An Aerodynamic Study of Phonations in Patients With Parkinson Disease (PD)

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.

Neuronal Encoding of Speech Features in the Human Thalamus in Parkinson's Disease and Essential Tremor Patients

BACKGROUND AND OBJECTIVES

The human thalamus is known, from stimulation studies and functional imaging, to participate in high-level language tasks. The goal of this study is to find whether and how speech features, in particular, vowel phonemes, are encoded in the neuronal activity of the thalamus, and specifically of the left ventralis intermediate nucleus (Vim), during speech production, perception, and imagery.

METHODS

In this cross-sectional study, we intraoperatively recorded single neuron activity in the left Vim of eight neurosurgical patients with Parkinson's disease (PD) (n = 4) or essential tremor (n = 4) undergoing implantation of deep brain stimulation (n = 3) or radiofrequency lesioning (n = 5) while patients articulated the five monophthongal vowel sounds.

RESULTS

In this article, we report that single neurons in the left Vim encode individual vowel phonemes mainly during speech production but also during perception and imagery. They mainly use one of two encoding schemes: broad or sharp tuning, with a similar percentage of units each. Sinusoidal tuning has been demonstrated in almost half of the broadly tuned units. Patients with PD had a lower percentage of speech-related units in each aspect of speech (production, perception, and imagery), a significantly lower percentage of broadly tuned units, and significantly lower median firing rates during speech production and perception, but significantly higher rates during imagery, than patients with essential tremor.

CONCLUSION

The results suggest that the left Vim uses mixed encoding schemes for speech features. Our findings explain, at the single neuron level, why deep brain stimulation and radiofrequency lesioning of the left Vim are likely to cause speech side effects. Moreover, they may indicate that speech-related units in the left Vim of patients with PD may be degraded even in the subclinical phase.

Computerized analysis of speech and voice for Parkinson's disease: A systematic review

BACKGROUND AND OBJECTIVE

Speech impairment is an early symptom of Parkinson's disease (PD). This study has summarized the literature related to speech and voice in detecting PD and assessing its severity.

METHODS

A systematic review of the literature from 2010 to 2021 to investigate analysis methods and signal features. The keywords "Automatic analysis" in conjunction with "PD speech" or "PD voice" were used, and the PubMed and ScienceDirect databases were searched. A total of 838 papers were found on the first run, of which 189 were selected. One hundred and forty-seven were found to be suitable for the review. The different datasets, recording protocols, signal analysis methods and features that were reported are listed. Values of the features that separate PD patients from healthy controls were tabulated. Finally, the barriers that limit the wide use of computerized speech analysis are discussed.

RESULTS

Speech and voice may be valuable markers for PD. However, large differences between the datasets make it difficult to compare different studies. In addition, speech analytic methods that are not informed by physiological understanding may alienate clinicians.

CONCLUSIONS

The potential usefulness of speech and voice for the detection and assessment of PD is confirmed by evidence from the classification and correlation results.

Early voice therapy for unilateral vocal fold paralysis improves subglottal pressure and glottal closure

PURPOSE

In cases of unilateral vocal fold paralysis (UVFP), voice disorders caused by glottic insufficiency can lead to a considerable reduction in the patient's quality of life. Voice therapy (VT) is an effective treatment that must be started early after the onset of vocal fold paralysis. This study examined the effect of early VT for patients with UVFP occurring after esophagectomy.

MATERIALS AND METHODS

Patients who had residual UVFP at 1 month postoperatively after esophagectomy for esophageal cancer between November 2014 and March 2017 were evaluated. Seventeen patients were divided into the VT group (n = 6) and non-VT group (n = 11). We compared these two groups and retrospectively examined the effect of early VT. The study endpoints included aerodynamic tests, laryngeal endoscopy, laryngeal stroboscopy, and glottal closure. All of these evaluations were performed at preoperatively and at 1 and 3 months postoperatively.

RESULTS

Subglottal pressure reduced notably in the VT group, and both the mean flow rate and maximum phonation time tended to improve after VT. Conversely, there were no significant differences in MFR and MPT in the non-VT group. Furthermore, although UVFP remained after VT, we achieved glottal closure for all three patients. Conversely, only two of the six patients with glottic insufficiency in the non-VT group achieved glottal closure.

CONCLUSION

VT may be effective for improving impaired vocal function in patients with UVFP. It is reasonable to expect that VT can be initiated 1 month after the onset of vocal fold paralysis.

