Multiple factors are involved in the dysarthria associated with Parkinson's disease: a review with implications for clinical practice and research

Effect of clear speech on acoustic measures of dysprosody in Parkinson disease for different reading tasks

PURPOSE

The purpose of the study was to determine the effect of clear speech instruction on acoustic measures of dysprosody between reading passages of differing linguistic content for speakers with and without Parkinson Disease (PD).

METHOD

Ten speakers with PD and 10 controls served as participants and read five simple and three standard reading stimuli twice. First, speakers read habitually and then following clear speech instruction. Acoustic measures of fundamental frequency variation (semitone standard deviation, STSD), articulation rate, and between-complex pause durations were calculated.

RESULT

Results indicated speakers with PD exhibited less fundamental frequency variation than controls across reading stimuli and instructions. All speakers exhibited lower STSD and longer between-complex pause durations for the standard compared to simple reading stimuli. For clear speech, all speakers reduced articulation rate and increased between-complex pause durations in both simple and standard reading stimuli. However, speakers with PD exhibited a significantly less robust reduction in articulation rate for clear speech than control speakers for all reading stimuli.

CONCLUSION

Linguistic content of reading stimuli contributes to differences in fundamental frequency variation and pause duration for all speakers. All speakers reduced articulation rate for clear speech compared to habitual instruction, but speakers with PD did so to a lesser extent than controls. Linguistic content of reading stimuli to examine dysprosody in PD should be considered for clinical application.

¿Notas La Diferencia? [Do You Hear the Difference?]: Perceptual Consequences of Intensive Voice Treatment in Spanish Speakers With Parkinson's Disease

PURPOSE

The primary objective of this study was to explore the effects of intensive voice-focused treatment on speech parameters in Spanish speakers with dysarthria associated with Parkinson's disease (PD) as perceived by naïve listeners.

METHOD

Fifteen Spanish speakers with dysarthria associated with PD received the Lee Silverman Voice Treatment (LSVT LOUD) for a month. Voice and speech recordings were conducted pretreatment, posttreatment, and at a 1-month follow-up. Thirty naïve adult listeners rated the perceptual dimensions of ease of understanding (EoU), resonance, articulatory precision, prosody, and voice quality from sentences extracted from an emotional monologue on a visual analogue scale.

RESULTS

EoU, resonance, articulatory precision, and voice quality significantly improved pre- to posttreatment, but gains were not maintained at follow-up. Speech severity was a significant source of variance in mean listener response for all perceptual dimensions, although the interaction between speech severity and time was only significant for resonance and voice quality.

CONCLUSIONS

LSVT LOUD may be beneficial to improve perceptual speech domains affected by PD in Spanish speakers with dysarthria. Its impact on the different speech subsystems may reflect a universal distribution of effects when directly targeting the glottal source. Language-specific contributions of each perceptual domain to speech intelligibility should be explored in further research to determine linguistically sensitive treatment targets.

Raising Awareness About Language- and Culture-Specific Considerations in the Management of Dysarthria Associated With Parkinson's Disease Within the United States

PURPOSE

The purpose of this article is to raise awareness about the importance of diverting from English-centric approaches in the management of dysarthria associated with Parkinson's disease (PD) in the United States, and embracing a language- and culture-specific perspective when working with linguistically and culturally diverse populations within the context of culturally responsive, precision medicine.

METHOD

This tutorial is divided into two primary components: a critical review of language universal and language-specific characteristics of dysarthria associated with PD and their relationship with speech intelligibility, and a practical guide to culturally responsive evidence-based practice for speech-language pathologists.

CONCLUSIONS

We offer a framework for linguistically and culturally appropriate considerations when working with clients with dysarthria associated with PD. While "universal" representations of dysarthria may be part of the big picture, language-specific contributions to speakers' intelligibility should be carefully examined to maximize treatment outcomes. Additionally, an evidence-based model that fully embraces clients' wishes and values within the context of culturally responsive, precision medicine should be prioritized, a practice that may include the use of interpreters.

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.

Revisiting Dysarthria Treatment Across Languages: The Hybrid Approach

PURPOSE

Ten years after Miller and Lowit's (2014) groundbreaking book providing a cross-linguistic perspective on motor speech disorders, we ask where we are regarding dysarthria treatment across languages in two specific populations: adults with Parkinson's disease (PD) and children with cerebral palsy (CP).

METHOD

In this commentary, we consider preliminary evidence for both language-independent and language-specific approaches to treatment and propose a hybrid approach to speech treatment across languages, centered on the individual with dysarthria who speaks any given language.

CONCLUSIONS

Treatment research on individuals with dysarthria secondary to PD and CP is advancing, but several areas remain to be explored. Next steps are suggested for addressing the paucity and complexity of cross-linguistic speech treatment research.

Smartphone Voice Calls Provide Early Biomarkers of Parkinsonism in Rapid Eye Movement Sleep Behavior Disorder

BACKGROUND

Speech dysfunction represents one of the initial motor manifestations to develop in Parkinson's disease (PD) and is measurable through smartphone.

OBJECTIVE

The aim was to develop a fully automated and noise-resistant smartphone-based system that can unobtrusively screen for prodromal parkinsonian speech disorder in subjects with isolated rapid eye movement sleep behavior disorder (iRBD) in a real-world scenario.

METHODS

This cross-sectional study assessed regular, everyday voice call data from individuals with iRBD compared to early PD patients and healthy controls via a developed smartphone application. The participants also performed an active, regular reading of a short passage on their smartphone. Smartphone data were continuously collected for up to 3 months after the standard in-person assessments at the clinic.

RESULTS

A total of 3525 calls that led to 5990 minutes of preprocessed speech were extracted from 72 participants, comprising 21 iRBD patients, 26 PD patients, and 25 controls. With a high area under the curve of 0.85 between iRBD patients and controls, the combination of passive and active smartphone data provided a comparable or even more sensitive evaluation than laboratory examination using a high-quality microphone. The most sensitive features to induce prodromal neurodegeneration in iRBD included imprecise vowel articulation during phone calls (P = 0.03) and monopitch in reading (P = 0.05). Eighteen minutes of speech corresponding to approximately nine calls was sufficient to obtain the best sensitivity for the screening.

CONCLUSION

We consider the developed tool widely applicable to deep longitudinal digital phenotyping data with future applications in neuroprotective trials, deep brain stimulation optimization, neuropsychiatry, speech therapy, population screening, and beyond. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

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

The purpose of this article is to review the scientific literature concerning speech in Parkinson's disease (PD) with reference to the DIVA/GODIVA neurocomputational modeling framework. Within this theoretical view, the basal ganglia (BG) contribute to several different aspects of speech motor learning and execution. First, the BG are posited to play a role in the initiation and scaling of speech movements. Within the DIVA/GODIVA framework, initiation and scaling are carried out by initiation map nodes in the supplementary motor area acting in concert with the BG. Reduced support of the initiation map from the BG in PD would result in reduced movement intensity as well as susceptibility to early termination of movement. A second proposed role concerns the learning of common speech sequences, such as phoneme sequences comprising words; this view receives support from the animal literature as well as studies identifying speech sequence learning deficits in PD. Third, the BG may play a role in the temporary buffering and sequencing of longer speech utterances such as phrases during conversational speech. Although the literature does not support a critical role for the BG in representing sequence order (since incorrectly ordered speech is not characteristic of PD), the BG are posited to contribute to the scaling of individual movements in the sequence, including increasing movement intensity for emphatic stress on key words. Therapeutic interventions for PD have inconsistent effects on speech. In contrast to dopaminergic treatments, which typically either leave speech unchanged or lead to minor improvements, deep brain stimulation (DBS) can degrade speech in some cases and improve it in others. However, cases of degradation may be due to unintended stimulation of efferent motor projections to the speech articulators. Findings of spared speech after bilateral pallidotomy appear to indicate that any role played by the BG in adult speech must be supplementary rather than mandatory, with the sequential order of well-learned sequences apparently represented elsewhere (e.g., in cortico-cortical projections).

