Pharm

Nitrous Induced Subacute Combined Degeneration of the Spinal Cord

search

Nitrous Induced Subacute Combined Degeneration of the Spinal Cord

  • See Also
  1. Nitrous Oxide Abuse
  2. Nitrous Oxide
  3. Vitamin B12 Deficiency
  • 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
  1. See Symmetric Peripheral Neuropathy
  • Labs
  1. Macrocytic Anemia
  2. Decreased Serum Vitamin B12
  • Management
  1. Vitamin B12 Replacement with 1000 mcg orally daily
  • References
  1. (2016) EM:Rap 16(12): 1
  2. Lin (2011) Acta Neurol Taiwan 20(2): 129-37 +PMID: 21739392 [PubMed]
  3. Pema (1998) Am J Neuroradiol 19:894-6 [PubMed]