce:given-name>J.</ce:given-name> <ce:surname>Phillips</ce:surname> </sb:author> <sb:author> <ce:given-name>R.P.</ce:given-name> <ce:surname>DiFabio</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Age, functional postural reflexes, and voluntary sway</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>J Gerontol</sb:maintitle> </sb:title> <sb:volume-nr>44</sb:volume-nr> </sb:series> <sb:date>1989</sb:date> </sb:issue> <sb:pages> <sb:first-page>B100</sb:first-page> <sb:last-page>B106</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib75"> <ce:label>75</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>L.</ce:given-name> <ce:surname>Sudarsky</ce:surname> </sb:author> <sb:author> <ce:given-name>M.</ce:given-name> <ce:surname>Ronthal</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Gait disorders among elderly patients: a survey study of 50 patients</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Arch Neurol</sb:maintitle> </sb:title> <sb:volume-nr>40</sb:volume-nr> </sb:series> <sb:date>1983</sb:date> </sb:issue> <sb:pages> <sb:first-page>740</sb:first-page> <sb:last-page>743</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib76"> <ce:label>76</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>R.D.</ce:given-name> <ce:surname>Terry</ce:surname> </sb:author> <sb:author> <ce:given-name>R.</ce:given-name> <ce:surname>DeTeresa</ce:surname> </sb:author> <sb:author> <ce:given-name>L.A.</ce:given-name> <ce:surname>Hansen</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Neocortical cell counts in normal human adult aging</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Ann Neurol</sb:maintitle> </sb:title> <sb:volume-nr>21</sb:volume-nr> </sb:series> <sb:date>1987</sb:date> </sb:issue> <sb:pages> <sb:first-page>530</sb:first-page> <sb:last-page>539</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib77"> <ce:label>77</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>E.S.</ce:given-name> <ce:surname>Tolosa</ce:surname> </sb:author> <sb:author> <ce:given-name>M.J.</ce:given-name> <ce:surname>Marti</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Adult–onset idiopathic torsion dystonias</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:edited-book> <sb:editors> <sb:editor> <ce:given-name>R.L.</ce:given-name> <ce:surname>Watts</ce:surname> </sb:editor> <sb:editor> <ce:given-name>W.C.</ce:given-name> <ce:surname>Koller</ce:surname> </sb:editor> </sb:editors> <sb:title> <sb:maintitle>Movement Disorders: Neurologic Principles and Practice.</sb:maintitle> </sb:title> <sb:date>1997</sb:date> <sb:publisher> <sb:name>McGraw-Hill</sb:name> <sb:location>New York</sb:location> </sb:publisher> </sb:edited-book> <sb:pages> <sb:first-page>431</sb:first-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib78"> <ce:label>78</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>M.M.</ce:given-name> <ce:surname>Tompkins</ce:surname> </sb:author> <sb:author> <ce:given-name>E.J.</ce:given-name> <ce:surname>Basgall</ce:surname> </sb:author> <sb:author> <ce:given-name>E.</ce:given-name> <ce:surname>Zamrini</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Apoptotic-like changes in Lewy–body–associated disorders and normal aging in substantia nigral neurons</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Am J Pathol</sb:maintitle> </sb:title> <sb:volume-nr>150</sb:volume-nr> </sb:series> <sb:date>1997</sb:date> </sb:issue> <sb:pages> <sb:first-page>119</sb:first-page> <sb:last-page>131</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib79"> <ce:label>79</ce:label> <sb:reference> <sb:host> <sb:edited-book> <sb:title> <sb:maintitle>U.S. Bureau of the Census. Current population reports, special studies, P23-190, 65+ in the United States.</sb:maintitle> </sb:title> <sb:date>1996</sb:date> <sb:publisher> <sb:name>U.S. Government Printing Office</sb:name> <sb:location>Washington, DC</sb:location> </sb:publisher> </sb:edited-book> <sb:pages> <sb:first-page>2.1</sb:first-page> <sb:last-page>2.24</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib80"> <ce:label>80</ce:label> <sb:reference> <sb:host> <sb:book> <sb:title> <sb:maintitle>U.S. Bureau of the Census. Population estimates for states by age, sex, race, and Hispanic origin</sb:maintitle> </sb:title> <sb:date>1998</sb:date> <sb:publisher> <sb:name>U.S. Government Printing Office</sb:name> <sb:location>Washington, DC</sb:location> </sb:publisher> </sb:book> </sb:host> <sb:comment>ST–98–40</sb:comment> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib81"> <ce:label>81</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>L.M.