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.
    • 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)
    • (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.

     

    • 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
    • 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(???)
    • 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
    • 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

     

     

     

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    • Investigations:  (ALL PATIENTS NEED:)
      •  

     

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