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

See Stroke syndromes

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

Clinical Features

• Thrombotic
  • Stuttering or waxing and waning
  • TIA involving same vascular distribution
• Embolic
  • Sudden onset of symptoms
  • TIAs involving different vascular distributions
  • A-fib
  • Valvular replacement
  • Recent MI
• Hemorrhagic
  • Sudden onset of symptoms
  • Preceded by severe headache
  • Recent neck trauma/manipulation

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

1. Seizures/postictal paralysis (Todd paralysis)
   1. Transient paralysis following a seizure which typically disappears quickly
   2. Note: seizures can be secondary to a CVA
2. Syncope
   1. No persistent or associated neurologic symptoms
3. Brain neoplasm or abscess
   1. Focal neurologic findings, signs of infection, detectable by imaging
4. Epidural/subdural hematoma
   1. History of trauma, ETOH, anticoagulant use, bleeding disorder; detectable by imaging
5. Hypoglycemia
   1. Can be detected by bedside glucose measurement, history of DM
6. Hyponatremia
   1. History of diuretic use, neoplasm, excessive free water intake
7. Hypertensive encephalopathy
   1. Gradual onset; global cerebral dysfunction, HA, delirium, HTN, cerebral edema
8. Meningitis/encephalitis
   1. Fever, immunocompromise may be present, meningismus, detectable on LP
9. Hyperosmotic Coma
   1. Extremely high glucose levels, history of DM
10. Wernicke Encephalopathy
    1. History of ETOH or malnutrition; triad of ataxia, ophthalmoplegia, and confusion
11. Labyrinthitis
    1. Predominantly vestibular symptoms; pt should have no other focal findings
12. Drug toxicity
    1. Lithium, phenytoin, carbamazepine
13. Bell's Palsy
    1. Neuro deficit confined to isolated peripheral 7th nerve palsy; often a/w younger age
14. Complicated migraine
    1. History of similar episodes, preceding aura, HA
15. Meniere Disease
    1. History of recurrent episodes dominated by vertigo symptoms, tinnitus, deafness
16. Demyelinating disease (MS)
    1. Gradual onset, may have hx of multiple episodes of findings in multiple distributions
17. Conversion disorder
    1. No cranial nerve findings, nonanatomic distribution of findings

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
• Stroke syndromes
• Cerebellar Stroke

External Links

• MDCalc - NIH Stroke Scale/Score

Source

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