title: Subacute combined degeneration of the spinal cord in a patient abusing nitrous oxide and self-medicating with cyanocobalamin.
abstract: OBJECTIVE
  A case of subacute combined degeneration (SCD) of the spinal cord manifesting as severe ataxia and urinary retention in a patient with a history of heavy nitrous oxide abuse and self-supplementation with cyanocobalamin is reported.
  
  
  CONCLUSIONS
  A 27-year-old woman was treated in the emergency department for complaints of abdominal pain and inability to urinate for about 12 hours. The patient also complained of worsening lower-extremity weakness for 10 days and a "pins and needles" sensation in the lower extremities for approximately 1 year. She reported nitrous oxide abuse over 3 years (an average of 100-200 "whippit" cartridges daily on 3 or 4 days per week), as well as long-term self-medication with oral and i.m. cyanocobalamin for the purpose of preventing nitrous oxide-induced neurologic symptoms. Results of magnetic resonance imaging (MRI) were highly suggestive of SCD, which is typically seen in primary vitamin B12 deficiency but has been reported in the context of chronic nitrous oxide exposure. Treatment was initiated with cyanocobalamin 1000 μg i.m. daily, to be continued for 5 days and followed by a four-week regimen of 1000 μg i.m. weekly. The patient was discharged after 3 days, despite continued symptoms, with instructions to obtain ongoing care but was lost to follow-up.
  
  
  CONCLUSIONS
  A patient who abused nitrous oxide chronically developed ataxia, paresthesia, and urinary retention while self-medicating with cyanocobalamin. A diagnosis of SCD was supported by MRI findings, symptoms, and the known relationship between nitrous oxide exposure and vitamin B12 deficiency.
authors.affiliation: Robert S. Pugliese, Pharm.D., BCPS, is Clinical Pharmacy Specialist, Emergency Medicine, Thomas Jefferson University Hospital, and Clinical Assistant Professor, School of Pharmacy, Thomas Jefferson University, Philadelphia, PA. Evan J. Slagle, Pharm.D., is Postgraduate Year 1 Pharmacy Practice Resident, Department of Pharmacy, Saint Joseph Medical Center, Reading, PA. Glenn R. Oettinger, Pharm.D., BCPS, is Clinical Pharmacy Specialist, Emergency Medicine, Thomas Jefferson University Hospital, and Clinical Assistant Professor, School of Pharmacy, Thomas Jefferson University. Kenneth J. Neuburger, M.D., is Clinical Assistant Professor of Emergency Medicine, Department of Emergency Medicine, Thomas Jefferson University. Timothy M. Ambrose, M.D., is Epilepsy Fellow, Department of Neurology, Thomas Jefferson University Hospital. robert.pugliese@jefferson.edu.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Pugliese
authors.affiliation: Robert S. Pugliese, Pharm.D., BCPS, is Clinical Pharmacy Specialist, Emergency Medicine, Thomas Jefferson University Hospital, and Clinical Assistant Professor, School of Pharmacy, Thomas Jefferson University, Philadelphia, PA. Evan J. Slagle, Pharm.D., is Postgraduate Year 1 Pharmacy Practice Resident, Department of Pharmacy, Saint Joseph Medical Center, Reading, PA. Glenn R. Oettinger, Pharm.D., BCPS, is Clinical Pharmacy Specialist, Emergency Medicine, Thomas Jefferson University Hospital, and Clinical Assistant Professor, School of Pharmacy, Thomas Jefferson University. Kenneth J. Neuburger, M.D., is Clinical Assistant Professor of Emergency Medicine, Department of Emergency Medicine, Thomas Jefferson University. Timothy M. Ambrose, M.D., is Epilepsy Fellow, Department of Neurology, Thomas Jefferson University Hospital.
authors.forename: Evan J
authors.initials: EJ
authors.lastname: Slagle
authors.affiliation: Robert S. Pugliese, Pharm.D., BCPS, is Clinical Pharmacy Specialist, Emergency Medicine, Thomas Jefferson University Hospital, and Clinical Assistant Professor, School of Pharmacy, Thomas Jefferson University, Philadelphia, PA. Evan J. Slagle, Pharm.D., is Postgraduate Year 1 Pharmacy Practice Resident, Department of Pharmacy, Saint Joseph Medical Center, Reading, PA. Glenn R. Oettinger, Pharm.D., BCPS, is Clinical Pharmacy Specialist, Emergency Medicine, Thomas Jefferson University Hospital, and Clinical Assistant Professor, School of Pharmacy, Thomas Jefferson University. Kenneth J. Neuburger, M.D., is Clinical Assistant Professor of Emergency Medicine, Department of Emergency Medicine, Thomas Jefferson University. Timothy M. Ambrose, M.D., is Epilepsy Fellow, Department of Neurology, Thomas Jefferson University Hospital.
authors.forename: Glenn R
authors.initials: GR
authors.lastname: Oettinger
authors.affiliation: Robert S. Pugliese, Pharm.D., BCPS, is Clinical Pharmacy Specialist, Emergency Medicine, Thomas Jefferson University Hospital, and Clinical Assistant Professor, School of Pharmacy, Thomas Jefferson University, Philadelphia, PA. Evan J. Slagle, Pharm.D., is Postgraduate Year 1 Pharmacy Practice Resident, Department of Pharmacy, Saint Joseph Medical Center, Reading, PA. Glenn R. Oettinger, Pharm.D., BCPS, is Clinical Pharmacy Specialist, Emergency Medicine, Thomas Jefferson University Hospital, and Clinical Assistant Professor, School of Pharmacy, Thomas Jefferson University. Kenneth J. Neuburger, M.D., is Clinical Assistant Professor of Emergency Medicine, Department of Emergency Medicine, Thomas Jefferson University. Timothy M. Ambrose, M.D., is Epilepsy Fellow, Department of Neurology, Thomas Jefferson University Hospital.
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Neuburger
authors.affiliation: Robert S. Pugliese, Pharm.D., BCPS, is Clinical Pharmacy Specialist, Emergency Medicine, Thomas Jefferson University Hospital, and Clinical Assistant Professor, School of Pharmacy, Thomas Jefferson University, Philadelphia, PA. Evan J. Slagle, Pharm.D., is Postgraduate Year 1 Pharmacy Practice Resident, Department of Pharmacy, Saint Joseph Medical Center, Reading, PA. Glenn R. Oettinger, Pharm.D., BCPS, is Clinical Pharmacy Specialist, Emergency Medicine, Thomas Jefferson University Hospital, and Clinical Assistant Professor, School of Pharmacy, Thomas Jefferson University. Kenneth J. Neuburger, M.D., is Clinical Assistant Professor of Emergency Medicine, Department of Emergency Medicine, Thomas Jefferson University. Timothy M. Ambrose, M.D., is Epilepsy Fellow, Department of Neurology, Thomas Jefferson University Hospital.
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Ambrose
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D009609:Nitrous Oxide / Q000633:toxicity*; D012651:Self Medication; D013118:Spinal Cord Diseases / Q000139:chemically induced*; D052879:Subacute Combined Degeneration / Q000139:chemically induced*; D019966:Substance-Related Disorders / Q000150:complications; D014805:Vitamin B 12 / Q000008:administration & dosage* / Q000627:therapeutic use; D014806:Vitamin B 12 Deficiency / Q000139:chemically induced* / Q000188:drug therapy*
chemical_list: D009609:Nitrous Oxide; D014805:Vitamin B 12