-Case Reports-

A Case of Fever, Impaired Consciousness, and Psychosis Caused by Nitrous Oxide Abuse and Misdiagnosed as Acute Meningitis

Naoto Matsuda, Hiroaki Wakakuri, Kazuyuki Uehara, Hideya Hyodo, Toshihiko Ohara and Masahiro Yasutake

Department of General Medicine and Health Science, Nippon Medical School, Tokyo, Japan

Nitrous oxide (N₂O) is readily available, and its abuse for recreational purposes has become a social problem. In Japan, where N₂O is strictly prohibited for non-medical use, abuse is often overlooked due to a lack of experience in the field. N₂O abuse causes various long-term symptoms, including vitamin B₁₂ deficiency, myelopathy, myeloneuropathy, subacute combined degeneration, mood changes, and psychosis. The diagnosis of N₂O abuse is difficult due to the compound's short half-life and rapid elimination through the lungs. This report describes a case of fever and impaired consciousness in a patient with a history of N₂O abuse.

J Nippon Med Sch 2023; 90: 404-407

Keywords
substance use disorder, N₂O, impaired consciousness

Correspondence to
Naoto Matsuda, Department of General Medicine and Health Science, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8602, Japan
naoto-matsuda@nms.ac.jp

Received, January 24, 2022
Accepted, July 8, 2022