</ce:given-name> <ce:surname>Waite</ce:surname> </sb:author> <sb:author> <ce:given-name>G.A.</ce:given-name> <ce:surname>Broe</ce:surname> </sb:author> <sb:author> <ce:given-name>H.</ce:given-name> <ce:surname>Creasey</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Neurological signs, aging and the neurodegenerative syndromes</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Arch Neurol</sb:maintitle> </sb:title> <sb:volume-nr>53</sb:volume-nr> </sb:series> <sb:date>1996</sb:date> </sb:issue> <sb:pages> <sb:first-page>498</sb:first-page> <sb:last-page>502</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib82"> <ce:label>82</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>J.</ce:given-name> <ce:surname>Wang</ce:surname> </sb:author> <sb:author> <ce:given-name>J.R.</ce:given-name> <ce:surname>Thomas</ce:surname> </sb:author> <sb:author> <ce:given-name>G.E.</ce:given-name> <ce:surname>Stelmach</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>A meta–analysis on cognitive slowing in Parkinson's disease: Are simple and choice reaction times differentially impaired?</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Parkinsonism and Related Disorders</sb:maintitle> </sb:title> <sb:volume-nr>4</sb:volume-nr> </sb:series> <sb:date>1998</sb:date> </sb:issue> <sb:pages> <sb:first-page>17</sb:first-page> <sb:last-page>29</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib83"> <ce:label>83</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>W.J.</ce:given-name> <ce:surname>Weiner</ce:surname> </sb:author> <sb:author> <ce:given-name>H.L.</ce:given-name> <ce:surname>Klawans</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Lingual–facial–buccal movements in the elderly. Pathogenesis and relationship to senile chorea</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>J Am Geriatr Soc</sb:maintitle> </sb:title> <sb:volume-nr>21</sb:volume-nr> </sb:series> <sb:date>1973</sb:date> </sb:issue> <sb:pages> <sb:first-page>318</sb:first-page> <sb:last-page>320</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib84"> <ce:label>84</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>L.</ce:given-name> <ce:surname>Wolfson</ce:surname> </sb:author> <sb:author> <ce:given-name>R.</ce:given-name> <ce:surname>Whipple</ce:surname> </sb:author> <sb:author> <ce:given-name>C.A.</ce:given-name> <ce:surname>Derby</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>A dynamic posturography study of balance in healthy elderly</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Neurology</sb:maintitle> </sb:title> <sb:volume-nr>42</sb:volume-nr> </sb:series> <sb:date>1992</sb:date> </sb:issue> <sb:pages> <sb:first-page>2069</sb:first-page> <sb:last-page>2075</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib85"> <ce:label>85</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>M.H.</ce:given-name> <ce:surname>Wollacott</ce:surname> </sb:author> <sb:author> <ce:given-name>D.L.</ce:given-name> <ce:surname>Manchester</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>Anticipatory postural adjustments in older adults: Are changes in response characteristics due to changes in strategy?</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>J Gerontol</sb:maintitle> </sb:title> <sb:volume-nr>48</sb:volume-nr> </sb:series> <sb:date>1993</sb:date> </sb:issue> <sb:pages> <sb:first-page>M64</sb:first-page> <sb:last-page>M70</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib86"> <ce:label>86</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>J.</ce:given-name> <ce:surname>Woo</ce:surname> </sb:author> <sb:author> <ce:given-name>S.C.</ce:given-name> <ce:surname>Ho</ce:surname> </sb:author> <sb:author> <ce:given-name>J.</ce:given-name> <ce:surname>Lau</ce:surname> </sb:author> <sb:et-al></sb:et-al> </sb:authors> <sb:title> <sb:maintitle>Age–associated gait changes in the elderly: Pathological or physiological?</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Neuroepidemiology</sb:maintitle> </sb:title> <sb:volume-nr>14</sb:volume-nr> </sb:series> <sb:date>1995</sb:date> </sb:issue> <sb:pages> <sb:first-page>65</sb:first-page> <sb:last-page>71</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> <ce:bib-reference id="bib87"> <ce:label>87</ce:label> <sb:reference> <sb:contribution> <sb:authors> <sb:author> <ce:given-name>W.J.