Nitrous oxide-related neurological disorders: Clinical, laboratory, neuroimaging, and electrophysiological findings.

The significant inverse correlation between initial vitamin B12 levels and clinical severity could aid prognosis prediction in patients with N2 O-related neurological disorders. Spinal MRI abnormalities were not related to clinical severity but depended on the time interval between initial N2 O abuse and hospitalization. Anxiety and depression were common comorbidity in these patients, and their severity increased with the intensity of clinical impairment and/or serum homocysteine levels.