Patient 1: A 56-year-old man who developed gait instability and falls over the last 3 years. Neurological examination was notable for ataxic gait. Patient 2: A 45-year-old-men marathon runner presented with a 6-month history of inability to run and lack of hand coordination. Clinical findings revealed subtle dysmetria to finger-to-nose test and inability to perform tandem walk. Patient 3: A 75-year-old-woman presented with a constant vertigo, gait ataxia, and tendency to fall over the last 10 years. Her examination revealed multidirectional nystagmus, dysarthria, dysmetria on finger-to-nose, and ataxic gait. All patients ambulated with walkers during their initial evaluations. None of the patients had significant past medical history of autoimmune diseases or a family history of cerebellar ataxia. Paraneoplastic antibodies and malignancy workup were negative. Brain MRIs were normal in Patient 1 and 2. Patient 3’s MRI revealed cerebellar atrophy and abnormal signal involving the left hippocampus, amygdala, and anterior temporal cortex. All patients had markedly elevated anti-GAD antibody titers (2,610-25,000 nmol/L). Patient 1 and 3 received intravenous immunoglobulin and had excellent responses and were able to ambulate without walkers after 6 treatment cycles.