Recreational nitrous oxide abuse related subacute combined degeneration of the spinal cord in adolescents - A case series and literature review

Abstract

Background: Nitrous oxide (N₂O) is a commonly used inhaled anesthetic in outpatient dental procedures. However, the increasing recreational use of N₂O may result in vitamin B₁₂ deficiency-related neurologic and psychiatric symptoms. The aim of this study was to demonstrate the clinical features of chronic N₂O abuse in pediatric patients.

Methods: Patients under 20 years of age who were diagnosed with N₂O-induced subacute combined degeneration of the spinal cord from 2012 to 2018 were enrolled in this study. Clinical presentations, laboratory, imaging, ancillary studies, treatments and outcomes were analyzed.

Results: Nine patients were included, all of whom presented with symptoms of myeloneuropathy including limb numbness, limb weakness or unsteady gait. Six patients had low or low-normal vitamin B₁₂ (cyanocobalamin) levels. Eight patients had evidence of subacute combined degeneration of the spinal cord via neuroimaging studies. All of the patients received vitamin B₁₂ supplementation as treatment. All had full recovery of muscle power within 2 months. Five patients had persistent sensory deficits.

Conclusion: Chronic N₂O abuse can cause permanent neurological damage if not treated promptly. Clinical staff should be aware of the various presentations of neurotoxicity related to N₂O abuse.

Keywords: Abuse; Nitrous oxide; Spinal cord; Vitamin B(12) deficiency.