A.R. Sitnikov, Yu.A. Grigoryan
Treatment Rehabilitation Centre of Russian Health Ministry, Moscow, Russia
The goal has been studying a zone, where the facial nerve root leaves the brain stem, as well as estimating neurovascular interrelations and efficacy of vascular decompression in hemifacial spasm (HS).
Material and Methods. The study of 20 roots of the facial nerve was carried out on 10 specimens of the brain stem. Neurovascular interrelations were analyzed in 37 cases with HS (29 females and 8 males, aged 20-77).
Results. According to micromorphologic data, a glial cone length was 0.9-3.6 mm (2.24 mm on the average). A mean diameter of the facial nerve root was 2.21 mm. Left- and right-side HS was diagnosed in 17 and 20 cases, respectively. MRI revealed signs of neurovascular conflict on an affected side in 29 cases. The intraoperative finding, watched in all cases, was compression of a zone, where the facial nerve root left the brain stem. Compression by one and several vessels was watched in 27 and 9 cases, respectively. As for compression of the facial nerve root by a single vessel, it was caused by the inferior anterior (11 cases) and inferior posterior (12) cerebellar arteries and the vertebral artery (4). Excellent results with complete disappearance of HS symptoms were received in 36 cases. A clinical picture of HS did not change in 1 case. It was caused by inadequate vascular decompression. There were no fatal outcomes and infectious complications. A period of long-term follow-up varied from 1 up to 18 years (9.7 years on the average). There were no delayed neurological complications and HS recurrences.
Conclusion. Vascular decompression of the facial nerve root is a highly effective method of HS treatment, characterized by complete and permanent elimination of hyperkinesis against a background of a relatively low rate of complications.