Relationship between diadochokinetic and speech measures in hypokinetic speakers

Abstract

Diadochokinetic (DDK) tasks are used routinely in the evaluation of dysarthric speech, but the relationship between DDK and speech measures remains controversial. The aim of this study was to investigate the relationship between DDK and connected speech measures in speakers with hypokinetic dysarthria. Eleven speakers with Parkinson disease participated (9 men and 2 women, aged 43 to 78 years). The DDK measures included DDK rate, DDK accuracy (percentage of correct targets) and DDK occlusion (an acoustic measure of complete occlusion). Speech measures included reading rate and sentence intelligibility. There was a moderate correlation between DDK accuracy and sentence intelligibility, and a moderate correlation between DDK accuracy and DDK occlusion. All other correlations were nonsignificant. Performance on DDK tasks was a poor predictor of connected speech in speakers with hypokinetic dysarthria. Possible explanations for this finding are presented.