Background
Symptomatic intracranial atherosclerotic disease (sICAD) is associated with high risk of recurrent cerebrovascular events. The study aims to investigate the impact of collaterals and infarct patterns on recurrent stroke and functional outcome in sICAD.
Methods
The study prospectively enrolled patients with sICAD. The demographics and clinical characteristics at the time of index event were documented. The collateral flow (ASITN/SIR and Tan grading) and the predominant infarct pattern were assessed by a neuroradiologist who is blinded to the study outcome. The recurrent stroke/TIA and the functional outcome (modified Rankin scale- mRS) were the clinical end points at 3 and 6 months. The unfavorable outcome was reported as mRS >2.
Results
Of the 118 patients enrolled in the study, the qualifying index event was ischemic stroke in 101 (85.6%) and TIA in 17 (14.4%) patients. The mean age of the study group was 58.86 ±10.2 years (men, 74.6%). The rate of recurrent stroke or TIA was found to be higher at 3 months than 6 months follow up (n= 24, 20.3% vs n= 5, 4.2%). The poor collateral flow showed significant association with stroke recurrence at 6 months (50% vs 4.4%, p= 0.004). The factors predicting unfavorable functional outcome were poor collateral flow (p= 0.003), perforator pattern of infarct (p= 0.04) and the baseline stroke severity (p= 0.001).
Conclusions
This study suggests that the good collateral compensation is associated with lower risk of stroke recurrence and more favorable outcome. This would support the treatment aimed at collateral augmentation or revascularization.