[Evaluation of peripheral facial nerve palsy with R 2 wave latency in blink reflex]

Electrically elicited blink reflexes were investigated in 60 patients with peripheral facial nerve palsy. The purpose of this study was to evaluate the utility of analysis of R 2 wave in blink reflex as a prognostic indicator for the patients with facial palsy. The patients treated by stellate ganglion block were classified into three groups: Group I scored more than 90 points (full score is 100 points) within 2 weeks, Group II scored more than 90 points over 2 weeks, and Group III scored less than 90 points. The examinations were performed at the first visit, and 2, 4, 6 weeks after the onset of facial palsy. Latencies of ipsilateral and contralateral R 2 wave were measured by electrical stimulation on both side. There were significant differences of R 2 latency between ipsilateral and contralateral side in each of the three groups at the first visit. In Group II, contralateral R 2 latency obtained by stimulation of the paralytic side was prolonged significantly. In Group III, the ipsilateral R 2 wave was not observed. The results of this study indicate that measurement of the R 2 latency of blink reflex is useful in judging the severity of the peripheral facial nerve palsy. The R 2 latencies obtained by stimulation of ipsilateral and contralateral side should be used as one of the parameters for evaluation of the prognosis of patients with peripheral facial nerve palsy.