Capsular Warning Syndrome: Features, Risk Profile, and Prognosis in a Large Prospective TIA Cohort

Area of Science:

• Neurology
• Cerebrovascular Diseases
• Stroke Prevention

Background:

• Capsular warning syndrome (CWS) and its prognostic implications following transient ischemic attack (TIA) remain under-investigated prospectively.
• Understanding CWS characteristics is crucial for refining stroke risk stratification and management strategies in TIA patients.

Purpose of the Study:

• To prospectively characterize the clinical features, risk factors, and short- and long-term prognosis of Capsular Warning Syndrome (CWS) within a large transient ischemic attack (TIA) cohort.
• To compare outcomes between CWS, lacunar (L-TIA), and nonlacunar (NL-TIA) events.

Main Methods:

• A prospective cohort study enrolled 1,035 consecutive TIA patients between August 2010 and December 2017.
• Demographic, clinical, and risk factor data were collected, and outcomes (stroke, composite outcomes, TIA recurrence, hemorrhage, new AF) were compared between CWS, L-TIA, and NL-TIA groups.
• Statistical analyses identified independent risk factors and compared treatment efficacies (DAPT vs. SAPT, IVT).

Main Results:

• Newly diagnosed hypertension, hypercholesterolemia, smoking, and leukoaraiosis were independent risk factors for CWS.
• CWS exhibited significantly higher risks of stroke (30.3%) and composite outcomes compared to L-TIA (0.5%) and NL-TIA (1.5%).
• Despite higher stroke risk, CWS patients showed better 3-month functional prognosis (mRS 0-2: 90.0%) post-stroke. Strokes occurred early (<48h) and were attributed to small vessel occlusion, often affecting the internal capsule.
• Dual antiplatelet therapy (DAPT) was associated with reduced 3-month stroke incidence compared to single antiplatelet therapy (SAPT). Intravenous thrombolysis (IVT) demonstrated similar efficacy and safety.

Conclusions:

• Capsular warning syndrome (CWS) is linked to an elevated stroke risk but a more favorable functional prognosis post-stroke compared to lacunar and nonlacunar TIAs.
• The risk profile suggests severe small vessel disease, with newly diagnosed hypertension as a potential key risk factor.
• Dual antiplatelet therapy (DAPT) and intravenous thrombolysis (IVT) appear to be effective and safe interventions for preventing and treating stroke following CWS.