[Saccadic system plasticity mechanisms in Parkinson disease patients].
J Fr Ophtalmol 2011;
35:242-50. [PMID:
22018708 DOI:
10.1016/j.jfo.2011.05.009]
[Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 04/28/2011] [Accepted: 05/05/2011] [Indexed: 11/21/2022]
Abstract
INTRODUCTION
Voluntary or reactive saccades predominate in rapid eye movements. Their goal is to preserve an active and optimal visual perception of the environment. Saccades cannot be guided once launched. Oculomotor plasticity, or saccadic adaptation, is still partially unknown, in particular the role played by the basal ganglia. New neuro-ophthalmological rehabilitation techniques require understanding the neurophysiological basis and demonstrating the neuronal structures involved in this plasticity.
OBJECTIVES
This study assessed the reactive saccade adaptation in patients with idiopathic Parkinson disease, as a model of basal ganglia dysfunction. We predicted that saccadic adaptation would be preserved in this pathology.
PATIENTS AND METHODS
Five patients with mild idiopathic hemi-Parkinson disease were included, as well as four age-matched controls. Reactive saccade adaptation was studied using the double-step target paradigm, in patients with OFF-Dopa treatment and in controls.
RESULTS
Group analysis demonstrated that patients had a lower level of adaptation than the controls (p<0.05). Individually, two patients did not adapt for bilateral saccades and one for ipsilateral (compared to Parkinson motor clinical syndrome) saccades. Two additional patients adapted on both sides but with a deficit in contralateral saccades when compared to the control group.
DISCUSSION
These preliminary results suggest basal ganglia involvement in reactive saccadic adaptation, which remains to be clarified.
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