Utterance Maintenance and Reprogramming Deficits in Hypokinetic Dysarthria

K Spencer, M Rogers

There are neurophysiological, limb motor control and motor speech indications that the basal ganglia control circuit is involved in the programming of movement. Specifically, the basal ganglia are thought to play an integral role in keeping programming representations active during the preparation and execution of actions, and in facilitating the rapid transitions that occur during sequential movements. Despite the support of a massive literature, few studies have investigated the utterance programming abilities of individuals with hypokinetic dysarthria from Parkinson’s disease. Manipulations of a priming paradigm provided a means to test the hypothesis that programming disruption occurs during (1) the maintenance of an utterance or (2) the rapid clearing and reprogramming of a novel utterance. Ten speakers with hypokinetic dysarthria/dysphonia, fifteen control participants and five participants with ataxic dysarthria completed this experiment. The results provided support for the hypothesized utterance programming deficits in speakers with hypokinetic dysarthria. That is, several participants exhibited speech reaction time patterns suggestive of compromised clearing or maintenance of the prime word. These patterns were not evidenced by the control participants or the participants with ataxic dysarthria, suggesting that this protocol may be sensitive to the specific programming aberrations of individuals with basal ganglia control circuit disruption.