Clinical Analysis of Bell's Palsy in One University Hospital

ABSTRACT

BACKGROUND: Bell's palsy (BP) is the most frequent disease of the seventh cranial nerve, and has a relatively good prognosis. However, the precise etiology of the disorder has not been well understood. During the last decade, many researchers have focused on the conditions that are associated with BP, including diabetes, hypertension, and viral infection. We therefore analyzed that the etiology and clinical course of acute BP in patients in one university hospital. METHODS: The study comprised 241 BP patients who were examined over a 60-month period. Their clinical history was taken, and neurologic examinations, laboratory tests, electrophysiologic studies, and brain imaging was performed. The clinical severity of the facial palsy was assessed using the House-Brackman (HB) facial nerve grading scale. Patients were followed up once a week during the first month, and for up to 2 months. RESULTS: Of the 241 patients, 103 (43.5%) were men and 138 (56.5%) were women, whose ages were 46.4+/-16.6 and 48.4+/-17.6 years, respectively (mean+/-SD). The initial examination revealed that 36.7% of the cohort had an HB grade below 4, while in 63.3% the HB grade was above 3. Combined symptoms were as follows postauricular pain (77.5%), increased tear flow (23.4%), taste change (15.6%), and hyperacusis (15.1%). The initial facial nerve conduction study performed within 1 week of presentation revealed a low compound muscle action potential amplitude in 140 (57.8%) and an absent blink reflex in 225 (93%). On follow-up examination, 134 (59%) of the patients exhibited a partial improvement by 4 weeks, and 166 (79.8%) had recovered completely within 2 months. CONCLUSIONS: We describe the epidemiologic, clinical, electrophysiologic, and radiologic characteristics of BP patients at one university hospital.