Definition and Evaluation of Transient Ischemic Attack

Definition and Evaluation of Transient Ischemic Attack

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AHA/ASA Scientific Statement
Definition and Evaluation of Transient Ischemic Attack

Stroke. 2009;40:2276-2293


Traditional Definition

Transient Ischemic Attack (TIA) was a sudden, focal neurological deficit of presumed vascular origin lasting <24 hours

2002 AHA-Endorsed Revised Definition of TIA

a transient episode of neurological dysfunction caused by focal brain, spinal cord, or retinal ischemia, without acute infarction

Risk Stratification

Patients with TIAs are at high risk of early stroke, and their risk may be stratified by clinical scale, vessel imaging, and diffusion MRI

The California score and the ABCD2 scores

• Age ≥60 years (1)
• Blood pressure ≥140/90 mmHg on first evaluation (1)
• Clinical symptoms of focal weakness with the spell (2) or speech impairment without weakness (1)
• Duration ≥60 minutes (2) or 10 to 59 minutes (1)
• Diabetes (1)

Hospitalization

It is reasonable to hospitalize patients with TIA if they present within 72 hours of the event and any of the following criteria are present:    

• ABCD2 scores of 3 (Class IIa, Level of Evidence C)
• ABCD2 scores of 0 to 2 and uncertainty that diagnostic workup can be completed within 2 days as an outpatient (Class IIa, Level of Evidence C)
• ABCD2 scores of 0 to 2 and other evidence that indicates the patient’s event was caused by focal ischemia (Class IIa, Level of Evidence C)

Patients with TIA or minor stroke who have DWI lesions, especially when multiple, are at higher risk of recurrent ischemic events

Diagnostic Evaluation

• Patients with TIA should preferably undergo neuroimaging evaluation within 24 hours of symptom onset 

• MRI, including DWI, is the preferred brain diagnostic imaging modality. If MRI is not available, CT should be performed (Class I, Level of Evidence B) 

• Noninvasive imaging of the cervicocephalic vessels should be performed routinely as part of the evaluation of patients with suspected TIAs (Class I, Level of Evidence A) 

• Initial assessment of the extracranial vasculature may involve any of the following: carotid ultrasound/ transcranial Doppler (CUS/TCD), MRA, or CTA, depending on local availability and expertise, and characteristics of the patient (Class IIa, Level of Evidence B)

• ECG and prolonged cardiac monitoring 

• Echocardiography (TTE or TEE) 

• Routine blood tests (CBC, chemistry panel, PT and aPPT, and fasting lipid panel) 

• Optional Coagulation Screening Tests 

Consider in Younger Patients With TIAs, Particularly When No Vascular Risk Factors Exist and No Underlying Cause Is Identified

• Protein C, protein S, antithrombin III activities
• Activated protein C resistance/factor V Leiden
• Fibrinogen
• D-Dimer
• Anticardiolipin antibody
• Lupus anticoagulant
• Homocysteine
• Prothrombin gene G20210A mutation
• Factor VIII
• Von Willebrand factor
• Plasminogen activator inhibitor-1
• Endogenous tissue plasminogen activator activity