title: Nitrous oxide "whippit" abuse presenting with cobalamin responsive psychosis.
abstract: BACKGROUND
  Nitrous oxide is a commonly abused inhalant drug. It is known to precipitate vitamin B12 deficiency when used chronically and acutely, especially in people having marginal vitamin B12 reserve.
  
  
  METHODS
  We are presenting a case of nitrous oxide "whippit" abuse in a thirty-three-year-old male with bizarre behavior and delusions. The patient had low normal levels of vitamin B12 (202 pg/ml), but he had markedly high methylmalonyl CoA (1078 nmol/L) and homocysteine (48.4 mcmol/L). Treatment with intramuscular cobalamin led to a resolution of his psychosis.
  
  
  CONCLUSIONS
  This case report highlights the need to consider vitamin B12 deficiency in patients who arrive at a hospital with psychiatric manifestations and who report having a history of nitrous oxide exposure or abuse in the recent or remote past. A review of the literature on the neuropsychological manifestations of vitamin B12 deficiency is provided.
authors: Department of Neurology, Saint Vincent's Hospital and Medical Centers, New York, NY 10011, USA. sethinitinmd@hotmail.com
authors: Nitin K
authors: NK
authors: Sethi
authors: Paul
authors: P
authors: Mullin
authors: Josh
authors: J
authors: Torgovnick
authors: Giuseppe
authors: G
authors: Capasso
mesh_terms: D000328:Adult; D006213:Hallucinogens / Q000506:poisoning*; D006801:Humans; D008297:Male; D020258:Neurotoxicity Syndromes / Q000209:etiology*; D009609:Nitrous Oxide / Q000506:poisoning*; D011605:Psychoses, Substance-Induced / Q000188:drug therapy / Q000209:etiology*; D016896:Treatment Outcome; D014805:Vitamin B 12 / Q000627:therapeutic use*; D014806:Vitamin B 12 Deficiency / Q000139:chemically induced / Q000150:complications* / Q000188:drug therapy; D014803:Vitamin B Complex / Q000627:therapeutic use*
chemical_list: D006213:Hallucinogens; D014803:Vitamin B Complex; D009609:Nitrous Oxide; D014805:Vitamin B 12