TIA Management

Today we reviewed the approach to a patient presenting with symptoms suggestive of a Transient Ischemic Attack (TIA).

A TIA is defined as an abrupt focal loss of neurologic function caused by reduction in blood flow that persists less than 24 hours and clears without residual disability.

Diagnosis is made with a thorough history and physical examination, where the latter can be normal in many patients.

The patient's risk for progression to stroke can be assessed by the ABCD score, which helps to guide the clinician on the need for admission:

A: Age - 1-pt if over 60 years old; 0-pt if less than 60

B: Blood Pressure - 1-pt if SBP greater than 140 OR 1-pt if DBP greater than 90

C: Clinical symptoms - 2-pts if unilateral weakness; 1-pt if language disturbance but no weakness; 0-pt for other symptoms

D: Diabetes - 1-pt if patient has diabetes; 0-pt if not

D: Duration - 2-pts if more than 60 min; 1-pt if 10-59 min; 0-pt if less than 10 min

Score 0-3: low risk, 2-day stroke risk 1%

Score 4-5: moderate risk, 2-day stroke risk 4%

Score 6-7: high risk, 2-day stroke risk 8%

Low risk patients don't need to be admitted for stroke work-up; however, they do require expedited investigations which sometimes warrant an admission. Moderate risk patients and High risk patients generally warrant an admission and investigations and monitoring for stroke.

Current Canadian Stroke Guidelines recommend rapid turn around times for investigations in a patient presenting with a TIA. Patients are categorized into Emergent, Urgent, and Semi-urgent; and based on these 3 categories, their stroke work-up is recommended to be performed within the given timeline.

Emergent: investigations within 24-hrs

• Symptoms within the previous 24-hrs with 2 or more high-risk clinical features (ABCD criteria)
• Acute persistent or fluctuating stroke symptoms
• One positive investigation (evidence of acute infarct on CT/MRI; evidence of carotid artery stenosis > 50%)
• Other factors based on individual presentation and clinical judgment

Urgent: investigations within 72-hrs

• TIA within the previous 72-hrs

Semi-urgent: investigations within 30-days

• Does not meet urgent or emergent criteria

Investigations include standard screening blood work, an assessment by a neurologist or stroke specialist, brain CT or MRI, carotid imaging (doppler, CT angio, or MR angio), and ECG.

Management should include initiation of an anti-platelet agent, once confirmation that there is no intracranial hemorrhage. If not already on ASA, start with 160-mg followed by 81-mg daily. If failing ASA treatment, then change to either Clopidogrel (load with 300-mg followed by 75-mg daily) or Aggrenox (1-tab BID).

Those with 70 - 99% blockages in their carotid arteries (matching their TIA symptom pattern)should undergo endarterectomy within 2-weeks.

If Atrial Fibrillation is discovered the patient should be initiated on anti-coagulation therapy immediately after their event, once an intracranial hemorrhage has been ruled out.

All modifiable risk factors should be addressed by way of smoking cessation, blood glucose control (HbA1C less than 7%), lipid management (LDL less than 2), and blood pressure reduction (less than 140/90).

The complete Current Canadian Stroke and TIA guidelines can be found here.