Stroke / Cerebrovascular Accident (CVA)

Definition & Overview

• Bradley and Daroff's Neurology in Clinical Practice classifies stroke into:
  • Cerebral infarction (ischemic stroke) - >70% of all cases
  • Intracerebral hemorrhage (ICH) - 10-15%
  • Subarachnoid hemorrhage (SAH) - <5%
  • Undetermined etiology - remainder

Classification

1. Ischemic Stroke (TOAST Classification)

2. Hemorrhagic Stroke

• Causes: hypertensive vasculopathy (most common), cerebral amyloid angiopathy, AVMs, cocaine use, anticoagulation
• Hypertensive hemorrhages occur in deep structures due to lipohyalinosis

Pathophysiology

• Below 15-18 mL/100g/min: Brain loses electrical activity ("electrically silent"), neurons viable but non-functional - this produces the neurological deficit
• Below 10 mL/100g/min: Membrane failure occurs; extracellular K⁺ rises, intracellular Ca²⁺ rises - irreversible cell death

Diffusion-weighted MRI (A) showing acute ischemic lesion; (B) showing hemorrhagic transformation - Adams and Victor's Neurology

Risk Factors

• Age (risk doubles each decade after 55)
• Male sex, Black race
• Family history, prior TIA or stroke

Clinical Features

Prehospital Recognition - FAST / LAPSS

LAPSS prehospital stroke screening tool - Rosen's Emergency Medicine

Anterior Circulation Strokes

• Contralateral leg weakness > arm weakness (opposite of MCA)
• Abulia, altered mentation, poor judgment, primitive reflexes (grasp, suck)
• Bowel and bladder incontinence
• Apraxia of gait

• Contralateral hemiplegia and hemisensory loss (arm and face > leg)
• Contralateral homonymous hemianopsia
• Aphasia (if dominant hemisphere):
  • Broca aphasia (expressive) - cannot speak fluently but comprehends
  • Wernicke aphasia (receptive) - fluent but incomprehensible speech, impaired comprehension
• Contralateral gaze deviation (eyes look toward the lesion)
• Agnosia, spatial neglect (non-dominant hemisphere)

• Contralateral homonymous hemianopsia
• Visual agnosia, alexia
• Third nerve palsy (ipsilateral)

Posterior Circulation Strokes (Vertebrobasilar)

• Loss of consciousness (unique to posterior circulation)
• Nausea and vomiting (brainstem CTZ involvement)
• Diplopia, dysphagia, dysarthria ("the Ds")
• Ipsilateral cranial nerve deficits with contralateral long tract signs (crossed signs)
• Vertigo, ataxia, nystagmus
• Posterior strokes can progress for up to 3 days (vs. 24 hours for anterior strokes)

Diagnosis

Imaging

• Non-contrast CT - first line; rapidly excludes hemorrhage (hemorrhage appears hyperdense)
• CT Angiography (CTA) - identifies large vessel occlusion (LVO)
• MRI/DWI - most sensitive for acute ischemic stroke; diffusion restriction visible within minutes
• CT Perfusion / MRI Perfusion - identifies penumbra vs. infarct core (used for extended window eligibility)

Scoring Tools

• NIHSS (NIH Stroke Scale) - quantifies stroke severity (0-42); used to determine tPA eligibility and monitor progression
• Glasgow Coma Scale (GCS) - for ICH; serial exams detect hemorrhage expansion
• ICH Score - predicts mortality in hemorrhagic stroke

Management

Acute Ischemic Stroke - "Time is Brain"

• Airway, breathing, circulation - ABC approach
• Supplemental O₂ if needed; avoid hyperthermia (worsens outcome); mild hypothermia is protective
• Cardiac monitoring for ≥48 hours (ECG + troponin on admission - 3-20% have concomitant myocardial ischemia)
• Blood pressure: optimal range post-stroke ~160-200 mmHg systolic; avoid over-treatment (impairs penumbra perfusion)
• Aspiration precautions - NPO until formal swallow evaluation; head-of-bed >30°
• Admission to a dedicated stroke unit - reduces mortality, hospital stay, and nursing-home discharge
• DVT prophylaxis

• Heparin (UFH/LMWH): No proven benefit in reducing morbidity or mortality in most acute ischemic strokes (IST and FISS trials)
• May be considered for: cerebral venous thrombosis, small cardioembolic infarcts with intracardiac thrombus
• Not recommended if septic embolism suspected

Acute Hemorrhagic Stroke

• Reverse anticoagulation immediately (Vitamin K, PCC, FFP, protamine as appropriate)
• BP control: Lower rapidly in hypertensive ICH to reduce hematoma expansion
• Monitor ICP; neurosurgical consultation for cerebellar hemorrhage >3 cm, hydrocephalus, or deteriorating patient
• Serial neurological exams and imaging for expansion monitoring
• Avoid early care limitations - prognosis is uncertain in acute ICH

Secondary Prevention

Transient Ischemic Attack (TIA)

Prognosis

• Stroke mortality in the US has declined by 75% since the late 1960s due to improved management and risk factor control
• Early rehabilitation begun within 24-48 hours improves functional outcomes
• Predictors of poor outcome in ICH: low GCS on arrival, large hematoma volume, intraventricular blood extension
• Globally, age-standardized stroke mortality decreased by 36.2% from 1990 to 2016

• Bradley and Daroff's Neurology in Clinical Practice, Chapters 47, 65
• Rosen's Emergency Medicine, Chapter 87
• Adams and Victor's Principles of Neurology, 12th Ed., Chapter on Cerebrovascular Disease
• Neuroanatomy Through Clinical Cases, 3rd Ed., Table 10.4