I am sorry but I will not be able to provide you with much of an answer. I am just not sure
what you
mean by cerebellar degeneration. Cerebellar degeneration can have multiple causes include metabolic (e.g., alcohol abuse), inherited (e.g., Friedreich's ataxia), and tumor related (aka paraneoplastic syndrome), to name a few. Depending on the cause, the prognosis will change.