A 46-year-old previously healthy man with abdominal pain and diarrhea was hospitalized and found to have an increased white blood count (WBC). He had a sigmoid colon resection with a colostomy under epidural anesthesia; he also received general anesthesia with nitrous oxide.

Following surgery, he complained of weakness in both lower extremities, numbness on both feet, lack of bilateral bladder control, and impaired erections.

A nonvegan man with possible subclinical cobalamin (vitamin B₁₂) deficiency developed lower extremity weakness and numbness, loss of bladder control, and impaired erections after exposure to nitrous oxide anesthesia. He also had received epidural anesthesia. Examination demonstrated predominantly distal lower extremity paresis, patellar hyperreflexia, Achilles areflexia, and sensory changes on L5-S1 distribution. He also had bilateral extensor plantar responses (not shown on the tape). Magnetic resonance imaging (MRI) of the thoracic and lumbosacral spine showed minimal posterior epidural fluid collection at the T12-L1 level, probably representing a resolving discrete epidural hematoma.

Electromyography (EMG) findings were consistent with an acute bilateral lumbosacral radiculopathy involving the L5-S1 nerve roots. Urodynamic studies showed a hypotonic neurogenic bladder with intact sensation. He was found to have low serum vitamin B₁₂. We interpreted his clinical and laboratory findings as strong evidence of a myeloneuropathy due to exposure to nitrous oxide in an individual who had subclinical vitamin B₁₂ deficiency. We felt the small epidural hematoma noted on MRI was not clinically significant.