Predictors for improvement after electroconvulsive therapy in parkinsonian patients with on-off symptoms

The antiparkinsonian effect of electroconvulsive therapy (ECT) was investigated in nine parkinsonian patients with "on-off" phenomena. The patients were maintained on previously adjusted doses of antiparkinsonian drugs during and after ECT. Parkinsonian as well as mental symptoms were rated before and after treatment. Basal serum levels of prolactin (PRL) and growth hormone (GH) as well as apomorphine induced changes (0.24 mg i.v.) in these levels were investigated three days before start of treatment. Marked improvement of parkinsonian symptoms was seen in five patients. Two further patients showed slight improvements. The improvement persisted for 2-41 weeks. Improvement after ECT was found to correlate with age at the time of treatment and with duration of L-dopa therapy as well as the estimated life-dose of L-dopa. No correlation was found between depression before treatment, basal serum levels of GH and PRL or apomorphine induced changes in these hormone levels. The investigation indicates that ECT is a valuable adjuvant in the treatment of a selected group of parkinsonian patients with "on-off" phenomena. Furthermore, the results support our earlier proposal that ECT increases the responsiveness in postsynaptic dopamine sensitive structures.