Abstract
An electrophysiological study of the blink reflex was undertaken in 150 normal subjects who composed from first to seventh decade.
Comparative work on minimum threshold of the stimulus and latencies, amplitudes and duration of early component (R1) and late component (R2) were done in each aging.
The normal values of each component of the reflex were determined in the subjects who were 5 to 59 years old as follows: the latency of Ri was 11.7±1.22 msec and varied little (less than 1.3 msec) between right and left sides, while R2 occurred at 34.20±4.73 msec ipsilateraly and at 34.46±4.99 msec contralateraly, and a rightleft difference was less than 5.5 msec.
Fifty patients of facial paresis (48 BELL'S palsy ; 8 Ramsay HUNT'S syndrome) were subjected for the long term serial study and the following results were obtained.
If the Ri was elicited within 4 weeks after the onset of the clinical recovery signs, and its latency recovered to the normal range within the following several weeks, their prognosis were found to be good in general.
In patients with poorly recovered groups and synkinesis, Ri was elicited after 5 weeks.
As a recovery sign of the reflex response pattern, the first appearance of R2 was the most important in the majority of cases, and a significant relationship was observed between the enhancement of the amplitude of the spike potential and the degree of functional recovery of the mimic muscles.
