Disturbed striatoprefrontal mediated visual behaviour in moderateto severe parkinsonian patients

OBJECTIVES—To study visuospatial and visualmemory functions in moderate to severe parkinsonian patients.
METHODS—Visual antisaccades (AS) and rememberedsaccades (RS) were examined in 30 patients with moderate to severeParkinson's disease and in 44 age matched controls. AS are saccades inthe direction opposite to the target. RS are saccades towards theremembered position of a target that is no longer visible.
RESULTS—Patients with Parkinson's disease hadserious difficulties in suppressing a reflex saccade ("visualgrasping") or they made no saccade at all ("visual akinesia").The remembered saccade was often wrongly directed.
CONCLUSIONS—These types of errors point to adysfunction in the striatoprefrontal loop. The discrepancy of theresults with those in the literature, which are mostly normal, could beexplained by the more advanced stage of our patients. This mightcorrespond to the development of unresponsiveness to levodopa or ofnon-dopaminergic lesions.