Dysarthria in individuals with Parkinson's disease: a protocol for a binational, cross-sectional, case-controlled study in French and European Portuguese (FraLusoPark)

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.

Models and Approaches for Comprehension of Dysarthric Speech Using Natural Language Processing: Systematic Review

BACKGROUND

Speech intelligibility and speech comprehension for dysarthric speech has attracted much attention recently. Dysarthria is characterized by irregularities in the speed, strength, pitch, breath control, range, steadiness, and accuracy of muscle movements required for articulatory aspects of speech production.

OBJECTIVE

This study examined the contributions made by other studies involved in dysarthric speech comprehension. We focused on the modes of meaning extraction used in generalizing speaker-listener underpinnings in light of semantic ontology extraction as a desired technique, applied method types, speech representations used, and databases sourced from.

METHODS

This study involved a systematic literature review using 7 electronic databases: Cochrane Database of Systematic Reviews, Web of Science Core Collection, Scopus, PubMed, ACM, IEEE Xplore, and Google Scholar. The main eligibility criterion was the extraction of meaning from dysarthric speech using natural language processing or understanding approaches to improve on dysarthric speech comprehension. In total, out of 834 search results, 30 studies that matched the eligibility requirements were acquired following screening by 2 independent reviewers, with a lack of consensus being resolved through joint discussion or consultation with a third party. In order to evaluate the studies' methodological quality, the risk of bias assessment was based on the Cochrane risk-of-bias tool version 2 (RoB2) with 23 of the studies (77%) registering low risk of bias and 7 studies (33%) raising some concern over the risk of bias. The overall quality assessment of the study was done using TRIPOD (Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis).

RESULTS

Following a review of 30 primary studies, this study revealed that the reviewed studies focused on natural language understanding or clinical approaches, with an increase in proposed solutions from 2020 onwards. Most studies relied on speaker-dependent speech features, while others used speech patterns, semantic knowledge, or hybrid approaches. The prevalent use of vector representation aligned with natural language understanding models, while Mel-frequency cepstral coefficient representation and no representation approaches were applied in neural networks. Hybrid representation studies aimed to reconstruct dysarthric speech or improve comprehension. Comprehensive databases, like TORGO and UA-Speech, were commonly used in combination with other curated databases, while primary data was preferred for specific or unique research objectives.

CONCLUSIONS

We found significant gaps in dysarthric speech comprehension characterized by the lack of inclusion of important listener or speech-independent features in the speech representations, mode of extraction, and data sources used. Further research is therefore proposed regarding the formulation of models that accommodate listener and speech-independent features through semantic ontologies that will be useful in the inclusion of key features of listener and speech-independent features for meaning extraction of dysarthric speech.

Phoneme Representation and Articulatory Impairment: Insights from Adults with Comorbid Motor Coordination Disorder and Dyslexia

Phonemic processing skills are impaired both in children and adults with dyslexia. Since phoneme representation development is based on articulatory gestures, it is likely that these gestures influence oral reading-related skills as assessed through phonemic awareness tasks. In our study, fifty-two young dyslexic adults, with and without motor impairment, and fifty-nine skilled readers performed reading, phonemic awareness, and articulatory tasks. The two dyslexic groups exhibited slower articulatory rates than skilled readers and the comorbid dyslexic group presenting with an additional difficulty in respiratory control (reduced speech proportion and increased pause duration). Two versions of the phoneme awareness task (PAT) with pseudoword strings were administered: a classical version under time pressure and a delayed version in which access to phonemic representations and articulatory programs was facilitated. The two groups with dyslexia were outperformed by the control group in both versions. Although the two groups with dyslexia performed equally well on the classical PAT, the comorbid group performed significantly less efficiently on the delayed PAT, suggesting an additional contribution of articulatory impairment in the task for this group. Overall, our results suggest that impaired phoneme representations in dyslexia may be explained, at least partially, by articulatory deficits affecting access to them.

An integrated biometric voice and facial features for early detection of Parkinson's disease

Hypomimia and voice changes are soft signs preceding classical motor disability in patients with Parkinson's disease (PD). We aim to investigate whether an analysis of acoustic and facial expressions with machine-learning algorithms assist early identification of patients with PD. We recruited 371 participants, including a training cohort (112 PD patients during "on" phase, 111 controls) and a validation cohort (74 PD patients during "off" phase, 74 controls). All participants underwent a smartphone-based, simultaneous recording of voice and facial expressions, while reading an article. Nine different machine learning classifiers were applied. We observed that integrated facial and voice features could discriminate early-stage PD patients from controls with an area under the receiver operating characteristic (AUROC) diagnostic value of 0.85. In the validation cohort, the optimal diagnostic value (0.90) maintained. We concluded that integrated biometric features of voice and facial expressions could assist the identification of early-stage PD patients from aged controls.

