Intravenous Thrombolysis in Posterior Circulation Stroke

Area of Science:

• Neurology
• Vascular Neurology
• Emergency Medicine

Background:

• Intravenous thrombolysis (IVT) is a standard treatment for both anterior circulation ischemic stroke (ACIS) and posterior circulation ischemic stroke (PCIS).
• Posterior circulation ischemic stroke (PCIS) accounts for 12-19% of all IVT-treated strokes, with embolism being the most common mechanism.
• PCIS involves ischemia in the posterior circulation arteries, distinct from ACIS.

Purpose of the Study:

• To assess intracerebral hemorrhage (ICH) and clinical outcomes in PCIS patients treated with IVT.
• To compare the safety and efficacy of IVT in PCIS versus ACIS.
• To identify patient subgroups and treatment windows for IVT in PCIS.

Main Methods:

• PubMed database search for studies on ICH and clinical outcomes in PCIS patients treated with IVT.
• Analysis of data from retrospective clinical studies and case series due to lack of randomized controlled trials (RCTs).
• Evaluation of factors influencing outcomes, including time to treatment and specific arterial occlusions.

Main Results:

• Intracerebral hemorrhage (ICH) rates in PCIS after IVT range from 0-6.9% (symptomatic) to 17-23.4% (any ICH).
• Favorable outcomes (mRS 0-1) occur in 38-49% of PCIS patients, which is better than in ACIS patients.
• Mortality rates in PCIS patients treated with IVT (9-19%) are not significantly different from ACIS patients.

Conclusions:

• IVT appears safer for PCIS than ACIS, with limited retrospective data supporting its use.
• Consider IVT for PCIS patients with brainstem ischemia, vertebral artery occlusion, or without basilar/posterior cerebral artery occlusion, even in borderline cases.
• Time to IVT may be less critical in PCIS, with potential benefits observed even after 4.5 hours from symptom onset.