What is the best treatment for spinocerebellar ataxia ? do we have some medicine available to slow or stop it's progress?

Only for symptoms: These are group of genetic disorders and there is no cure and no medicine to stop the progression of these diseases.You can be prescribed meds for system control like tremors, depression, stiffness, and spasticity etc.Rehabilitatipn therapies can be used , to improve some functioning ability.

No cure, but: Many of the conditions can be analyzed via genetic profiles, and this may help future family planning. Treatment may help, and some meds, especially Buspirone can control some of the ataxia, but this is tough. Have found weighted bracelets over wrists and ankles benefit many. Also, contact nat institutes of health, as research studies may be available.