[A case presenting with ataxic gait and dementia due to vitamin B₁₂ deficiency without megaloblastic anemia or subacute combined degeneration of the spinal cord].

A 36-year-old man was admitted to our hospital because of subacute progressive ataxic gait and dementia. His blood test results vitamin B₁₂ deficiency due to presence of anti-intrinsic factor antibody and his endoscopic examination findings showed chronic gastritis. Treatment was administered on the bass of on a diagnosis of vitamin B₁₂ deficiency.