Bell palsy.

Volume 84, Number 8 www.aafp.org/afp American Family Physician 947 Bell palsy is an idiopathic, unilateral, acute paresis or paralysis of facial movement caused by dysfunction of the lower motor neuron. Up to 30 percent of persons with acute peripheral facial palsy have an alternative cause diagnosed at presentation or during the course of their facial palsy. Alternative causes are higher in children (more than 50 percent), warranting specialist evaluation at presentation. Severe pain, vesicles (ear or oral), and hearing loss or imbalance suggest Ramsay Hunt syndrome caused by herpes zoster virus infection, which requires specialist management. • Most persons with paresis (partial weakness) make a spontaneous recovery within three weeks. Up to 30 percent of persons, typically those with paralysis (complete palsy), have a delayed or incomplete recovery. Corticosteroids alone improve the rate of recovery, increase the proportion of persons who make a full recovery, and reduce cosmetically disabling sequelae, motor synkinesis, and autonomic dysfunction compared with placebo or no treatment. Antiviral treatment alone is no more effective than placebo and is less effective than corticosteroid treatment at improving recovery of facial motor function and at reducing the risk of disabling sequelae. For persons with paresis at presentation (approximately 70 percent), there is no evidence of a clinically important effect of adding antivirals to corticosteroid therapy. • For persons who develop paralysis (approximately 30 percent), and who may demonstrate a trend toward complete degeneration on electrophysiologic testing, it is unknown whether adding antiviral treatment to corticosteroid therapy has a significant additive or synergistic effect. Hyperbaric oxygen therapy may improve time to recovery and the proportion of persons who make a full recovery, compared with corticosteroids; however, the evidence for this is weak. We do not know whether facial nerve decompression surgery is beneficial in the treatment of Bell palsy. Facial retraining may improve recovery of facial motor function scores, including stiffness and lip mobility, and may reduce the risk of motor synkinesis in Bell palsy, but the evidence is too weak to draw conclusions.