Investigating How Age Affects Self-Perception and Voice Awareness in Parkinson's Disease

Parkinson's disease (PD) presents with voice disturbances accompanied by sensory processing and awareness deficits. Sensory feedback from the voice, which is essential in speech production, is often impaired in individuals with PD (IwPD), potentially leading to such difficulties in the self-perception and awareness of voice disorder. However, aging naturally affects sensory and motor brain systems, including those involved in voice production; therefore, it remains unclear whether the combined effects of age and PD exacerbate deficits in voice self-perception and awareness deficit. This study explored how age and sensory feedback in IwPD interact and affect self-perception and awareness of voice changes. Patient-reported outcome measures (PROMs) specific to the voice may not be efficient enough to capture voice changes in IwPD.

The study included three groups of similar ages: 27 IwPD (61-79 years), 25 individuals with general voice disorders (GVD, aged 57-83 years), and 28 healthy controls (HC, aged 60-80 years). Self-perception of the voice was assessed by three PROMs: the Voice Symptoms Scale, Voice Handicap Index-10, and Voice-Related Quality of Life. Voice loudness was recorded and analyzed using univariate comparisons between the PROM scores. Further, multivariate techniques, such as principal component analysis (PCA) and cluster analysis, were used to identify intergroup differences in voice quality and voice self-awareness.

The IwPD group showed lower self-perception and awareness of voice problems than the GVD and HC groups. Within the IwPD group, age did not show a significant impact on self-perception of voice and awareness. This group showed slightly higher PROM scores than the HCs. In contrast, the GVD group showed marked differences in all PROMs and voice parameters compared with the HC and PD groups. PCA revealed significant differences in total scores and voice loudness between the groups.

These findings suggest that age-related changes in sensory feedback are not significant factors affecting reduced self-perception and awareness of voice changes in IwPD. PCA and cluster analysis revealed distinct patterns among the groups, with GVD forming a separate cluster and IwPD displaying variability, partially overlapping with HC and GVD. This variability underscores the limited diagnostic utility of PROMs used to identify voice problems in IwPD compared with older individuals without PD, who generally exhibit greater awareness of voice disorders. Future studies should focus on developing tailored PROMs to better capture these challenges in IwPD.