Abstract
Objective Early diagnosis of speech disorders in children with cerebral palsy (CP) is of critical importance. A key problem is differentiating those with borderline or mild speech motor deficits from those who are within an age-appropriate range of variability. We sought to quantify how well functional speech measures differentiated typically developing (TD) children from children with CP. Method We studied speech production in 45 children with CP (26 with clinical speech motor impairment [SMI] and 19 with no evidence of speech motor impairment [NSMI]) and in 29 TD children of the same age. Speech elicitation tasks were used. Intelligibility, speech rate, and intelligible words per minute were examined. Results All measures differentiated between all 3 groups of children with considerable precision based on area under the receiver operating characteristic curve (AUC) data. AUC was highest for overall intelligibility, which ranged from .88 to .99. Intelligible words per minute also yielded very strong AUCs, ranging from .81 to .99. In each of the receiver operating characteristic models, discrimination between groups was highest for children with speech motor impairment versus TD children. Data indicated that 90% of TD children had overall intelligibility above 87% at 5 years of age, but that no child was 100% intelligible. Furthermore, 90% children with SMI had intelligibility below 72%. Conclusion Findings suggest that functional speech measures differentiate very clearly between children with and without CP and that even children who do not show evidence of speech motor impairment have functional differences in their speech production ability relative to TD peers.