The encoding of speech modes in motor speech disorders: whispered versus normal speech in apraxia of speech and hypokinetic dysarthria

Speakers with motor speech disorders (MSD) present challenges in speech production, one of them being the difficulty to adapt their speech to different modes. However, it is unclear whether different types of MSD are similarly affected when it comes to adapting their speech to various communication contexts. This study investigates the encoding of speech modes in individuals with AoS following focal brain damage and in individuals with hypokinetic dysarthria (HD) secondary to Parkinson's disease. Participants with mild-to-moderate MSD and their age-matched controls performed a delayed production task of pseudo-words in two speech modes: normal and whispered speech. While overall accuracy did not differ significantly across speech modes, participants with AoS exhibited longer response latencies for whispered speech, reflecting difficulties in the initiation of utterances requiring an unvoiced production. In contrast, participants with HD showed faster response latencies for whispered speech, indicating that this speech mode is easier to encode/control for this population. Acoustic durations followed these same trends, with participants with AoS showing greater lengthening for whispered speech as compared to controls and to participants with HD, while participants with HD exhibited milder lengthening. Contrary to the predictions of speech production models, suggesting that speech mode changes might be particularly difficult in dysarthria, the present results suggest that speech mode adaptation rather seems particularly costly for participants with AoS.

The Effect of Upright Stance and Vision on a Cognitive Task in Elderly Subjects and Patients with Parkinson's Disease

Standing compared to sitting enhances cognitive performance in healthy subjects. The effect of stance on cognitive performance has been addressed here in patients with Parkinson's disease (PwPD). We hypothesized that a simple cognitive task would be less enhanced in PwPD by standing with respect to sitting, because of a larger cognitive effort for maintenance of standing posture than in healthy subjects. We recruited 40 subjects (20 PwPD and 20 age-matched healthy subjects, HE). Each participant performed an arithmetic task (backward counting aloud by 7) in two postural states, sitting and standing, with eyes open (EO) and with eyes closed (EC). All trials lasted 60 s and were randomized across subjects and conditions. The number of correct subtractions per trial was an index of counting efficiency and the ratio of correct subtractions to total subtractions was an index of accuracy. All conditions collapsed, the efficiency of the cognitive task was significantly lower in PwPD than HE, whilst accuracy was affected to a lower extent. Efficiency significantly improved from sitting to standing in HE under both visual conditions whilst only with EO in PwPD. Accuracy was not affected by posture or vision in either group. We suggest that standing, compared to sitting, increases arousal, thus improving the cognitive performance in HE. Conversely, in PwPD this improvement was present only with vision, possibly due to their greater balance impairment with EC consuming an excess of attentional resources. These findings have implications for balance control and the risk of falling in PwPD in the absence of visual cues.

Machine Learning-Assisted Speech Analysis for Early Detection of Parkinson's Disease: A Study on Speaker Diarization and Classification Techniques

Parkinson's disease (PD) is a neurodegenerative disorder characterized by a range of motor and non-motor symptoms. One of the notable non-motor symptoms of PD is the presence of vocal disorders, attributed to the underlying pathophysiological changes in the neural control of the laryngeal and vocal tract musculature. From this perspective, the integration of machine learning (ML) techniques in the analysis of speech signals has significantly contributed to the detection and diagnosis of PD. Particularly, MEL Frequency Cepstral Coefficients (MFCCs) and Gammatone Frequency Cepstral Coefficients (GTCCs) are both feature extraction techniques commonly used in the field of speech and audio signal processing that could exhibit great potential for vocal disorder identification. This study presents a novel approach to the early detection of PD through ML applied to speech analysis, leveraging both MFCCs and GTCCs. The recordings contained in the Mobile Device Voice Recordings at King's College London (MDVR-KCL) dataset were used. These recordings were collected from healthy individuals and PD patients while they read a passage and during a spontaneous conversation on the phone. Particularly, the speech data regarding the spontaneous dialogue task were processed through speaker diarization, a technique that partitions an audio stream into homogeneous segments according to speaker identity. The ML applied to MFCCS and GTCCs allowed us to classify PD patients with a test accuracy of 92.3%. This research further demonstrates the potential to employ mobile phones as a non-invasive, cost-effective tool for the early detection of PD, significantly improving patient prognosis and quality of life.

An interpretable model based on graph learning for diagnosis of Parkinson's disease with voice-related EEG

Parkinson's disease (PD) exhibits significant clinical heterogeneity, presenting challenges in the identification of reliable electroencephalogram (EEG) biomarkers. Machine learning techniques have been integrated with resting-state EEG for PD diagnosis, but their practicality is constrained by the interpretable features and the stochastic nature of resting-state EEG. The present study proposes a novel and interpretable deep learning model, graph signal processing-graph convolutional networks (GSP-GCNs), using event-related EEG data obtained from a specific task involving vocal pitch regulation for PD diagnosis. By incorporating both local and global information from single-hop and multi-hop networks, our proposed GSP-GCNs models achieved an averaged classification accuracy of 90.2%, exhibiting a significant improvement of 9.5% over other deep learning models. Moreover, the interpretability analysis revealed discriminative distributions of large-scale EEG networks and topographic map of microstate MS5 learned by our models, primarily located in the left ventral premotor cortex, superior temporal gyrus, and Broca's area that are implicated in PD-related speech disorders, reflecting our GSP-GCN models' ability to provide interpretable insights identifying distinctive EEG biomarkers from large-scale networks. These findings demonstrate the potential of interpretable deep learning models coupled with voice-related EEG signals for distinguishing PD patients from healthy controls with accuracy and elucidating the underlying neurobiological mechanisms.

Sex Differences in the Speech of Persons With and Without Parkinson's Disease

BACKGROUND

Sex differences are apparent in the prevalence and the clinical presentation of Parkinson's disease (PD), but their effects on speech have been less studied.

METHOD

Speech acoustics of persons with (34 females and 34 males) and without (age- and sex-matched) PD were examined, assessing the effects of PD diagnosis and sex on ratings of dysarthria severity and acoustic measures of phonation (fundamental frequency standard deviation, smoothed cepstral peak prominence), speech rate (net syllables per second, percent pause ratio), and articulation (articulatory-acoustic vowel space, release burst precision).

RESULTS

Most measures were affected by PD (dysarthria severity, fundamental frequency standard deviation) and sex (smoothed cepstral peak prominence, net syllables per second, percent pause ratio, articulatory-acoustic vowel space), but without interactions between them. Release burst precision was differentially affected by sex in PD. Relative to those without PD, persons with PD produced fewer plosives with a single burst: females more frequently produced multiple bursts, whereas males more frequently produced no burst at all.

CONCLUSIONS

Most metrics did not indicate that speech production is differentially affected by sex in PD. Sex was, however, associated with disparate effects on release burst precision in PD, which deserves further study.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24388666.

Self-perceived affective, behavioral, and cognitive reactions associated with voice use in people with Parkinson's disease: a pilot study

PURPOSE

This study aimed to compare the affective, behavioral, and cognitive reactions related to vocal function in people with Parkinson's disease (PWPD) and healthy controls using the Behavior Assessment Battery - Voice (BAB-Voice). The test's internal consistency was also described.

METHODS

31 PWPD and 19 healthy controls were recruited from September 2020 to March 2021. Participants completed four BAB-Voice subtests: Speech Situation Checklist - Emotional Reaction (SSC-ER), the Speech Situation Checklist - Speech Disruption (SSC-SD), Behavior Checklist (BCL), and Communication Attitude Test for Adults (BigCAT), describing the experienced negative emotional reaction, voice disruptions, coping behaviors, and negative attitude regarding communication respectively. Subtest scores were calculated and analyzed.

RESULTS

The scores of the PWPD were significantly different from those of the controls (Pillai's Trace = 0.344, F[4] = 5.508, p = .001, ηp2 = .344): PWPD showed more negative emotions and voice problems, more coping behaviors, and more negative speech-related attitude compared to healthy controls. All subtests showed excellent internal consistency.

CONCLUSIONS

The BAB-Voice proved a tool with a good internal consistency that measured different psychosocial reactions in PWPD versus controls. PWPD exhibited significantly more negative emotions and voice problems in specific speech situations, more coping behaviors, and a more negative speech-related attitude. The specificity of information obtained from the BAB-Voice may aid in improving the treatment planning of voice disorders in PWPD.

Premotor cortex is hypoactive during sustained vowel production in individuals with Parkinson's disease and hypophonia

Introduction

Hypophonia is a common feature of Parkinson's disease (PD); however, the contribution of motor cortical activity to reduced phonatory scaling in PD is still not clear.

Methods

In this study, we employed a sustained vowel production task during functional magnetic resonance imaging to compare brain activity between individuals with PD and hypophonia and an older healthy control (OHC) group.

