Accidental seizure with repetitive transcranial magnetic stimulation.

Accidental induction of convulsions by using repetitive transcranial magnetic stimulation (rTMS) has been reported to have occurred in 6 normal voluntary subjects, in 1 patient with depression and in 1 patient who had temporal lobe epilepsy, with secondary generalization. In addition, 3 other cases have been published relating its use with seizure induction and in 1 case, using 1-Hz stimulation. In this paper, we report a patient who was participating in a protocol for the use of rTMS in chronic pain, with stimulation in the motor cortex, who developed a generalized seizure in the fifth application. Intertrain interval was within safety guidelines, but the combination of 10 Hz for 10 seconds was excessive and must be considered the main cause for the episode. No further complication has been noted after she was withdrawn from the study protocol.