Facial palsy following head injury: topognosis, prognosis and indications for surgical decompression

It is a common experience that the facial nerve is affected in closed head injury. 781 patients with head injury were treated at Kobe Central Municipal Hospital over a period of 5 years from January 1977 to April 1982, and facial palsy occurred in 25 cases (3.2%). The male to female ratio was 22: 3 and age ranged from 9 to 78 (average 36). The patients were studied, using radiological, topognostic and electrodiagnostic methods. Facial nerve decompression was done in 5 cases and 20 cases were treated conservatively. Results were as follows. The overall rate of complete recovery was 64% (16 of 25 cases). In the conservative treatment group, all patients with incomplete paralysis and normal maximal stimulation test (MST) recovered completely. With complete paralysis, if the initial nerve excitability (MST) was normal, recovery could be expected by conservative treatment. Even if the patients had abnormal nerve excitability (MST) at first, complete recovery could be observed, when signs of recovery could be elicited and normalization of MST occurred within 3 weeks from the onset of the palsy. In severe cases, even with abnormal MST from the onset, complete or partial recovery can be expected after surgery. Therefore, microsurgical decompression of the facial nerve is indicated in the following cases: patients with complete paralysis and no response to MST from the onset. patients with complete paralysis and deteriorating response to MST 1 month after onset. Maximal stimulation test is a good guide for determining the necessity for surgical intervention.