Results

When comparing vowel production versus rest, the PD group showed fewer regions with significant BOLD activity compared to OHCs. Within the motor cortices, both OHC and PD groups showed bilateral activation of the laryngeal/phonatory area (LPA) of the primary motor cortex as well as activation of the supplementary motor area. The OHC group also recruited additional activity in the bilateral trunk motor area and right dorsal premotor cortex (PMd). A voxel-wise comparison of PD and HC groups showed that activity in right PMd was significantly lower in the PD group compared to OHC (p < 0.001, uncorrected). Right PMd activity was positively correlated with maximum phonation time in the PD group and negatively correlated with perceptual severity ratings of loudness and pitch.

Discussion

Our findings suggest that hypoactivation of PMd may be associated with abnormal phonatory control in PD.

Intergenerational choral singing to improve communication outcomes in Parkinson's disease: Development of a theoretical framework and an integrated measurement tool

Purpose: This study presented an initial step towards developing the evidence base for intergenerational choral singing as a communication-focussed rehabilitative approach for Parkinson's disease (PD).Method: A theoretical framework was established to conceptualise the rehabilitative effect of intergenerational choral singing on four domains of communication impairments - motor drive, timing mechanism, sensorimotor integration, higher-level cognitive and affective functions - as well as activity/participation, and quality of life. A computer-assisted multidimensional acoustic analysis was developed to objectively assess the targeted domains of communication impairments. Voice Handicap Index and the World Health Organization's Quality of Life assessment-abbreviated version were used to obtain patient-reported outcomes at the activity/participation and quality of life levels. As a proof of concept, a single subject with PD was recruited to participate in 9 weekly 1-h intergenerational choir rehearsals. The subject was assessed before, 1 week post, and 8 weeks post-choir.Result: Notable trends of improvement were observed in multiple domains of communication impairments at 1 week post-choir. Some improvements were maintained at 8 weeks post-choir. Patient-reported outcomes exhibited limited pre-post changes.Conclusion: This study provided the theoretical groundwork and an empirical measurement tool for future validation of intergenerational choral singing as a novel rehabilitation for PD.

Conversational Vocal Intensity in Parkinson's Disease: Treatment and Environmental Comparisons

BACKGROUND

Vibrotactile Feedback (VF) using wearable devices is an emerging treatment option for hypophonia in Individuals with Parkinson's disease (IwPD). Studies evaluating the effectiveness of VF in improving conversational vocal intensity in real-life environment in IwPD are limited.

OBJECTIVE

To determine the effect of VF on conversational vocal intensity and compare vocal intensity between a) clinic and real-life environment b) VF and Lee Silverman Voice Treatment (LSVT LOUD®)vs. VF alone in IwPD using a portable voice monitor (VocaLog2).

METHODS

Eight individuals with hypophonia secondary to PD were randomly assigned to two treatment groups- VF and LSVT LOUD® (Group 1) and VF (Group 2). VF was provided using VocaLog2 device. Duration of treatment was 4 weeks for both groups. Vocal intensity was measured in the real-life environment at baseline, during treatment, and at one-month follow-up. Vocal intensity in clinic was obtained at baseline and one-month follow-up. Voice Handicap Index (VHI) questionnaire was administered at baseline and one-month follow-up.

RESULTS

There was no significant difference in conversational vocal intensity between a) clinic and real-life environment at any point of time b) baseline and follow up for both treatment groups c) the two treatment groups at baseline, during each of the 4 weeks of treatment and at follow up d) VHI baseline and one month follow up scores.

CONCLUSION

VF, including when combined with LSVT LOUD®, is limited in improving conversational vocal intensity in real-life in IwPD. The effects of frequency and duration of VF on conversational vocal intensity must be systematically investigated using large scale studies in IwPD.

Vowel production: a potential speech biomarker for early detection of dysarthria in Parkinson's disease

Objectives

Our aim is to detect early, subclinical speech biomarkers of dysarthria in Parkinson's disease (PD), i.e., systematic atypicalities in speech that remain subtle, are not easily detectible by the clinician, so that the patient is labeled "non-dysarthric." Based on promising exploratory work, we examine here whether vowel articulation, as assessed by three acoustic metrics, can be used as early indicator of speech difficulties associated with Parkinson's disease.

Study design

This is a prospective case-control study.

Methods

Sixty-three individuals with PD and 35 without PD (healthy controls-HC) participated in this study. Out of 63 PD patients, 43 had been diagnosed with dysarthria (DPD) and 20 had not (NDPD). Sustained vowels were recorded for each speaker and formant frequencies were measured. The analyses focus on three acoustic metrics: individual vowel triangle areas (tVSA), vowel articulation index (VAI) and the Phi index.

Results

tVSA were found to be significantly smaller for DPD speakers than for HC. The VAI showed significant differences between these two groups, indicating greater centralization and lower vowel contrasts in the DPD speakers with dysarhtria. In addition, DPD and NDPD speakers had lower Phi values, indicating a lower organization of their vowel system compared to the HC. Results also showed that the VAI index was the most efficient to distinguish between DPD and NDPD whereas the Phi index was the best acoustic metric to discriminate NDPD and HC.

Conclusion

This acoustic study identified potential subclinical vowel-related speech biomarkers of dysarthria in speakers with Parkinson's disease who have not been diagnosed with dysarthria.

Optimising verbal fluency analysis in neurological patients with dysarthria: examples from Parkinson's disease and hereditary ataxia

BACKGROUND

Verbal fluency tests (VFTs) are widely used to assess cognitive-linguistic performance in neurological diseases. However, the influence of dysarthria on performance in tests requiring oral responses is unclear in ataxia and Parkinson's disease.

OBJECTIVES

To determine the impact of dysarthria on VFT performance and evaluate the validity and reliability of alternative methods for analyzing VFT data.

METHOD

Trained raters evaluated dysarthria using VFT recordings in people with ataxia (N = 61) or Parkinson's disease (PD; N = 69). Total Correct Items scores and qualitative parameters (intrusions, ambiguous verbalizations, perseverations, and interjections) were compared across semantic, phonemic, and alternating fluency tasks. Disease severity was considered as a covariate in the regression model.

RESULTS

VFT dysarthria ratings correlated with the benchmark (ground truth) dysarthria scores derived from a monologue. Ambiguous responses resulting from unclear speech impeded the rater's ability to determine if a response was correct. Regression analysis indicated that more severe dysarthria ratings predicted diminished scores in all three tasks (semantic fluency, phonemic fluency and alternating fluency) in the ataxia group. The contribution of disease severity to semantic, phonemic and alternating fluency was reduced substantially in the ataxia group after accounting for dysarthria severity in the model in both groups.

CONCLUSIONS

Dysarthria severity can be estimated based on speech samples derived from VFT. Dysarthria can lead to lower total correct items and is associated with more ambiguous verbalizations in VFT. Dysarthria severity should be considered when interpreting VFT performance in common movement disorders.

Distinct phenotypes of stimulation-induced dysarthria represent different cortical networks in STN-DBS

BACKGROUND

Deep brain stimulation of the subthalamic nucleus is an effective treatment of Parkinson's disease, yet it is often associated with a general deterioration of speech intelligibility. Clustering the phenotypes of dysarthria has been proposed as a strategy to tackle these stimulation-induced speech problems.

METHODS

In this study, we examine a cohort of 24 patients to test the real-life application of the proposed clustering and attempt to attribute the clusters to specific brain networks with two different approaches of connectivity analysis.

RESULTS

Both our data-driven and hypothesis-driven approaches revealed strong connections of variants of stimulation-induced dysarthria to brain regions that are known actors of motor speech control. We showed a strong connection between the spastic dysarthria type and the precentral gyrus and supplementary motor area, prompting a possible disruption of corticobulbar fibers. The connection between the strained voice dysarthria and more frontal areas hints toward a deeper disruption of the motor programming of speech production.

CONCLUSIONS

These results provide insights into the mechanism of stimulation-induced dysarthria in deep brain stimulation of the subthalamic nucleus and may guide reprogramming attempts for individual Parkinson's patients based on pathophysiological understanding of the affected networks.

