Electrodiagnosis and Recovery of Facial Paralysis at King Chulalongkorn Memorial Hospital
Wasuwat Kitisomprayoonkul MD*, Puangpet Sirileartthananon MD*, Dootchai Chaiwanichsiri MD*
Affiliation : * Department of Rehabilitation Medicine, Faculty of Medicine, King Chulalongkorn Memorial Hospital, Chulalongkorn University, Bangkok
Objective : To study electrodiagnostic findings and recovery patterns of patients with facial nerve paralysis.
Materials and Methods : 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 < 0.01. All cases of Bell’s palsy with CMAP amplitude > 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
