A Study on Synkinetic Behavior 
in Hemifacial Spasm 
Using Blink Reflex Methodology

J Korean Neurol Assoc > Volume 16(1); 1998 > Article

Journal of the Korean Neurological Association 1998;16(1): 55-62.

순목반사검사를 이용한 편측안면연축 환자의 동시운동 형태에 관한 연구

김대성, 박규현

부산대학교 병원 신경과

A Study on Synkinetic Behavior in Hemifacial Spasm Using Blink Reflex Methodology

Dae-Seong Kim, M.D. and Kyu-Hyun Park, M.D.

Department of Neurology, Pusan National University Hospital

Abstract

Background and Purpose; Hemifacial spasm is clinically characterized by involuntary co-contraction of unilateral facial muscles innervated by facial nerve and presence of synkinetic response between facial muscles innervated by different branches of facial nerve is considered as the electrophysiological hallmark of this disease. We performed this study in order to analyse and thereby to approach the pathogenesis of these synkinetic responses in detail. Methods; Blink reflex test was applied to the 21 patients with hemifacial spasm. With some modification of conventional blink reflex methodology, synkinetic responses between orbicularis oculi and orbicularis oris muscles were recorded on both affected and unaffected sides. Results; Among 21 patients, 10( 47.6% ) showed synkinetic responses both on affected and unaffected side, 8( 38.1% ) only on affected side, and 3( 14.3% ) did not show any evidence of synkinesis on either side. Conclusion; These findings could be considered as additional supportive evidence that the facial neuronal hyperexcitability is working in hemifacial spasm as synkinesis on unaffected side cannot be explained solely by peripheral mechanism. Further research on change of synkinetic behavior after microvascular decompression surgery seems to be needed. Key Words; Hemifacial spasm, Synkinesis, Unaffected side, Blink reflex study, Facial neuronal hyperexcitability