PROSPECTIVE-STUDY OF MICROVASCULAR DECOMPRESSION IN HEMIFACIAL SPASM

OBJECTIVES: Although, in most cases, the symptoms of hemifacial spasm (HFS) disappear immediately after microvascular decompression (MVD), i n some cases, they disappear more gradually. The objectives of this st udy were to observe the time course and the rate of the delayed resolu tion and to attempt to explain the phenomenon through long-term follow -up of HFS after MVD. METHODS: Two hundred and sixty-one patients with HFS who underwent MVD were followed up to observe clinical changes. T wo hundred and twenty-six of the 261 patients were followed up for a d uration of 6 months to 2 years, from 1985 to 1995. RESULTS: After the ist week of the surgery, 61.1% of the patients were rated as having ac hieved excellent results, When the patients were followed up for more than 6 months, however, the rate improved to 82.7%, The clinical resul ts of HFS after MVD improved significantly with time (P < 0.05). Delay ed resolution of HFS was observed in 37.4% of the patients who experie nced complete resolution; it was the most important factor for clinica l improvement during the follow-up period. Abnormal muscle response im mediately after MVD in the operating room was also positively col rela ted with resolution during the follow-up period (correlation coefficie nt 0.3099, P < 0.05), CONCLUSIONS: In conclusion, the clinical picture of HFS after MVD improves with time, and abnormal muscle response can be used as a prognostic indicator for the resolution of HFS during th e follow-up period.