Clusters of Deviant Speech Dimensions in the Dysarthrias

TLDR

The study proposes hypotheses to guide more precise physiologic and neurophysiologic measurements for better delineation of dysarthria. The authors used correlation matrices to identify co‑occurring deviant speech dimensions and to name clusters based on the underlying defective physiology. The analysis revealed eight distinct clusters of speech dysfunction, each linked to specific neuromuscular substrates, with some clusters shared across disorders and intercluster correlations suggesting common neuromuscular defects.

Abstract

Correlation matrices were used to demonstrate co-occurrence of deviant speech dimensions observed. Application of this technique led to the emergence of eight distinctive clusters of dysfunction. Each of seven neurologic disorders studied had its own unique group or pattern of clusters. However, any one cluster emerged in and was shared by more than one disorder. Inspection of the dimensions present in a cluster permitted giving the cluster a logically determined name based usually on the defective physiology responsible for the cluster. Knowledge of the neuromuscular characteristics of each disorder led to deductions concerning the neuromuscular substrate for each cluster. Intercluster correlations yielded clues concerning co-occurrence of certain neuromuscular defects. Further inspection led to identification of the probable neuromuscular bases of individual deviant speech dimensions. These conclusions may serve as hypotheses for more accurate physiologic and neurophysiologic measurements to further delineate the problems of dysarthria.