Bell's Palsy: The Spontaneous Course of 2,500 Peripheral Facial Nerve Palsies of Different Etiologies

The Copenhagen Facial Nerve Study aims to explain the spontaneous course of idiopathic peripheral facial nerve palsy which occurs without any kind of treatment. In this study Bell's palsy and idiopathic palsy are considered to be synonymous and specify an acute, monosymptomatic, unilateral peripheral facial paresis of unknown etiology.The material includes 2,570 cases of peripheral facial nerve palsy studied during a period of 25 years. It includes 1,701 cases of Bell's palsy and 869 of non-Bell's palsy. In the total patient sample, 116 had herpes zoster, 76 were diabetic, 46 were pregnant and 169 were neonates. A total of 38 different etiologies were observed. At the first consultation a standard ENT examination was performed, including a thorough description of the grade and localization of the paresis, taste, stapedius reflex and nasolacrimal reflex tests and acoustic-vestibular examination. Follow-up was done once a week during the first month and subsequently once a month until normal function was restored or for up to 1 year.The initial examination revealed 30% incomplete and 70% complete palsies. Follow-up showed that in 85% of patients function was returned within 3 weeks and in the remaining 15% after 3-5 months. In 71% of patients normal mimical function was obtained. Sequelae were slight in 12% of patients, mild in 13% and severe in 4%. Contracture and associated movements were found in 17% and 16% of patients, respectively.A survey of the literature showed that no kind of treatment, including prednisone, was able to give a better prognosis. The use of prednisone raises a big ethical problem because no evidence of its efficacy exists and the euphoric side-effect induces a false feeling of benefit in the patients.