Carbamazepine-induced dystonia.

To the Editor.— Chadwick et al1reviewed the topic of anticonvulsant-induced dyskinesia in 1976. They described limb chorea, orofacial dyskinesia, and dystonia occurring in association with phenytoin administration. They only found asterixis secondary to carbamazepine toxic reaction in one female patient who had a cerebellar syndrome. Carbamazepine, in addition to its anticonvulsant action, has been reported as helpful in treating paroxysmal kinesigenic choreoathetosis2and refractory inherited and acquired dystonia (Geller et al, 229:1755, 1974). During the past year, I had the opportunity of observing four patients admitted to the Epilepsy Unit of the University of Minnesota because of intractable seizures. Three of the patients showed development of transient dystonia of the axial muscles, and one, of the hands, after carbamazepine was added as an anticonvulsant therapy in three of the patients and in the other, after the previous dose of carbamazepine was doubled. In all of the patients