Diagnostic Challenges and Key insights of Nitrous Oxide Neuropathy: A Case series

Nitrous oxide (N₂O) is increasingly misused due to its easy availability. Chronic misuse causes irreversible oxidation of cobalamin which results in vitamin B12 deficiency and impaired myelination leading to neurological complications. We present two cases highlighting diagnostic challenges consisting of a 34-year-old male and a 52-year-old, both initially misdiagnosed as chronic inflammatory demyelinating polyneuropathy (CIDP). They were eventually diagnosed as N₂O-induced neuropathy based on lab testing and electrodiagnostic findings. Clinicians should maintain a high suspicion of N₂O misuse in unclear neuropathies. Early recognition with prompt and sustained vitamin B12 supplementation is crucial for preventing irreversible neurological damage and avoiding unnecessary immunotherapy.