Incidence of atherosclerosis in the Circle of Willis: an autopsy study of 100 cases

The incidence of atherosclerosis of the Circle of Willis was evaluated in a study of 100 unselected autopsy cases at the University Hospital of the West Indies. Atheroma was observed in 46 cases. Males were affected slightly more than females. Cerebral atherochlerosis was commonly associated with diabetes mellitus and hypertension. Comparisons are made with the findings in studies conducted elsewhere (AU)

The pattern of fatal cerebrovascular disease in Jamaica

The data presented shows that the pattern of fatal cerebrovascular disease as seen at necropsy in Jamaica is very different from that in comparable studies in white communities. In a 15-year period (1952-1967) cerebro-vascular disorders accounted for 296 (9.9 percent) of all adult necropsies performed in a large general teaching hospital. Of these no less than 77 percent were due to haemorrhage whereas only 23 percent were due to infarction. This high incidence of haemorrhagic strokes probably reflects the high incidence of hypertension which has been shown to exist on the Island. 89 percent of spontaneous intracerebral haemorrhages are associated with hypertension and there is a far lower proportion of hind brain as compared with cerebral hemisphere haemorrhages. A small but significant group appears to be due to hypertension occurring during or shortly after childbirth. Subarachnoid haemorrhages due to rupture of berry aneurysms of the circle of Willis also present unusual features. 70 percent of all such aneurysms occur at the junction of the internal carotid arteries and their branches whereas middle cerebral and anterior communicating artery aneurysms are relatively uncommon. Multiple aneurysms of the Willisian vessels and intracerebral extensions of haemorrhages from ruptured aneurysms also appear to be far less common than generally reported elsewhere.Cerebral infarction due to atheroma and thrombosis is rare - only 54 cases being encountered during the period under consideration. This is even more surprising in view of the fact that cerebral artery atheroma is probably as common as in North America and Europe (Summary)

Distribution of cerebral atherosclerosis by geographic location, race, and sex

The cerebral arteries (common carotid, internal carotid, vertebral, middle cerebral, and basilar arteries) were examined from 1547 autopsied persons in five countries (Norway, Guatemala, United States, Jamaica, and Chile). Subgroups comparisons were made using a basal group of cases from which were excluded all persons with coronary heart disease, peripheral arterial disease, other atherosclerotic complication, hypertension, and diabetes. The prevalence and mean extent of atherosclerotic lesions increase in each succeeding age group. Lesions appear to develop later in life in the cerebral arteries than in the aorta and the cerebral arteries than in the aorta and the coronary arteries. Men have more raised atherosclerotic lesions than women. The mean extent of fatty streaks in the cartoid arteries does not differ among age groups from 35 to 69 years of age, nor does it differ among location-race groups. The mean extent of raised atherosclerotic lesions in the carotid arteries increases in each succeeding age group after 35 years of age, and differs among location-race groups.The pattern of development of atherosclerosis in the carotid arteries follows that of the aorta. Fatty streaks appear in the intracranial and vertebral arteries much later in life than they do in the carotid arteries.The mean extent of both fatty streaks and raised lesions increases in each succeeding age group after 35 years of age, and the average involvement of both types of lesions differs among location-race groups. The pattern of development of atherosclerosis in the vertebral and intracranial arteries follows that of the coronary arteries. When location-race groups are ranked by extent of cerebral atherosclerosis, they rank in approximately the same order as when they are ranked by aortic and coronary atherosclerosis. (AU)