Effects of intensive speech treatment on Mandarin speakers with Parkinson's Disease: A review

BACKGROUND

Benefits of intensive speech treatment have been documented for a range of speech signs in English speakers with Parkinson's Disease (PD). However, the answer to a critical question that whether the same treatment benefits speech variables including intelligibility in Mandarin speakers is still unclear. In order to develop a targeted speech treatment for Mandarin speakers with PD, we reviewed the efficacy of intensive speech treatment to improve vocal loudness and functional communication and discuss possible explanations for efficacy on Mandarin speakers with PD.

METHODS

Literatures about intensive speech treatment for Mandarin speakers with PD were retrieved from PubMed, Web of Science, Embase, China National Knowledge Infrastructure (CNKI), Wanfang and Weipu Database for Chinese Technical Periodicals (VIP) Database. Search strategy was (voice therapy OR speech therapy OR voice treatment OR speech treatment OR voice training OR speech training OR voice rehabilitation OR speech rehabilitation OR Lee Silverman voice treatment OR intensive speech treatment) and (Parkinson's disease) and (Mandarin speakers OR Chinese OR Chinese people).

RESULTS

Five randomized controlled trials were selected and possible explanations for efficacy on individuals with PD are discussed. Further research directions are suggested.

CONCLUSION

The existing evidence from treatment efficacy studies of intensive speech treatment provides support for improving vocal loudness, speech intelligibility, pitch and rate in Mandarin speakers with PD. Our future research will continue to work to conduct a large sample multicenter randomized controlled trial to provide high quality evidence and understand the basic mechanisms accompanying treatment-related change.

Human subthalamic nucleus neurons differentially encode speech and limb movement

Deep brain stimulation (DBS) of the subthalamic nucleus (STN), which consistently improves limb motor functions, shows mixed effects on speech functions in Parkinson's disease (PD). One possible explanation for this discrepancy is that STN neurons may differentially encode speech and limb movement. However, this hypothesis has not yet been tested. We examined how STN is modulated by limb movement and speech by recording 69 single- and multi-unit neuronal clusters in 12 intraoperative PD patients. Our findings indicated: (1) diverse patterns of modulation in neuronal firing rates in STN for speech and limb movement; (2) a higher number of STN neurons were modulated by speech vs. limb movement; (3) an overall increase in neuronal firing rates for speech vs. limb movement; and (4) participants with longer disease duration had higher firing rates. These data provide new insights into the role of STN neurons in speech and limb movement.

Long-Term Averaged Spectrum Descriptors of Dysarthria in Patients With Parkinson's Disease Treated With Subthalamic Nucleus Deep Brain Stimulation

PURPOSE

This study aimed to evaluate whether long-term averaged spectrum (LTAS) descriptors for reading and monologue are suitable to detect worsening of dysarthria in patients with Parkinson's disease (PD) treated with subthalamic nucleus deep brain stimulation (STN-DBS) with potential effect of ON and OFF stimulation conditions and types of connected speech.

METHOD

Four spectral moments based on LTAS were computed for monologue and reading passage collected from 23 individuals with PD treated with bilateral STN-DBS and 23 age- and gender-matched healthy controls. Speech performance of patients with PD was compared in ON and OFF STN-DBS conditions.

RESULTS

All LTAS spectral moments including mean, standard deviation, skewness, and kurtosis across both monologue and reading passage were able to significantly distinguish between patients with PD in both stimulation conditions and control speakers. The spectral mean was the only LTAS measure sensitive to capture better speech performance in STN-DBS ON, as compared to the STN-DBS OFF stimulation condition (p < .05). Standardized reading passage was more sensitive compared to monologue in detecting dysarthria severity via LTAS descriptors with an area under the curve of up to 0.92 obtained between PD and control groups.

CONCLUSIONS

Our findings confirmed that LTAS is a suitable approach to objectively describe changes in speech impairment severity due to STN-DBS therapy in patients with PD. We envisage these results as an important step toward a continuum development of technological solutions for the automated assessment of stimulation-induced dysarthria.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21644798.

Continuous theta burst stimulation over left supplementary motor area facilitates auditory-vocal integration in individuals with Parkinson’s disease

Accumulating evidence suggests that impairment in auditory-vocal integration characterized by abnormally enhanced vocal compensations for auditory feedback perturbations contributes to hypokinetic dysarthria in Parkinson’s disease (PD). However, treatment of this abnormality remains a challenge. The present study examined whether abnormalities in auditory-motor integration for vocal pitch regulation in PD can be modulated by neuronavigated continuous theta burst stimulation (c-TBS) over the left supplementary motor area (SMA). After receiving active or sham c-TBS over left SMA, 16 individuals with PD vocalized vowel sounds while hearing their own voice unexpectedly pitch-shifted two semitones upward or downward. A group of pairwise-matched healthy participants was recruited as controls. Their vocal responses and event-related potentials (ERPs) were measured and compared across the conditions. The results showed that applying c-TBS over left SMA led to smaller vocal responses paralleled by smaller P1 and P2 responses and larger N1 responses in individuals with PD. Major neural generators of reduced P2 responses were located in the right inferior and medial frontal gyrus, pre- and post-central gyrus, and insula. Moreover, suppressed vocal compensations were predicted by reduced P2 amplitudes and enhanced N1 amplitudes. Notably, abnormally enhanced vocal and P2 responses in individuals with PD were normalized by c-TBS over left SMA when compared to healthy controls. Our results provide the first causal evidence that abnormalities in auditory-motor control of vocal pitch production in PD can be modulated by c-TBS over left SMA, suggesting that it may be a promising non-invasive treatment for speech motor disorders in PD.

Impaired perceptual phonetic plasticity in Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative condition primarily associated with its motor consequences. Although much of the focus within the speech domain has focused on PD's consequences for production, people with PD have been shown to differ in the perception of emotional prosody, loudness, and speech rate from age-matched controls. The current study targeted the effect of PD on perceptual phonetic plasticity, defined as the ability to learn and adjust to novel phonetic input, both in second language and native language contexts. People with PD were compared to age-matched controls (and, for three of the studies, a younger control population) in tasks of explicit non-native speech learning and adaptation to variation in native speech (compressed rate, accent, and the use of timing information within a sentence to parse ambiguities). The participants with PD showed significantly worse performance on the task of compressed rate and used the duration of an ambiguous fricative to segment speech to a lesser degree than age-matched controls, indicating impaired speech perceptual abilities. Exploratory comparisons also showed people with PD who were on medication performed significantly worse than their peers off medication on those two tasks and the task of explicit non-native learning.

Effects of Resonance Tube Voice Therapy on Parkinson's Disease: Clinical Trial

PURPOSE

To verify the effect of resonance tube voice therapy on the vocal aspects of patients with Parkinson's Disease (PD).

METHOD

Intra-subject comparative controlled clinical trial with a single group assignment. Fourteen individuals with PD (10 men, mean age 66.1 years; four women, mean age 73.75 years) received eight 45-minute sessions of voice therapy, twice a week for 4 weeks. The therapy consisted of semi-occluded vocal tract exercises - phonation method in a resonance tube (glass, 27 cm x 9 mm) in water. Tube depth in water ranged from 2 cm to 9 cm, as the difficulty in carrying out the exercises increased (usual pitch, high pitch, low pitch, ascending/descending glissandos), followed by sentence production. The assessments were made three times: at baseline (Time0), after 30 days without intervention (Time1), and 1 day after eight intervention sessions (Time2). The following aspects were assessed: vocal intensity; acoustic parameters (Smoothed Cepstral Peak Prominence - CPPs, alpha ratio, and L1-L0 difference); auditory-perceptual analysis of the overall degree of vocal quality deviation; voice symptoms (Voice Symptom Scale protocol - VoiSS) and voice-related quality of life (Voice-Related Quality of Life Protocol - V-RQOL). The results were compared at the three times of assessment Time0/Time1/Time2 using one-way repeated measures ANOVA test and Tukey test (5% significance).

RESULTS

intervention significantly increased: vocal intensity, L1-L0 value of vowel /a/ and counting, CPP value in counting, and decreased: the overall degree of vocal quality deviation in 78% of participants, the total score of VoiSS protocol, the limitation, and emotional subscales. In addition, the intervention increased the score of all the domains of V-RQOL protocol - physical, socio-emotional, and total.

CONCLUSION

Resonance tube phonation in voice therapy was effective in increasing vocal intensity and long-term acoustic parameters, the improved overall degree of vocal quality, reducing voice symptoms, and increasing voice-related quality of life in individuals with PD.

