[Visual evoked potentials in Parkinson's disease (author's transl)].

Visual evoked potentials were studied in 23 patients with Parkinson's disease at varying stages, and in 23 normal subjects of the same age. The latency of the P wave is increased in the Parkinson group in a significant manner and becomes more marked as the disease progresses. The difference in latency between the potentials evoked by stimuli applied to both eyes is also significantly increased in Parkinson's disease. The interpretation of these results remains obscure, but "peripheral" retinal and "central" mechanisms are probably involved. From a practical point of view, these results demonstrate that increases in latency of visual evoked potentials are not always due to localized demyelinization. Study of visual evoked potentials could be of values when investigating patients with Parkinson's disease.