Abstract
CAG repeat-expansion spinocerebellar ataxias (CAG-SCAs) are genetically defined multisystemic degenerative diseases, resulting in motor symptoms including dysarthria with a substantial impact on daily living. Whilst speech therapy is widely recommended in ataxia, very limited evidence exists for its use. We evaluated the efficacy of a home-delivered, ataxia-tailored biofeedback-driven speech therapy in CAG-SCA in 16 individuals with SCA1, 2, 3, or 6. Treatment was delivered intensively over 20 days. Efficacy was evaluated by blinded ratings of intelligibility (primary) and acoustic measures (secondary) leveraging an intra-individual control design. Intelligibility improved post-treatment (Z = -3.18, p = 0.004) whilst remaining stable prior to treatment (Z = 0.53, p = 1.00).