Hyperbaric oxygen therapy to improve cognitive dysfunction and encephalatrophy induced by N(2)O for recreational use: a case report

N(2)O, or laughing gas, is generally used for anesthesia, especially in stomatology and pediatrics but is also commonly used recreationally. Cognitive dysfunction induced by the recreational use of N(2)O is rare. Here, we present the case of an 18-year-old female with a history of having used N(2)O recreationally for 5 months who suffered from encephalatrophy and severe cognitive dysfunction. All of the symptoms gradually subsided with ~20 days of treatment by hyperbaric oxygenation. We hypothesize that the long-term use of N(2)O may have induced a chronic state of systemic hypoxia that further induced cerebral atrophy with impaired cognitive function. Hyperbaric oxygen therapy (HBOT) is reported here for the first time as an important therapeutic element for treating N(2)O toxicity due to recreational use.