[Magnetic stimulation in patients with facial hemispasm]

A total of 28 patients with a hemifacial spasm were examined using transcranial magnetic stimulation. The potentials were evoked cortically and cisternally; latencies and amplitudes of each potential were measured in the levator labii muscle and in the orbicularis oculi muscle. After cortical stimulation, differences in latencies were found between the healthy and the diseased side of the levator labii muscle. Prolonged latencies were measured more frequently on the diseased side (cortical stimulation). The method of magnetic stimulation is an important addition to electrophysiological diagnostic procedures in facial hyperkinesias. Cortical stimulation combined with measurements of the blink reflex and neuromyography may allow separate parts of the route of the whole facial nerve and supranuclear structures to be examined.