Purpose: We summarized the clinical manifestations, laboratory and electrodiagnostic characteristics and magnetic resonance imaging (MRI) findings of nitrous oxide (N₂O) abuse-induced neurological disorders.
Patients and Methods: 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.
Results: 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.
Conclusion: 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.
Keywords: nitrous oxide, neurological disorders, subacute combined degeneration, neuropathy, vitamin B₁₂