Random Forest Algorithm Based on Speech for Early Identification of Parkinson's Disease

To investigate the effectiveness of identifying patients with Parkinson's disease (PD) from speech signals, various acoustic parameters including prosodic and segmental features are extracted from speech and then the random forest classification (RF) algorithm based on these acoustic parameters is applied to diagnose early-stage PD patients. To validate the proposed method of RF algorithm in early-stage PD identification, this study compares the accuracy rate of RF with that of neurologists' judgments based on auditory test outcomes, and the results clearly show the superiority of the proposed method over its rival. Random forest algorithm based on speech can improve the accuracy of patients' identification, which provides an efficient auxiliary method in the early diagnosis of PD patients.

Minimally Detectable Change of Speech Intelligibility in Speakers With Multiple Sclerosis and Parkinson's Disease

PURPOSE

This study sought to determine the minimally detectable change (MDC) of sentence intelligibility for speakers with multiple sclerosis (MS) and Parkinson's disease (PD).

METHOD

Speakers included 78 participants consisting of 32 neurologically healthy control speakers, 30 speakers with MS, and 16 speakers with PD. All speakers were recorded reading 11 sentences comprising the Speech Intelligibility Test (SIT), which were subsequently transcribed by inexperienced listeners. Percent correct scores were calculated for each sentence. An average percent correct score was also calculated for each speaker. The MDC at the 95% confidence interval was calculated using the following formula: MDC₉₅ = 1.96 × √2 × standard error of measurement. Speakers were divided into operationally defined categories of severity, and MDCs were calculated for each category to permit comparison to MDCs reported for speakers with amyotrophic lateral sclerosis (ALS). Kruskal-Wallis tests were conducted to compare MDCs between groups and severity categories.

RESULTS

The average MDC₉₅ for control speakers was 5.53% (range = 3.21%-7.47%) and was statistically smaller than MDCs for speakers with MS (average = 10.08%, range = 5.30%-15.62%) and those for speakers with PD (average = 10.98%, range = 8.60%-13.98%). Statistical analyses further revealed significant differences between MDCs across severity categories.

CONCLUSIONS

In agreement with previous work in ALS conducted under similar conditions (i.e., orthographic transcription of SIT sentences in a quiet listening environment), the MDC₉₅ of speech intelligibility ranged from 3% to 10% for speakers with MS and PD who have mildly impaired speech. These estimates are a step toward the development of a universal language with which to evaluate speech changes in a variety of patient populations.

Immediate and long-term effects of speech treatment targets and intensive dosage on Parkinson's disease dysphonia and the speech motor network: Randomized controlled trial

This study compared acoustic and neural changes accompanying two treatments matched for intensive dosage but having two different treatment targets (voice or articulation) to dissociate the effects of treatment target and intensive dosage in speech therapies. Nineteen participants with Parkinsonian dysphonia (11 F) were randomized to three groups: intensive treatment targeting voice (voice group, n = 6), targeting articulation (articulation group, n = 7), or an untreated group (no treatment, n = 6). The severity of dysphonia was assessed by the smoothed cepstral peak prominence (CPPS) and neuronal changes were evaluated by cerebral blood flow (CBF) recorded at baseline, posttreatment, and 7-month follow-up. Only the voice treatment resulted in significant posttreatment improvement in CPPS, which was maintained at 7 months. Following voice treatment, increased activity in left premotor and bilateral auditory cortices was observed at posttreatment, and in the left motor and auditory cortices at 7-month follow-up. Articulation treatment resulted in increased activity in bilateral premotor and left insular cortices that were sustained at a 7-month follow-up. Activation in the auditory cortices and a significant correlation between the CPPS and CBF in motor and auditory cortices was observed only in the voice group. The intensive dosage resulted in long-lasting behavioral and neural effects as the no-treatment group showed a progressive decrease in activity in areas of the speech motor network out to a 7-month follow-up. These results indicate that dysphonia and the speech motor network can be differentially modified by treatment targets, while intensive dosage contributes to long-lasting effects of speech treatments.

Oral and Laryngeal Diadochokinesis Across the Life Span: A Scoping Review of Methods, Reference Data, and Clinical Applications

PURPOSE

The aim of this study was to conduct a scoping review of research on oral and laryngeal diadochokinesis (DDK) in children and adults, either typically developing/developed or with a clinical diagnosis.

METHOD

Searches were conducted with PubMed/MEDLINE, Google Scholar, CINAHL, and legacy sources in retrieved articles. Search terms included the following: DDK, alternating motion rate, maximum repetition rate, sequential motion rate, and syllable repetition rate.

RESULTS

Three hundred sixty articles were retrieved and included in the review. Data source tables for children and adults list the number and ages of study participants, DDK task, and language(s) spoken. Cross-sectional data for typically developing children and typically developed adults are compiled for the monosyllables /pʌ/, /tʌ/, and /kʌ/; the trisyllable /pʌtʌkʌ/; and laryngeal DDK. In addition, DDK results are summarized for 26 disorders or conditions.

DISCUSSION

A growing number of multidisciplinary reports on DDK affirm its role in clinical practice and research across the world. Atypical DDK is not a well-defined singular entity but rather a label for a collection of disturbances associated with diverse etiologies, including motoric, structural, sensory, and cognitive. The clinical value of DDK can be optimized by consideration of task parameters, analysis method, and population of interest.

Evaluating a Speech-Specific and a Computerized Step-Training-Specific Rhythmic Intervention in Parkinson's Disease: A Cross-Over, Multi-Arms Parallel Study

Background:

Recent studies suggest movements of speech and gait in patients with Parkinson's Disease (PD) are impaired by a common underlying rhythmic dysfunction. If this being the case, motor deficits in speech and gait should equally benefit from rhythmic interventions regardless of whether it is a speech-specific or step-training-specific approach.

Objective:

In this intervention trial, we studied the effects of two rhythmic interventions on speech and gait. These rhythmic intervention programs are similar in terms of intensity and frequency (i.e., 3x per week, 45 min-long sessions for 4 weeks in total), but differ regarding therapeutic approach (rhythmic speech vs. rhythmic balance-mobility training).

Methods:

This study is a cross-over, parallel multi-arms, single blind intervention trial, in which PD patients treated with rhythmic speech-language therapy (rSLT; N = 16), rhythmic balance-mobility training (rBMT; N = 10), or no therapy (NT; N = 18) were compared to healthy controls (HC; N = 17; matched by age, sex, and education: p > 0.82). Velocity and cadence in speech and gait were evaluated at baseline (BL), 4 weeks (4W-T1), and 6 months (6M-T2) and correlated.

Results:

Parameters in speech and gait (i.e., speaking and walking velocity, as well as speech rhythm with gait cadence) were positively correlated across groups (p < 0.01). Statistical analyses involved repeated measures ANOVA across groups and time, as well as independent and one-samples t-tests for within groups analyses. Statistical analyses were amplified using Reliable Change (RC) and Reliable Change Indexes (RCI) to calculate true clinically significant changes due to the treatment on a patient individual level. Rhythmic intervention groups improved across variables and time (total Mean Difference: 3.07 [SD 1.8]; 95% CI 0.2–11.36]) compared to the NT group, whose performance declined significantly at 6 months (p < 0.01). HC outperformed rBMT and NT groups across variables and time (p < 0.001); the rSLT performed similarly to HC at 4 weeks and 6 months in speech rhythm and respiration.

Conclusions:

Speech and gait deficits in PD may share a common mechanism in the underlying cortical circuits. Further, rSLT was more beneficial to dysrhythmic PD patients than rBMT, likely because of the nature of the rhythmic cue.

Progression of Self-Perceived Speech and Swallowing Impairment in Early Stage Parkinson's Disease: Longitudinal Analysis of the Unified Parkinson's Disease Rating Scale

PURPOSE

The purpose of this study was to investigate the presence and progression of self-perceived speech and swallowing impairments in newly diagnosed people with Parkinson's disease (PD) longitudinally across 6 years.

METHOD

Longitudinal data from the Parkinson's Progression Markers Initiative were analyzed across six consecutive years in a cohort of 269 newly diagnosed people with PD, and a subset of those (n = 211) who were assessed at every time point across the 6 years. Dependent variables included self-perceived ratings of speech and swallowing impairment severity from the Unified Parkinson's Disease Rating Scale. Patient-centered factors of age at diagnosis and motor phenotype were also assessed to determine if they were related to the change in self-perceived speech and swallowing impairments.

