Electrodiagnosis and Recovery of Facial Paralysis at King Chulalongkorn Memorial Hospital

Objective: To study electrodiagnostic findings and recovery patterns of patients with facial nerve paralysis. Material and Method: Seventy-six medical records of patients who had a facial paralysis and had their electrodiagnosis performed in a 2-year period were reviewed. Patients were invited for re-evaluation. The patients would be evaluated according to House-Brackmann Facial Nerve Grading Scale (HBFNGS), residual impairment, disability, emotional and social consequences. Results: Complete data were obtained from 50 patients whose mean age was 47.0 + 17.9 years. Seventy-two percent were diagnosed as Bell’s palsy. There was significant correlation between %CMAP amplitude and HBFNGS (grade I-VI) at r = 0.5; p 70% of normal side regained full recovery. Patients with CMAP amplitude > 30% had good recovery. Bell’s palsy with CMAP amplitude < 10% and with other causes had poor outcome. Nine patients had synkinesis. Most of them were of traumatic cause and had severe nerve degeneration. No evidence showed that electrical stimulation was a factor inducing synkinesis. Conclusion: Percent CMAP amplitude could moderately predict the outcome of Bell’s palsy better than other causes of facial palsy. The paralysis from traumatic cause with low %CMAP amplitude had more chance to develop synkinesis. Keywords: Facial paralysis, Facial nerve palsy, Electrodiagnosis, House-Brackmann Facial Nerve Grading Scale, Synkinesis, Recovery