Communicative participation in Parkinson’s Disease: effect of cognition, motor functioning and speech intelligibility

Communicative participation is often affected in people with Parkinson’s Disease (PD)— and it is has been shown that an individual’s speech intelligibility, cognitive and motor functioning are related to their level of communicative participation. However, to date, much of the evidence for these relationship has commonly been demonstrated using self-report and questionnaires tools. Whether these same relationships would exist if objective measures of these variables were undertaken is not known. Therefore, the present study sought to examine the relationship between communicative participation and objective measures of speech intelligibility, cognition and motor functioning in PD. Eighty-two people with PD completed the Communication Participation Item Bank (CPIB), Montreal Cognitive Assessment (MoCA), and the Unified Parkinson’s Disease Rating Scale – Motor subtest (UPDRS-III), and provided a sample of connected speech. To gain a measure of speech intelligibility, 30 healthy listeners completed a speech perception experiment in which they rated the intelligibility of each individual with PD. A backward stepwise regression analysis, with the CPIB rating as the dependent variable, showed that the communicative participation of the participants with PD was significantly predicted by MoCA and UPDRS-III scores, but not by speech intelligibility. Together, the MoCA and UPDRS-III scores explained 26% of the variance in the CPIB scores (F=12.38, p < 0.01, Adj.R2 = 0.26). The findings highlight the role of cognition and motor functioning as significant contributors to communicative participation in people with PD. Clinically, these results point to the need to consider the cognitive and motor functioning of the individual when determining the need for intervention