Chapter 12-04: Diseases & Pathophysiology in Neurology

TRANSIENT ISCHEMIC ATTACK AND ACUTE ISCHEMIC STROKE

Transient ischemic attack (TIA)

• Definition: Transient neurologic deficit that lasts <24 hr with a normal brain MRI

• Management: ABCD² score (Age, BP, Clinical presentation, Duration, DM2) helps risk stratify patients. If score >3, consider hospitalization. Workup same as for stroke (see below).

Acute ischemic stroke

• Etiology:

  • - Thrombotic: Rupture of atherosclerotic plaque

  • - Embolic: Cardioembolic event due to atrial fibrillation, cardiac thrombus, aortic atheroma, or paradoxical emboli from an intracardiac shunt

  • - Lacunar: Due to lipohyalinosis of small vessels which occurs in the setting of hypertension and/or diabetes

  • - Arterial dissection: Arterial wall compromise leading to thrombus formation. Common cause of stroke in young people in the setting of trauma, neck manipulation (e.g., during a chiropractor visit), connective tissue disease

• Symptoms: See Table 12.4. Symptoms depend on the vascular territory involved and thus which anatomic areas are affected.

• Diagnosis:

  • - If concern for a stroke, call a code stroke. If a code stroke is activated, simultaneously:

    • Perform a complete neurologic exam and document any new neurologic deficits

    • Establish the “time last seen normal” (i.e., time when the patient was last seen by another person at their neurologic baseline; not the same as when the patient was found to be symptomatic)

    • Check vital signs and point of care glucose

    • Order CT stroke protocol

    • Review medication list. If the patient is confused, in particular check for administration of any delirium-inducing medications. Determine whether the patient is on any anticoagulants as an inpatient or outpatient

    • Establish whether the patient has a history of stroke (and subsequent deficits) or seizure

    • Determine if the patient underwent any recent invasive procedures/surgeries

  • - Imaging:

    • CT stroke protocol (CT brain w/o contrast, CT angiogram head/neck, CT perfusion) to rule out hemorrhage, evaluate for early signs of ischemia, and diagnose large vessel occlusion

    • MRI brain w/o contrast: Ischemia is bright on DWI and dark on ADC sequences

• Treatment:

  • - Tissue plasminogen activator (tPA): If no contraindications for administration and last seen normal time <4.5 hours prior

  • - Consider thromectomy if large vessel occlusion

• Work-up: Telemetry/cardiac event monitor, TTE (with bubble if age < 60 yr), carotid ultrasound (for anterior circulation strokes if no CTA neck), fasting lipid panel, HgA1c

• Secondary prevention:

  • - Lifestyle changes (exercise, diet)

  • - Management of risk factors (e.g., hypertension, hyperlipidemia, diabetes, smoking cessation)

  • - Antiaggregant/anticoagulation:

    • Aspirin

    • If stroke while on aspirin, consider switching to clopidogrel

    • If acute stroke with minor deficits, consider aspirin + clopidogrel (clopidogrel for 21 days per the POINT trial N Eng J Med 2018 or clopidogrel for 3 months per the SAMPRISS N Eng J Med 2015)

    • If atrial fibrillation/valvular disease, recommend anticoagulation