An Autopsy Study of Cerebrovascular Atherosclerosis in the Elderly

Stroke is an important cause of mortality with intracranial atherosclerosis as an important risk factor. Geographical variation in the pattern of atherosclerosis is well documented with various studies in stroke patients showing that African Americans and Japanese people tend to have intracranial vascular occlusion, whereas Caucasians more often have extracranial atherosclerotic lesions.

This is a prospective study of 50 cases of Indian elderly patients over 60 years of age where we have studied the CNS vasculature in detail including intracranial atherosclerosis with regards to its incidence, severity, distribution, plaque composition and associated risk factors. We compared the atherosclerotic pathology in the intracranial vessels and the extracranial vessels including the carotids.

Out of 50 cases 31 showed intracranial atherosclerosis. Anterior circulation was more commonly affected. A total of 87 of the intracranial arteries showed atherosclerotic plaques, most common nature of the plaques being fibrofatty. Majority of the intracranial vessels showed mild stenosis and multiple vessels were involved in 15 cases while single vessel involvement was seen in 16 cases with the middle cerebral artery being the most common single vessel involvement. Infarcts were seen in 7 cases and all these cases had history of hypertension. Cerebral atrophy was seen in 28 cases. All cases showing frontoparietal and generalized atrophy had carotid artery stenosis. Of the 100 carotid arteries studied (2 per case) 59 showed atherosclerosis. Majority of the carotid arteries showed mild degree of atherosclerosis and the content was predominantly fatty.

This study concludes that the pattern of atherosclerosis is different in the Indian population as compared to the western literature. Intracranial atherosclerosis is more common in Indian population with the anterior portion of circle of Willis being more commonly affected.