Blockade of the Postictal Prolactin Surge by Methysergide

To the Editor.— Plasma prolactin (PRL) levels increase severalfold immediately following tonic-clonic seizures, complex partial seizures, and electroconvulsive therapy (ECT).1-5 Depth electroencephalographic recordings suggest that spreading of the ictal discharge to subcortical (limbic) structures is necessary for the observed PRL release.6 The neurochemical substrate of this neuroendocrine response, however, remains unknown. We report here that pretreatment with the classic serotonin receptor antagonist methysergide blocks the ECTinduced PRL surge.Patients and Methods.— Eight drug-free patients receiving a course of unilateral (n = 5) or bilateral (n = 3) ECT as the clinically indicated treatment for their illness were the subjects of our study. The doses of thiopental sodium and succinylcholine chloride and the voltage and duration of the electrical stimulus were individually adjusted for each patient during the first two treatments and remained constant for treatments 3 through 5. Seizure duration was monitored by the pressure cuff method and averaged