Do Acoustic Characteristics of Dysarthria in People With Parkinson's Disease Differ Across Languages?

PURPOSE: Cross-language studies suggest more similarities than differences in how dysarthria affects the speech of people with Parkinson's disease (PwPD) who speak different languages. In this study, we aimed to identify the relative contribution of acoustic variables to distinguish PwPD from controls who spoke varieties of two Romance languages, French and Portuguese. METHOD: This bi-national, cross-sectional, and case-controlled study included 129 PwPD and 124 healthy controls who spoke French or Portuguese. All participants underwent the same clinical examinations, voice/speech recordings, and self-assessment questionnaires. PwPD were evaluated off and on optimal medication. Inferential analyses included Disease (controls vs. PwPD) and Language (French vs. Portuguese) as factors, and random decision forest algorithms identified relevant acoustic variables able to distinguish participants: (a) by language (French vs. Portuguese) and (b) by clinical status (PwPD on and off medication vs. controls). RESULTS: French-speaking and Portuguese-speaking individuals were distinguished from each other with over 90% accuracy by five acoustic variables (the mean fundamental frequency and the shimmer of the sustained vowel /a/ production, the oral diadochokinesis performance index, the relative sound level pressure and the relative sound pressure level standard deviation of the text reading). A distinct set of parameters discriminated between controls and PwPD: for men, maximum phonation time and the oral diadochokinesis speech proportion were the most significant variables; for women, variables calculated from the oral diadochokinesis were the most discriminative. CONCLUSIONS: Acoustic variables related to phonation and voice quality distinguished between speakers of the two languages. Variables related to pneumophonic coordination and articulation rate were the more effective in distinguishing PwPD from controls. Thus, our research findings support that respiration and diadochokinesis tasks appear to be the most appropriate to pinpoint signs of dysarthria, which are largely homogeneous and language-universal. In contrast, identifying language-specific variables with the speech tasks and acoustic variables studied was less conclusive.

Results of a Randomized Clinical Trial of Speech After Early Neurostimulation in Parkinson's Disease.

BACKGROUND: The EARLYSTIM trial demonstrated for Parkinson's disease patients with early motor complications that deep brain stimulation of the subthalamic nucleus (STN-DBS) and best medical treatment (BMT) was superior to BMT alone. OBJECTIVE: This prospective, ancillary study on EARLYSTIM compared changes in blinded speech intelligibility assessment between STN-DBS and BMT over 2 years, and secondary outcomes included non-speech oral movements (maximum phonation time [MPT], oral diadochokinesis), physician- and patient-reported assessments. METHODS: STN-DBS (n = 102) and BMT (n = 99) groups underwent assessments on/off medication at baseline and 24 months (in four conditions: on/off medication, ON/OFF stimulation-for STN-DBS). Words and sentences were randomly presented to blinded listeners, and speech intelligibility rate was measured. Statistical analyses compared changes between the STN-DBS and BMT groups from baseline to 24 months. RESULTS: Over the 2-year period, changes in speech intelligibility and MPT, as well as patient-reported outcomes, were not different between groups, either off or on medication or OFF or ON stimulation, but most outcomes showed a nonsignificant trend toward worsening in both groups. Change in oral diadochokinesis was significantly different between STN-DBS and BMT groups, on medication and OFF STN-DBS, with patients in the STN-DBS group performing slightly worse than patients under BMT only. A signal for clinical worsening with STN-DBS was found for the individual speech item of the Unified Parkinson's Disease Rating Scale, Part III. CONCLUSION: At this early stage of the patients' disease, STN-DBS did not result in a consistent deterioration in blinded speech intelligibility assessment and patient-reported communication, as observed in studies of advanced Parkinson's Disease. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

At-Home Training With a Rhythmic Video Game for Improving Orofacial, Manual, and Gait Abilities in Parkinson's Disease: A Pilot Study.

Rhythm disorders are consistently reported in Parkinson's disease (PD). They manifest across motor domains, such as in orofacial (oral diadochokinesis), manual (finger tapping), and gait tasks. It is still unclear, however, whether these disorders are domain- and task-specific, or result from impaired common mechanisms supporting rhythm processing (general dysrhythmia). We tested the possibility that an at-home intervention delivered via a rhythmic video game on tablet improves motor performance across motor domains in PD. Patients with PD (n = 12) played at home a rhythmic video game (Rhythm Workers) on tablet, in which they finger-tapped to the beat of music, for 6 weeks. A control group (n = 11) played an active non-rhythmic video game (Tetris). A third group (n = 10) did not receive any intervention. We measured rhythmic abilities in orofacial, manual and gait motor domains, as well as rhythm perception, before and after the intervention. Patients who performed the rhythmic training improved their orofacial and manual rhythmic performance. This beneficial effect was linked to improved rhythm perception only following the rhythmic training period. We did not observe any improvement in rhythmic abilities in the other two groups. In this pilot study, we demonstrated that at-home intervention with a rhythmic video game using finger tapping can have beneficial effects on motor performance across different motor domains (manual and orofacial). This finding provides evidence of a general dysrhythmia in PD and paves the way to technology-driven interventions aiming at alleviating rhythm-related motor deficits in PD.

Acoustic, perceptual and clinical correlates of speech and voice in isolated dystonia: Preliminary findings.

