Abstract
Sixty-four cases of intracranial AVM were examined by angiography and CT scan. Their clinical symptoms, CT findings, operative results and pathological findings were then studied. There were 64 patients with AVM of the brain who were admitted to the Department of Neurosurgery of Nippon Medical School from 1974 to 1983. Fifty-nine cases were confirmed by angiography and five cases were diagnosed by histological examination. There were 38 males and 26 females. The ratio of males to females was 1.5 : 1. Age at the onset of the symptoms ranged from 2 months to 48 years, median age was 26.2 years. Symptoms due to intracranial hemorrhage were the in 38 cases (59.3%), epileptic attack in 13 cases (20.3%), and headache in 6 cases (9.3%). The median age of the hemorrhage group was 26.9 years and the median age of the seizure group was 16.0 years. Ten cases of the non hemorrhage group suffered the hemorrhage afterward, so 48 out of the 64 cases (75.0%) had a single or a recurrent hemorrhage. The AVMs were located as follows : frontal (37.5%), parietal (20.3%), temporal (9.3%), occipital (15.6%), diffuse type (1.56%), corpus callosum (7.8%), thalamus (3.12%), brain stem (3.12%), cerebellum (15.6%). AVMs occurred about equally in the right and the left hemisphere (right 24, left 29). In 8 cases (12.5%) AVMs were in the midline and in 3 cases they occupied both cerebral hemispheres. Four cases were dural, and supplied by the external carotid artery. Three patients had 4 associated aneurysms, 2 occurring in one patient. Smaller and deeply located AVMs had bleeding tendency, while larger ones had a tendency to have a seizure. Smaller AVMs were more often situated superficially, while larger AVMs were situated deeply.
The 12 cases of non ruptured AVM were classified into two categories on the basis of the plain CT. Eleven cases (9.6%) exhibited a mixed density (M type), and one case (8.4%) showed a normal density (N type). Contrast enhancements were obtained in all cases. Hetero-geneous patterns were obtained in 11 cases, and a homogeneous pattern in 1 case. Of the 26 cases of ruptured AVM, M type was seen in 8 cases (30.7%) and N type in 18 cases. Contrast enhancements were obtained in 16 cases (61.5%). Heterogeneous pattern was obtained in 12 cases, curvilinear pattern in 4 cases. The CT scan was carried out for 34 cases with ruptured AVM. Intracerebral hematomas were noted in 27 cases (75.0%), intraventricular extension of hemorrhages was seen in 20 cases (55.8%), and no case showed subarachnoid hemorrhage. Five cases were not demonstrated by angiography but they were diagnosed by histological examination. Two of them were small AVM. The pathological examination revealed features of an AVM, and they also showed the telangiectatic features in parts. Three cases of them were thrombosed AVM. Pathological examination revealed various degree of thrombosis in abnormal vessels and depositions of hematoidin and hemosiderin adjacent to the AVM. Forty-seven cases (73.400) were treated surgically. Thirty cases (63.8%) had totally extirpated, seven cases had partially extirpated, seven cases had clipped afferent vessels, three cases had removed hematoma only. Thirteen cases were treated conservatively. Two of totally extirpated cases, one of partially extirpated case, two drainaged cases, and one of conservatively treated case expired. All patients who died or completely incapacitated suffered intracranial hemorrhage, so it is important to protect against hemorrhage from AVM.
