Speech is the primary means through which most people express themselves. However, speech must be sufficiently intelligible to enable successful communication. The estimated 2.5 per 1000 children who have cerebral palsy (CP) are at significant risk for communication disorders. Different speech, language, and communication disorder profiles have been documented in children with CP. However, a common theme across profiles is reduced speech intelligibility relative to typical age expectations. For about half of children with CP, intelligibility deficits can be clearly associated with clinical manifestation of the speech motor disorder dysarthria. Recent work from our laboratory also indicates that many additional children with CP may have sub-clinical speech motor deficits resulting in subtle intelligibility reductions. Reduced intelligibility has significant negative consequences for functional communication, social participation, and quality of life. Enhancing intelligibility is a primary goal of intervention. One critical challenge in children with CP is early diagnosis of speech disorders. A key problem is differentiating those with borderline or mild speech motor deficits from those who are within an age appropriate range of variability. A significant barrier is that systematic age-based performance standards establishing benchmarks and cut-points for typical versus atypical development on variables that reflect functional speech motor performance and are valued outcome measures in dysarthria do not exist. Thus, empirical differentiation of typical from atypical speech motor ability is extremely difficult, especially for children with more subtle deficits (i.e. those with mild dysarthria and those with CP who may have sub-clinical speech motor issues). As a result many children with CP may miss an important window of opportunity for intervention. This research will address the problem of early diagnosis of speech motor disorders in children with CP by 1.) creating growth curves based on empirical data that establish age- specific expectations and quantify the range of typical variability for children between the ages of 3-7 years on measures of functional speech capacity (intelligibility, speech rate, intelligible words per minute) that are known to be problematic in dysarthria but that have never been comprehensively quantified from a developmental perspective in typical children. 2.) establishing standards (via directly measured and statistically validated age-based cut-points) for the identification of typical and atypical functional speech performance. Results will enable early empirical identification of speech motor deficits in children who are at-risk based on their CP diagnosis. The ability to confirm speech motor deficits in the early years and to differentiate the mildest cases from typical developmental variability will ensure that children are identified for treatment, capitalizing on the benefits of neuroplasticity and growth. Furthermore, a child's distance from age-level benchmarks will be quantifiable, which may have treatment implications. Results also will have broad application to other populations of children with speech disorders and will lay the foundation other population-specific tools.
The estimated 2.5 per 1000 children who have cerebral palsy (CP) are at significant risk for communication disorders; the presence of the speech motor disorder dysarthria occurs in about 50% of the population and almost always has detrimental effects on speech intelligibility. This research will improve early identification and treatment of functional speech motor deficits, such as reduced intelligibility, in children with CP by developing empirically based, developmentally sensitive standards to differentiate between children with typical and atypical speech motor abilities between the ages of 3-7 years on measures that are valued functional outcomes in dysarthria but that have not been comprehensively quantified in typical children through the following specific aims: 1.) to develop growth curves and quantify the range of age-based typical performance on functional speech measures relevant to pediatric dysarthria (speech intelligibility, speech rate, and intelligible words per minute); and 2.) to develop and validate age-specific measures that differentiate between atypical and typical functional speech motor control in children with CP. Using a cross sectional design to examine 320 age-stratified existing speech samples from children with CP, and new data on 400 age-stratified typically developing children, results will advance a model of speech development that has specific application to identification and treatment of functional speech motor deficits in children with CP and will have broad application to other populations of children with speech disorders (e.g. deaf speech, and cleft palate speech), laying the foundation for creation of other population-specific tools.
