Reflex response of orbicularis oculi muscle to supraorbital nerve stimulation. Study in normal subjects and in peripheral facial paresis.

A REFLEX blink was first described by Overend 1 in 1896. Wartenberg 2 in 1945 recognized that blink reflexes evoked with different maneuvers were probably identical and proposed the term oculi Kugelberg 3 studied the response of the orbicularis oculi muscle to a tap over the brow. He recognized two different responses, an early ipsilateral reflex (latency: 12 msec) and a late bilateral reflex (latency: 21 to 40 msec). From a comparison with the masseter reflex (latency: 7.5 msec), he postulated that the early reflex was transmitted through a simple arc compatible with a myotatic reflex. However, the nature and pathway of this arc is still in dispute. On the basis of animal experiments, Tokunaga et al 4 suggested that the early reflex was relayed through the main sensory nucleus of the trigeminal nerve rather than through the mesencephalic nucleus. The late bilateral reflex is probably transmitted through