• Epidemiology
  1. Age over 55 years
  2. More common in men than women by ratio of 2 to 1
  • Risk Factors
  1. Vigorous Exercise of affected extremity
  2. Similar to Cardiac Risk Factor
    1. Hypertension
    2. Diabetes Mellitus
    3. Hyperlipidemia
    4. Tobacco use
  • Pathophysiology
  1. Proximal subclavian artery Occlusion
  2. Vertebral Artery supplies retrograde flow
  3. Results in decreased Blood Flow to posterior brain
  • Causes
  1. Arteriosclerosis of subclavian artery (95% of cases)
  2. Dissecting Aortic Aneurysm
  3. Embolism
  4. Takayasu's Arteritis
  • Symptoms
  1. Vertebrobasilar Insufficiency
    1. Light-headedness or Dizziness
    2. Ataxia or Vertigo
    3. Visual disturbance
    4. Motor deficit
    5. Confusion
    6. Focal Seizure
    7. Aphasia
    8. Headache
    9. Syncope
  2. Subclavian Insufficiency (onset after CNS symptoms)
    1. Arm weakness
    2. Arm coldness or Paresthesias
    3. Arm Claudication with Exercise
  3. Provocative Maneuvers
    1. Vigorous Exercise of affected arm
    2. Sudden turning of head to affected side
  • Signs
  1. Diminished radial and ulnar pulses on affected side
  2. Blood Pressure difference >20 mmHg between arms
  3. Subclavian bruit
  4. Radial pulse disappears on arm Exercise or elevation
  • Radiology
  1. Carotid Ultrasound
  2. Magnetic resonance angiography
  3. Arch Aortography
  • Management
  • Surgical Options
  1. Axillo-axillary bypass
  2. Carotid-Subclavian bypass
  3. Percutaneous transluminal Angioplasty with stenting
  • Prevention
  1. See Hypertension Management
  2. See Diabetes Mellitus Management
  3. Tobacco Cessation
  • References
  1. Chan-Tack (2001) South Med J 94:445-7