Subacute Combined Degeneration Due to Inhalant Use: Not a Laughing Matter.

Nitrous oxide, known as "laughing gas," is a substance that can be used to induce analgesia and euphoria. It is easily accessible in certain household products, such as aerosol canisters used for food products. However, chronic use of nitrous oxide can inhibit cobalamin (vitamin B12), causing severe deficiencies that result in psychiatric, hematologic, and neurological toxicities, including subacute combined degeneration of the spinal cord. We present a case of a young adult male who developed progressive, ascending bilateral paresthesias and gait disturbances, ultimately attributed to nitrous oxide use. This case highlights the neurotoxic effects and symptoms associated with recreational nitrous oxide use, as well as the patient's treatment and subsequent clinical recovery.