{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,15]],"date-time":"2026-05-15T06:11:56Z","timestamp":1778825516189,"version":"3.51.4"},"reference-count":21,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,5,15]],"date-time":"2026-05-15T00:00:00Z","timestamp":1778803200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Psychiatry"],"abstract":"<jats:p>Nitrous oxide is a dissociative hallucinogen that is increasingly used recreationally, in part due to its widespread availability. Its use is known to cause subacute combined degeneration via inactivation of vitamin B12; it may also result in acute delirium and chronic progressive encephalopathy. Though current practice guidelines call for treatment of neurological sequelae of nitrous oxide use with vitamin B12 supplementation, a paucity of long-term outcome data limits our ability to guide extended courses of treatment. In this report, we discuss a case of protracted encephalopathy associated with nitrous oxide use. We track the response to vitamin B12 supplementation in the hospital setting using the Mini-Mental Status Exam to assess the severity and improvement of cognitive impairment. We also review the patient\u2019s comorbid medical and psychiatric conditions, which complicate diagnosis and treatment planning in this patient population.<\/jats:p>","DOI":"10.3389\/fpsyt.2026.1797631","type":"journal-article","created":{"date-parts":[[2026,5,15]],"date-time":"2026-05-15T05:41:33Z","timestamp":1778823693000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Protracted encephalopathy and subacute combined degeneration associated with chronic nitrous oxide use: a case report"],"prefix":"10.3389","volume":"17","author":[{"given":"Kaevon","family":"Brasfield","sequence":"first","affiliation":[{"name":"Department of Psychiatry, Mission Community Hospital","place":["Panorama City, CA, United States"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Eugene","family":"Pahk","sequence":"additional","affiliation":[{"name":"Department of Psychiatry, Mission Community Hospital","place":["Panorama City, CA, United States"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Conrado","family":"Sevilla","sequence":"additional","affiliation":[{"name":"Department of Psychiatry, Mission Community Hospital","place":["Panorama City, CA, United States"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2026,5,15]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"1639","DOI":"10.1186\/s12889-024-19142-0","article-title":"Burden of drug use disorders in the United States from 1990 to 2021 and its projection until 2035: Results from the GBD study","volume":"24","author":"Zhang","year":"2024","journal-title":"BMC Public Health"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.31234\/osf.io\/xb8ve","article-title":"Global drug survey (GDS) 2021 key findings report","author":"Winstock","year":"2021"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1016\/j.yrtph.2015.10.017","article-title":"Recreational nitrous oxide use: Prevalence and risks","volume":"73","author":"van Amsterdam","year":"2015","journal-title":"Regul Toxicol Pharm"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.3389\/fneur.2023.1132542","article-title":"Nitrous oxide-induced neurotoxicity: Clinical characteristics and impacts on overall neurological impairments","volume":"14","author":"Gao","year":"2023","journal-title":"Front Neurol"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.1007\/s12640-021-00352-y","article-title":"Recreational nitrous oxide abuse: Prevalence, neurotoxicity, and treatment","volume":"39","author":"Xiang","year":"2021","journal-title":"Neurotoxic Res"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.3390\/toxics11120962","article-title":"Nitrous oxide abuse: Clinical outcomes, pharmacology, pharmacokinetics, toxicity and impact on metabolism","volume":"11","author":"Gernez","year":"2023","journal-title":"Toxics"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.1080\/15563650.2021.1938107","article-title":"Does vitamin B12 deficiency explain psychiatric symptoms in recreational nitrous oxide users? 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