Electrophysiologic Study of the Hemifacial Spasm.

Ahn, Sang Ki; Kim, Jae Chan; Shyn, Kyung Whan; Kim, Doo Eung

Original Article

Journal of the Korean Ophthalmological Society 1995;36(1):1-6.
Published online January 1, 1995.

Electrophysiologic Study of the Hemifacial Spasm.

Sang Ki Ahn, Jae Chan Kim, Kyung Whan Shyn, Doo Eung Kim

¹Department of Ophthalmology, Chung Ang University, Hospital, Korea.
²Department of Neurology, Chung Ang University, Hospital, Korea.

반측안면연축의 전기생리학적 연구

안상기(Sang Ki Ahn),김재찬(Jae Chan Kim),신경환(Kyung Whan Shyn),김두응(Doo Eung Kim)

Abstract

There has been controversy between compression of the facial nerve in the cerebellopontine recess and focal demyelination of the facial nerve on the pathogenesis of hemifacial spasm(HFS). To know the pathophysiology of HFS, we performed the facial nerve stimulation test and blink reflex test in 15 patients with HFS. And then we analyzed change of electrophysiologic findings after botulinum toxin in jection. We could not find any differences of latency between affected and unaffected side in facial nerve stimulation test(p>0.05). In the blink reflex test, there were prolonged R1 latency(p<0.01) and occurance of late response on the affected side. There has no change after botulinum toxin injection. These results suggest that there is no facial neuropathy and no electrophysiological evidence of dysfunction in the blink reflex system. Also, there may be two pathophysiologic lesions in HFS. compression and focal demyelination of the facial nerve. And we think that the botulinum toxin is no effect on facial nerve conduction itself.

Key Words: Blink reflex test;Facial nerve stimulation test;Hemifacial spasm