A 76-year-old woman presents to the clinic with difficulty walking. She describes having a high-stepping and stamping gait that has progressively

A 76-year-old woman presents to the clinic with difficulty walking. She describes having a high-stepping and stamping gait that has progressively worsened over the past year. She also reports frequent falls and a feeling of unsteadiness when standing with her eyes closed. Her history is significant for type 2 diabetes mellitus well controlled on metformin. Physical examination reveals diminished vibratory sense in her lower extremities and absent ankle reflexes. The rest of the examination is unremarkable. Which of the following is the most likely diagnosis? Cerebellar ataxia Proprioceptive sensitivity loss Spasticity Vestibular dysfunction