What are transient ischemic attacks (TIAs)?

Updated: Mar 13, 2017
  • Author: Hesham M Samy, MD, PhD; Chief Editor: Robert A Egan, MD  more...
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Transient ischemic attacks (TIAs) are episodes of focal neurologic symptoms involving isolated or combined brainstem symptoms such as dizziness, diplopia, or weakness. These attacks are of sudden onset and resolve within 24 hours without residual subjective symptoms or objective signs on examination. TIAs are usually due either to reduced blood flow (the hemodynamic theory; eg, cardiac dysrhythmia) or to obstructed blood flow (the embolic theory; eg, plaques from the heart).

TIAs are commonly (75% of cases) due to posterior circulation (vertebrobasilar territory). The differential diagnosis of TIAs includes migraine, partial seizures, hypoglycemia, syncope, and hyperventilation.

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