Factors influencing the efficacy of delayed auditory feedback in treating dysarthria associated with Parkinson\u27s disease

Parkinson\u27s disease patients exhibit a high prevalence of speech deficits including excessive speech rate, reduced intelligibility, and disfluencies. The present study examined the effects of delayed auditory feedback (DAF) as a rate control intervention for dysarthric speakers with Parkinson\u27s disease. Adverse reactions to relatively long delay intervals are commonly observed during clinical use of DAF, and seem to result from improper matching of the delayed signal. To facilitate optimal use of DAF, therefore, clinicians must provide instruction, modeling, and feedback. Clinician instruction is frequently used in speech-language therapy, but has not been evaluated during use of DAF-based interventions. Therefore, the primary purpose of the present study was to evaluate the impact of clinician instruction on the effectiveness of DAF in treating speech deficits. A related purpose was to compare the effects of different delay intervals on speech behaviors. An A-B-A-B single-subject design was utilized. The A phases consisted of a sentence reading task using DAF, while the B phases incorporated clinician instruction into the DAF protocol. During each of the 16 experimental sessions, speakers read with four different delay intervals (0 ms, 50 ms, 100 ms, and 150 ms). During the B phases, the experimenter provided verbal feedback and modeling pertaining to how precisely the speaker matched the delayed signal. Dependent variables measured were speech rate, percent intelligible syllables, and percent disfluencies. Three males with Parkinson\u27s disease and an associated dysarthria participated in the study. Results revealed that for all three speakers, DAF significantly reduced reading rate and produced significant improvements in either intelligibility (for Speaker 3) or fluency (for Speakers 1 and 2). A delay interval of 150 ms produced the greatest reductions in reading rates for all three speakers, although any of the DAF settings used was sufficient to produce significant improvements in either intelligibility or fluency. In addition, supplementing the DAF intervention with clinician instruction resulted in significantly greater gains achieved with DAF. These findings confirmed the effectiveness of various intervals of DAF in improving speech deficits in Parkinson\u27s disease speakers, particular when patients are provided with instruction and modeling from the clinician

Role of Therapeutic Devices in Enhancing Speech Intelligibility and Vocal Intensity in an Individual with Parkinson’s Disease

The prevailing speech therapy techniques for treating hypokinetic dysarthria in individuals with Parkinson\u27s disease (PD) yields improvements within the clinical setting, however, maintenance and generalization of acquired behaviors continue to be a challenge. The purpose of this study was to investigate the effects of portable therapeutic devices including Ambulatory Phonation Monitor with biofeedback (APM) and auditory masker in maintenance and carryover of improved speech. Our participant was an individual diagnosed with PD for the past 25 years who continued to display speech disturbances despite undergoing several behavioral speech therapy programs and neurosurgical procedures. Speech intelligibility and average intensity measures under automatic, elicited, and spontaneous speech tasks were recorded pre- and postusage of APM and auditory masker for a period of 1 week each. Preliminary findings showed no significant difference in the measures between means (P\u3e0.05) across all tasks for both the devices. Suggestions for future research on therapeutic devices are discussed

Music-based interventions for aphasia could act through a motor-speech mechanism : a systematic review and case-control analysis of published individual participant data

Background: Melodic Intonation Therapy, a music-based intervention for the recovery of oral language production in aphasia, has been shown to be particularly effective in patients with Broca’s aphasia compared to other aphasia subtypes. It has been suggested that this therapy might improve language output by acting on motor-speech deficits often associated with Broca’s aphasia. In this article, we examine the relevance of a motor-speech mechanism for music-based interventions designed to improve verbal expression in patients with any type of aphasia. Aim: To test the association between the presence of motor-speech disorders (MSDs) and improvement with music-based protocols targeting verbal expression in participants with aphasia. Methods and procedures: We conducted a systematic review of publications reporting language production outcomes following a music-based intervention in participants with aphasia and performed a case–control analysis on extracted individual participant data (IPD). The databases PubMed, MEDLINE (1800 to 9 March 2018), and PsycINFO (1806 to March 2018) were screened, followed with cross-referencing. We recorded data at the level of study and, when possible, at the IPD level. When not explicitly reported, we applied a series of heuristics to infer the presence/absence of an MSD in participants. Binomial logistic regressions were performed to ascertain the effects of the presence of an MSD, aphasia severity, treatment duration (in weeks), and treatment intensity (hours/week) on the likelihood that participants would show a speech or a language improvement following intervention. Outcomes & Results: Forty original articles were included in this review. Twenty-two reported sufficient details to be included in our IPD analysis, for a total sample of 105 participants. Most interventions included some sort of singing as their primary music-based facilitation technique for language production. For speech improvement, statistically significant predictor variables were the presence of an MSD and treatment intensity. For language improvement, statistically significant predictor variables were the presence of an MSD, treatment intensity, and duration. Severity of aphasia was not associated with the likelihood of speech or language improvement. Conclusion: Music-based interventions for language production in aphasia may act via a motor-speech mechanism. We suggest that music and singing-based therapies might be further investigated as treatment options for patients with MSDs, whether associated with aphasia or not

