NATURAL-HISTORY OF STENOSIS FROM INTRACRANIAL ATHEROSCLEROSIS BY SERIAL ANGIOGRAPHY

Background and Purpose-Knowledge of the natural history of stenoses du e to intracranial atherosclerosis may be useful for evaluating possibl e treatments such as angioplasty. Methods-We retrospectively reviewed records over a 7-year period to identify patients with intracranial at herosclerotic stenoses and serial angiograms. Quantitative measurement s of stenoses were made in a blinded manner, and clinical outcomes wer e reviewed. Results-We identified 21 patients with 45 intracranial ste noses who underwent repeat angiography at an average interval of 26.7 months. The average stenosis for all intracranial lesions was 43.9% in itially and 51.8% on follow-up (P=.032). The average stenosis in the i ntracranial internal carotid artery (ICA) was stable (51.2% versus 52. 6%). The average stenosis in the anterior cerebral artery (ACA), middl e cerebral artery (MCA), and posterior cerebral artery (PCA) progresse d from 32.4% to 49.7% (P=.037). Based on a minimum 10%, change, 20% of intracranial ICA lesions progressed compared with 61% of ACA, MCA, an d PCA lesions. Regression occurred in 14% of the intracranial ICA grou p and 28% of the ACA-MCA-PCA group. Cerebrovascular events were infreq uent during this period, with 4 transient ischemic attacks and 1 intra cerebral hemorrhage. Conclusions-Intracranial atherosclerotic stenoses are dynamic lesions demonstrating both progression and regression.