RESULTS

Overall, self-perceived speech and swallowing impairments were present in newly diagnosed people with PD, although over time, the degree of severity for both remained in the mild range. However, the rate of change over time was significant for perceived speech impairment, F(5.5, 1158.8) = 21.1, p < .001), and perceived swallowing impairment, F(5.2, 1082.6) = 8.6, p < .001. Changes for speech and swallowing impairment were both in the direction of progressive severity. There were no effects of age at diagnosis or motor phenotype on the degree of change for either speech or swallowing.

CONCLUSIONS

Self-perceptions of speech and swallowing impairment changed significantly over time in newly diagnosed people with PD (PWPD). Consistent with existing literature, self-perceptions of speech impairment were rated as more severe than those of swallowing impairment. These findings reveal that even in the early years postdiagnoses, PWPD are experiencing changes to speech and swallowing function, albeit within the mildly severe range. The presence of self-perceived mild speech and swallowing impairments in the initial years postdiagnosis may support the need for intervention to improve and or sustain function over time.

Partner perception of affective, behavioral, and cognitive reactions to voice use in people with Parkinson’s disease

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Behavior Assessment Battery – Voice in people with Parkinson’s disease and proxies.

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Proxies and people with Parkinson’s Disease rate psychosocial impact similarly.

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Proxies can be part of vocal assessment and treatment in Parkinson’s Disease.

Introduction

People with Parkinson’s disease (PWPD) experience negative feelings, thoughts, and coping behaviors due to the experienced communication challenges. This study aimed to compare the perceptions of PWPD with those of proxies for the affective, behavioral, and cognitive reactions specific to voice production during communicative interactions.

Methods

The Behavior Assessment Battery – Voice (BAB-Voice) was administered to 31 PWPD and their close communication partner/proxy. The BAB-Voice contained four subtests: Speech Situation Checklist – Emotional Reaction (SSC-ER), Speech Situation Checklist – Speech Disruption (SSC-SD), Behavior Checklist (BCL), and Communication Attitude Test for Adults (BigCAT). The scores for each of these subtests were calculated and statistically analyzed.

Results

A repeated measures MANOVA did not find statistically significant differences between the subscores of PWPD and proxies (Pillai’s trace = 0.25, F[4] = 2.22, p =.094, η_p² = 0.25). Fair to excellent agreement between the PWPD and proxies was found. The highest agreement was found on the BigCAT (ICC = 0.80). The SSC-SD (ICC = 0.77) and SSC-ER (ICC = 0.71) still showed excellent agreement, while only fair agreement was found for the BCL (ICC = 0.57).

Conclusion

Proxies were able to identify the affective, behavioral, and cognitive reactions to voice use in PWPD. Communication partners close to the PWPD could, therefore, provide valuable information regarding the assessment and treatment of hypophonia in PD.

Effects of Rhythmic Interventions on Cognitive Abilities in Parkinson's Disease

OBJECTIVE

The objective of this study is to compare 2 different rhythmic, high-intensive interventions, that is, rhythmic speech-language therapy (rSLT) versus rhythmic balance-mobility training (rBMT), against a no-therapy (NT) condition in patients with Parkinson's disease and against healthy controls (HCs) with regard to the change in or enhancement of cognitive abilities.

METHODS

The 4 groups (rSLT: N = 16; rBMT: N = 10; NT: N = 18; and HC: N = 17) were matched for age, sex, and educational level and were tested in 6 cognitive domains: working memory, executive function, visuo-construction, episodic memory, attention, and word retrieval. Assessments took place at baseline, at 4 weeks (T1), and at 6 months (T2). Rhythmic interventions were provided 3 times per week for 4 weeks in total. To analyze true intervention effects between groups and across time, statistical analyses included reliable change index. Intergroup differences were assessed with multivariate assessment of variance, while differences within groups were assessed with 95% confidence intervals of mean difference.

RESULTS

The rSLT improved working memory and word retrieval (p < 0.05), possibly a beneficial transfer effect of the training method per se. In contrast, the NT group worsened in phonemic and semantic shifting (p < 0.01). Observed improvements in flexibility and in episodic memory in the HC may be linked to training effects of retesting.

CONCLUSIONS

Rhythmic cues are resistant to neurodegeneration and have a strong motivating factor. As thus, these may facilitate high-intensive and demanding training. Although both trainings were superior to NT, the improvement of cognitive abilities depends on the specific training method. Further, therapy may be more effective when delivered by a therapist rather than by an impersonal computer program.

Genotype- and Age-Dependent Differences in Ultrasound Vocalizations of SPRED2 Mutant Mice Revealed by Machine Deep Learning

Vocalization is an important part of social communication, not only for humans but also for mice. Here, we show in a mouse model that functional deficiency of Sprouty-related EVH1 domain-containing 2 (SPRED2), a protein ubiquitously expressed in the brain, causes differences in social ultrasound vocalizations (USVs), using an uncomplicated and reliable experimental setting of a short meeting of two individuals. SPRED2 mutant mice show an OCD-like behaviour, accompanied by an increased release of stress hormones from the hypothalamic–pituitary–adrenal axis, both factors probably influencing USV usage. To determine genotype-related differences in USV usage, we analyzed call rate, subtype profile, and acoustic parameters (i.e., duration, bandwidth, and mean peak frequency) in young and old SPRED2-KO mice. We recorded USVs of interacting male and female mice, and analyzed the calls with the deep-learning DeepSqueak software, which was trained to recognize and categorize the emitted USVs. Our findings provide the first classification of SPRED2-KO vs. wild-type mouse USVs using neural networks and reveal significant differences in their development and use of calls. Our results show, first, that simple experimental settings in combination with deep learning are successful at identifying genotype-dependent USV usage and, second, that SPRED2 deficiency negatively affects the vocalization usage and social communication of mice.

Articulatory Gain Predicts Motor Cortex and Subthalamic Nucleus Activity During Speech

Speaking precisely is important for effective verbal communication, and articulatory gain is one component of speech motor control that contributes to achieving this goal. Given that the basal ganglia have been proposed to regulate the speed and size of limb movement, that is, movement gain, we explored the basal ganglia contribution to articulatory gain, through local field potentials (LFP) recorded simultaneously from the subthalamic nucleus (STN), precentral gyrus, and postcentral gyrus. During STN deep brain stimulation implantation for Parkinson's disease, participants read aloud consonant-vowel-consonant syllables. Articulatory gain was indirectly assessed using the F2 Ratio, an acoustic measurement of the second formant frequency of/i/vowels divided by/u/vowels. Mixed effects models demonstrated that the F2 Ratio correlated with alpha and theta activity in the precentral gyrus and STN. No correlations were observed for the postcentral gyrus. Functional connectivity analysis revealed that higher phase locking values for beta activity between the STN and precentral gyrus were correlated with lower F2 Ratios, suggesting that higher beta synchrony impairs articulatory precision. Effects were not related to disease severity. These data suggest that articulatory gain is encoded within the basal ganglia-cortical loop.

(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.

Self-Perception of Voice and Swallowing Handicap in Parkinson's Disease

BACKGROUND

Hypokinetic dysarthria and dysphagia are known features of Parkinson's disease; however, self-perception of their handicapping effects on emotional, physical, and functional aspects of quality of life over disease duration is less understood.

OBJECTIVE

1) Based upon patient self-perception, to determine the relationship of the handicapping effects of dysphagia and dysphonia with time since diagnosis in individuals with Parkinson's disease; 2)To determine if there is a relationship between voice and swallowing handicap throughout the course of Parkinson's disease.

METHOD

277 subjects completed the Dysphagia Handicap Index and the Voice Handicap Index. Subjects were divided into three groups based on disease duration: 0-4 years, 5-9 years, and 10 + years.

RESULTS

Subjects in the longer duration group identified significantly greater perceptions of voice and swallowing handicap compared to the shorter duration groups. There was a significant positive correlation between the DHI and VHI.

CONCLUSION

Self-perception of swallowing and voice handicap in Parkinson's disease are associated with later stages of disease and progress in a linear fashion. Self-perception of voice and swallowing handicap parallel each other throughout disease progression in Parkinson's disease. Individuals may be able to compensate for changes in voice and swallowing early while sensory perceptual feedback is intact. Results support early targeted questioning of patient self-perception of voice and swallowing handicap as identification of one problem indicates awareness of the other, thus creating an opportunity for early treatment and maintenance of swallowing and communication quality of life for as long as possible.

