A patient presents with sudden focal neurologic deficit lasting less than 24 hours and symptoms resolve. What is the diagnosis?

• A. Stroke
• B. Transient ischemic attack (TIA)
• C. Migraine with aura
• D. Seizure

Answer: (B)

Recognizing transient ischemic attacks hinges on the pattern of a sudden focal neurologic deficit that completely resolves within a short period. A TIA occurs when blood flow to a brain area is briefly reduced, causing symptoms that mirror a stroke but without lasting brain tissue damage. Because the ischemia is transient, the symptoms disappear within 24 hours and there’s no enduring infarction, which is the hallmark that sets it apart from a stroke.

This distinguishes it from a stroke, where deficits persist and imaging would show infarction. Migraine with aura can mimic focal symptoms, but the aura typically evolves over minutes and is often followed by a headache, with a pattern and timing that differ from a pure vascular ischemia event. Seizures can cause postictal weakness after convulsions, but that context includes a seizure history and postictal state, not a transient ischemic interruption of blood flow.

Therefore, the presentation described is best explained by a transient ischemic attack.