Current Rehabilitation Therapies in Parkinson’s Disease

Rehabilitation is one of the important non-pharmacological interventions for Parkinson’s disease (PD). At the time of diagnosis, an appropriate exercise regimen can be prescribed based on the patient’s symptoms. Rehabilitative therapies should be continued throughout the disease course. This chapter summarized the standard specifications and research progression on PD from perspectives of assessment and treatment of rehabilitation. The physical therapy, occupational therapy, speech-language therapy, and neuromodulation therapy are the focus of the introduction. Accurate and comprehensive functional assessment is the premise of rehabilitation plan. Various approaches are used individually or in combined targeted at one or more dysfunction. Although there is still no consensus about the optimal approach about intensity, the frequency of treatment sessions, and complexity, rehabilitation is proved to be able to induce short-term, but clinically important benefits, particularly for gait and balance. The rehabilitative program for PD should be targeted to practicing and learning specific activities in the core areas and be tailored to the individual patients’ characteristics. In addition to improving patient’s performance, environmental modification and alleviation of caregivers are also included in rehabilitation intervention. Innovative techniques have been recently proposed: virtual reality and exergaming, motor imagery and action observation, robot-assisted physiotherapy, and nonconventional therapies

Models and Analysis of Vocal Emissions for Biomedical Applications

The MAVEBA Workshop proceedings, held on a biannual basis, collect the scientific papers presented both as oral and poster contributions, during the conference. The main subjects are: development of theoretical and mechanical models as an aid to the study of main phonatory dysfunctions, as well as the biomedical engineering methods for the analysis of voice signals and images, as a support to clinical diagnosis and classification of vocal pathologies

Effects of deep brain stimulation on speech in patients with Parkinson’s disease and dystonia

Disorders affecting the basal ganglia can have a severe effect on speech motor control. The effect can vary depending on the pathophysiology of the basal ganglia disease but in general terms it can be classified as hypokinetic or hyperkinetic dysarthria. Despite the role of basal ganglia on speech, there is a marked discrepancy between the effect of medical and surgical treatments on limb and speech motor control. This is compounded by the complex nature of speech and communication in general, and the lack of animal models of speech motor control. The emergence of deep brain stimulation of basal ganglia structures gives us the opportunity to record systematically the effects on speech and attempt some assumptions on the role of basal ganglia on speech motor control. The aim of the present work was to examine the impact of bilateral subthalamic nucleus deep brain stimulation (STN-DBS) for Parkinson’s disease (PD) and globus pallidus internus (GPi-DBS) for dystonia on speech motor control. A consecutive series of PD and dystonia patients who underwent DBS was evaluated. Patients were studied in a prospective longitudinal manner with both clinical assessment of their speech intelligibility and acoustical analysis of their speech. The role of pre-operative clinical factors and electrical parameters of stimulation, mainly electrode positioning and voltage amplitude was systematically examined. In addition, for selected patients, tongue movements were studied using electropalatography. Aerodynamic aspects of speech were also studied. The impact of speech therapy was assessed in a subgroup of patients. The clinical evaluation of speech intelligibility one and three years post STN-DBS in PD patients showed a deterioration of speech, partly related to medially placed electrodes and high amplitude of stimulation. Pre-operative predictive factors included low speech intelligibility before surgery and longer disease duration. Articulation rather than voice was most frequently affected with a distinct dysarthria type emerging, mainly hyperkinetic-dystonic, rather than hypokinetic. Traditionally effective therapy for PD dysarthria had little to no benefit following STN-DBS. Speech following GPi-DBS for dystonia did not significantly change after one year of stimulation. A subgroup of patients showed hypokinetic features, mainly reduced voice volume and fast rate of speech more typical of Parkinsonian speech. Speech changes in both STN-DBS and GPi-DBS were apparent after six months of stimulation. This progressive deterioration of speech and the critical role of the electrical parameters of stimulation suggest a long-term effect of electrical stimulation of basal ganglia on speech motor control

Unveiling the impact of neuromotor disorders on speech: a structured approach combining biomechanical fundamentals and statistical machine learning

