Auditory-perceptual motor speech features in preschoolers: Norms and utility in differentiating childhood apraxia of speech and dysarthria - PROJECT SUMMARY Childhood apraxia of speech (CAS) and dysarthria are two neurological motor speech disorders that can have long-term negative effects on communication and participation for 1-2/1000 children in the general population and up to 80% of children with other neurodevelopmental, genetic or metabolic disorders. Although CAS and dysarthria have distinct neural bases, they can be challenging to differentially diagnose because several of the speech features used for diagnosis overlap between the disorders and can also be present in young children with typical development (e.g., slow rate, consonant distortions). Currently, no validated assessments exist that speech-language pathologists can use to reliably make these diagnoses. As such, many children remain un- or misdiagnosed and therefore unable to receive early and appropriate treatment, contributing to gaps in services and life-long negative impacts on social-emotional, academic and vocational outcomes for these individuals. The long-term goal of this work is to develop and validate a clinically feasible, norm-referenced assessment protocol to identify children with speech features that are atypical for their age and facilitate early and accurate differential diagnosis of CAS and dysarthria. The proposed project represents the first step towards this goal, using a rigorous approach to quantifying auditory-perceptual features of motor speech disorders in children and systematically considering the overlapping and unique features of CAS and dysarthria in the context of typical development. The goals of this project are three-fold. Aim 1 will use a cross-sectional design to establish growth curves for development of auditory-perceptual speech features associated with motor speech disorders in 3-6-year-old children with typical development. This information will provide the normative framework needed to identify speech features that indicate atypical motor speech function in young children. Aim 2 will use a random forest approach to identify speech features that best classify children with motor speech disorders into clinically validated groups (i.e., CAS and dysarthria), adjusting for age. Aim 3 will use exploratory factor analyses to identify data-driven clusters of motor speech features (latent classes) that will be compared to feature profiles of the clinically validated diagnostic groups. Together, results of Aims 2 and 3 will yield objectively determined sets of speech features with high diagnostic utility for identifying and differentiating children with CAS and dysarthria. Results of this work will provide the scientific foundation for development of a validated assessment tool that will improve early and accurate motor speech diagnosis, leading to enhanced communication and quality of life outcomes for millions of children with motor speech disorders and their families, consistent with the mission of the NIH.
