[Cerebellar AVM--clinical analysis of 14 cases]

The authors report on their experience with 14 cases of cerebellar arteriovenous malformation (AVM), with emphasis on their clinical symptoms and treatment problems. The incidence of cerebellar AVM was 7.5% in all cases of intracranial AVM. Twelve of them presented with hemorrhages, one with a headache and one with a focal neurological deficit related to the "steal" phenomenon. Three out of 4 poor risk patients with intracerebellar hematoma recovered well after their operations. Thus, we can say that surgical treatment should be performed even if the patient's state seems hopeless. The nidus was located at the vermis in 7, at the cerebellar hemisphere in 5, and at the tonsil in 2 cases. The surgical approach to the superior surface of cerebellum or the tonsil near the brainstem became a problem. In our series, all surgically treated cases were approached through the suboccipital route with the patient in the prone position and the surgical results were favorable. On the other hand, one case which underwent conservative treatment died due to rebleeding. Thus, as the follow-up mortality with conservative treatment is higher and the results of surgery are better, surgical treatment should be attempted. Preoperative MR imaging is one of the useful methods used to determine whether an excision is possible without significant deficit, especially in cases in which the AVM is located near the brain stem. In our series, two patients had concomitant aneurysms related to feeding arteries. Another interesting case of a neonate who had a small tonsillar AVM is reported.