An exploration of ocular fixation in Parkinson’s disease, multiple system atrophy and progressive supranuclear palsy

Pinnock, Ralph; McGivern, R. Canice; Forbes, Raeburn B; Gibson, J. M.

doi:10.1007/s00415-009-5356-3

Cited by 29 publications

(26 citation statements)

References 29 publications

(30 reference statements)

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“…However, our patients had an established diagnosis of PSP, with a median duration of 4 years, so it remains to be proven whether SWJs made by patients earlier in their disease course are distinguishable from SWJs made by healthy subjects. Future research should moreover establish whether SWJs made by patients with other parkinsonian disorders, such as multiple system atrophy (Rascol et al, 1991; Pinnock et al, 2009), or cerebellar conditions such as Friedreich's ataxia, can be distinguished on this basis. Such studies seem justified (Rascol et al, 1991; Garbutt et al, 2004; Antoniades et al, 2007; Pinnock et al, 2009).…”

Section: Discussionmentioning

confidence: 99%

Distinctive Features of Saccadic Intrusions and Microsaccades in Progressive Supranuclear Palsy

Otero‐Millan¹,

Serra²,

Leigh³

et al. 2011

J. Neurosci.

109

115

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The eyes do not stay perfectly still during attempted fixation; fixational eye movements and saccadic intrusions (SIs) continuously change the position of gaze. The most common type of SI, square-wave jerk (SWJ), consists of saccade pairs that appear purely horizontal on clinical inspection: the first saccade moves the eye away from the fixation target and, after a short interval, the second saccade brings it back towards the target. SWJs are prevalent in certain neurological disorders, including progressive supranuclear palsy (PSP). Here we developed an objective method to identify SWJs. We found that SWJs are more frequent, larger and more markedly horizontal in PSP patients than in healthy human subjects. Further, the loss of a vertical component in fixational saccades and SWJs was the eye movement feature that best distinguished PSP patients from controls. We moreover determined that in PSP patients and controls, the larger the saccade the more likely it was part of a SWJ. Further, saccades produced by PSP patients had equivalent properties whether they were part of a SWJ or not, suggesting that normal fixational saccades (microsaccades) are rare in PSP. We propose that fixational saccades and SIs are generated by the same neural circuit, and that, both in PSP patients and in controls, SWJs result from a coupling mechanism that generates a second corrective saccade shortly after a large fixation saccade. Due to brainstem and/or cerebellum impairment, fixational saccades in PSP are abnormally large, and thus more likely to trigger a corrective saccade, giving rise to SWJs.

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Section: Discussionmentioning

confidence: 99%

Distinctive Features of Saccadic Intrusions and Microsaccades in Progressive Supranuclear Palsy

Otero‐Millan¹,

Serra²,

Leigh³

et al. 2011

J. Neurosci.

109

115

View full text Add to dashboard Cite

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“…The latency, velocity, and precision of the saccades were recorded and automatically calculated. (4) Smooth pursuits, the patients were told to track a pendular light dot. The gain (eye velocity/target velocity) of the five pursuits at each velocity and direction was recorded using stimuli of 20 and 30°/s horizontally at a constant speed.…”

Section: Methodsmentioning

confidence: 99%

“…Ocular fixation is thought to be under basal ganglia control, and fixation parameters in PD, MSA and PSP were investigated in detail by Pinnock et al [4]. They found significant variations between groups for amplitude and frequency of saccadic intrusions and mean displacement of fixation without a visible target [4]. Altiparmak et al [5] demonstrated that the ratio of square wave jerks (SWJs) to blink rates could distinguish PSP from PD.…”

Section: Introductionmentioning

confidence: 98%

“…In a study by Rivaud-Pechoux et al [3], patients who had the clinical diagnosis of ''atypical corticobasal degeneration'' at the first examination and who fulfilled the diagnostic criteria for PSP 6 months later, had oculomotor findings supportive of PSP already at the first examination. Ocular fixation is thought to be under basal ganglia control, and fixation parameters in PD, MSA and PSP were investigated in detail by Pinnock et al [4]. They found significant variations between groups for amplitude and frequency of saccadic intrusions and mean displacement of fixation without a visible target [4].…”

