NEW ASSESSMENT FOR PERIPHERAL FACIAL PALSY BY SYMPATHETIC SKIN RESPONSE(SSR)

Abstract

S292 Introduction The cause of facial palsy is mainly considered due to the peripheral circulartory disturbance. Satellate ganglion block(SGB) is as one of the treatments for the facial palsy. Susceptible effect of SGB is to increase the blood flow and to improve peripheral circulation around the facial nerve. On the other hand, there still lacks the basic data whether facial palsy is correlated with sympathetic dysfunction. The reason why is that there was no simple way to evaluate sympathetic function. Skin sympathetic response(SSR) is newly non-invasive electrophysiological technique for assessing sympathetic functions [1]). The aim of this study is to investigate the relationship between facial palsy and sympathetic dysfunction and to evaluate the prognosis of the patient due to SSR. Method The study was carried out in 40 peripheral facial palsy patients (25 men and 15 women ranging in age from 24 to 70 years, with a mean age of 48 years). Sympathetic function test was performed by means of skin sympathetoic response(SSR). Pairs of surface electrodes were placed on the bilateral palms and dorsum of the hands. SSR was evoked by magnetic single stimulation of median nerve at wrist. (intensity 400 V, magnetic field 0.2 tesla). Neuropack 4 (Nihonkohden co. ltd.)was used for this study(analysis time 10s, high cut 1 kHz, low cut 1 Hz). Each responses was recorded on a photographic paper. Differences of amplitude and latency between intact side and palsy side were investigated. The significant differences of sympathetic function between left and right side(amplitude) were more than 30%. We have classified the patient who was treated by SGB for 20 times into two groups, GI and GII. GI was that facial palsy score is more than 20 points (full score is 40) and GII is that the score was less than 20. Both SSR and facial palsy score were estimated at every 10 times of SGB treatment. All subjects gave their informed consent for this study. Result The period of treatment in GI was 1.3 +/- 0.7 month and GII was but 8.3 +/- 4.4 month, respectively(mean +/- SD, p<0.05). The facial palsy score at first treatment in GI was 8.0 +/- 4.4 points and 5.0 +/- 3.3 in GII. Four week after treatment, the facial palsy score in GI improved to 36.1 +/- 3.9, although the score of GII was still significantly less compare to that of GI(12.5 +/- 4.5, p<0.05). Differences of SSR amplitude between left and right side were seen in both GI and GII in the early periods. Differences disappeared according to increase of facial palsy score in GI. However GII showed the significant differences between left and right side and showed less recovery of facial palsy scores. Discussion From our results, it was indicated that disturbance of sympathetic function might correlate with the prognosis of facial palsy. SSR is considered as one of the valuable method to assess the sympathetic function and could be one of the parameters for anticipating the prognosis of facial palsy.