Transient Ischemic Attack (TIA)
A transient ischemic attack (TIA) is a stroke-like episode caused by a brief reduction in brain blood flow, usually lasting under an hour and resolving completely without permanent damage. Although it leaves no permanent infarct, it warns of a high risk of stroke and requires urgent evaluation.
آخرین بهروزرسانی: 2026-06-07
Definition
A transient ischemic attack (TIA) is a sudden, short-lived (usually under one hour) and fully reversible set of neurological symptoms caused by a temporary reduction in blood flow to the brain. Imaging shows no permanent infarct (tissue death). Current practice defines the event as a TIA when diffusion MRI shows no acute infarct. A TIA is not a 'mini stroke' but a warning sign of an impending stroke.
Causes and Risk Factors
The mechanisms of TIA are the same as ischemic stroke: most often clots breaking off from atherosclerotic plaque in the neck and brain arteries (thromboembolism), followed by cardiac embolism (especially atrial fibrillation) and small-vessel disease. Risk factors include hypertension, diabetes, high cholesterol, atrial fibrillation, smoking, advanced age and carotid artery stenosis.
Symptoms
Symptoms begin suddenly and resolve completely. Anterior circulation involvement causes one-sided arm/leg weakness or numbness, speech disturbance and transient loss of vision in one eye (like a curtain coming down). Posterior circulation involvement may cause dizziness, double vision, speech and swallowing difficulty and imbalance. Complete resolution does not make the event trivial; every TIA should be evaluated urgently.
Diagnosis
TIA is a neurological emergency and should be evaluated within the first 24-48 hours. Diffusion-weighted MRI is used to exclude acute infarction; brain CT is performed when hemorrhage is suspected. Vascular assessment uses carotid Doppler ultrasound and CT/MR angiography. To investigate a cardiac source, ECG, rhythm monitoring (Holter) and echocardiography are performed. Clinical scoring helps stratify early risk.
Treatment
The goal is to prevent stroke. Antiplatelet therapy is started early; in high-risk patients short-course dual antiplatelet therapy reduces stroke risk. If atrial fibrillation is present, anticoagulation is preferred. Statins, blood-pressure and diabetes control and lifestyle changes are applied. In significant (symptomatic) carotid stenosis, carotid surgery (endarterectomy) or stenting is considered, ideally in the early period.
Prognosis
TIA heralds a high early risk of stroke; the risk is greatest in the first days and weeks. Early diagnosis, antiplatelet/anticoagulant therapy, statins and risk-factor control substantially reduce stroke risk. Regular use of medication and follow-up are critical; stopping treatment increases risk. Outcomes differ by patient and cannot be guaranteed.
منابع
- Greenberg MS. Greenberg's Handbook of Neurosurgery. 10th ed. Thieme; 2023:1549-1554.
- Winn HR, ed. Youmans Neurological Surgery. 6th ed. Saunders; 2011:3615-3620.
- Kleindorfer DO, et al. Guideline for the Prevention of Stroke in Patients With Stroke and TIA. Stroke (AHA/ASA). 2021.
- Johnston SC, et al. Clopidogrel and Aspirin in Acute Ischemic Stroke and High-Risk TIA (POINT). N Engl J Med. 2018.
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