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Published on: July 31, 2019
Predominant cortical dysfunction in Guadeloupean parkinsonism
Emmanuelle Apartis1, Bertrand Gaymard, Stéphane Verhaeghe
1Department of Physiology, Saint Antoine Hospital, AP-HP, Paris VI University, Paris, France.
Brain : a Journal of Neurology
|October 23, 2008
Summary
Atypical parkinsonism in Guadeloupe (Gd-PSP) presents with cortical myoclonus and oculomotor deficits. This suggests a distinct clinical entity with predominant cortical dysfunction, differing from progressive supranuclear palsy (PSP).
Area of Science:
- Neurology
- Neurophysiology
- Movement Disorders
Background:
- Atypical parkinsonism is highly prevalent in Guadeloupe, potentially linked to environmental factors.
- Guadeloupean patients exhibit tauopathy with progressive supranuclear palsy (PSP)-like features, including dopa-resistant parkinsonism, dementia, and abnormal eye movements, but also hallucinations and dysautonomia not typical of PSP.
- Distinct oculomotor abnormalities and jerky tremors in Guadeloupean patients necessitate detailed electrophysiological characterization.
Purpose of the Study:
- To electrophysiologically characterize the atypical parkinsonism observed in Guadeloupean patients (Gd-PSP).
- To differentiate the observed clinical and electrophysiological features from classical progressive supranuclear palsy (PSP).
- To investigate the origin of abnormal limb movements and oculomotor dysfunction in Gd-PSP.
Main Methods:
- Electrophysiological recordings of horizontal eye movements (visually guided saccades, antisaccades, smooth pursuit) in nine Gd-PSP patients.
- Clinical evaluation of vertical saccade velocity.
- Electrophysiological analysis of limb movements including electromyographic polygraphy and EEG jerk-locked-back-averaging (JLBA).
Main Results:
- Reduced vertical saccade velocity in five patients; normal horizontal visually guided saccade velocity with increased latency.
- Predominantly saccadic horizontal smooth pursuit and high error rates (>70%) in antisaccades.
- Myoclonus (89% of patients), primarily cortical in origin, detected in upper limbs.
- Minor brainstem oculomotor signs contrasted with significant cortical oculomotor impairments.
Conclusions:
- Gd-PSP patients exhibit cortical myoclonus and oculomotor impairments, indicating predominant cortical dysfunction.
- The findings suggest Guadeloupean atypical parkinsonism represents a novel clinical entity distinct from classical PSP.
- Electrophysiological data enrich the characterization of this unique neurological condition.
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