Pathology of Atherosclerotic Intracranial Stenosis.

Background and Purpose: Atherosclerotic intracranial stenosis is now recognized as a major cause of ischemic stroke. Data on the pathology of atherosclerotic intracranial stenosis are scarce; hence this study aims to describe the gross and histopathologic findings of intracranial arterial stenosis in autopsied cases. Methods: Eighty (80) consecutive autopsy cases were grossly and histologically examined from 2000 to 2006. Eighteen (18) autopsied cases satisfied the selection criteria. Gross and histologic atherosclerotic changes of the stenotic middle cerebral and basilar arteries were examined. Intracranial atherosclerotic stenosis was categorized as either focal or diffuse and the degree of stenosis was determined. Results: Of the 18 autopsy cases included, 9 (50%) had at least one atherosclerotic segment. Mean age of the atherosclerotic group was 65.3 years. There were 5 males (55.6%) in the atherosclerotic cases. Of the 16 abnormal vessels examined, 11 (68.7%) involved the middle cerebral artery and five (31.3%) involved the basilar artery. Nine out of the 16 (56.2%) atherosclerotic vessels showed focal atherosclerotic segment, while 7 (43.8%) had diffuse atherosclerotic changes. The severity of stenosis was as follows: 1 (6.3%) had ≤ 30% arterial stenosis, 9 (56.2%) had 31 - 50%, 5 (31.2%) had 51 - 70% and 1 (6.3%) had >70% stenosis. Conclusion: Nine out of 18 autopsied brains had atherosclerotic segment in at least one intracranial vessel. The middle cerebral artery was commonly involved and focal type of stenosis was the most common finding. The majority of these stenosed blood vessels had 31% to 70% luminal narrowing. [ABSTRACT FROM AUTHOR]