Transcranial magnetic stimulation. Its role in the evaluation of patients with partial epilepsy.

Transcranial magnetic stimulation (TMS) is a relative new method in the evaluation of patients with various neurological diseases. With the introduction of repetitive (rapid rate) transcranial magnetic stimulators (RTMS), it has been possible to apply cortical stimuli with a stimulus rate up to 100 Hz. The preliminary results with TRMS suggest that it may be used in the study of speech lateralization. Seizures have been reported in patients with partial epilepsy during TMS. In these cases it remains uncertain whether the seizures were induced by the TMS or coincidentally with it. Minor changes in paroxysmal activity have been reported in some patients. These data suggest, that TMS is neither sensitive nor specific as an activation procedure of the epileptic focus in patients with partial epilepsy. Seizures have been provoked using RTMS, but its use as a seizure-inducing method is not yet evaluated.