[Electroneurography and other electric tests on prognostic assessment of Bell's palsy]

Twenty-two patients with Bell's palsy who had complete unilateral facial paralysis were selected for this study. Electroneurography (ENoG), nerve excitability test (NET), maximal stimulation test and facial nerve latency test were done on each patient. The patients were examined within 21 days of onset of facial paralysis and evaluated at least six months after onset to determine the degree of recovery of facial motor function. ENoG was the most accurate test for prognostic assessment of Bell's palsy when it was performed within 3 weeks after onset. When the response loss of ENoG on the involved side was 90% or less of that on the normal side, 83.3% of the patients had complete recovery of facial function, however, when loss was more than 90%, there was 70% chance for incomplete recovery. NET is a relatively accurate test, perhaps, it should be recommended because it is inexpensive and easy to manipulate.