What are the causes of unilateral facial nerve palsy?
Lower motor neuron (all the muscles of one half of the face are affected): · Bell’s palsy (idiopathic). Recent studies using a polymerase chain reaction have implicated herpes simplex viral infection in Bell’s palsy. The incidence of Bell’s palsy is 23 per 100 000 individuals per year or about 1 in 60-70 individuals per year. Men and women are equally affected and the peak incidence is between the ages of 10 and 40. Both the right and left sides are affected with equal frequency. · Herpes zoster. · Cerebellopontine angle tumours. · Parotid tumours. · Old polio. · Otitis media. · Skull fracture. Upper motor neuron (forehead spared): · Stroke (hemiplegia). Is the facial nerve a motor nerve or a sensory nerve? The facial nerve is predominantly a motor nerve and supplies all muscles concerned with facial expression and the stapedius muscle. Uncommonly, it may have a sensory component which is small – the nervus intermedius of Wrisberg. It conveys tastesensation from the anterior two thirds
