The effect of chlorpromazine on the electroencephalogram of epileptic patients.

Investigations by Courvoisier, Fournel, Ducrot, Kolsky, and Koetschet in 1953 had shown that chlorpromazine reduces convulsions in mice after coramine and in rabbits after nicotine Therefore, the drug seemed to suggest itself as an anticonvulsant in epilepsy But in 1954 Bente and Itil, De Castro and Brard, and Mayr and Lechner observed activation of the electroencephalogram (E.E.G.) in epilepsy after the injection of chlorpromazine, and similar findings were reported in that year by Terzian and Ruberti. In 1954, 1955, and 1956 clinical observers noticed that some patients suffering from idiopathic epilepsy showed an increased number of seizures after chlorpromazine and there were also reports of more frequent epileptiform seizures after brain surgery, insulin coma treatment, in old age, and among large not otherwise specified groups of patients in mental hospitals during treatment with the drug (Barsa and Kline, 1956; Bonafede, 1955; Denber and Bird, 1955; Fabisch, 1955; Kinross-Wright, 1955; Lomas, Boardman, and Markowe, 1955; Munzinger, 1954; Robb, 1955; Samad, 1955; Schlichther, Bristow, Schultz, and Henderson, 1956; Schmid, 1954; Vaughan, Lieberman, and Cook, 1955). Activation of the E.E.G. in patients with idiopathic epilepsy and symptomatic epileptiform seizures was reported by some of these authors as well as by Lyberi and Last (1956), Szatmari (1956), Turner, Berard, Turner, and Franco (1956), Zanocco (1955), Balestrieri (1955), and Balestrieri and Franceschini (1956) observed that in rabbits chlorpromazine in doses up to 10 mg./kg. rarely raises but more often lowers the threshold for pharmacologically and electrically induced convulsions. However, Moyer, KinrossWright, and Finney (1955) reported that three out of four epileptic patients were improved with oral chlorpromazine. The fourth patient was made much worse. The present investigation and a survey of the literature was started when an epileptic patient, who had been free from convulsions for about two years and was given chlorpromazine against a tension state, suffered a convulsive seizure under photic stimulation during a routine E.E.G. examination.