Subacute Combined Degeneration of the Spinal Cord Caused by Autoimmune Gastritis.

A 68-year-old woman presented with a 2-year history of worsening unsteady gait. Her neurological examination revealed peripheral neuropathy with lower limb sensory dominance. T2-weighted imaging revealed a disorder of the posterior cervical cord. Blood test findings revealed vitamin B deficiency, and gastroscopy revealed typical findings of autoimmune gastritis. She received vitamin B supplementation, but some peripheral neuropathy symptoms persisted due to longstanding vitamin B deficiency. Asymptomatic patients should undergo gastroscopy to detect autoimmune gastritis, as chronic vitamin B deficiency causes irreversible peripheral neuropathy.