The purpose of this study is to determine whether a person's ability to adapt (i.e. short term motor learning) predicts their ability to benefit from physical therapy exercises.

The cerebellum is important for coordination of movement and for motor learning. No medications systematically improve cerebellar ataxia, and little is known about the effectiveness of rehabilitation exercises, which are often the only treatment option. Here, we ask whether a person's ability to adapt (i.e. short term motor learning) predicts their ability to benefit from physical therapy exercises. This pilot-clinical trial will test a subject's ability to adaptively learn a new walking pattern in a single session, and then any improvement of walking and balance over a 13 week time period during which they participate in a specialized home exercise training program. Our prediction is that those individuals with some preserved adaptive learning ability will be the best rehabilitation candidates.

Inclusion Criteria:

• Cerebellar damage from stroke, tumor, or degeneration
• Able to stand and take steps with or without assistance
• Age 18-95

Exclusion Criteria:

• Extrapyramidal symptoms
• Peripheral vestibular loss (e.g. absence of VOR)
• Congestive heart failure
• Peripheral artery disease with claudication
• Pulmonary or Renal Failure
• Unstable angina
• Uncontrolled hypertension ( > 190/100 mmHg)
• Dementia (Mini-Mental State exam > 22)
• Severe aphasia
• Orthopedic or pain conditions
• Pregnancy
• Prisoner
• Evidence of chronic white matter disease on MRI