Catatonia induced by nitrous oxide anesthesia in a healthy adolescent: A case report.

Background: Catatonia can arise from various conditions, not only psychiatric but also non-psychiatric etiologies. This diversity of underlying causes makes it challenging to identify the underlying etiology, which is crucial for appropriate management. Nitrous oxide (N₂O) is widely used for recreational purposes, and its adverse effects have become a growing concern. Chronic exposure can lead to vitamin B12 deficiency, which manifests both neurological and psychiatric symptoms, including catatonia. Vitamin B12 supplementation is an effective treatment, but the diverse clinical manifestations of N₂O toxicity, coupled with the diverse etiologies of catatonia, can delay diagnosis and intervention.

Case presentation: The patient, a healthy man in his 20s, had been receiving N₂O anesthesia regularly for pain relief while undergoing cosmetic hair removal. After his seventh inhalation, he developed a catatonia and was admitted to a previous hospital. After a comprehensive examination failed to identify the etiology, he was transferred to our hospital for psychiatric assessment. Intravenous benzodiazepine failed to improve his catatonia. Re-evaluation of the underlying etiologies of benzodiazepine-refractory catatonia raised the possibility of a vitamin B12 deficiency resulting from chronic N₂O exposure. Vitamin B12 supplementation promptly improved his catatonia, and the patient was discharged without any recurrence of his symptoms.

Conclusion: Catatonia developed in the present patient after multiple exposures to N₂O. Active vitamin B12 may be administered if N₂O is suspected of causing psychotic symptoms. Moreover, reassessing the differential diagnosis is worthwhile when managing refractory catatonia.