TRIGEMINALLY TRIGGERED EPILEPTIC HEMIFACIAL CONVULSIONS

WE present whole-head magnetoencephalographic recordings from a patien t suffering from trigeminally triggered left-sided hemifacial convulsi ons. The patient was a candidate for surgical treatment, but regardles s of extensive scalp EEG, videotelemetry and PET recordings, an epilep tic focus could not be identified, Magnetic signal distribution during a seizure suggested focal epileptic activity in the face area of the right primary motor cortex. A secondary focus was activated 22 ms late r in the left hemisphere. Discharges could be triggered by sensory sti mulation of the left lower gum. The similarities of this seizure produ ction mechanism to trigeminal neuralgia and kindling are discussed.