neurologic disorders
Transient Ischemic Attack (TIA)
Diagnosis of TIA
Resolution of stroke-like symptoms within 1 hour Neuroimaging Evaluation to identify the cause Transient ischemic attacks are diagnosed retrospectively when sudden neurologic deficits referable to ischemia in an arterial territory resolve within 1 hour. Isolated peripheral facial nerve palsy, loss of consciousness, or impaired consciousness does not suggest TIA. TIAs must be distinguished from other causes of similar symptoms, such as Hypoglycemia None Symptoms and Signs None Postictal [Todd] paralysis (a transient neurologic deficit, usually weakness, of the limb contralateral to the seizure focus) Because an infarct, a small hemorrhage, and even a mass lesion cannot be excluded clinically, neuroimaging is required. Usually, CT is the study most likely to be immediately available. However, CT may not identify infarcts for>24 hours. MRI usually detects evolving infarction within hours. Diffusion-weighted MRI is the most accurate imaging test to rule out an infarct in patients with presumed TIA but is not always available. The cause of a TIA is sought as for Etiology ; evaluation includes tests for carotid stenosis, cardiac sources of emboli, Patients are at high risk of TIA if they have an ABCD2 score > 4. The ABCD2 score is used to estimate risk of stroke after TIA and is calculated by adding the following: A (age): ≥ 60 = 1 B (blood pressure): Systolic blood pressure ≥ 140 and/or diastolic blood pressure > 90 = 1 C (clinical features): Weakness = 2, speech disturbance without weakness = 1 D (TIA duration): ≥ 60 min = 2, 10 to 59 min = 1, < 10 minutes = 0 D2 (diabetes) = 1 Risk of stroke within 2 days based on the ABCD2 score is about For a score of 6 to 7: 8% For a score of 4 to 5: 4% For a score of 0 to 3: 1% All patients who have had a TIA require CT angiography, magnetic resonance angiography (MRA), or diffusion-weighted MRI of the carotid and cerebral circulation. 