Criteria for Emergency Brain MRI During Stroke-Alert

Area of Science:

• Neurology
• Emergency Medicine
• Radiology

Background:

• Intravenous (IV) tissue plasminogen activator (tPA) is crucial for acute ischemic stroke (AIS) but contraindicated in stroke mimics (SM).
• Selective use of emergency brain magnetic resonance imaging (eMRI-brain) can aid diagnosis in stroke alerts.
• Currently, accepted utilization criteria for eMRI-brain in this context are lacking.

Purpose of the Study:

• To develop and validate history-based criteria for performing eMRI-brain during stroke alerts.
• To assess the diagnostic yield of eMRI-brain in differentiating AIS from SM.
• To evaluate the impact of selective eMRI-brain on IV tPA administration decisions.

Main Methods:

• Developed three history-based criteria for eMRI-brain: prior similar deficits, altered consciousness at onset, and migraine aura-like symptoms.
• Conducted a 5-year retrospective chart review of stroke-alert patients.
• Analyzed the effect of these criteria on IV tPA administration for AIS and SM.

Main Results:

• Of 3,512 stroke alerts, 230 (8.1%) met eMRI-brain criteria, with 92.6% identified as SM and 7.4% as AIS.
• eMRI-brain use led to less frequent IV tPA administration in SM (PCC=0.841, p=0.036) and fewer failures to administer tPA in AIS (PCC=-0.907, p=0.013).
• No delays in IV tPA eligibility were attributed to MRI procedures.

Conclusions:

• History-based criteria for selective eMRI-brain in stroke alerts demonstrate a high yield for identifying stroke mimics.
• Targeted eMRI-brain utilization enhances the accuracy of IV tPA administration decisions.
• This approach optimizes treatment for acute stroke patients while avoiding unnecessary thrombolysis in mimics.