[Visual evoked potentials among parkinsonism patients in the older age groups]

Using an ATAC 501-20 system and an RM-85 polygraph manufactured by Nihon-Cogden, visual evoked potentials (VEP) were examined in 60 middle-aged and senile patients with parkinsonism and also in 40 clinically healthy age-matched test subjects. Three major types of the response configuration were identified. The authors established a lengthening of the latent periods of the majority of the VEP components in the patients with parkinsonism which was combined with a reduction in the age differences characteristic of these parameters in clinically normal subjects. Parkinsonism was also associated with opposite changes in the amplitudes of the early (an increase) and the late (a decrease) components of VEP.