Facial nerve palsy after head injury: Case incidence, causes, clinical profile and outcome

Background: To investigate the case incidence, causes, clinical profile, and outcome of facial nerve palsy complicating head trauma. Method: A 10-year (1991-2000) retrospective study of head injured patients at the University Teaching Hospital, Ilorin, Nigeria. Age, gender, and neurologic findings were analyzed. Results: Of 794 patients, facial nerve palsy occurred in 40 (5.04%). Facial nerve was the most frequently injured cranial nerve, followed by vestibulo-cochlear (12 [1.5%]) and abducens (8 [1.0%]). Majority (70%) of the seventh nerve palsies were of the lower motor neurone type. The left nerve was more frequently affected (60%). Facial nerve palsy was more common in male patients and adults with a peak incidence at the 4th decade. Spontaneous functional recovery occurring within 6 to 24 months of injury was total in 12 (30%), partial in 5 (12.3%), and none in 3 (7.5%) subjects. Thirteen patients died giving a mortality rate of 32.5%. The patients were aged 5 to 85 years (mean, 34 years). Causes of head trauma were traffic injuries (82.5%), fall from height (7.5%), assault (5%), and gunshot (2.5 %). Though patient mortality rate was higher among patients with facial nerve palsy (32.5%) than those without (23.04%), facial nerve palsy was not a strong predictor of fatality (p = 0.2950). Conclusion: The case incidence of facial nerve palsy in head injured patients in our center is 5.04%. The lower motor neurone type predominates. It is commoner in men and on the left side with spontaneous recovery occurring in 30% of cases.