Stroke (main)

Revision as of 19:32, 25 September 2014 by Rossdonaldson1 (talk | contribs) (See Also)

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

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

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

Cerebellar

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

See Also

External Links

Source

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