Reversible nitrous oxide myelopathy and a polymorphism in the gene encoding 5,10-methylenetetrahydrofolate reductase

• Published in: British journal of anaesthesia : BJA Vol. 96; no. 2; pp. 222 - 225
• Main Authors: Lacassie, H.J., Nazar, C, Yonish, B, Sandoval, P, Muir, H.A., Mellado, P
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-02-2006; Oxford University Press; Oxford Publishing Limited (England)
• Subjects: 10-methylenetetrahydrofolate reductase; anaesthesia; anaesthesia, inhalation; anaesthetics gases; anaesthetics gases, nitrous oxide; Anesthesia; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Anesthetics, Inhalation - adverse effects; Biological and medical sciences; complications; complications, myelopathy; enzymes; enzymes, 5,10-methylenetetrahydrofolate reductase; folic acid; Folic Acid - therapeutic use; gene; gene, MTHFR; Genetic Predisposition to Disease; Humans; Hyperhomocysteinemia - complications; inhalation; Male; Medical sciences; Methylenetetrahydrofolate Reductase (NADPH2) - genetics; Middle Aged; MTHFR; myelopathy; nitrous oxide; Nitrous Oxide - adverse effects; Paralysis - chemically induced; Polymorphism, Genetic; Postoperative Complications; Spinal Cord Diseases - chemically induced; Spinal Cord Diseases - drug therapy; Spinal Cord Diseases - genetics; Vitamin B 12 - therapeutic use; vitamins; vitamins, folic acid; anaesthesia, inhalation; gene, MTHFR; complications, myelopathy; vitamins, folic acid; anaesthetics gases, nitrous oxide; enzymes, 5,10-methylenetetrahydrofolate reductase; nitrous oxide; complications; Motor system disorder; Vitamin; inhalation; anaesthetics gases; Lower extremity; Folic acid; Paraplegia; Anesthesia; Complication; Neurological disorder; Human; Nervous system diseases; Urinary system disease; Enzyme; 5,10-methylenetetrahydrofolate reductase; gene; Urinary tract disease; Upper extremity; Cyanocobalamin; Inhalation; MTHFR; vitamins; Paresis; Neurogenic bladder; myelopathy; enzymes; Bladder disease; Oxidoreductases; Polymorphism; Reductase; anaesthesia
• ISSN: 0007-0912; 1471-6771
• DOI: 10.1093/bja/aei300

We present a case of a patient who received nitrous oxide on two occasions within a period of 8 weeks and who subsequently developed a diffuse myelopathy, characterized by upper extremity paresis, lower extremity paraplegia and neurogenic bladder. Laboratory testing revealed hyperhomocysteinaemia and low levels of vitamin B12. Because of this uncommon clinical presentation, we analysed the patient's DNA, and found a polymorphism in the MTHFR gene that is associated with the thermolabile isoform of the 5,10-methylenetetrahydrofolate reductase enzyme, which explained the myelopathy experienced by the patient after being exposed to nitrous oxide. Soon after initiating supplementary therapy with folic acid and vitamin B12, the neurological symptoms subsided.