Abstract
Autoimmune polyglandular syndrome (APS) causes autoimmune diseases of multiple organs and can also present with neurological symptoms. We here report a 58-year-old man who presented with progressive gait disturbance that had started 7 years ago. He had spasticity, reduced deep sensations, and truncal cerebellar ataxia. Laboratory examinations revealed autoantibody-related cobalamin deficiency and the presence of anti-thyroid antibodies and anti-glutamic acid decarboxylase antibodies. His gait worsened after cobalamin replenishment, but additional steroid therapy was effective. APS can cause refractory gait disturbance that requires not only cobalamin replenishment but also immunotherapy.