LAUSR

An 85-year-old man with alcoholism developed lasting gait disturbance that deteriorated over 6 months, until he was unable to stand even with help. Distal proprioception and vibratory sensation were absent. T2-weighted magnetic resonance imaging (MRI) revealed hyperintensity in the posterior column stretching nearly the entire length of the spinal cord (Picture A-C) with an inverted V-sign (Picture D-E). Blood tests revealed macrocytic hypochromic anemia and undetectable serum vitamin B12, and serum anti-aquaporin 4 antibody was negative, while the serum copper level was normal. He was diagnosed with subacute combined degeneration (SCD). Vitamin B12 therapy improved the symptoms partially until he was able to stand while being supported and diminished the MRI lesions, although the signal abnormalities persisted. SCD is caused by vitamin B12 deficiency, affecting the posterior and lateral