자기자극시 안면신경 활성부위에 대한 전기생리학적 연구

Abstract

In order to investigate the activation site of the facial nerve on the transcranial magnetic stimulation, we studied 113 patients with the hemifacial spasm from March 1994 to December 1995.

The abnormal muscle responses(AMR) of the involved side were measured with the antidromic electrical stimulation, the compound muscle action potentials(CMAP) of both sides were measured with the orthodromic electrical stimulation at the stylomastoid foramen and at the distal nerve branches, and the motor evoked potentials(MEP) of both sides were measured with the transcranial magnetic stimulation at the mentalis and the orbicularis oculi, respectively.

The measured latencies of the AMR were 8.69msec from the mentalis and 9.10msec from the orbicularis oculi, respectively. We calculated the latencies of the AMR using the latencies of the CMAP and those of the MEP to identify the origin of the MEP. The latencies of the calculated AMR were 6.10msec from the mentalis and 6.23msec from the orbicularis oculi. The differences between the measured and the calculated latencies of the AMR were statistically significant(p<0.01).

According to the above results, the actual activation site of the facial nerve on the transcranial magnetic stimulation seems to be the area distal to the origin of the AMR, possibly the labyrinthine segment.