Clinical, Electrophysiological and Radiological Features of Nitrous Oxide-Induced Neurological Disorders

We summarized the clinical manifestations, laboratory and electrodiagnostic characteristics and magnetic resonance imaging (MRI) findings of nitrous oxide (N₂O) abuse-induced neurological disorders.

We retrospectively reviewed 33 patients with N₂O abuse-induced neurological disorders and reported their demographic data, clinical manifestations, laboratory examinations, nerve conduction studies, together with spinal and brain MRI.

The most frequent clinical manifestations included numbness and weakness in the extremities and unspecified gait disturbance. Low serum vitamin B₁₂ levels were found in 9 patients, and high homocysteine levels were noted in 27 patients. Nerve conduction studies showed a sensory-motor neuropathy. Sixteen patients showed bilateral high-intensity T2 signal within the posterior column on spinal MRI, and four patients showed cerebral white matter lesions on brain MRI.

N₂O abuse has become a significant public health problem because of the severe neurological disorders related to chronic abuse. Clinical physicians should be aware of the toxic effects of N₂O.