Higher Frequency of Stuttered Disfluencies Negatively Affects Communicative Participation in Parkinson's Disease

Abstract

Purpose: Up to 90% of people with Parkinson's disease (PD) develop communication difficulties over the course of the disease. While the negative effect of dysarthria on communicative participation has been well-documented, the impact of the occurrence of acquired stuttered disfluencies on communication in different speech situations is unknown. This study aimed to determine if the frequency of occurrence of stuttered disfluencies affects communicative participation in individuals with PD, and whether such a relationship is mediated by examiner- and self-rated measures of disease severity. Method: Conversational speech samples were collected from 100 people with PD aged 53–91 years to calculate the frequency of occurrence of stuttered disfluencies. Participants completed the Communicative Participation Item Bank to assess participation in communicative situations. Information on overall speech, cognitive, and motor performance was collected using both self-rated and examiner-rated methods. Results: Participants with PD presented with 0.2%–9.9% stuttered disfluencies during conversation. Overall, participants with PD reported their communicative participation to be impacted “a little” (19.5 ± 7.0), but there was considerable interindividual variation. A higher frequency of stuttered disfluencies was associated with significantly lower communicative participation (ρ = −0.32, p < .01). In addition, examiner-rated frequency of stuttered disfluencies ( p < .01), speech ( p < .01), and motor severity ( p = .04) were all significant predictors of communicative participation. Using self-ratings, speech ( p < .01) and cognitive ( p < .01) measures significantly predicted communicative participation. Conclusions: In people with PD, communicative participation was significantly worse for those with a higher frequency of stuttered disfluencies. Examiner- and self-rated measures of disease severity contributed different information related to communicative constraints. Together, these results highlight the importance of individualized and holistic speech therapy that considers a wide variety of symptoms, including stuttered disfluencies, to ensure positive functional outcomes. Supplemental Material: https://doi.org/10.23641/asha.26850169