Relationships between cognitive status, speech impairment and communicative participation in Parkinson’s disease

Aim: To assess the relationships between cognitive status, speech impairment and communicative participation in Parkinson’s disease. Introduction: Speech and communication difficulties, as well as cognitive impairment, are prevalent in Parkinson’s. The contributions of cognitive impairment and acoustic speech characteristics remain equivocal. Relationships between Impairment and Participation levels of the International Classification of Functioning, Disability and Health (ICF) have not been thoroughly investigated. Methods: 45 people with Parkinson’s and 29 familiar controls performed read, mood and conversational speech tasks as part of a multimethod investigation. Data analysis formed three main parts. Depression, cognition and communication were assessed using questionnaires. Phonetic analysis was used to produce an acoustic characterisation of speech. Listener assessment was used to assess conveyance of emotion and intelligibility. Qualitative Content Analysis was used to provide a participant’s insight into speech and communicative difficulties associated with Parkinson’s disease. Results: Cognitive status was significantly associated with certain read speech acoustic characteristics, emotional conveyance and communicative participation. No association was found with intelligibility or conversational speech acoustic characteristics. The only acoustic speech characteristics that predicted intelligibility were intensity and pause in the read speech condition. The contribution of intelligibility to communicative participation was modest. People with Parkinson’s disease reported a range of psychosocial, cognitive and physical factors affecting their speech and communication. Conclusions: I provide evidence for a role for cognitive status in emotional conveyance and communicative participation, but not necessarily general speech production, in Parkinson’s disease. I demonstrate that there may not be a strong relationship between ICF Impairment level speech measures and functional measures of communication. I also highlight the distinction between measures of communication at the ICF Activity and Participation levels. This study demonstrates that reduced participation in everyday communication in Parkinson’s disease appears to result from a complex interplay of physical, cognitive and psychosocial factors. Further research is required to apply these findings to contribute to future advances in speech and language therapy for Parkinson’s disease