Dysarthria treatment for Parkinson's disease: one-year follow-up of SPEAK OUT!® with the LOUD Crowd®

INTRODUCTION

SPEAK OUT! with The LOUD Crowd is a standardized speech therapy program typically consisting of 12 one-on-one treatments and ongoing weekly group maintenance sessions for patients with dysarthria due to Parkinson's disease (PD). It is based upon the hypothesis that increased attention to speech, which is a goal-directed motor activity, may compensate for the impairment in automatic sequential motor behaviors often demonstrated in patients with PD. We present results on the 1-year response to treatment.

METHODS

Forty individuals with idiopathic PD received SPEAK OUT! delivered in 12 one-on-one 40-min treatment sessions 3 times per week for four consecutive weeks in addition to ongoing group maintenance sessions called The LOUD Crowd. Evaluations occurred 3 times at baseline, within one and six weeks after completion of the SPEAK OUT! sessions (N = 40) and 1-year later (N = 35). Assessments included mean speech intensity and intonation from reading and monolog, the voice quality acoustic measure called cepstral peak prominence (CPP), and scores on the voice-related quality of life questionnaire.

RESULTS

The significant improvements achieved in all outcome measures from baseline to completion of SPEAK OUT! were maintained 1-year later. Participation throughout the year in regular group maintenance sessions (The LOUD Crowd) was positively correlated with level of improvement at 1 year for all measures except patient perception of voice.

CONCLUSIONS

These long-term data contribute evidence of the effectiveness of this speech therapy program for improving communication for individuals with PD and emphasize the importance of regular and ongoing group sessions to sustain therapeutic gains.

Changes to Ventilation, Vocalization, and Thermal Nociception in the Pink1-/- Rat Model of Parkinson's Disease

BACKGROUND

Individuals with Parkinson's disease (PD) experience significant vocal communication deficits. Findings in the Pink1-/- rat model of early-onset PD suggest that ultrasonic vocal communication is impaired early, progressively worsens prior to nigrostriatal dopamine depletion, and is associated with loss of locus coeruleus neurons, brainstem α-synuclein, and larynx pathology. Individuals with PD also demonstrate ventilatory deficits and altered sensory processing, which may contribute to vocal deficits.

OBJECTIVE

The central hypothesis is that ventilatory and sensory deficits are present in the early disease stages when limb and vocal motor deficits also present.

METHODS

Pink1-/- rats were compared to wildtype (WT) controls at longitudinal timepoints. Whole-body flow through plethysmography was used to measure ventilation in the following conditions: baseline, hypoxia, and maximal chemoreceptor stimulation. Plantar thermal nociception, and as a follow up to previous work, limb gait and vocalization were analyzed. Serotonin density (5-HT) in the dorsal raphe was quantified post-mortem.

RESULTS

Baseline breathing frequencies were consistently higher in Pink1-/- rats at all time points. In hypoxic conditions, there were no significant changes between genotypes. With hypercapnia, Pink1-/- rats had decreased breathing frequencies with age. Thermal withdrawal latencies were significantly faster in Pink1-/- compared with WT rats across time. No differences in 5-HT were found between genotypes. Vocal peak frequency was negatively correlated to tidal volume and minute ventilation in Pink1-/- rats.

CONCLUSION

This work suggests that abnormal nociceptive responses in Pink1-/- rats and ventilatory abnormalities may be associated with abnormal sensorimotor processing to chemosensory stimuli during disease manifestation.

Intensive voice treatment (the Lee Silverman Voice Treatment [LSVT®LOUD]) for individuals with Wilson's disease and adult cerebral palsy: two case reports

Objective: In this case report, we aimed to examine the effects of an intensive voice treatment (the Lee Silverman Voice Treatment [LSVT^®LOUD]) for Wilson's disease (WD), and adult cerebral palsy (CP), and dysarthria.Method: The participants received LSVT^®LOUD four times a week for 4 weeks. Acoustic, perceptual (GRBAS) analyses were performed and data from the Voice Handicap Index (VHI) were obtained before and after treatment.Results: Besides the Harmonics-to Noise Ratio (HNR) value (dB) of the participant with WD, for both participants' fundamental frequencies (Hz), jitter (%), and shimmer (%) values showed significant differences (p < .05) after therapy. Both participants showed significant improvements (p < .05) in the duration (s) and the sound pressure level (dB, SPL) of sustained vowel phonation (/a/), in SPL (dB) of pitch range (high and low /a/) and reading and conversation (p < .01). There was a positive improvement in the high-frequency values (Hz) of both participants but not in the low-frequency values (Hz) in the participant with WD. Perceptual analysis with GRBAS judgements of sustained vowel (/a/) and paragraph reading of two participants also showed improvement. After therapy, perceived loudness of the participants' voice increased.Conclusions: The findings provide some preliminary observations that the individuals with WD and the adult individuals with CP can respond positively to intensive speech treatment such as LSVT^®LOUD. Further studies are needed to investigate speech treatments specific to WD and adult CP.

Single Word Intelligibility of Individuals with Parkinson's Disease in Noise: Pre-Specified Secondary Outcome Variables from a Randomized Control Trial (RCT) Comparing Two Intensive Speech Treatments (LSVT LOUD vs. LSVT ARTIC)

The majority of people with Parkinson's disease (PD) experience both prosodic changes (reduced vocal volume, reduced pitch range) and articulatory changes (imprecise articulation) that often limit speech intelligibility and may contribute to significant declines in quality of life. We conducted a randomized control trial comparing two intensive treatments, voice (LSVT LOUD) or articulation (LSVT ARTIC) to assess single word intelligibility in the presence of background noise (babble and mall). Participants (64 PD and 20 Healthy) read words from the diagnostic rhyme test (DRT), an ANSI Standard for measuring intelligibility of speech, before and after one month (treatment or no treatment). Teams of trained listeners blindly rated the data. Speech intelligibility of words in the presence of both noise conditions improved in PD participants who had LSVT LOUD compared to the groups that had LSVT ARTIC or no treatment. Intensive speech treatment targeting prominent prosodic variables in LSVT LOUD had a positive effect on speech intelligibility at the single word level in PD.

A Neuromotor to Acoustical Jaw-Tongue Projection Model With Application in Parkinson's Disease Hypokinetic Dysarthria

Aim

The present work proposes the study of the neuromotor activity of the masseter-jaw-tongue articulation during diadochokinetic exercising to establish functional statistical relationships between surface Electromyography (sEMG), 3D Accelerometry (3DAcc), and acoustic features extracted from the speech signal, with the aim of characterizing Hypokinetic Dysarthria (HD). A database of multi-trait signals of recordings from an age-matched control and PD participants are used in the experimental study.

Hypothesis:

The main assumption is that information between sEMG and 3D acceleration, and acoustic features may be quantified using linear regression methods.

Methods

Recordings from a cohort of eight age-matched control participants (4 males, 4 females) and eight PD participants (4 males, 4 females) were collected during the utterance of a diadochokinetic exercise (the fast repetition of diphthong [aI]). The dynamic and acoustic absolute kinematic velocities produced during the exercises were estimated by acoustic filter inversion and numerical integration and differentiation of the speech signal. The amplitude distributions of the absolute kinematic and acoustic velocities (AKV and AFV) are estimated to allow comparisons in terms of Mutual Information.

Results

The regression results show the relationships between sEMG and dynamic and acoustic estimates. The projection methodology may help in understanding the basic neuromotor muscle activity regarding neurodegenerative speech in remote monitoring neuromotor and neurocognitive diseases using speech as the vehicular tool, and in the study of other speech-related disorders. The study also showed strong and significant cross-correlations between articulation kinematics, both for the control and the PD cohorts. The absolute kinematic variables presents an observable difference for the PD participants compared to the control group.

Conclusion

Kinematic distributions derived from acoustic analysis may be useful biomarkers toward characterizing HD in neuromotor disorders providing new insights into PD.

Speech aging: Production and perception

In this overview we describe literature on how speech production and speech perception change in healthy or normal aging across the adult lifespan. In the production section we review acoustic characteristics that have been investigated as potentially distinguishing younger and older adults. In the speech perception section studies concerning speaker age estimation and those investigating older listeners' perception are addressed. Our discussion focuses on major themes and other fruitful areas for future research. This article is categorized under: Linguistics > Language in Mind and Brain Linguistics > Linguistic Theory Psychology > Development and Aging.

