Abstract
The cause of facial palsy is thought to be due to peripheral circulatory disturbance, polyneuropathy, and immunological features, yet the conclusion is still debatable. We consider whether or not SSR could be a new, non-invasive electrophysiological technique for assessing sympathetic functions. The aim of this study is to investigate the relationship between facial palsy and sympathetic dysfunction and to evaluate the prognosis of a facial palsy patient by SSR.
SSR was carried out in 35 peripheral facial nerve palsy patients. We have classified those patients treated by SGB for 20 times into two groups, GI and GII. GI scored more than 20 points (full score is 40) and GII scored less than 20. Pairs of surface electrodes were placed on the bilateral palms and backs of the hands. SSR was evoked by magnetic single stimulation of the median nerve at the wrist. Differences of amplitude and latency between the intact side and the palsy side were investigated. The significant differences of sympathetic function between left and right side (amplitude) were more than 30%.
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 in facial palsy score of GI. However, GII showed significant differences between left and right side and showed less recovery of facial palsy scores. The period of treatment in GI was 45±15 and GE was 240±60 days, respectively (mean±SD, p<0.05).
These results suggest that SSR is maybe a valuable method to assess the sympathetic function and could be a parameter for anticipating prognosis.