</ce:given-name> <ce:surname>Zetusky</ce:surname> </sb:author> <sb:author> <ce:given-name>J.</ce:given-name> <ce:surname>Jankovic</ce:surname> </sb:author> <sb:author> <ce:given-name>F.J.</ce:given-name> <ce:surname>Pirozzolo</ce:surname> </sb:author> </sb:authors> <sb:title> <sb:maintitle>The heterogeneity of Parkinson's disease: Clinical and prognostic implications</sb:maintitle> </sb:title> </sb:contribution> <sb:host> <sb:issue> <sb:series> <sb:title> <sb:maintitle>Neurology</sb:maintitle> </sb:title> <sb:volume-nr>35</sb:volume-nr> </sb:series> <sb:date>1985</sb:date> </sb:issue> <sb:pages> <sb:first-page>522</sb:first-page> <sb:last-page>526</sb:last-page> </sb:pages> </sb:host> </sb:reference> </ce:bib-reference> </ce:bibliography-sec> </ce:bibliography> </tail></article></istex:document></istex:metadataXml><mods version="3.6"><titleInfo><title>Movement disorders and normal aging</title></titleInfo><titleInfo type="alternative" contentType="CDATA"><title>Movement disorders and normal aging</title></titleInfo><name type="personal"><namePart type="given">Padma R.</namePart><namePart type="family">Mahant</namePart><namePart type="termsOfAddress">MD</namePart><affiliation>From the Movement Disorders, Muhammad Ali Parkinson Research Center at Barrow Neurological Institute, Phoenix, Arizona</affiliation><role><roleTerm type="text">author</roleTerm></role></name><name type="personal"><namePart type="given">Mark A.</namePart><namePart type="family">Stacy</namePart><namePart type="termsOfAddress">MD</namePart><affiliation>From the Movement Disorders, Muhammad Ali Parkinson Research Center at Barrow Neurological Institute, Phoenix, Arizona</affiliation><role><roleTerm type="text">author</roleTerm></role></name><typeOfResource>text</typeOfResource><genre type="other" displayLabel="N/A"></genre><originInfo><publisher>ELSEVIER</publisher><dateIssued encoding="w3cdtf">2001</dateIssued><copyrightDate encoding="w3cdtf">2001</copyrightDate></originInfo><language><languageTerm type="code" authority="iso639-2b">eng</languageTerm><languageTerm type="code" authority="rfc3066">en</languageTerm></language><physicalDescription><internetMediaType>text/html</internetMediaType></physicalDescription><note>Address reprint requests to, Mark A. Stacy, MD, Muhammad Ali Parkinson Research Center, 500 W. Thomas Avenue, Suite 700, Phoenix, AZ 85013</note><note type="content">Section title: Movement Disorders and Normal Aging</note><relatedItem type="host"><titleInfo><title>Neurologic Clinics</title></titleInfo><titleInfo type="abbreviated"><title>NCL</title></titleInfo><genre type="journal">journal</genre><originInfo><dateIssued encoding="w3cdtf">20010801</dateIssued></originInfo><identifier type="ISSN">0733-8619</identifier><identifier type="PII">S0733-8619(05)X7003-7</identifier><part><date>20010801</date><detail type="volume"><number>19</number><caption>vol.</caption></detail><detail type="issue"><number>3</number><caption>no.</caption></detail><extent unit="issue pages"><start>523</start><end>782</end></extent><extent unit="pages"><start>553</start><end>563</end></extent></part></relatedItem><identifier type="istex">F5189D93C275183A1E0C46319EA89B601DD445C0</identifier><identifier type="DOI">10.1016/S0733-8619(05)70034-7</identifier><identifier type="PII">S0733-8619(05)70034-7</identifier><accessCondition type="use and reproduction" contentType="copyright">©2001 W. B. Saunders Company</accessCondition><recordInfo><recordContentSource>ELSEVIER</recordContentSource><recordOrigin>W. B. Saunders Company, ©2001</recordOrigin></recordInfo></mods></metadata><serie></serie></istex></record>Pour manipuler ce document sous Unix (Dilib)
EXPLOR_STEP=$WICRI_ROOT/Wicri/Psychologie/explor/DanceTherParkinsonV1/Data/Istex/Corpus
HfdSelect -h $EXPLOR_STEP/biblio.hfd -nk 000016 | SxmlIndent | more
Ou
HfdSelect -h $EXPLOR_AREA/Data/Istex/Corpus/biblio.hfd -nk 000016 | SxmlIndent | more
Pour mettre un lien sur cette page dans le réseau Wicri
{{Explor lien
|wiki= Wicri/Psychologie
|area= DanceTherParkinsonV1
|flux= Istex
|étape= Corpus
|type= RBID
|clé= ISTEX:F5189D93C275183A1E0C46319EA89B601DD445C0
|texte= Movement disorders and normal aging
}}
| This area was generated with Dilib version V0.6.35. |  |