Section: Introductionmentioning

confidence: 98%

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Impaired oculomotor function in a community-based patient population with newly diagnosed idiopathic parkinsonism

et al. 2011

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The differential diagnosis of idiopathic parkinsonism can be very challenging, especially early in the course of the disease. Oculomotor function has been reported to differ between the diseases constituting idiopathic parkinsonism. A detailed examination of the oculomotor functions could thus possibly be useful in the early differential diagnostic procedure. Oculomotor function could also differ between subgroups of patients with Parkinson's disease (PD). We examined the oculomotor function in a population-based incidence cohort with newly diagnosed idiopathic parkinsonism and 38 controls. We examined 135 patients with parkinsonism 105 PD, 11 progressive supranuclear palsy (PSP), and 19 multiple system atrophy with predominant parkinsonism (MSA-P)] within 3 months of their first visit to our clinic and before initiation of dopaminergic medication. The oculomotor measurements were repeated after 12 months. The clinical diagnosis was that of the latest clinical follow-up (median follow-up was 3 years). All patients were examined with (123)I-N-(omega)-fluoropropyl-2-β-carbomethoxy-3-β-(4-iodophenyl) nortropane single-photon emission computed tomography (FP-CIT SPECT), and only patients with pathological uptake of the ligand were included. Pathological changes in the oculomotor function were found in all patient groups compared to controls at the baseline examination. In PD, there were correlations between total axial motor scores and vertical saccade velocity and precision, horizontal saccade velocity and precision, and smooth pursuit gain at 20 and 30°/s. Oculomotor test results could not separate the different forms of idiopathic parkinsonism in the early phase from each other. Few changes in the oculomotor functions were observed between the baseline and the 12-month follow-up examinations. No correlations were found between the oculomotor measurements and disease severity or duration.

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“…PD patients have been reported to have an increased frequency of SWJs [20,21], as well as an overall increased number of SIs [22]. While there are reports of PD patients showing an increase in SWJ frequency after undergoing unilateral pallidotomy [6,23], there are no previously reported studies on whether GPi DBS changes the frequency of SIs or SWJs.…”

Section: Discussionmentioning

confidence: 86%

Effect of Subthalamic Nucleus or Globus Pallidus Interna Stimulation on Oculomotor Function in Patients with Parkinson’s Disease

Fridley¹,

Adams²,

Sun³

et al. 2013

Stereotact Funct Neurosurg

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Background: Deep brain stimulation (DBS) of either the globus pallidus interna (GPi) or subthalamic nucleus (STN) is similarly effective for treating somatomotor manifestations of Parkinson’s disease (PD), but differences in how stimulation of each target affects oculomotor function are poorly understood. Objective: We sought to determine if stimulation of the STN, but not the GPi, affects oculomotor function in PD patients. Methods: Nineteen PD patients with DBS implants (8 bilateral GPi, 9 bilateral STN and 2 unilateral STN) were studied. Testing was performed with stimulation on, then off. Somatomotor function was tested using the Unified Parkinson’s Disease Rating Scale (UPDRS) motor exam. For oculomotor testing, patients performed pro- and antisaccade tasks while monitored with an infrared eye tracker. Saccadic latency, saccadic intrusions, and square-wave jerks (SWJs) were measured for each trial. Results: As expected, UPDRS motor scores improved with both GPi and STN stimulation. With GPi stimulation, there was no significant difference in oculomotor function with stimulation on or off. However, with STN stimulation on, there was a significant increase in the mean number of SWJs/s, as well as a significant decrease in latency for both pro- and antisaccade tasks. Conclusion: Stimulation of either GPi or STN had similar effects on somatomotor function, but only STN stimulation significantly altered oculomotor function.

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An exploration of ocular fixation in Parkinson’s disease, multiple system atrophy and progressive supranuclear palsy

Cited by 29 publications

References 29 publications

Distinctive Features of Saccadic Intrusions and Microsaccades in Progressive Supranuclear Palsy

Distinctive Features of Saccadic Intrusions and Microsaccades in Progressive Supranuclear Palsy

Impaired oculomotor function in a community-based patient population with newly diagnosed idiopathic parkinsonism

Effect of Subthalamic Nucleus or Globus Pallidus Interna Stimulation on Oculomotor Function in Patients with Parkinson’s Disease

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