Abstract
The exact involvement of each part of the basal ganglia in obtaining ocular movements has not yet been totally revealed. Comparing information of oculographic studies of patients and those of experimental studies on primates, may lead us to solve the enigma of the different components of ocular motility.
A patient presenting with a multiple system atrophy consisting of a combination of olivo-ponto-cerebellar atrophy and striato-nigral degeneration showed remarkable features on oculography. Besides the typical impairment of the eye movements found in Parkinson syndromes, the patient also showed a major impairment of the vertical optokinetic nystagmus, where the vertical smooth pursuit and saccades were only slightly altered.
In reviewing animal studies and through anatomopathological findings in the patient, the authors suggest that the striato-nigral system in humans is involved in eliciting vertical optokinetic nystagmus. Oculography may reveal an unexpected symptom, orienting the correct diagnosis and its topographic relationship.
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