Akinesia, hypokinesia, and bradykinesia in the oculomotor system of patients with Parkinson's disease

Dejong, J D; Jones, G. Melvill

doi:10.1016/0014-4886(71)90165-8

Cited by 215 publications

(31 citation statements)

References 10 publications

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“…3A), patients also showed a tendency to higher numbers of saccades per gaze shift to reach the target (Fig. 3B) 12 , the difference between subject groups was statistically significant for M2 (p < 0.0001), but not for V1, V2 and M1. Noticeably, discrimination of patients from controls on the basis of MSP percentage with M2 was high; the lower 95 % confidence limits of median MSP percentage in patients was 63 %, while the corresponding upper limit for controls amounted to 58 %.…”

Section: Number Of Saccadesmentioning

confidence: 81%

“…These findings differentiate the saccade hypometria considered here from other forms of hypometria (e. g. the one observed with drowsiness; see below) and suggests that it arises in the pre-motor drive at some intermediate processing stage between cortex and brainstem machinery. There is a vast amount of literature, which suggests that the performance of tasks with the complexity of M2 involves the fronto-striatal loops and basal ganglia functions [10,12,15,17,19,24,28,33]. These loops play a crucial role in behavior that involves internal drives and movement sequences.…”

Section: Discussionmentioning

confidence: 99%

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What is pathological with gaze shift fragmentation in Parkinson's disease?

Kimmig

Haußmann

Mergner

et al. 2002

Journal of Neurology

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Oculomotor dysfunction in Parkinson's disease (PD) is mainly characterized by a fragmentation of memory-guided gaze shifts (target is reached by several hypometric saccades). Since this phenomenon can also be observed in normal subjects, we scrutinized its pathophysiological significance in PD patients. We recorded horizontal eye movements in eleven mildly- or moderately-affected PD patients and eleven control subjects. A quantitative assessment of gaze shift fragmentation was made possible by increasing its incidence over a sequence of two visually- and two subsequent memory-guided gaze shifts. Basic saccade measures (latency, velocity, etc.) were similar in the two subject groups as well as in fragmented versus non-fragmented gaze shifts. Fragmentation probability is increased in the second memory-guided gaze shift, and this clearly more so in patients than in controls. The fragmentation shows a typical gain pattern (uniform increase of gain of saccadic amplitudes across correction saccades towards 1.0 with the last saccade of the gaze shift) independent of subject group, stimulus mode, and fragmentation degree. Gaze shift fragmentation represents a physiological phenomenon, which has thus far been overlooked. It reflects a robust correction mechanism, which assures that target is reached even if the pre-oculomotor drive through the basal ganglia to the superior colliculus becomes abnormally weak or under inadequately strong inhibition - as is postulated for PD. Thus, only the abnormally high incidence of fragmentation, and of the associated amplitude reduction of the primary saccades, rather than the phenomenon per se, can be used as a diagnostic criterion in early stages of PD.

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Section: Number Of Saccadesmentioning

confidence: 81%

Section: Discussionmentioning

confidence: 99%

What is pathological with gaze shift fragmentation in Parkinson's disease?

Kimmig

Haußmann

Mergner

et al. 2002

Journal of Neurology

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show abstract

“…Both the frequency and metrics of voluntary saccades generated between two fixed targets are reduced in PD compared with controls [39]. Predictive …”

Section: Sinusoidal Pursuit Peformancementioning

confidence: 99%

Abnormalities of smooth eye and head movement control in parhson's disease

Waterston

Barnes

Grealy

et al. 1996

Annals of Neurology

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The control of horizontal head and eye movements was examined in 13 nondemented patients with Parkinson's disease (PD) of mild to moderate severity. During pursuit of single-frequency sine waves, smooth component eye velocity was lower in the PD group at frequencies of 1.2 Hz and above; but the differences in overall eye displacement were even greater, indicating an impaired ability to generate catch-up saccades at high frequencies. A corresponding deficit in saccadic performance was observed during a high-frequency saccadic tracking task where predictive saccades of reduced gain and variable timing were generated. During pursuit of pseudo-random target motion with varying degrees of predictability, small differences in smooth component eye velocity were observed, but prediction was otherwise well preserved in the patient group. Vestibulo-ocular reflex (VOR) suppression was also normal during head-free pursuit. No major improvement in smooth pursuit gain could be attributed to drug treatment, based on a comparison of patient results before and after administration of levodopa.

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“…When PD patients scanned pictures, they explored a smaller area of them with smaller saccades compared to normal subjects. Reduced saccadic amplitudes have been reported mostly for advanced PD patients for comparable tasks with a predefined target stimulus, and data about saccadic dynamics in these patients are sometimes inhomogeneous due to differences that exist during the disease stage [37,38,39,40,41]. …”

Section: Discussionmentioning

confidence: 99%

Visual Attention and Saccadic Oculomotor Control in Parkinson's Disease

et al. 2015

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Background: In patients with Parkinson's disease (PD) we aimed at differentiating the relation between selective visual attention, deficits of programming and dynamics of saccadic eye movements while searching for a target and hand-reaction time as well as hand-movement time. Visual attention is crucial for concentrating selectively on one aspect of the visual field while ignoring other aspects. Eye movements are anatomically and functionally related to mechanisms of visual attention. Saccadic dysfunction might confound selective visual attention in PD. Methods: We studied visual selective attention in 22 medicated PD patients (clinical ON status, mild to moderate disease severity) and 22 age matched controls. We looked for possible interferences through oculomotor deficits. Two tasks were compared: free viewing of photographs and time optimal visual search of a hidden target. Visual search times (VST), task related dynamics of saccades, and hand-reaction and hand-movement times were analyzed. Results: In the free viewing task mild to moderately affected PD patients did not differ statistically from healthy subjects with respect to saccade dynamics. However, patients differed significantly from healthy subjects in the time optimal visual search task with 25% lower rates of successful searches. Hand movement reaction time did not differ in both groups, whereas hand movement execution time was significantly prolonged in PD patients. Conclusion: Saccadic oculomotor control and hand movement reaction times were intact, whereas in our less severely affected treated PD patients, visual selective attention was not. The highly reduced successful search rate might be related to disturbed programming and delayed execution of saccades during time optimal visual search due to decreased execution of serial-order sequential generation of saccades.

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Akinesia, hypokinesia, and bradykinesia in the oculomotor system of patients with Parkinson's disease

Cited by 215 publications

References 10 publications

What is pathological with gaze shift fragmentation in Parkinson's disease?

What is pathological with gaze shift fragmentation in Parkinson's disease?

Abnormalities of smooth eye and head movement control in parhson's disease

Visual Attention and Saccadic Oculomotor Control in Parkinson's Disease

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