Effectiveness of Telerehabilitation on Motor Impairments, Non-motor Symptoms and Compliance in Patients With Parkinson's Disease: A Systematic Review

Introduction: Parkinson's disease (PD) is a chronic neurodegenerative disease involving a progressive alteration of the motor and non-motor function. PD influences the patient's daily living and reduces participation and quality of life in all phases of the disease. Early physical exercise can mitigate the effects of symptoms but access to specialist care is difficult. With current technological progress, telemedicine, and telerehabilitation is now a viable option for managing patients, although few studies have investigated the use of telerehabilitation in PD. In this systematic review, was investigated whether telerehabilitation leads to improvements in global or specific motor tasks (gait and balance, hand function) and non-motor dysfunction (motor speech disorder, dysphagia). The impact of TR on quality of life and patient satisfaction, were also assessed. The usage of telerehabilitation technologies in the management of cognitive impairment was not addressed.

Method: An electronic database search was performed using the following databases: PubMed/MEDLINE, COCHRANE Library, PEDro, and SCOPUS for data published between January 2005 and December 2019 on the effects of telerehabilitation systems in managing motor and non-motor symptoms. This systematic review was conducted in accordance with the PRISMA guideline and was registered in the PROSPERO database (CRD42020141300).

Results: A total of 15 articles involving 421 patients affected by PD were analyzed. The articles were divided into two categories based on their topic of interest or outcome. The first category consisted of the effects of telerehabilitation on gait and balance (3), dexterity of the upper limbs (3), and bradykinesia (0); the second category regarded non-motor symptoms such as speech disorders (8) and dysphagia (0). Quality of life (7) and patient satisfaction (8) following telerehabilitation programs were also analyzed, as well as feasibility and costs.

Conclusion: Telerehabilitation is feasible in people affected by PD. Our analysis of the available data highlighted that telerehabilitation systems are effective in maintaining and/or improving some clinical and non-clinical aspects of PD (balance and gait, speech and voice, quality of life, patient satisfaction).

Systematic Review Registration:https://www.crd.york.ac.uk/prospero/, identifier: CRD42020141300.

(Dys)Prosody in Parkinson's Disease: Effects of Medication and Disease Duration on Intonation and Prosodic Phrasing

The phonology of prosody has received little attention in studies of motor speech disorders. The present study investigates the phonology of intonation (nuclear contours) and speech chunking (prosodic phrasing) in Parkinson’s disease (PD) as a function of medication intake and duration of the disease. Following methods of the prosodic and intonational phonology frameworks, we examined the ability of 30 PD patients to use intonation categories and prosodic phrasing structures in ways similar to 20 healthy controls to convey similar meanings. Speech data from PD patients were collected before and after a dopaminomimetic drug intake and were phonologically analyzed in relation to nuclear contours and intonational phrasing. Besides medication, disease duration and the presence of motor fluctuations were also factors included in the analyses. Overall, PD patients showed a decreased ability to use nuclear contours and prosodic phrasing. Medication improved intonation regardless of disease duration but did not help with dysprosodic phrasing. In turn, disease duration and motor fluctuations affected phrasing patterns but had no impact on intonation. Our study demonstrated that the phonology of prosody is impaired in PD, and prosodic categories and structures may be differently affected, with implications for the understanding of PD neurophysiology and therapy.

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.

Subthalamic deep brain stimulation aggravates speech problems in Parkinson's disease: Objective and subjective analysis of the influence of stimulation frequency and electrode contact location

BACKGROUND

Speech disorders, including stuttering and hypophonia, have been reported in patients with Parkinson's disease (PD) after subthalamic deep brain stimulation (STN-DBS).

OBJECTIVE

To evaluate the effect of stimulation frequency or electrode contact location on speech disorders in PD patients with STN-DBS.

