Relationship between antisaccades and the clinical symptoms in Parkinson's disease.

We studied voluntary control of saccadic eye movement in 32 parkinsonian patients using the antisaccade task (the subjects were instructed not to look at the target but to look in the opposite direction). Mean latencies and error rates in the antisaccade task were significantly increased in advanced parkinsonian patients. The latencies of the antisaccades correlated with the severity of bradykinesia as well as the results of the Wisconsin Card Sorting Test. Patients taking anticholinergics showed significantly higher error rates. These results suggest that disturbance in the initiation of voluntary saccades in advanced patients may be associated with frontal lobe dysfunction, while anticholinergics may affect the inhibitory control of reflexive saccades.