Surgical Results of Microvascular Decompression and Partial Sensory Rhizotomy in the Treatment of 154 Patients with Trigeminal Neuralgia

OBJECTIVE: To evaluate the efficacy of microvascular decompression(MVD) for trigeminal neuralgia(TN) and to discuss current understanding of the mechanism of MVD for this disorder. PATIENTS AND METHODS:Since 1987, 154 patients treated for trigeminal neuralgia(TN) had been followed for an average 4.3 years. Among these patients, 145 had vascular compression of the nerve and underwent microvascular decompression(MVD). Remaining 9 patients had no offending vessels, so partial sensory rhizotomy(PSR) was performed in these patients. RESULTS: Immediate pain relief was achieved in 95%(147/154) of all patients, but the rate dropped to 90%(140/154) during the follow-up period. Recurrence rate in the MVD group was 2% and in the PSR group 55%. Among those patients underwent MVD, permanent sequelae occurred in only 1 patient(sensorineural hearing loss) and transient complications(impaired hearing due to hemotympanum, minor sensory deficit etc.) were more frequent. There were no differences in the outcome, considering age, sex and the duration of symptoms. There was a close relationship between operative findings of arterial compression on the nerve and long-term complete pain relief. Prognosis for patients with severe arterial compression was better than that for patients with mild or venous compression. CONCLUSION: MVD provides a high rate of success with a minor risk of complications, and this study gives support to the hypothesis that in most cases of TN is caused by neurovascular compression.

Clinical Analysis Following Microvascular Decompression and/or Partial Sensory Rhizotomy in 26 Cases of Trigeminal Neuralgia

Microvascular decompression of the trigeminal nerve at it's zone of entry into the pons and/or selective partial sensory rhizotomy of the portio major were performed in 26 patients with typical trigeminal neuralgia. Recently, microvascular decompression, partial sensory rhizotomy and percutaneous radiofrequency technique are the most commonly used and effective methods of treatment of this troublesome disorder. Since May, 1986 to October, 1994, the authors performed 26 cases of neurovascular decompression and/or partial sensory rhizotomy for trigeminal neuralgia and 22 patients(85%) had relief from neuralgic pain, 2(8%) had mild pain recurrence, 1 had moderate relief of pain and 1 had no relief from neuralgic pain after 13 months of mean follow up period. The trigeminal nerves were compressed by blood vessels in 19 cases(73%) and by tumor in 3 cases(12%). There were no pathologic lesions compressing the trigeminal nerve at its root entry zone in 4 cases (25%). The offending vessels were the superior cerebellar artery in 12 cases(46%), and 7 cases(27%) were associated with the anterior inferior cerebellar artery. There were no significant persisting complications or death in those operative treatments in the above described series.