What Is The Prognosis For 'olivioponto Cerebellar Atrophy'?

Are you able to give full prognosis of someone disgnosed with olivioponto cerebellar atrophy. Aware of the ataixia, speech difficulties and and deterioration of motor functions but wondering if a sufferer would also suffer from dementia. Just looking at ways we can prepare and be able to support after the recent diagnosis of a family member.