Is Functional Outcome Different in Posterior and Anterior Circulation Stroke?

Area of Science:

• Neurology
• Stroke Medicine
• Clinical Outcomes Research

Background:

• Posterior circulation stroke (PCS) constitutes 20% of all ischemic strokes.
• Limited evidence exists comparing functional outcomes between PCS and anterior circulation stroke (ACS).

Purpose of the Study:

• To analyze and compare the 3-month functional outcomes of patients with PCS versus ACS.
• To identify factors influencing functional outcome disparities between PCS and ACS.

Main Methods:

• Prospective enrollment of acute ischemic stroke patients in the Austrian Stroke Unit Registry.
• Stratification by infarct localization (PCS vs. ACS) using Oxfordshire Community Stroke Project Classification.
• Propensity score matching to control for covariates including stroke severity, thrombolysis, and risk factors.
• Assessment of 3-month functional outcome using modified Rankin Scale and proportional odds models.

Main Results:

• A total of 9208 patients (4604 PCS/4604 ACS) were matched, with 954 receiving recombinant tissue-type plasminogen activator.
• ACS patients showed significantly better 3-month functional outcomes compared to PCS patients (OR, 1.19; P<0.0001).
• Worse outcomes in PCS were observed for onset-to-door times >270 minutes (OR, 1.34) and unknown onset times (OR, 1.26).
• No significant difference in functional outcome between PCS and ACS was found for onset-to-door times ≤270 minutes.
• Among patients treated with recombinant tissue-type plasminogen activator, no significant difference in functional outcome was detected between PCS and ACS groups.

Conclusions:

• Posterior circulation stroke is associated with poorer functional outcomes compared to anterior circulation stroke, particularly in cases with delayed hospital arrival (>4.5 hours) or unknown symptom onset.
• These findings underscore the need to integrate PCS symptom recognition into preclinical patient-triage protocols.
• Optimizing early detection and management of PCS is essential for improving patient prognoses.