Differential diagnosis of facial nerve palsy

Facial nerve palsy is the most frequent neurological presentation of sarcoidosis. It occurs with equal frequency on the right or left side, and equally unilateral or bilateral. When bilateral facial palsy develops in a young adult, sarcoidosis is the most likely cause. In our series of 147 patients with ocular sarcoidosis, facial palsy occurred in 12 per cent and parotid gland enlargement in 10 per cent. Resolution of facial palsy is complete in 80 per cent of patients. It does not recur, unlike orofacial granulomatosis in which facial palsy tends to be recurrent. The differential diagnosis is large (Table I) and needs full investigation in order to provide a better understanding of the treatment and prognosis. A 7-point scheme of management is set out for the patient with idiopathic facial nerve palsy.