A 49-year-old man presented with several months of burning sensation and numbness in the lower extremities. According to his statement of the medical history, there were no excessive drinking, intake of toxic substances, and special illnesses and treatments (including chemotherapy). Examination revealed mild emaciation and decreased tendon reflexes in the legs. Cognitive, motor, and autonomic functions were preserved. A comprehensive laboratory workup (including blood glucose, vitamin, and thyroid hormone levels) and lumbar spine MRI failed to reveal any abnormalities.
