title: Nitrous oxide anesthesia-associated myelopathy.
abstract: BACKGROUND
  The role of nitrous oxide exposure in neurologic complications of subclinical cobalamin deficiency has been reported, but few cases are well documented.
  
  
  METHODS
  Two weeks after surgery for prosthetic adenoma, a 69-year-old man developed ascending paresthesia of the limbs, severe ataxia of gait, tactile sensory loss on the 4 limbs and trunk, and absent tendon reflexes. After a second surgical intervention, the patient became confused. Four months after onset, the patient had paraplegia, severe weakness of the upper limbs, cutaneous anesthesia sparing the head, and confusion. Moderate macrocytosis, low serum B12 levels, and a positive Schilling test result led to the diagnosis of pernicious anemia. Results of electrophysiologic examinations showed a diffuse demyelinating neuropathy. Magnetic resonance imaging of the spinal cord disclosed hyperintensities of the dorsal columns on T2-weighted images.
  
  
  CONCLUSIONS
  Pernicious anemia can result in severe neurologic symptoms with only mild hematologic changes. The role of nitrous oxide anesthesia in revealing subclinical B12 deficiency must be emphazised. Magnetic resonance imaging of the spinal cord might be helpful in making the diagnosis.
authors.affiliation: Service de Neurologie, Centre Hospitalier Universitaire de Caen, France.
authors.forename: R M
authors.initials: RM
authors.lastname: Marié
authors.forename: E
authors.initials: E
authors.lastname: Le Biez
authors.forename: P
authors.initials: P
authors.lastname: Busson
authors.forename: S
authors.initials: S
authors.lastname: Schaeffer
authors.forename: L
authors.initials: L
authors.lastname: Boiteau
authors.forename: B
authors.initials: B
authors.lastname: Dupuy
authors.forename: F
authors.initials: F
authors.lastname: Viader
mesh_terms: D000236:Adenoma / Q000601:surgery; D000368:Aged; D000752:Anemia, Pernicious / Q000139:chemically induced* / Q000150:complications; D018685:Anesthetics, Inhalation / Q000009:adverse effects*; D003711:Demyelinating Diseases / Q000139:chemically induced* / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009609:Nitrous Oxide / Q000009:adverse effects*; D011471:Prostatic Neoplasms / Q000601:surgery; D013116:Spinal Cord / Q000473:pathology; D014806:Vitamin B 12 Deficiency / Q000150:complications / Q000175:diagnosis
chemical_list: D018685:Anesthetics, Inhalation; D009609:Nitrous Oxide