Objective: Peripheral facial paralysis is one of the commonest mononeuropathies. The frequency of idiopathic peripheral paralysis or Bell's palsy varies between 62% and 93% of all cases, with an incidence of between 14 and 25 cases per 100,000 inhabitants per year. However, in spite of its relative frequency in the population, there is still no definite unanimously agreed strategy currently used by neurologists. Although its course is relatively benign, up to 16% of the patients show moderate or severe sequelae according to follow-up data in 1,011 untreated patients. In this article we review the aetiology, diagnostic methods and therapeutical strategies at the present time.
Development: The topographic diagnosis of the lesion is based on the symptoms associated with the paralysis. The neurophysiological studies (trigeminofacial reflection and electroneurogram), usually done after the first week are prognoses that permit differentiation of the degree of the lesion (neuropraxis, axonotmesis or neurotmesis). In spite of recent trials with combined therapy (acyclovir and steroids) the most generally accepted treatment at present is still prednisose at a dose of 1 mg/kg/day.
Conclusions: Peripheral facial paralysis is a common condition, usually with no apparent cause and an eminently clinical diagnosis. The electrophysiological studies determine the prognosis. Currently the standard treatment is still oral prednisone.