BACKGROUND: Hyperkinetic dysarthria is often present in isolated dystonia (ID) and is still understudied. Four main clusters of deviant speech dimensions in dystonia hyperkinetic dysarthria were initially provided: articulatory inaccuracy, phonatory stenosis, prosodic excess and prosodic insufficiency. AIM: The aim of our exploratory study was to provide preliminary data on both perceptual and acoustic analyses in relation to three out of these four main clusters. METHODS & PROCEDURES: Eleven patients with ID and 11 healthy controls (HC) participated in this study. Clinical/perceptual assessments and acoustic analyses of speech recordings were performed, the latter allowing for the analysis of parameters referring to aerophonatory control, voice quality, prosodic features and speech intelligibility estimated by nine listeners. Between-group statistical comparisons were performed (Wilcoxon tests, p < 0.05). Single-case differences between each patient and the control group were also carried out (effect size index and t < 0.05). OUTCOMES & RESULTS: Between-group comparisons confirmed the presence of a 'phonatory stenosis'; in addition, deficit in aerophonatory control and hypophonia was also displayed. 'Prosodic insufficiency' was confirmed, but not at the individual level. 'Prosodic excess' manifested only in patients with marked and severe dysarthria. Correlations between altered maximum phonation time, loudness variation, speech and articulatory rates on the one hand, and several clinical speech assessments on the other hand, were also found. CONCLUSIONS & IMPLICATIONS: From these findings, altogether, perceptual characteristics of hyperkinetic dysarthria, as suggested by Darley et al., were quantified by the acoustic parameters we measured. As regards to our data obtained in a small participant sample, we would suggest that Darley et al.'s clusters of excess and insufficiency prosody should be questioned in future studies involving larger numbers of dystonic patients. Our study provides novel and preliminary results that demonstrate the relevance of using quantitative measures to further characterise speech/voice deficits in patients with ID.

Heightened orofacial, manual, and gait variability in Parkinson's disease results from a general rhythmic impairment.

Individuals with Parkinson's disease (PD) experience rhythm disorders in a number of motor tasks, such as (i) oral diadochokinesis, (ii) finger tapping, and (iii) gait. These common motor deficits may be signs of "general dysrhythmia", a central disorder spanning across effectors and tasks, and potentially sharing the same neural substrate. However, to date, little is known about the relationship between rhythm impairments across domains and effectors. To test this hypothesis, we assessed whether rhythmic disturbances in three different domains (i.e., orofacial, manual, and gait) can be related in PD. Moreover, we investigated whether rhythmic motor performance across these domains can be predicted by rhythm perception, a measure of central rhythmic processing not confounded with motor output. Twenty-two PD patients (mean age: 69.5 ± 5.44) participated in the study. They underwent neurological and neuropsychological assessments, and they performed three rhythmic motor tasks. For oral diadochokinesia, participants had to repeatedly produce a trisyllable pseudoword. For gait, they walked along a computerized walkway. For the manual task, patients had to repeatedly produce finger taps. The first two rhythmic motor tasks were unpaced, and the manual tapping task was performed both without a pacing stimulus and musically paced. Rhythm perception was also tested. We observed that rhythmic variability of motor performances (inter-syllable, inter-tap, and inter-stride time error) was related between the three functions. Moreover, rhythmic performance was predicted by rhythm perception abilities, as demonstrated with a logistic regression model. Hence, rhythm impairments in different motor domains are found to be related in PD and may be underpinned by a common impaired central rhythm mechanism, revealed by a deficit in rhythm perception. These results may provide a novel perspective on how interpret the effects of rhythm-based interventions in PD, within and across motor domains.

Psychosocial Impact of Dysarthria: The Patient-Reported Outcome as Part of the Clinical Management.

BACKGROUND: Dysarthria in neurological disorders can have psychosocial consequences. The dysarthric speaker's perspective towards the disorder's psychosocial impact is essential in its global assessment and management. For such purposes, assessment tools such as the Dysarthria Impact Profile (DIP) are indispensable. OBJECTIVE: We aimed to confirm the relevance of using the DIP to quantify the psychosocial consequences of dysarthria in neurological diseases. METHODS: We studied 120 participants, 15 healthy controls and 105 patients with different kinds of dysarthria induced by several neurological disorders (Parkinson's disease [PD], Huntington's disease, dystonia, cerebellar ataxia, progressive supranuclear palsy [PSP], multiple system atrophy, lateral amyotrophic sclerosis). All participants underwent a cognitive evaluation and a speech intelligibility assessment and completed three self-reported questionnaires: the 36-Item Short Form Health Survey, the Voice Handicap Index (VHI), and the DIP. RESULTS: The psychometric properties of the DIP were confirmed, including internal consistency (α = 0.93), concurrent validity (correlation with the VHI: r = -0.77), and discriminant validity (accuracy = 0.93). Psychosocial impact of dysarthria was revealed by the DIP for all patients. Intelligibility loss was found strongly correlated with the psychosocial impact of dysarthria: for a similar level of intelligibility impairment, the DIP total score was similar regardless of the pathological group. However, our findings suggest that the psychosocial impact measured by the DIP could be partially independent from the severity of dysarthria (indirectly addressed here via speech intelligibility): the DIP was able to detect patients without any intelligibility impairment, but with a psychosocial impact. CONCLUSIONS: All patients reported a communication complaint, attested by the DIP scores, despite the fact that not all patients, notably PD, ataxic, and PSP patients, had an intelligibility deficit. The DIP should be used in clinical practice to contribute to a holistic evaluation and management of functional communication in patients with dysarthria.