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

Background: Nitrous oxide (NO) is a commonly used inhaled anesthetic in outpatient dental procedures. However, the increasing recreational use of NO may result in vitamin B deficiency-related neurologic and psychiatric symptoms. The aim of this study was to demonstrate the clinical features of chronic NO abuse in pediatric patients.

Methods: Patients under 20 years of age who were diagnosed with NO-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 B (cyanocobalamin) levels. Eight patients had evidence of subacute combined degeneration of the spinal cord via neuroimaging studies. All of the patients received vitamin B supplementation as treatment. All had full recovery of muscle power within 2 months. Five patients had persistent sensory deficits.

Conclusion: Chronic NO abuse can cause permanent neurological damage if not treated promptly. Clinical staff should be aware of the various presentations of neurotoxicity related to NO abuse.