METHOD

In this case-controlled study, we enrolled 50 PD patients with, and 100 PD patients without STN-DBS to compare their vocal intensities, measured by a sound pressure meter, and perceptual speech ratings, obtained from the speech sections of the United Parkinson's Disease Rating Scale (UPDRS) and subjective ratings regarding the impediment of functional communication by stuttering. For patients with STN-DBS, comparisons were made between high-frequency (HFS; 130 Hz), low-frequency (LFS; 80 Hz), and off-stimulation. We also evaluated the effect of electrode contact locations on speech function.

RESULTS

Patients with STN-DBS had decreased vocal intensities and UPDRS scores compared to those without (p < 0.05). Vocal intensity was significantly lower during HFS than during LFS and off-stimulation (both, p < 0.05). Stuttering impeded STN-DBS patients' communication to greater extent than for those without (p < 0.001). Vocal intensity was lower when active contacts were in the dorsal zone compared to those in the ventral zone (p < 0.05). Only STN-DBS treatment was a predictive factor for low vocal intensity (OR = 9.53, p = 0.04).

CONCLUSION

High-frequency STN-DBS with dorsal zone contacts can aggravate certain speech problems in PD patients. Therefore, it is important to balance between motor control and speech impairments in these patients.

Filled Pauses as a Special Case of Automatic Speech Behaviors and the Effect of Parkinson's Disease

Purpose In Parkinson's disease (PD), there are significant changes in the basal ganglia, a structure known to be important for controlling automatic responses to cues. Changes to the basal ganglia in PD impair an individual's ability to trigger a behavior in response to cues, but more so in response to internal cues more than external ones. Filled pauses are considered a subconscious or automatic speech response to an internal cue that there are difficulties with ongoing communication. Typical speakers use filled pauses (such as uh or um) to mark silent pauses. The purpose of this study was to examine how automatic speech responses are impacted in PD by looking at filled and silent pausing behaviors, extending our understanding of the role of the basal ganglia in automatic behaviors. We hypothesized that individuals with PD would use fewer filled pauses and longer silent pauses. We also hypothesized that longer pauses would be more likely to be marked with filled pauses and that this relationship would be weaker in speakers with PD. Method Speech samples were collected via a story-retelling task from 15 individuals with PD and 18 age-matched controls. Duration and frequency of filled and silent pauses were measured using spectrographic analysis. Number and duration of marked silent pauses (those consecutive with 1 or more filled pauses) were measured. The t tests and analyses of variance were used to test our hypotheses. Results There was no significant difference in the number of silent pauses between groups, but the duration of silent pauses was significantly greater for individuals with PD. Despite this, individuals with PD produced significantly fewer filled pauses and fewer marked silent pauses. For both groups, longer silent pauses were more likely to be marked by filled pauses, but individuals with PD marked a smaller percentage of silent pauses at longer durations than controls. Conclusions Producing fewer marked silent pauses, coupled with longer silent pauses, reduces natural cues to discourse and puts people with PD at greater risk of sounding unnatural and losing their communicative turn. These results suggest that automatic responses regarding speech production difficulties are impaired by PD. This interpretation fits with nonspeech literature where automatic responses have been demonstrated to be impaired in PD.

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.

Differences between Subjective and Objective Assessment of Speech Deficiency in Parkinson Disease

OBJECTIVES

This study aims to establish the frequency at which patients with Parkinson disease subjectively assess the intensity of their speech disorders, factors that the patients believe determine the severity of their vocal impairment, and how their subjective self-assessment of vocal impairment by means of the Voice Handicap Index compares with the objective evaluation of the performance of the articulatory organs by means of Frenchay Dysarthria Assessment.

MATERIALS AND METHODS

The methods used Voice Handicap Index, Frenchay Dysarthria Assessment, and the Hoehn and Yahr scale.

RESULTS

Positive correlation was found between the subjective assessment of the performance of the speech organs and the impaired differentiation of lip movements and tongue sideways movements, impaired saliva control, dysfunction of the soft palate, and the pitch. Negative correlation was found between the subjective assessment of the severity of speech disorder, breathing at rest, and sentence comprehension.

CONCLUSIONS

Although we observed correlation between the subjective perception of certain speech disorders of patients with Parkinson disease and the objective assessment carried out by means of the Frenchay Dysarthria Assessment scale, the subjects did not believe the disorders had a significant impact on the quality of speech. Negative results of an examination do not necessarily reflect the subjective perception of the decline in the functioning of the articulatory organs. It should be assumed that lack of correlation between the subjective perception measured using Voice Handicap Index and the objective Frenchay Dysarthria-based assessment of the performance of the articulatory organs may result from a good adaptation to the progressive changes.