Blink reflex: normal values and its findings on peripheral facial paralysis

To establish the normal values of blink reflex (BR) in healthy subjects and investigate the manifestations of BR in patients with peripheral facial paralysis (PFP).

BR was investigated in 23 patients with PFP and 50 healthy persons serving as control. While stimulating the supraorbital nerve on one side, the reflex responses of bilateral inferior-orbicularis oculi were recorded respectively, in which the two components recorded on the ipsilateral side of stimulation were named R1, R2 and the contralateral one, R2'.

There was no significant difference between sexes, sides and among various groups of age R1, R2 and R2'. The mean latency of R1 was 10 msec and R2, R2', 29 msec. The absolute values of the amplitude were of relatively smaller significance due to their great variance, whereas the amplitude ratio between two sides was of some value. All patients showed absent response, delayed latency or/and abnormal amplitude on the paretic side, regardless of the side of stimulation, indicating a typically efferent involvement.

BR is another objective and noninvasive test for facial paralysis in evaluating the lesion site, scope and the abnormality degree, and predicting the prognosis if combined with the clinical conditions.