Magnetic resonance imaging in a patient with nitrous oxide-induced subacute combined degeneration of the spinal cord

Chronic nitrous oxide use can lead to neurological findings that are clinically and radiographically identical to those found in patients with pernicious anemia, specifically subacute combined degeneration of the spinal cord and peripheral neuropathy.A 22-year-old man presented with lower extremity weakness and ataxia in the setting of inhaling 250 nitrous oxide cartridges two to three times weekly for two years.Magnetic resonance imaging showed T2 hyperenhancement of the dorsal columns of the cervical spine from the first to the sixth vertebrae, which helped to establish a diagnosis of nitrous oxide-induced subacute combined degeneration of the spinal cord.Chronic nitrous oxide use should be included in the differential diagnosis of any patient with otherwise unexplained neurological complaints that localize to the dorsal columns and has the changes on magnetic resonance imaging described here.