The development of synkinesis after facial nerve paralysis.
In this study, the development of clinical synkinesis after facial nerve paralysis (FP) and its relationship to electrophysiological findings were investigated. Thirty-four patients who were examined within the first 5 days after onset of FP and who could also be followed up for at least 4 months were included in the study. Electrophysiological investigations consisted of: (1) recording of the direct responses by facial nerve stimulation at the stylomastoid fossa; (2) recording of the 'synkinetic spread' of the supraorbital nerve reflex to the lower facial muscles; (3) recording of the 'lateral spread responses' by stimulating the mandible and zygomatic branches of the facial nerve. Clinical synkinesis developed in 14 of 18 patients (78%) with a direct response ratio (DRr) of less than 40%. Among the 16 patients with a DRr of 40% or more, synkinesis was observed in 3 cases (18.7%) only. The DRr provided reliable information concerning the development of synkinesis. Forty percent seemed to be a reasonable limit to distinguish the high-risk group for the development of clinical synkinesis.
Celik
M
M
Department of Neurology, Sişli Etfal Hospital, Istanbul, Turkey. fmcelik@ibm.net
Forta
H
H
Vural
C
C
D000293:Adolescent; D000328:Adult; D000368:Aged; D001767:Blinking / Q000502:physiology; D002648:Child; D004568:Electrodiagnosis; D005152:Facial Muscles / Q000294:innervation*; D005154:Facial Nerve / Q000503:physiopathology*; D005158:Facial Paralysis / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000503:physiopathology*; D009416:Nerve Regeneration / Q000502:physiology; D012307:Risk Factors; D009435:Synaptic Transmission / Q000502:physiology*