Abstract
In a retrospective study of 40 patients with a cerebral arteriovenous malformation, we examined the clinical courses, angiographical findings, and operative results. We divided the patients clinically according to their initial symptoms, that is, bleeding, convulsion and other. Furthermore, patients were divided into two groups, those who consulted a doctor early (less than 6 months from onset), and those who consulted a doctor late (more than 6 months from onset). Twenty-six out of 40 cases are in the late group and the others fall in the early group. Mean intervals from initial symptoms until visiting hospitals in the late group are 10.7 years. Overall results (including surgically treated patients) are slightly better in the early group than in the late group.
In particular, we analyzed the late consulting group and conservatively treated cases (total 28 cases) for the purpose of defining the natural history of the arteriovenous malformations. The results are as follows: 1) Mortality was 3.6%(1/28). One patient with a huge AVM in the left cerebral hemisphere died because of bleeding from the AVM. 2) Morbidity was 35.7%(10/28). Five cases initially ruptured and 5 cases were unruptured. 3) Risk of bleeding is 25%(8/28). Five cases initially ruptured and 3 were unruptured. Two out of 8 cases had localized deep-seated or posterior fossa. Two out of 8 had small AVMs. 4) Mean follow-up period was 12 years.
In our examination, the results of natural history is relatively good. But, in the late consulting group, because of recurrent hemorrhages and frequent convulsive seizures, progressive worsening of neurological symptoms are frequently observed. For that reason, results for the late consulting group are slightly poorer than those for the early group. We have to give careful consideration to those facts in deciding whether to operate.
