medication for cerebellar ataxiainherited cerebellar ataxiaparaneoplastic cerebellar ataxiacerebellar ataxia curecerebral ataxia prognosisspinal cellular ataxiahereditary cerebellar atrophyprogressive cerebellar atrophyidiopathic cerebellar degenerationcerebellar degeneration syndromehereditary cerebellar degenerationcerebral ataxia treatment