Analysis of Unsuccessfully Operated Patients in Microvascular Decompression for Hemifacial Spasm

ABSTRACT

Seventy six patients with hemifacial spasm(HFS) were operated with microvascular decompression(MVD) at Soonchunhyang University Hospital from January, 1987 to June, 1994. We report an analysis of 30 patients who were not relieved from or had a recurrence of their symptoms immediately after MVD. 1) 14 patients(46.7%) showed delayed remission. Among them, 8 patients improved within 3 months and 1, after 6 months. 5 patients reoperated, at which time incomplete decompression of small vessels were identified in 4 patients. The vessels were then completely decompressed at the facial nerve root exit zone(FNREZ) and the surrounding pia-arachoid membrane were incised. 2) 12 patients(40%) showed partial remission. Among them, 9 patients did not show complete remission after the operation and continued to show only partial remission during the follow-up periods. 3 patients showed the same severity of HFS after the operation but 2 patients improved spontaneously at first and then at 3 months postoperatively. 3) 4 patients(13.3%) showed recurrence. The symptoms of one patient right 1 month after the operation, and 3 patients at 3 months. These findings suggest that the ideal time to evaluate the surgical outcome of MVD for HFS is 3 months or later after the operation, and that the procedure of opening up the piaarachnoid menbrane at FNREZ may be effective for a complete remission.