Table of contents
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Source: AHA/ASA Guidelines 2009
Transient Ischemic Attack
- Defined classically as: focal neurologic deficit of ischemic origin of <24hrs duration. (most <4hrs).
- Found that many "Classic TIAs" have MRI findings of infarcts. These clinically silent infarcts thought to contribute to vascular dementia.
- New definition: No MRI findings of infarct.
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2009 AHA/ASA Definition:
- A transient episode of neurological dysfunction caused by focal brain,
spinal cord, or retinal ischemia, without acute infarction. - (new definition does not define <24hrs, and requires neuroimaging)
- A transient episode of neurological dysfunction caused by focal brain,
- (new definition does not define <24hrs, and requires neuroimaging)
- Diagnosis:
- Can use clinical judgement to diagnose, but can also use this criteria:
-
Asymptomatic Carotid Atherosclerosis Study team used criteria:
- Change in:
- Speech
- Visual loss
- diplopia
- numbness or tingling
- paralysis or weakness
- nonorthostatic dizziness.
80% agreement between criteria and expert panel review.
- Change in:
- Approach
- ALL PATIENTS need urgent evaluation ASAP
- MRI (with DWI) within 24hrs
- Risk Stratify
- TIAs is an important risk factor - predicts 5.3% risk of stroke in 2 days and 10.5% stroke in 90 days.
- ABCD2 score traditionally used to risk stratify (admission vs. outpatient and urgency of neurology referral), but no longer used.
- Now many neurologists favour "high risk vs. low risk" stratification based on severity of deficit (unilateral hemiparesis, speech deficit etc.. are considered high risk).
- Also risk depends on time of symptom onset (see below)
- ABCD2 score is no longer used to risk stratify them. The only thing that matter is timing of evaluation:
-
Time from
Sympt. Onset
Risk Recommended Timing of Evaluation in ER/Stroke
Unit with stroke capability (CT, MRI, tPA)
0-48hrs HIGHEST IMMEDIATE 48hrs - 2w INCREASED Risk
Within 24 hrs >2wk LOWER Risk
Within 1 month - Symptoms without motor/speech (i.e. Sensory) are considered less urgent
-
- TIAs is an important risk factor - predicts 5.3% risk of stroke in 2 days and 10.5% stroke in 90 days.
- Hospitalization Criteria [Class IIa, C]
- Within 72hrs of event AND
- ABCD2 score of ≥3
- ABCD2 score 0-2 + uncertain diagnostic w/u can be completed in <2 days
- ABCD2 0-2 + other evidence event was caused by focal ischemia(???)
- Within 72hrs of event AND
- Investigations:
- Intra-Cranial Imaging within 24hrs of symptom onset
- With MRI with DWI within 24hrs of symptom onset
- If MRI not available, CT will suffice
- Extra-Cranial Imaging (Class IIa, B)
- To look at cervicocephalic vessels
- Any of: CUS/TCD, CTA or MRA of cervicocephalic vessels
(depends on patients and local expertise) - Often two investigations are needed before endarterectomy
OR the gold standard, which is angiography
- Cardiac
- ECG STAT
- + cardiac monitoring (holter or telemetry)
- Echo (ONLY if no other cause identified) [Class Iia, level B]
- TTE reasonable, but TEE useful for PFOs, valve dz, arch atheroscerosis.
- Bloodwork
- CBC, Chemistry, PT, PTT, fasting lipids [Class Iia, B]
- Other:
- Screen for sleep apnea - Berlin Questionnaire or STOP-BANG score
- Intra-Cranial Imaging within 24hrs of symptom onset
- Management:
- Risk Reduction!
- Healthy, balanced diet as per Canada's Food Guide
- (High fibre, proteins from fish/vegetables, unsaturated fats, whole grains, fruits)
- Exercise
- Moderate intensity (Brisk walking, jogging, cycling, swimming) --> 150min/week, ≥10min/session
- Weight
- BMI 18.5 - 24.9, waist 102cm (men) 88cm (women)
- Smoking/drugs
- Alcohol consumption
- Max 15 drinks/week (men), 10 drinks/week (women), no more than 4 on on occasion
- Hypertension --> CHEP guidelines
- Oral contraceptives should be stopped
- Diabetic control
- HbA1c ≤ 7%, fasting glucose 4.0-7.0 mmol/L, 2hr post-prandial 5.0-10.0 (consider targeting 5.0-8.0 if unable to reach target HbA1c)
- See CDA guidelines
- Investigations: (ALL PATIENTS NEED:)
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