[Somatosensory evoked potentials and symptomatic response to dopaminergic drugs in Parkinson's disease]

Short latency somatosensory evoked potentials were measured in 10 patients with Parkinson's disease before and after the administration of Apomorphine 5 mg sc. Eight of these subjects were reassessed after one month of treatment with Levo-Dopa. These potentials were measured in other nine subjects before and after one month of treatment with Selegiline 10 mg od. There was a significant increase of frontal potential N30 in nine of 10 subjects that received apomorphine, in seven of eight patients treated with Levo-dopa and seven of nine patients treated with Selegiline. No changes in N20 parietal potential were observed. During apomorphine test, changes in N30 potential preceded clinical improvement in six patients and occurred simultaneously in three patients. No changes with apomorphine in N30 potential were observed in two healthy males. There was no relationship between electrophysiological changes and duration of disease or motor fluctuations. It is concluded that short latency somatosensory evoked potentials are an objective means of measuring dopaminergic response in patients with Parkinson's disease.