Recreational nitrous oxide-associated neurotoxicity

A previously healthy 21-year-old woman presented with subacute onset of confusion and gait ataxia. She reported habitual inhalation of nitrous oxide (N₂O) purchased online over the past year, with increased consumption over the preceding weeks of up to 300 canisters/week. Examination revealed pale skin with diffuse hyperpigmented macular patches over the trunk (figure 1) and atrophic glossitis. Cognitive impairment was evident with impaired insight, orientation, short-term memory and attention. She had impaired limb proprioception with sensory ataxia and positive Romberg's test. Distal limb power was significantly reduced with milder weakness proximally and globally depressed reflexes.

Laboratory testing demonstrated low vitamin B₁₂ (44 pmol/L; normal 150–700) and holotranscobalamin levels (18 pmol/L; normal 50–165). She was also pancytopaenic with haemoglobin of 74 g/L (normal 115–165), white cell count of 2.81x10⁹/L (normal 4–11) and platelet count of 99x10⁹/L (normal 150–400). Pernicious anaemia screen was negative, and the cerebrospinal fluid was acellular with normal protein and absent oligoclonal bands. MRI...

from #ORL-AlexandrosSfakianakis via ola Kala on Inoreader http://ift.tt/2n4EMDG