An Imitation-Based Treatment for Ataxic Dysarthria: A Retrospective Multiple Single-Case Study

Background/Objectives: Ataxic dysarthria is a speech disorder characterized by the impaired coordination of movement due to cerebellar dysfunction. Despite its clinical relevance, few studies have explored its rehabilitation. This study aimed to evaluate the applicability of IMITAF, an adaptive computer-based clinical treatment protocol originally developed to target aphasia with a novel population comprising individuals with ataxic dysarthria. The approach leverages principles of procedural motor learning. Methods: Ten patients with ataxic dysarthria due to neurodegenerative disease were retrospectively studied. All patients received approximately one month of speech-language (SL) treatment. Among them, (1) three patients (LL, MD, and BoA) adjunctively received the IMITAF treatment, forming the experimental group, and (2) the remaining seven patients did not receive IMITAF, serving as the control group. Dysarthria was assessed using the "Protocollo di Valutazione Disartria e Disfonia" (PVDD). The applicability of IMITAF was assessed through within-session performance and by direct single-case comparisons of total PVDD scores pre- and post-treatment. Additionally, multiple single-case Crawford analyses were conducted using PVDD scores and subscores to compare trained (i.e., directly targeted) and untrained abilities between the experimental and control groups Results: Patients in the IMITAF group showed improvements during exercises, with further increases in total PVDD scores post-treatment. Two patients (LL and BoA) showed significant gains, while MD's scores remained stable. Compared to the control group, all three experimental patients demonstrated measurable improvements in trained core deficits associated with dysarthria, including phonation, articulation, intelligibility, and prosody (as assessed by PVDD). Conclusions: These findings suggest that IMITAF may offer therapeutic benefits for patients with ataxic dysarthria. By engaging a cortico-subcortical network involved in procedural motor learning, IMITAF may help mitigate speech deficits resulting from cerebellar dysfunction. This preliminary evidence supports the potential of IMITAF as a promising adjunctive tool in the rehabilitation of ataxic dysarthria.