Prevalence and Clinical Correlates of Intracranial Dolichoectasia in Individuals With Ischemic Stroke

Abstract

Background and Purpose: Acute ischemic stroke is a known complication of intracranial dolichoectasia (IDE). However, the frequency of IDE causing brain infarction is unknown. We aim to determine the prevalence and clinical correlates of IDE in acute ischemic stroke by employing an objective IDE definition for major intracranial arteries of the anterior and posterior circulation. Methods: Consecutive patients with acute ischemic stroke admitted to a tertiary-care hospital during a 4-month period were analyzed. Intracranial arterial diameter, length, and tortuosity were determined by semiautomatic vessel segmentation and considered abnormal if ≥2 SDs from the study population mean. Either ectasia (increased diameter) or dolichosis (increased length or tortuosity) of at least one proximal intracranial artery defined IDE. Symptomatic IDE was considered when the infarct was located in the territory supplied by an affected artery in the absence of any alternative pathogenic explanation. Multivariate models were fitted to determine IDE clinical correlates. Results: Among 211 cases screened, 200 patients (mean age 67±14 years, 47.5% men) with available intracranial vessel imaging were included. IDE was identified in 24% cases (5% with isolated ectasia, 9.5% with isolated dolichosis, and 9.5% with both ectasia and dolichosis). IDE was considered the most likely pathogenic mechanism in 12 cases (6% of the entire cohort), which represented 23.5% of strokes initially categorized as undetermined cause. In addition, 21% of small-artery occlusion strokes had the infarct territory supplied by a dolichoectatic vessel (3% of the entire cohort). IDE was independently associated with male sex (odds ratio, 4.2 [95% CI, 1.7–10.6]) and its component of ectasia was associated with advanced age (odds ratio, 3.5 [95% CI, 1.3–9.5]). Vascular risk profile was similar across patients with stroke with and without IDE. Conclusions: Our findings suggest that IDE is an arteriopathy frequently found in patients with acute ischemic stroke and is likely responsible for a sizable fraction of strokes initially categorized as of undetermined cause and perhaps also in those with small-artery occlusion.