[Long-term follow up of trigeminal neuralgic patients treated by retrogasserian rhizotomy or by microvascular decompression].

The authors studied the long-term follow up of trigeminal neuralgic patients treated by retrogasserian rhizotomy with anhydrous glycerol injection (GI) or by microvascular decompression (MVD) and compared the satisfaction rates between them. Since 1983, 67 patients had been treated either by GI or MVD. The authors analyzed the results of the treatment by the method of questionnaire. Fifty-two patients of these 67 answered the questions, on which the present analysis was based. GI group consisted of 27 patients and MVD group 29 patients. The average follow-up period was 30.9 months in GI group (maximum follow-up: 84 months) and 50.9 months in MVD group (maximum follow-up: 95 months), respectively. The technique of GI used was Härtel's method with cisternography of Meckel's cave. The operations of MVD were performed by J.H. and A.K.. One patient out of 29 failed to be treated by MVD and two recurred within one year. On the other hand, 2 patients out of 27 failed to be treated by GI and 11 recurred. The recurrence was seen earlier in patients who had undergone GI, while one patient recurred the neuralgia at 76 months later. The recurrence rate in patients treated by MVD is 7.0% at 95 months, while that by GI is 49.0% at 84 months based on Kaplan-Meier survival analysis. The pathogenesis of trigeminal neuralgia is speculated to be an emphatic conduction caused by segmental demyelination and artificial synapse formation at the junction of central and peripheral myelin. The factors of this demyelination may be multiple sclerosis, basilar impression, aneurysm, arteriovenous malformation, atheroscleroses and natural aging.(ABSTRACT TRUNCATED AT 250 WORDS)