Short-term effect of dopaminergic medication on speech in early-stage Parkinson’s disease

Abstract

The effect of dopaminergic medication on speech has rarely been examined in early-stage Parkinson’s disease (PD) and the respective literature is inconclusive and limited by inappropriate design with lack of PD control group. The study aims to examine the short-term effect of dopaminergic medication on speech in PD using patients with good motor responsiveness to levodopa challenge compared to a control group of PD patients with poor motor responsiveness. A total of 60 early-stage PD patients were investigated before (OFF) and after (ON) acute levodopa challenge and compared to 30 age-matched healthy controls. PD patients were categorised into two clinical subgroups (PD responders vs. PD nonresponders) according to the comparison of their motor performance based on movement disorder society-unified Parkinson’s disease rating scale, part III. Seven distinctive parameters of hypokinetic dysarthria were examined using quantitative acoustic analysis. We observed increased monopitch (p > 0.01), aggravated monoloudness (p > 0.05) and longer duration of stop consonants (p > 0.05) in PD compared to healthy controls, confirming the presence of hypokinetic dysarthria in early PD. No speech alterations from OFF to ON state were revealed in any of the two PD groups and speech dimensions investigated including monopitch, monoloudness, imprecise consonants, harsh voice, slow sequential motion rates, articulation rate, or inappropriate silences, although a subgroup of PD responders manifested obvious improvement in motor function after levodopa intake (p > 0.001). Since the short-term usage of levodopa does not easily affect voice and speech performance in PD, speech assessment may provide a medication state-independent motor biomarker of PD.

A neurocomputational view of the effects of Parkinson’s disease on speech production

“…Despite providing significant clinical improvement for motor signs in PD, DRT appears to have limited efficacy for improving functional speech outcomes. The majority of studies examining the acute effects of dopaminergic therapy found no significant group-level treatment effects on measures of speech and voice function ( Kompoliti et al, 2000 ; Ho et al, 2008 ; Plowman-Prine et al, 2009 ; Skodda et al, 2010 , 2011 ; Fabbri et al, 2017 ; Whitfield et al, 2018 ; Cavallieri et al, 2021 ; Tykalova et al, 2022 ). However, some studies have reported levodopa-related improvements in acoustic measures of vocal pitch and quality ( Sanabria et al, 2001 ; Lechien et al, 2019 ; Pah et al, 2021 ).…”

The efficacy of acoustic-based articulatory phenotyping for characterizing and classifying four divergent neurodegenerative diseases using sequential motion rates

“…While not controlling for these variables may limit the generalizability of our findings, we do not view the absence of this information as a confound for our results. The purpose of this study was to examine disease classification accuracy based solely on speech function, and there are many cases where speech severity is distinct from disease severity, duration, or medication use (Ball et al, 2002;Barnett et al, 2020;Cavallieri et al, 2021;Fabbri et al, 2017;Rusz, Tykalova, Novotny, Zogala, et al, 2021;Skodda, Flasskamp, et al, 2011;Tykalova et al, 2022). Thus, given the study's focus on speech function, we believe the most critical component to control for was speech severity.…”

Acoustic assessment in mandarin-speaking Parkinson’s disease patients and disease progression monitoring and brain impairment within the speech subsystem

“…Furthermore, for the dramatic impairment in quality of life and social isolation brought by speech disorders in PD patients, espically for advanced-stage PD patients, current PD therapeutic approaches, such as dopamine-based pharmacotherapy and deep brain stimulation (DBS) 22 – 24 , fall short in providing substantial benefits. Personalized and objectively monitored interventions are required for the effective management of speech disorders in PD.…”