Question: What is “nanging” and what clinical symptoms may result from repeated nanging?
Answer: “Nanging” is the practice of repeated inhalation of nitrous oxide. According to the cited reference, “Nitrous oxide causes irreversible oxidation of the cobalt atom of vitamin B12 rendering the vitamin inactive. Vitamin B 12 is essential for the formation of methionine by methylation of homocysteine. In turn, methionine is converted to S-adenosyl-methionine (SAM) which is required for all methylation reactions including those of myelin phospholipids. Vitamin B12 deficiency can produce spinal cord disease particularly affecting the dorsal columns causing subaute combined degeneration. Clinical symptoms result from myopathy, peripheral axonal neuropathy or both, with combinations of paresthesias, gait ataxia, sphincter disturbances and pyramidal weakness. Impaired cognition and altered mentation may occur. (Ng J and Frith R. Nanging. 2002 Lancet 360:384)