Recurrent trigeminal neuralgia after microvascular decompression using an interposing technique. Teflon felt adhesion and the sling retraction technique.

The causes of recurrence after microvascular decompression for trigeminal neuralgia and the results of re-operations were studied in 6 cases. Eighty-two patients with trigeminal neuralgia were operated on through microvascular decompression using the technique of interposing Teflon felt between the offending artery and the pons and/or nerve. Recurrence occurred in 14 cases (17.1%) and re-operations were carried out in 6 severe cases at which time the sling retraction technique was used. At the second operation, the adhesion of the interposed Teflon felt was found at the trigeminal nerve in all cases and the adhesions were the main cause of recurrence. The Teflon felt was dissected from the nerve, and the sling of the Teflon felt adhering to the offending arteries was fixed to the tentorium in order to transpose the arteries and avoid re-adhesion. All cases resulted in an excellent relief from pain and experienced no pain for at least 2 years. The intra-operative findings of our cases indicated that the microvascular decompression using the interposing technique may result in adhesion of the prosthesis to the nerve and thus eventually lead to recurrence. Our surgical experience also suggests that such recurrent cases should be re-operated on using the sling retraction technique instead of the interposing technique, even for the first microvascular decompression procedure.

Linkage analysis of moyamoya disease on chromosome 6.

Genetic factors have been suggested to contribute to the etiology of moyamoya disease. The authors have previously reported an association between moyamoya disease and several alleles for human leukocyte antigens (HLA). To further specify the genetic component of moyamoya disease, a linkage study of moyamoya disease using markers on chromosome 6, where the HLA gene is located, was performed. The 15 microsatellite markers of chromosome 6 were studied in 20 affected sibling pairs. From an identical-by-descent analysis of these markers, an allele with possible linkage to moyamoya disease was identified. Sharing of the allele among affected members in 19 families was investigated, considering the haplotype. The marker, D6S441, might be linked to moyamoya disease. Considering the haplotype, the allele was shared among the affected members in 16 (82%) of the 19 families, but not in two others. In one family, sharing of the allele could not be determined because of low heterozygosity. Further studies are necessary to clarify multiple genetic factors that are definitely linked with moyamoya disease.

Surgical techniques and the results of a fronto-temporo-parietal combined indirect bypass procedure for children with moyamoya disease: a comparison with the results of encephalo-duro-arterio-synangiosis alone.

We recently treated children with Moyamoya disease using a fronto-temporo-parietal combined indirect bypass procedure. Three different indirect bypass procedures (frontal EMAS, EDAS, EMS) were simultaneously carried out at three different sites. We thus treated 16 sides in 12 pediatric patients with Moyamoya disease using this method. Both the collateral formation and the improvement in the clinical symptoms were evaluated postoperatively. These results were then compared with those of the patients treated by EDAS alone. The postoperative collateral formation was more extensively seen in the patients treated with the combined bypass procedure than in those treated by EDAS alone. The improvement in ischemic symptoms was also better in the patients treated by the combined indirect bypass procedure. We therefore conclude that the combined indirect bypass procedure is more effective than EDAS alone.

Analysis of class II genes of human leukocyte antigen in patients with moyamoya disease.

Moyamoya disease is a progressive steno-occlusive disease at the terminal portion of the bilateral internal carotid arteries. An unusual vascular network is formed as a result of ischemic change of cerebrovascular system. Although some investigations suggested possible etiological factors of Moyamoya disease, the etiology is still unknown. To elucidate the genetic factors of Moyamoya disease, class II genes of human leukocyte antigen (HLA) were analyzed at the DNA level. The DNA typing of HLA was performed in the unrelated Japanese patients with definite Moyamoya disease using extracted genomic DNA from the leukocyte. The genotype was confirmed by polymerase chain reaction-sequence specific oligonucleotide probe (PCR-SSOP) technique. The class II genotypes were analyzed in 71 samples. As a result, several alleles of class II genes showed significant association with Moyamoya disease. DQB1*0502 had positive association with the disease. On the other hand DRB1*0405 and DQB1*0401 had negative association. Moyamoya disease seems to have a genetic background in its etiology because certain alleles of HLA are associated with Moyamoya disease.

DNA typing of HLA in the patients with moyamoya disease.

Moyamoya disease is a clinical entity demonstrating a chronic occlusion of the cerebrovascular system. Although some possible etiological factors have been postulated, the etiology of this disease is still unknown. So far, some investigations have suggested the association between moyamoya disease and HLA in the serological typing. However, DNA typing of HLA have not been performed yet. Thus, we performed DNA-typing of HLA in the unrelated Japanese patients with definite moyamoya disease, using the polymerase chain reaction-sequence specific oligonucleotide probe (PCR-SSOP) technique. In the total patients, DQB1*0502 had a positive association with the disease. On the other hand, DRB1*0405 and DQB1*0401 showed a negative association. In comparing the early-onset and late-onset groups, two groups did not share the same disease associated alleles at all. Thus, the etiology of moyamoya disease seem to have a genetic background. Furthermore, different genetic factors might also be involved in the difference between the early-onset and late-onset groups.