Abstract
Forty patients with hemifacial spasm were treated by neurovascular decompression during the 4 years from June 1978 through June 1982. Of 40 patients, 31 were female and 9 were male, with ages ranging from 31-71 years (mean 52). In 24 patients the left side was involved and in 15, the right side. One had bilateral hemifacial spasms.
As symptoms concomitant to hemifacial spasm, tinnitus synchronous with spasm, and hyperlacrimation and hypersalivation on the affected side were frequently present. Facial paresis of the peripheral type due to previous nerve blocks was observed in 10 cases. Vertebral angiography performed in 38 cases showed tortuous and elongated vertebral arteries protruding to the cerebellopontine angle in 12, and a common AICA and PICA trunk branching off from the vertebral or basilar artery in 19. The causative artery was confirmed at surgery to be AICA in 25, vertebral artery in 8, and PICA in 7.
Electromyography of typical hemifacial spasm showed abnormal discharges of two types; one was continuous, tonic discharges at low amplitude, and the other was intermittent, coarse, clonic discharges at high amplitude. Blink reflex demonstrated synkinetic R1 discharge in both the orbicularis oculi and orbicularis oris muscles. Postoperatively, the synkinetic discharge disappeared concomitantly with disappearance of clinical facial spasm. Postoperative courses of hemifacial spasm were divided into four types. In Type 1 (18 cases), spasm disappeared immediately after surgery. In Type 2 (9 cases), the spasm gradually decreased within about one week, and in Type 3 (8 cases), within about one month. Spasm disappeared immediately after surgery in the 4th type (4 cases), but reappeared in a few days to a lesser degree, then gradually decreased and again disappeared within about one month. The temporary suppression of the spasm immediately after surgery was assumed to be due to minor surgical trauma to the 7th nerve.
According to Jannetta's classification, operative results in these 40 cases were excellent in 29, good in 8, fair in 2, and poor in one.
