[Long-latency auditory evoked responses in Parkinson disease and in parkinsonism induced by neuroleptics].

The amplitude and latency of the N100 wave (auditory evoked potentials) were studied in 28 normals, 85 parkinsonians, 24 extrapyramidal syndromes induced by neuroleptics and 12 neurological control patients. The latency decreases as an inverse function of the intensity of stimulation in normals, controls, treated parkinsonians and in extrapyramidal syndrome induced by neuroleptics. Untreated parkinsonians do not show an evident relation between the latency and the stimulation level. The amplitude of the N100 decreases when neuroleptic induced parkinsonism improves.