**3.5 Idiopathic degenerative ataxia**

As well as being referred to as sporadic adult-onset ataxia (SAOA) of unknown etiology or even idiopathic sporadic cerebellar ataxia, MSA-C and idiopathic lateonset cerebellar ataxia are two examples of the diseases with unknown etiology that fall within the category of idiopathic cerebellar degeneration [26, 27, 29, 30, 37, 38].