Speech has been shown to convey clinically useful information in the study of Neurodegenerative Disorders (NDs), such as Parkinson’s Disease (PD). Traditionally the use of speech as an exploratory tool in People with Parkinson’s (PwP) has focused on the estimation of acoustic characteristics and their study at face value, analysing the physio-acoustical markers and using them as features for the differentiation between Healthy Controls (HC) and PwP. The present work takes a step further, given the intricate interoperation between neuromotor activity, responsible for both planning and driving the system, and the production of the acoustic speech signal; by the study of speech, this relationship may be properly exploited and analysed, providing a non-invasive method for the diagnosis, analysis, and observation of NDs. This work aims to introduce a working model that is capable of linking both domains and serves as a projection tool to provide insights about a speaker’s neuromotor state. This is based on a review of the neurophysiological background of the structure and function of the nervous system, and a review of the main nervous system dysfunctions involved in PD and other related neuromotor disorders. The role of the respiratory, phonatory, and articulatory systems is reviewed in the production of voice and speech under normal and pathological circumstances. This setting might allow for speech to be considered a useful trait within the precision medicine framework, as it provides a personal biometric marker that is innate and easy to elicit, can be recorded remotely with inexpensive equipment, is non-invasive, cost-effective, and easy to process. The problem can be divided into two main categories: firstly, a binary detection task distinguishing between healthy controls and individuals with NDs based on the projection model and phonatory estimates; secondly, a progression and tracking task providing a set of quantitative indices that enable clinically interpretable scores. This study aims to define a set of features and models that help to characterise hypokinetic dysarthria (HD). These incorporate the neuroscientific knowhow semantically and quantitatively to be used in clinical decision support tools that provide mechanistic insight on the processes involved in speech production, incorporating into the algorithmic element neuromotor considerations that add to better interpretability, consequently leading to improved clinical decisions and diagnosis. An overview of the acoustic signal processing algorithms for use in speech articulation and phonation system inversion regarding neuromotor disorder assessment is provided. An algorithmic methodology for model inversion and exploration has been proposed for the functional characterization and system inversion of each subsystem involved under the neuro-biomechanical foundations exposed before. A description of the vocal fold biomechanics using the glottal source, and formant dynamics provides the base for specific mapping to articulation kinematics. The statistical methods used in performance evaluation are based on three-way comparisons and transversal and longitudinal assessment by classical hypothesis testing. Three related experimental studies are shown to empirically illustrate the potential of phonation and articulation analysis: the characterization of PD from glottal biomechanics based on the amplitude distributions of the glottal flow and on the vocal fold body stiffness in assessing the efficiency of transcranial magnetic stimulation, and the description of PD dysarthria through an articulation projection model. The results from the biomechanical analysis of phonation showed that the behaviour of glottal source amplitude distributions from PD and healthy controls using three-way comparisons and hierarchical clustering were essentially distinguishable from those from normative young participants with the best accuracy scores produced by SVM classifiers of 94.8% (males) and 92.2% (females). Nevertheless, PD participants were barely separable from age-matched controls, possibly pointing to confounding factors due to age. The outcomes from using vocal fold stiffness in assessing the efficiency of transcranial magnetic stimulation showed mixed results, as some PD participants reflected clear improvements in phonation stability after stimulation, whereas some others did not. Some cases of sham controls experienced also minor improvements of unknown origin, possibly expressing a placebo effect. The overall results on the efficiency of stimulation showed an accuracy global score of 67% over the 18 cases studied. The results from articulation projection modelling showed the possibility of formulating personalised models for PD and control participants to transform acoustic formant dynamics into articulation kinematics. This might open the possibility of characterising PD dysarthria based on speech audio records. The most remarkable findings of the study include the determination of the glottal source amplitude distribution behaviour of normative and PD participants; the impact of age effects in phonation as a confounding factor in neuromotor disorder characterization; the importance of ensuring that the classification of speech dysarthria is based on principles that can be explained and interpreted; the need of taking into account the effects of medication when framing new classification experiments; the potential of using EEG-band decomposition to analyse vocal fold stiffness correlates, as well as the possibility of using these descriptions in longitudinal monitoring of treatment efficiency; the feasibility of establishing a relationship between acoustic and kinematic variables by projection model inversion; and the potential of these descriptions for estimating neuromotor activities in midbrain related to phonation and articulation activity. The most important outcome to be brought forth from the thesis is that the methodology used throughout the project uses a bottom-up approach based on speech model inversion at the acoustical, biomechanical, and neuromotor levels allowing to estimate glottal signals, biomechanical correlates, and neuromotor activity from speech alone, establishing a common neuromechanical characterisation framework on its own

Models and Analysis of Vocal Emissions for Biomedical Applications

The MAVEBA Workshop proceedings, held on a biannual basis, collect the scientific papers presented both as oral and poster contributions, during the conference. The main subjects are: development of theoretical and mechanical models as an aid to the study of main phonatory dysfunctions, as well as the biomedical engineering methods for the analysis of voice signals and images, as a support to clinical diagnosis and classification of vocal pathologies

Models and Analysis of Vocal Emissions for Biomedical Applications

The International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications (MAVEBA) came into being in 1999 from the particularly felt need of sharing know-how, objectives and results between areas that until then seemed quite distinct such as bioengineering, medicine and singing. MAVEBA deals with all aspects concerning the study of the human voice with applications ranging from the neonate to the adult and elderly. Over the years the initial issues have grown and spread also in other aspects of research such as occupational voice disorders, neurology, rehabilitation, image and video analysis. MAVEBA takes place every two years always in Firenze, Italy. This edition celebrates twenty years of uninterrupted and succesfully research in the field of voice analysis