Stroke (main)

Background

• Any disease process that interrupts blood flow to the brain

Anatomy

1. Anterior Circulation (internal carotid system)
   1. Ophthalmic artery - optic nerve and retina
   2. ACA - frontal pole, anteromedial cortex, ant corpus callosum
   3. MCA - frontoparietal lobe, anterotemporal lobe
2. Posterior circulation (vertebral system)
   1. Vertebral artery - brainstem
   2. Posteroinferior cerebellar - Cerebellum
   3. Basilar - Thalamus
   4. Post cerebral - Auditory/vestibular structures, medial temporal lobe, occipital cortex

Work-Up

1. Glucose
2. CBC
3. Chemistry
4. Coags
5. Troponin
6. Lipid profile
7. Head CT
8. ECG
9. Also consider:
   1. Pregnancy test
   2. Utox
   3. TTE with bubble study

DDX

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

Treatment

Ischemic

1. Glycemic control
   1. Use insulin to maintain blood sugar < 185
2. Temperature control
   1. Treat fever > 37.5 (99.5)
3. If pt is tPA candidate go to --> CVA (tPA Criteria)
   1. Consider tPA
      1. If give tPA DO NOT give antiplatelets/anticoagulants for at least 24 hours
   2. BP Control
      1. If potential candidate for tPA but BP > 185/110:
         1. Labetalol 10-20mg IV over 1-2min, may repeat x 1, OR
         2. Nicardipine IV 5mg/hr, titrate up by 2.5mg/hr q5-15min, max 15mg/hr; when desired BP reached lower to 3mg/hr OR
         3. other agents (hydralazine, enalaprit, etc) may be considered when appropriate
4. If pt is NOT a tPA candidate:
   1. Aspirin
   2. BP control
      1. Only tx BP if > 220/120
   3. Anticoagulation
      1. Heparin only if cardiac embolic source/ a-fib

Hemorrhagic

See Intracranial Hemorrhage (ICH)

Cerebellar Stroke

• Can be confused w/ acute vestibular syndrome (e.g. labyrinthitis)
• HINTS Exam can reliably distinguish the two (more effective than early DWI MRI)
  • Head Impulse Testing
    • Tests vestibulo-ocular reflex
    • Have pt fix their eyes on your nose
    • Move their head in the horizontal plane to the left and right
    • If reflex is intact their eyes will stay fixed on your nose
    • If reflex is abnormal their head will move 1st and then their eyes will "catch up"
    • It is reassuring if the reflex is abnormal (due to dysfunction of the nerve)
  • Nystagmus
    • Benign nystagmus only beats in one direction no matter which direction their eyes look
    • Bad nystagums beats in every direction their eyes look
      • If pt looks left, get left nystagmus, if looks right, get right-beating nystagmus
  • Test of Skew
    • Vertical dysconjugate gaze is bad
    • Alternating cover test
      • Have pt look at your nose w/ their eyes and then cover one eye
        • When rapidly uncover the eye look to see if the eye quickly moves to re-align
  • If any of the above are abnormal obtain full CVA w/u (including MRI)

See Also

• Transient Ischemic Attack (TIA)
• CVA (tPA Criteria)
• CVA (Post-tPA Hemorrhage)
• Intracranial Hemorrhage (ICH)
• Subarachnoid Hemorrhage (SAH)

Source

• UpToDate
• AHA/ASA Acute Stroke Guidelines
• EMCrit