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Nitrous Induced Subacute Combined Degeneration of the Spinal Cord

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Nitrous Induced Subacute Combined Degeneration of the Spinal Cord

  • Pathophysiology
  1. Nitrous Oxide inhalation interferes with Vitamin B12 Metabolism
  2. Longterm abuse results in Vitamin B12 Deficiency
    1. Long segmental changes involving the Posterior Columns
  • Signs
  1. Progressive ascending Polyneuropathy (especially sensory)
  2. Distal extremity Paresthesias (starting with legs, ultimately involving arms)
  3. Lower extremity weakness or Incoordination (ultimately involving arms)
  4. Ataxia
  5. Lower extremity Deep Tendon Reflexes diminished or lost
    1. Positive Babinski Reflex
  • Differential Diagnosis
  • Labs
  1. Macrocytic Anemia
  2. Decreased Serum Vitamin B12
  • Management
  1. Vitamin B12 Replacement with 1000 mcg orally daily