Differences in Ischemic Anterior and Posterior Circulation Strokes: A Clinico-Radiological and Outcome Analysis

There are limited data comparing posterior (PC) and anterior (AC) circulation acute ischemic strokes (AIS). We aimed to identify specific features of PC and AC strokes regarding clinical, etiological, radiological, and outcome factors.

Patients from the Acute STroke Registry and Analysis of Lausanne, a prospective cohort of consecutive AIS, from years 2003 to 2008 were included. The stroke territory was determined by a combination of neuroimaging and clinical symptoms. Patients with uncertain localization or with simultaneous AC and PC strokes were excluded. Multivariate associations between territory and multiple variables were investigated.

A total of 1449 patients were included, 466 (32.2%) had a PC territory stroke and 983 (67.8%) an AC. On multivariate analysis, those with PC AIS had lower National Institutes of Health Stroke Scale at admission, more often showed decreased consciousness, visual field defects, and vestibulo-cerebellar signs, but less hemisyndromes, dysarthria, and cognitive symptoms compared to AC AIS patients. Male sex, arterial dissection, lacunar mechanisms, and endovascular recanalization were more frequent in PC strokes, whereas cardioembolic strokes and IV-thrombolysis rates were lower. Less early ischemic signs on admission CT, overall arterial pathology, and 24-hour recanalization were present in PC strokes but intracranial arterial pathology was more prevalent than in AC. The adjusted clinical outcome at 3 months was similar in both groups.

In this large retrospective consecutive AIS series, there were specific differences in clinical presentation, etiology, and arterial pathology between PC and AC strokes which did not influence clinical outcome. These findings could lead to a tailored diagnostic work-up, acute treatment strategies, and secondary prevention.