Modified DWI-FLAIR mismatch guided thrombolysis in unknown onset stroke

Area of Science:

• Neurology
• Radiology
• Emergency Medicine

Background:

• DWI-FLAIR mismatch is used to identify unknown onset stroke (UOS) patients for thrombolysis.
• This criterion may exclude potential candidates who could benefit from treatment.
• Wake-up stroke (WUS) and UOS patients present diagnostic challenges for reperfusion therapy.

Purpose of the Study:

• To evaluate the feasibility, safety, and efficacy of thrombolysis in WUS and UOS patients using a modified DWI-FLAIR mismatch criterion.
• To assess outcomes in patients treated with intravenous thrombolysis (IVT) who had partial FLAIR positivity.

Main Methods:

• A modified DWI-FLAIR mismatch criterion was applied to WUS/UOS patients.
• IVT-treated patients were compared to propensity score-matched controls who did not receive IVT due to FLAIR positivity.
• Primary endpoint: symptomatic intracranial hemorrhage (SICH). Secondary endpoints: NIHSS and mRS score improvement at 3 months.

Main Results:

• No significant difference in SICH between the IVT group and controls (3.1% vs. 1.6%).
• Greater improvement in NIHSS score (≥4 points) was observed in the IVT group (40.6% vs. 18.8%).
• Functional outcomes (mRS 0-1 at 3 months) were comparable between groups (23.4% vs. 18.8%). Outcomes were also similar for thrombolyzed patients with negative vs. partial positive FLAIR.

Conclusions:

• Thrombolysis appears feasible and safe in selected WUS/UOS patients with partial FLAIR signal positivity.
• The modified DWI-FLAIR mismatch criterion may expand eligibility for thrombolysis in these patient groups.
• Further research is warranted to confirm these findings in larger cohorts.