Whip It Good: A Case of Vitamin B12 Deficiency and Subacute Combined Degeneration of the Spinal Cord.

A 40-year-old male patient with no significant past history presented to the emergency room with bilateral upper and lower extremity numbness and difficulty walking for three weeks. MRI of the thoracic spine revealed cord signal abnormalities in the dorsal columns consistent with selective degeneration. This was congruent with the patient's presentation and symptoms of myelopathy with dorsal column involvement along with peripheral polyneuropathy. Nitrous oxide inhalation was the culprit, causing acute vitamin B12 deficiency and subsequent myeloneuropathies.