Disfluencies in Parkinson’s Disease. A study on Italian early-stage patients

Although Parkinsonian speech is often described as “disfluent”, a detailed description of disruption phenomena in Parkinson’s Disease (PD) has not been provided so far. The aim of this study is to identify uses and patterns of disfluencies in early-stage Italian PD subjects. The monological speech of 10 PD patients and 10 age- and sex-matched healthy subjects, all Italian native speakers, was annotated, distinguishing between Forward-Looking Disfluencies (silent pauses, lexical and non-verbal fillers, and prolongations, useful to plan message delivery) and Backward-Looking Disfluencies (repetitions, insertions, deletions, and substitutions, used by the speaker to edit something already uttered). PD and healthy productions were compared on four parameters: the number and frequency of disfluencies; their main functions; the syntactic positioning of the items; the duration of silent pauses, filled pauses, and prolongations. Results highlight the presence of specific uses, types, and characteristics of disfluency phenomena in Italian Parkinsonian speech, even at a very early stage.