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PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1992-10-30
pubmed:abstractText
We studied reflexive and predictive saccades by direct current electro-oculography in nine patients with mild hemi-Parkinson's disease (hemi-PD) and in 16 age-matched controls. In five patients, the neurological syndrome was predominant on the right side of the body (RPD) and in four patients, on the left side (LPD). Reflexive saccades were elicited in response to the random appearance (timing and location) of a light-emitting diode (LED). Predictive saccades were elicited by alternatively illuminating LEDs at 10 degrees right and left, at various fixed frequencies (0.25-1 Hz). In the reflexive task, latency and amplitude of the saccades were normal in both PD groups. In the predictive task, mean saccade latency was not significantly different between patients and normals but there were two significant abnormalities in timing: first, but only in LPD, a directional asymmetry in latency (left greater than right, e.g. at 0.25 Hz, mean difference of 90 ms); secondly, especially in RPD, an abnormal tracking pattern, reflected by more variability of the mean value (for each group of patients) of saccade latency at each point in time, throughout a period of tracking at a given frequency. Predictive saccades were also strongly hypometric in both PD groups but especially in LPD (e.g. for rightwards saccades: controls = 19 degrees, SD = 1.6; LPD = 14 degrees, SD = 2.7; RPD = 15.7 degrees, SD = 2.3). These defects in saccadic timing and amplitude during predictive tracking were most salient at low frequencies. While these defects were largely bilateral, our findings suggest slightly different contributions of the right and left cerebral hemispheres to the spatial and timing components, respectively, that comprise optimal predictive saccadic behaviour.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-8950
pubmed:author
pubmed:issnType
Print
pubmed:volume
115 ( Pt 4)
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1147-65
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Abnormalities of predictive saccades in hemi-Parkinson's disease.
pubmed:affiliation
Vision et Motricite, INSERM U94, Bron, France.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.