Behavioral and neural correlates of speech motor sequence learning in stuttering and neurotypical speakers: an fMRI investigation

Stuttering is a neurodevelopmental disorder characterized by impaired production of coordinated articulatory movements needed for fluent speech. It is currently unknown whether these abnormal production characteristics reflect disruptions to brain mechanisms underlying the acquisition and/or execution of speech motor sequences. To dissociate learning and control processes, we used a motor sequence learning paradigm to examine the behavioral and neural correlates of learning to produce novel phoneme sequences in adults who stutter (AWS) and neurotypical controls. Participants intensively practiced producing pseudowords containing non-native consonant clusters (e.g., "gvasf") over two days. The behavioral results indicated that although the two experimental groups showed comparable learning trajectories, AWS performed significantly worse on the task prior to and after speech motor practice. Using functional magnetic resonance imaging (fMRI), the authors compared brain activity during articulation of the practiced words and a set of novel pseudowords (matched in phonetic complexity). FMRI analyses revealed no differences between AWS and controls in cortical or subcortical regions; both groups showed comparable increases in activation in left-lateralized brain areas implicated in phonological working memory and speech motor planning during production of the novel sequences compared to the practiced sequences. Moreover, activation in left-lateralized basal ganglia sites was negatively correlated with in-scanner mean disfluency in AWS. Collectively, these findings demonstrate that AWS exhibit no deficit in constructing new speech motor sequences but do show impaired execution of these sequences before and after they have been acquired and consolidated.

Neurophysiological investigation of auditory intensity dependence in patients with Parkinson's disease

There is accumulating evidence for auditory dysfunctions in patients with Parkinson's disease (PD). Moreover, a possible relationship has been suggested between altered auditory intensity processing and the hypophonic speech characteristics in PD. Nonetheless, further insight into the neurophysiological correlates of auditory intensity processing in patients with PD is needed primarily. In the present study, high-density EEG recordings were used to investigate intensity dependence of auditory evoked potentials (IDAEPs) in 14 patients with PD and 14 age- and gender-matched healthy control participants (HCs). Patients with PD were evaluated in both the on- and off-medication states. HCs were also evaluated twice. Significantly increased IDAEP of the N1/P2 was demonstrated in patients with PD evaluated in the on-medication state compared to HCs. Distinctive results were found for the N1 and P2 component. Regarding the N1 component, no differences in latency or amplitude were shown between patients with PD and HCs regardless of the medication state. In contrast, increased P2 amplitude was demonstrated in patients with PD evaluated in the on-medication state compared to the off-medication state and HCs. In addition to a dopaminergic deficiency, deficits in serotonergic neurotransmission in PD were shown based on increased IDAEP. Due to specific alterations of the N1-P2 complex, the current results suggest deficiencies in early-attentive inhibitory processing of auditory input in PD. This interpretation is consistent with the involvement of the basal ganglia and the role of dopaminergic and serotonergic neurotransmission in auditory gating.

The impact of Lee Silverman Voice Treatment (LSVT LOUD®) on voice, communication, and participation: Findings from a prospective, longitudinal study

BACKGROUND

Lee Silverman Voice Treatment (LSVT LOUD®), an intensive 4-week program of voice therapy, is regarded as the most well-researched, efficacious treatment for hypokinetic dysarthria in individuals with Parkinson's disease (PD). Although numerous studies have published acoustic and perceptual findings, there is comparatively little information about the impact of LSVT LOUD® on functional communication outcomes.

METHODS

This prospective, longitudinal study investigated the impact of treatment on daily communication in 25 individuals with PD. Three validated communication measures (the Voice Handicap Index, the Communicative Effectiveness Scale, and the Communicative Participation Item Bank) were given before and after treatment and again 4-8 weeks and 3-6 months following treatment. Communication partners were also asked to rate communication effectiveness at all four timepoints.

RESULTS

Significant improvements were found for all three self-reported scales which remained above baseline across all post-treatment timepoints. In addition, self-reported communicative effectiveness was significantly correlated with the assessments of communication partners. Particular benefits were reported for more complex communicative activities such as asking questions, giving detailed information, communicating in noisy situations, and speaking in groups.

CONCLUSIONS

Overall, the findings suggested that LSVT LOUD® promotes an increased sense of personal control over the communication difficulties resulting from PD by decreasing voice handicap and improving communication effectiveness and communicative participation. For individuals with PD, LSVT LOUD® may reduce the risk of social isolation by improving communication and facilitating social participation.

LEARNING OUTCOMES

As a result of this activity, the participant will be able to (1) describe the impact of PD on voice and communication, (2) discuss how these characteristics may be associated with more global measures of functional communication and particularly communicative participation, (3) explain which aspects of functional communication were affected by LSVT LOUD® as assessed by study participants and their communication partners.

Social Symptoms of Parkinson's Disease

Parkinson's disease (PD) is typically well recognized by its characteristic motor symptoms (e.g., bradykinesia, rigidity, and tremor). The cognitive symptoms of PD are increasingly being acknowledged by clinicians and researchers alike. However, PD also involves a host of emotional and communicative changes which can cause major disruptions to social functioning. These incude problems producing emotional facial expressions (i.e., facial masking) and emotional speech (i.e., dysarthria), as well as difficulties recognizing the verbal and nonverbal emotional cues of others. These social symptoms of PD can result in severe negative social consequences, including stigma, dehumanization, and loneliness, which might affect quality of life to an even greater extent than more well-recognized motor or cognitive symptoms. It is, therefore, imperative that researchers and clinicans become aware of these potential social symptoms and their negative effects, in order to properly investigate and manage the socioemotional aspects of PD. This narrative review provides an examination of the current research surrounding some of the most common social symptoms of PD and their related social consequences and argues that proactively and adequately addressing these issues might improve disease outcomes.

Guidelines for Speech Recording and Acoustic Analyses in Dysarthrias of Movement Disorders

Most patients with movement disorders have speech impairments resulting from sensorimotor abnormalities that affect phonatory, articulatory, and prosodic speech subsystems. There is widespread cross-discipline use of speech recordings for diagnostic and research purposes, despite which there are no specific guidelines for a standardized method. This review aims to combine the specific clinical presentations of patients with movement disorders, existing acoustic assessment protocols, and technological advances in capturing speech to provide a basis for future research in this field and to improve the consistency of clinical assessments. We considered 3 areas: the recording environment (room, seating, background noise), the recording process (instrumentation, vocal tasks, elicitation of speech samples), and the acoustic outcome data. Four vocal tasks, namely, sustained vowel, sequential and alternating motion rates, reading passage, and monologues, are integral aspects of motor speech assessment. Fourteen acoustic vocal speech features, including their hypothesized pathomechanisms with regard to typical occurrences in hypokinetic or hyperkinetic dysarthria, are hereby recommended for quantitative exploratory analysis. Using these acoustic features and experimental speech data, we demonstrated that the hyperkinetic dysarthria group had more affected speech dimensions compared with the healthy controls than had the hypokinetic speakers. Several contrasting speech patterns between both dysarthrias were also found. This article is the first attempt to provide initial recommendations for a standardized way of recording the voice and speech of patients with hypokinetic or hyperkinetic dysarthria; thus allowing clinicians and researchers to reliably collect, acoustically analyze, and compare vocal data across different centers and patient cohorts. © 2020 International Parkinson and Movement Disorder Society.

The Relationship Between Speech Characteristics and Motor Subtypes of Parkinson's Disease

Purpose The aim of this study was to examine whether acoustic dysarthria characteristics align with overall motor profile in individuals with Parkinson's disease (PD). Potential speech differences between tremor-dominant and non-tremor-dominant subtypes are theoretically motivated but empirically inconclusive. Method Twenty-seven individuals with dysarthria from PD provided a contextual speech sample. Participants were grouped into non-tremor-dominant (n = 12) and tremor-dominant (n = 15) motor subtypes according to the Unified Parkinson Disease Rating Scale. Dependent speech variables included fundamental frequency range, average pause duration, cepstral peak prominence, stuttering dysfluencies, and maze dysfluencies. Results There were no significant differences between the speech of the tremor-dominant and non-tremor-dominant groups. High within-group variability existed across parameters and motor subtypes. Conclusion Speech characteristics across the areas of phonation, prosody, and fluency did not differ appreciably between PD motor subtypes.