OBJECTIVE:We evaluated the follow-up results of microvascular decompression in 1032 patients with trigeminal neuralgia (TN) and hemifacial spasm (HFS), who underwent operations between 1976 and 1991 and were followed for more than 5 years.METHOD:Patients were divided into two groups, and their follow-up results were compared and studied. The early series, Group A (1976-1986), comprised 588 patients (127 with TN and 461 with HFS) followed from 10 to 20 years (mean, 12.6 ± 2.1 yr), and the recent series, Group B (1987-1991), comprised 444 patients (154 with TN and 290 with HFS) followed from 5 to 9 years (mean, 7.0 ± 1.4 yr).RESULTS:The immediate postoperative cure rates were 92.9% in Group A and 96.7% in Group B for TN and 97.4% in Group A and 98.3% in Group B for HFS. Satisfactory results obtained by the follow-up study were 80.3% in Group A and 82.5% in Group B for TN and 84.2% in Group A and 89.0% in Group B for HFS. Incomplete cure rates were 7.1% in Group A and 3.3% in Group B for TN and 2.6% in Group A and 1.7% in Group B for HFS. Recurrence rates were 10.2% in Group A and 6.5% in Group B for TN and 8.9% in Group A and 6.9% in Group B for HFS. Postoperative hearing dysfunction occurred in 7.1% of patients with TN in Group A and 4.5% in Group B and 9.1% of patients with HFS in Group A and 3.7% in Group B.CONCLUSION:Improved methods of repositioning the affected vessels and of straightening the axis of the trigeminal nerve are important to obtain satisfactory follow-up results after microvascular decompression.