The physical significance of acoustic parameters and its clinical significance of dysarthria in Parkinson's disease

Dysarthria is universal in Parkinson's disease (PD) during disease progression; however, the quality of vocalization changes is often ignored. Furthermore, the role of changes in the acoustic parameters of phonation in PD patients remains unclear. We recruited 35 PD patients and 26 healthy controls to perform single, double, and multiple syllable tests. A logistic regression was performed to differentiate between protective and risk factors among the acoustic parameters. The results indicated that the mean f0, max f0, min f0, jitter, duration of speech and median intensity of speaking for the PD patients were significantly different from those of the healthy controls. These results reveal some promising indicators of dysarthric symptoms consisting of acoustic parameters, and they strengthen our understanding about the significance of changes in phonation by PD patients, which may accelerate the discovery of novel PD biomarkers.

Voice Parameter Changes in Professional Musician-Singers Singing with and without an Instrument: The Effect of Body Posture

BACKGROUND AND AIM

The impact of body posture on vocal emission is well known. Postural changes may increase muscular resistance in tracts of the phono-articulatory apparatus and lead to voice disorders. This work aimed to assess whether and to which extent body posture during singing and playing a musical instrument impacts voice performance in professional musicians.

SUBJECTS AND METHODS

Voice signals were recorded from 17 professional musicians (pianists and guitarists) while they were singing and while they were singing and playing a musical instrument simultaneously. Metrics were extracted from their voice spectrogram using the Multi-Dimensional Voice Program (MDVP) and included jitter, shift in fundamental voice frequency (sF0), shimmer, change in peak amplitude, noise to harmonic ratio, Voice Turbulence Index, Soft Phonation Index (SPI), Frequency Tremor Intensity Index, Amplitude Tremor Intensity Index, and maximum phonatory time (MPT). Statistical analysis was performed using two-tailed t tests, one-way ANOVA, and χ2 tests. Subjects' body posture was visually assessed following the recommendations of the Italian Society of Audiology and Phoniatrics. Thirty-seven voice signals were collected, 17 during singing and 20 during singing and playing a musical instrument.

RESULTS

Data showed that playing an instrument while singing led to an impairment of the "singer formant" and to a decrease in jitter, sF0, shimmer, SPI, and MPT. However, statistical analysis showed that none of the MDVP metrics changed significantly when subjects played an instrument compared to when they did not. Shoulder and back position affected voice features as measured by the MDVP metrics, while head and neck position did not. In particular, playing the guitar decreased the amplitude of the "singer formant" and increased noise, causing a typical "raucous rock voice."

CONCLUSIONS

Voice features may be affected by the use of the instrument the musicians play while they sing. Body posture selected by the musician while playing the instrument may affect expiration and phonation.

The Effects of Respiratory Muscle Training on Phonatory Measures in Individuals with Parkinson's Disease

INTRODUCTION

In individuals with Parkinson's disease (PD), respiratory muscle weakness and rigidity, bradykinesia of abdominal muscles and stiffness of the chest wall, affect the respiratory component of voice intensity due to reduced pulmonary capacity and airflow needed to vibrate the vocal folds. It may be possible to improve voice production by strengthening respiratory muscles. The purpose of this study was to evaluate the effects of inspiratory and expiratory muscle training on voice production outcomes in individuals with PD.

METHOD

Thirty-one participants with PD were randomly allocated to three study groups (control group n = 10, inspiratory training group, n = 11, and expiratory training group, n = 11). The inspiratory and expiratory group performed a home-based inspiratory and expiratory muscle training program, respectively (five sets of five repetitions). Both groups trained six times a week for 2 months using a progressively increased resistance. The control group performed expiratory muscle training using the same protocol and a fixed resistance. Phonatory measures, maximum inspiratory/expiratory pressure, and spirometric indexes were assessed before and at 2 months after training.

RESULTS

Differences in peak subglottic pressure were moderate (d = 0.59) between expiratory and inspiratory groups, large between inspiratory and control groups (d = 1.32), and large between expiratory and control groups (d = 1.96). Differences in maximum phonation time were large (d = 1.26) between inspiratory and control groups, moderate (negative) between expiratory and inspiratory groups (d = -0.60), and moderate between expiratory and control groups (d = 0.72). Differences in peak sound pressure level were large (d = 1.27) between inspiratory and control groups, trivial between expiratory and inspiratory groups (d = -0.18), and large between expiratory and control groups (d = 1.10).

CONCLUSIONS

Inspiratory muscle training is effective in improving maximum phonation time, and expiratory muscle training is more effective for improving peak subglottic pressure, and peak sound pressure level in individuals with PD.