Maximum performance tests in children with developmental spastic dysarthria.

Three noninvasive Maximum Performance Tasks (MPT)--Maximum Sound Prolongation (MSP), Fundamental Frequency Range (FFR), and Maximum Repetition Rate (MRR)--were administered to 11 children with spastic dysarthria due to cerebral palsy and to 11 control children with normal speech in order to determine the value of the tasks for differentiating between these groups of children. From the acoustic measurements, nine parameters were calculated, and in seven of them highly significant group differences were found. By adding the unweighted z-scores of four parameters (maximum sound prolongation, syllable duration, fundamental frequency range, inter-utterance variability of syllable duration), a composite z-score was constructed with nonoverlapping distributions for both groups. The authors conclude that maximum performance tasks, despite the large intrasubject and intersubject variability in both normal and pathological speakers, are powerful tools for detecting spastic dysarthria.