Subgroups in ataxic dysarthria


This study investigated whether subgroups in ataxic dysarthria can be identified based on their diadochokinetic speech performance. Twenty-seven persons with ataxic dysarthria resulting from a variety of diseases affecting the cerebellum or its pathways were asked to read a standard passage and rapidly repeat the syllables /pΛ/, /tΛ/, and /kΛ/. For each utterance type, syllable repetition rate and two measures of variability in syllable repetition rate (i.e., the coefficient of variation and rate variation from syllable to syllable) were computed. In addition, variations in intensity (SPL) were determined across syllables as well as from syllable to syllable. The rate and variability parameters were entered into a Q-factor analysis to determine if subgroups exist. Additionally, post hoc analyses (Scheffé) were conducted to examine diadochokinetic performance patterns within and between the groups. Results revealed that subject classification into three groups was based on heterogeneity in the variability of rate and intensity during syllable repetition and not on differences in absolute rate. Dysarthria severity and type of neurologic lesion did not appear to be associated with the differential patterns of variability among utterance types (pΛ, tΛ, and kΛ) in each group.


Communication Sciences and Disorders

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Journal of Medical Speech-Language Pathology