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Stroke Pathophysiology

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Stroke Pathophysiology, CVA Causes, Transient Ischemic Attack Causes, TIA Risk Factors, Cerebrovascular Accident Risk Factors, CVA Risk Factors

  • See Also
  1. Cerebrovascular Accident
  2. Cerebrovascular Accident Risk in Women
  3. Prevention of Ischemic Stroke
  • Epidemiology
  1. Modifiable risk factors are responsible for 87% of stroke risk (e.g. Obesity, diabetes, Hypertension, Hyperlipidemia)
  2. Behavioral factors are responsible for 47% of modifiable factors (e.g. smoking, sedentary, unhealthy diet)
  • Risk Factors
  1. Hypertension (increased systolic Blood Pressure)
    1. Hypertension Management (with Diuretic or ACE Inhibitor) significantly lowers the risk of CVA
    2. (2001) Lancet 358(9287):1033-41 [PubMed]
  2. African American or Hispanic Race
  3. Hypothyroidism
  4. Obesity
  5. Sedentary lifestyle
  6. Family History of CVA or Hyperlipidemia
  7. Age over 65 years
  8. Diabetes Mellitus
  9. Coronary Artery Disease (esp. Myocardial Infarction in last month)
  10. Increased Apolipoprotein-a
  11. Congestive Heart Failure with ejection fraction <30%
  12. Atrial Fibrillation or Atrial Flutter
  13. Bioprosthetic or mechanical Heart Valve Replacement
  14. Patent Foramen Ovale
  15. Hypercoagulable state
  16. Fibromuscular dysplasia
  17. Polycythemia Vera
  18. Thrombocytosis
  19. Arteritis or Vasculitis
  20. Obstructive Sleep Apnea
    1. Consider Sleep Study in cryptogenic stroke if suspected Sleep Apnea
  21. Migraine Headache with aura
    1. Especially in women over age 35, Tobacco Abuse or Oral Contraceptive use
  22. Cigarette smoking (Tobacco Abuse)
    1. Particularly if Oral Contraceptive use age >35 years
  23. Aortic Arch Plaque
    1. Evaluated by TEE Echocardiogram
    2. Measured aortic arch wall thickness
    3. Risk increased 4 fold with thickness >3 mm
      1. Any vascular event
      2. Recurrent Ischemic CVA
    4. Reference
      1. (1996) N Engl J Med, 334:1216-21 [PubMed]
  24. Hypercholesterolemia or Hypertriglyceridemia
    1. Meta-analysis on Cholesterol and Stroke: No effect
      1. Eleven trials, total N=36,000
      2. Cholesterol reduction: 6 to 23%
      3. No significant reduction in fatal or non-fatal CVA
      4. No decrease CVA for selected high risk CAD patients
    2. Reference
      1. Hebert (1995) Arch Intern Med 155:50-5 [PubMed]
  • Prevention
  • Protective factors
  1. Lower CVA risk with moderate Alcohol use
    1. Reynolds (2003) JAMA 289:579-88 [PubMed]
  • Causes
  1. Vessel wall embolus (most common)
    1. Carotid Artery most often the source
    2. Related to thrombus formation distal to stenosis
  2. Cardiac source (Hemispheric attack >60 minutes)
    1. Atrial Fibrillation
      1. Underlying cause of 1 in 7 strokes
      2. For those with crypogenic CVA, consider insertable cardiac monitor (or non-invasive monitor)
      3. Paroxymsal Atrial Fibrillation episodes >2.5 minutes may be significant CVA risk
    2. Mitral valve stenosis
    3. Mitral Valve Prolapse
    4. Calcified mitral annulus
    5. Ventricular aneurysm or Dyskinesia
    6. Atrial or ventricular clot
    7. Valvular vegetation or Bacterial Endocarditis
    8. Atrial Septal Defect or Patent Foramen Ovale
  3. Other vascular sources
    1. Intracranial artery thrombus (esp. African-Americans)
    2. Aortic arch atherosclerotic Plaque
    3. Transient Hypotension with Carotid Stenosis >75%
    4. Arteritis or Vasculitis
  4. Less common etiologies (age <45 years)
    1. Subclavian Steal Syndrome
    2. Hyperviscosity Syndrome (e.g. Polycythemia Vera, Leukemia, Multiple Myeloma)
    3. Hypercoagulable State
    4. Carotid dissection
    5. Vertebral Artery Dissection
    6. Aortic Dissection
    7. Moyamoya Disease
  • References
  1. Choi (2022) Am Fam Physician 105(6): 616-24 [PubMed]
  2. Sacco (2001) Neurology 57:S31-4 [PubMed]