Stroke (main)

Background

• Vascular injury that reduces CBF to specific region of brain causing neuro impairment
• Accurate determination of last known time when pt was at baseline is essential

Causes

1. Ischemic (87%)
   1. Thrombotic (80% of ischemic CVA)
      1. Atherosclerosis
      2. Vasculitis
      3. Arterial dissection
      4. Polycythemia
      5. Hypercoagulable state
      6. Infection
   2. Embolic (20% of ischemic CVA)
      1. Valvular vegetations
      2. Mural thrombi
      3. Arterial-arterial emboli from proximal source
      4. Fat emboli
      5. Septic emboli
   3. Hypoperfusion
      1. Cardiac failure resulting in systemic hypotension
2. Hemorrhagic (13%)
   1. Intracerebral
      1. HTN
      2. Amyloidosis
      3. Anticoagulation
      4. Vascular malformations
      5. Cocaine use
   2. SAH
      1. Berry aneurysm rupture
      2. Vascular malformation rupture

Diagnosis

Anterior Circulation

• Blood supply via internal carotid system
• Includes ACA and MCA

Anterior Cerebral Artery (ACA)

Signs and Symptoms:

• Contralateral sensory and motor symptoms in the lower extremity (sparing hands/face)
• Left sided lesion: akinetic mutism, transcortical motor aphasia
• Right sided lesion: Confusion, motor hemineglect

Middle Cerebral Artery (MCA)

Signs and Symptoms:

• Hemiparesis, facial plegia, sensory loss contralateral to affected cortex
• Motor deficits found more commonly in face and upper extremity than lower extremity
• Dominant hemisphere involved: aphasia
• Nondominant hemisphere involved: inattention, neglect, dysarthria without aphasia
• Homonymous hemianopsia and gaze preference toward side of infarct may also be seen

Posterior circulation

• Blood supply via the vertebral vertebral artery
• Branches include, Basilar artery, PCA and PICA

Signs and Symptoms:

• Crossed neuro deficits (i.e., ipsilateral CN deficits w/ contralateral motor weakness)
• Multiple, simultaneous complaints are the rule
• 5 Ds: Dizziness (Vertigo), Dysarthria, Dystaxia, Diplopia, Dysphagia
• Isolated events are not attributable to vertebral occlusive disease (e.g. isolated lightheadedness, vertigo, transient ALOC, drop attacks)

Basilar artery

Signs and Symptoms:

• Quadriplegia, coma, locked-in syndrome

Posterior Cerebral Artery (PCA)

Signs and Symptoms:

• Unilateral headache (most common presenting complaint)
• Visual field defects (contralateral homonymous hemianopsia, unilateral blindness)
• Motor function is typically minimally affected

Posteroinferior Cerebellar Artery (PICA)

Signs and Symptoms:

• Vertigo, gait instability, limb ataxia, Headache, dysarthria, Nausea and Vomitting, Cranial Nerve abnormalities

DDX

• Seizures/postictal paralysis (Todd paralysis)
• Syncope
• Hypoglycemia
• Hyponatremia
• Meningitis/encephalitis
• Hyperosmotic Coma
• Labyrinthitis
• Drug toxicity
  • Lithium, phenytoin, carbamazepine
• Bell's Palsy
• Complicated migraine
• Meniere Disease
• Demyelinating disease (MS)
• Conversion disorder

Work-Up

1. Bedside glucose
2. Bedside Hb (polycythemia)
3. CBC
4. Chemistry
5. Coags
6. Troponin
7. ECG (esp A-fib)
8. Head CT
   1. Primarily used to exclude intracranial bleeding, abscess, tumor, other stroke mimics
9. Also consider:
   1. Pregnancy test
   2. CXR (if infection suspected)
   3. UA (if infection suspected)
   4. Utox (if ingestion suspected

Treatment

Ischemic

• tPA AND non-tPA candidates:
  • Prevent dehydration
  • Maintain SpO2 >92%
  • Prevent fever
  • Controversial

tPA Candidate

1. tPA
   1. See Thrombolysis in Acute Ischemic Stroke (tPA)
2. Hypertension
   1. Lower SBP to <185, DBP to <110
   2. Options:
      1. Labetalol 10–20mg IV over 1–2 min; may repeat x1 OR
      2. Nitroglycerin paste, 1–2 in. to skin OR
      3. Nicardipine 5mg/hr, titrate up by 2.5mg/hr at 5-15min intervals; max dose 15mg/hr
         1. When desired blood pressure attained reduce to 3mg/hr

Non-tPA Candidate

1. Hypertension
   1. Allow permissive HTN unless SBP >220 or DBP >120 (lower by 10-25%)
2. Aspirin 325mg (within 24-48hr)
3. Anticoagulation not recommended for acute stroke (even for A-fib)

Hemorrhagic

• See Intracerebral Hemorrhage (ICH)

Cerebellar

• Early neurosurgical consultation is needed (herniation may lead to rapid deterioration)
• See Cerebellar Stroke

See Also

• Transient Ischemic Attack (TIA)
• Thrombolysis in Acute Ischemic Stroke (tPA)
• CVA (Post-tPA Hemorrhage)
• Intracranial Hemorrhage (ICH)
• Subarachnoid Hemorrhage (SAH)
• Cervical Artery Dissection
• NIH Stroke Scale
• Cerebellar Stroke

External Links

• MDCalc - NIH Stroke Scale/Score

Source

• Tintinalli
• UpToDate
• AHA/ASA Acute Stroke Guidelines
• EMCrit