Incomplete facial nerve palsy: new lessons from activated orbicularis oculi muscles.

Motor nerve conduction studies (MNCS) and blink reflexes (BR) were done on a 42-year-old female patient who presented with peripheral facial nerve palsy (PFNP); these investigations were done while she had her facial muscles relaxed ("A"), and contracted ("B"). While in the "A" state, MNCS of the facial nerves had prolonged latency and low amplitude and R3 of the blink reflex was absent in the affected side; an early contralateral R1 response was recorded on the unaffected side. In state "B," the third silent period was "prolonged" on the affected side and absent on the unaffected one. This is an illustrative case of a variant of facial nerve palsy in humans.