Phonoarticulation is characterized by changes in resonance, diadochokinesis, prosody, sound frequency, vocal quality, and intraoral pressure. The main aim of this study was to characterize the phonoarticulation in spinocerebellar ataxia type 3 (SCA3) and correlate it with clinical and genetic factors. Thirty-one patients with SCA3 who were subjected to spontaneous speech recordings and phonoarticulatory diadochokinesis (DDK) participated in the study. Speech analyses were performed starting after 10 s of spontaneous speech, by three experienced speech therapists, using a protocol for dysarthria adapted from the Mayo Clinic. The intra-evaluator reliability was analyzed. The lower the patient's age at disease onset was, the more frequent the occurrences of monofrequency and altered speech rhythm were. Articulation, DDK, resonance, and prosody showed a moderate correlation with the number of "CAG" triplet repeats. We conclude that the phonoarticulation of patients with Machado-Joseph disease (MJD) is characterized by mixed dysarthrophonia with cerebellar and hypokinetic components, and that there is a tendency toward higher frequency of dysarthrophonia symptoms with lower age of disease onset, longer time since onset and higher number of "CAG" triplet repeats.
Keywords: Dysarthria; Machado–Joseph disease; Speech; Spinocerebellar ataxia; Voice.