Transient Ischemic Attack — TIA
The symptoms vanished in 20 minutes and the patient feels fine — but without urgent workup and intervention, a completed stroke may follow within 48 hours.
Core Concept
A transient ischemic attack is a temporary episode of neurological dysfunction caused by focal brain ischemia without acute infarction on imaging. Symptoms — unilateral weakness, slurred speech, visual loss, ataxia — resolve completely, typically within minutes to an hour. The classic teaching of a 24-hour window is outdated; current evidence defines TIA by absence of tissue injury on diffusion-weighted MRI, not by symptom duration. The 90-day stroke risk after TIA is 10–15%, with the highest danger in the first 48 hours. Rapid risk stratification uses the ABCD² score: Age ≥60 (+1), Blood pressure ≥140/90 at presentation (+1), Clinical features of unilateral weakness (+2) or speech impairment without weakness (+1), Duration ≥60 min (+2) or 10–59 min (+1), and Diabetes (+1). Scores ≥4 warrant hospitalization for expedited workup including brain MRI with diffusion-weighted imaging, carotid imaging (duplex ultrasound or CTA), ECG and telemetry for atrial fibrillation, and labs (CBC, glucose, lipids, coagulation). Immediate antiplatelet therapy (aspirin, or dual antiplatelet with aspirin + clopidogrel for high-risk TIA) is initiated unless contraindicated. Nursing priorities center on serial neurological assessments using a standardized stroke scale, frequent vital signs, and immediate notification if any deficit returns or worsens — because that signals progression to a completed stroke.
Watch Out For
Don't confuse TIA with a minor stroke — TIA shows no infarction on DWI-MRI, while even mild strokes do. Students often dismiss a resolved deficit as low-risk; the 48-hour window is the most dangerous period. The ABCD² score guides urgency of workup, not treatment decisions — it predicts short-term stroke risk, not whether to give thrombolytics (TIA patients don't receive tPA because there is no ongoing ischemia).
Clinical Pearl
"Gone doesn't mean safe." Resolved symptoms after TIA are a warning shot — treat the next 48 hours as a stroke-prevention emergency.
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