Acoustic Intensity and Speech Breathing Kinematics in a Patient with Parkinson’s Disease

Parkinson’s disease (PD) is a neurodegenerative disease which affects the basal ganglia control circuit (Duffy, 2013). The motor speech disorder most strongly associated with PD is hypokinetic dysarthria, which presents with distinctive speech characteristics including reduced loudness and the inability to adequately maintain loud speech (Darley, Aronson, & Brown 1969; Duffy 2013). This is due to the variable kinematics for speech breathing associated with PD, which may result in abnormal muscular excursions, reduced vital capacity, and irregular breathing cycles (Duffy, 2013). The impaired ventilatory control can be attributed to the rigidity of muscles of inhalation and exhalation, as well as bradykinesia and hypokinesia. The study aimed to evaluate whether a patient with PD was able to manipulate their acoustic intensity, and if such intensity changes were accompanied by changes in speech breathing kinematics in a novel intraoperative environment. The study’s data were collected intra-operatively during surgery for deep brain stimulation and recordings from the subthalamic nucleus and cortex. The patient was instructed to modulate acoustic intensity while repeating three syllable CV triplets. Speech breathing kinematics of the rib cage were obtained using a Piezo Crystal Effort Sensor with a double buckle band throughout speech production. The speech breathing kinematics of interest were duration, displacement, and peak velocity of inhalation, peak velocity of exhalation, and duration from onset of exhalation to onset of speech, as well as a descriptive comparison between tidal breathing and speech breathing. Spearman Rho correlations indicated that there were weak to no relationships observed between speech breathing kinematics and intensity in this specific participant. However, a medium effect size (Hedge’s g) was observed between tidal and speech breathing for inhalation duration, and small to medium effect size for inhalation displacement and peak velocity. While previous literature suggests that people with PD can manipulate intensity when cued as a result of kinematic modulations for speech breathing, the current study does not support these findings for this one patient. However, previously reported differences between tidal and speech breathing were supported. Potential explanations for the lack of intensity modulation are explored, including constraints induced by the intra-operative environment

PERIORAL BIOMECHANICS, KINEMATICS, AND ELECTROPHYSIOLOGY IN PARKINSON'S DISEASE

This investigation quantitatively characterized the orofacial biomechanics, labial kinematics, and associated electromyography (EMG) patterns in individuals with Parkinson's disease (PD) as a function of anti-PD medication state. Passive perioral stiffness, a clinical correlate of rigidity, was sampled using a face-referenced OroSTIFF system in 10 mildly diagnosed PD and 10 age/sex-matched control elderly. Labial movement amplitudes and velocities were evaluated using a 4-dimensional computerized motion capture system. Associated perioral EMG patterns were sampled to examine the characteristics of perioral muscles and compensatory muscular activation patterns during repetitive syllable productions. This study identified several trends that reflect various characteristics of perioral system differences between PD and control subjects: 1. The presence of high tonic EMG patterns after administration of dopaminergic treatment indicated an up-regulation of the central mechanism, which may serve to regulate orofacial postural control. 2. Multilevel regression modeling showed greater perioral stiffness in PD subjects, confirming the clinical correlate of rigidity in these patients. 3. Similar to the clinical symptoms in the upper and lower limb, a reduction of range of motion (hypokinesia) and velocity (bradykinesia) was evident in the PD orofacial system. Administration of dopaminergic treatment improved hypokinesia and bradykinesia. 4. A significant correlation was found between perioral stiffness and the range of labial movement, indicating these two symptoms may result in part from a common neural substrate. 5. As speech rate increased, PD speakers down-scaled movement amplitude and velocity compared to the control subjects, reflecting a compensatory mechanism to maintain target speech rates. 6. EMG from orbicularis oris inferior (OOIm) and depressor labii inferioris (DLIm) muscles revealed a limited range of muscle activation level in PD speakers, reflecting the underlying changes in motor unit firing behavior due to basal ganglia dysfunction. The results of this investigation provided a quantitative description of the perioral stiffness, labial kinematics, and EMG patterns in PD speakers. These findings indicate that perioral stiffness may provide clinicians a quantitative biomechanical correlate to medication response, movement aberrations, and EMG compensatory patterns in PD. The utilization of these objective assessments will be helpful in diagnosing, assessing, and monitoring the progression of PD to examine the efficacy of pharmacological, neurosurgical, and behavioral interventions

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

Impact of speech rate and speaker-modulated vocal effort on laryngeal kinematics in people with Parkinson’s disease

PURPOSE: Communication difficulties in Parkinson’s Disease (PD) are multifactorial. Observing cardinal motor symptoms may be insufficient in qualifying speech dysfunction in people with Parkinson’s Disease (PwPD). This study aimed to use high-speed video (HSV) endoscopy to explore the use of three measures of laryngeal kinematics – spatiotemporal index, asymmetry index, and kinematic stiffness ratio – as a novel means of examining vocal motor control in PD, to better understand the pathophysiology of PwPD within the phonatory subsystem. METHOD: 24 PwPD and 24 age- and sex-matched controls were trained to produce repetitions of a VCV target, /ifi/, while varying their speech rate and vocal effort during simultaneous HSV nasoendoscopic and acoustic recordings. Kinematic measures were calculated from HSV recordings during vocal fold adduction using both manual glottal angle tracking and a semi-automated algorithm. Six separate repeated measures analyses of variance (ANOVAs) were completed to determine the spatiotemporal index, asymmetry index and kinematic stiffness ratio, with main effects of group and condition (fast rate, regular rate, slow rate, mild effort, moderate effort, maximum effort). Alpha levels < .05 were considered statistically significant. Effect sizes of significant differences were calculated by using partial eta squared. RESULTS: The repeated ANOVAs showed a statistically significant effect of group on spatiotemporal index values across both rate (p < .01) and effort (p <.05) and on asymmetry index values across rate (p < .01). No statistically significant main effect of rate or effort or interaction effects between group × rate or group × effort were observed for all kinematic measures. CONCLUSION: This study determined that spatiotemporal index, a measure of variability in movement, and asymmetry index, a measure of movement efficiency, are significantly higher for PwPD compared to controls. These findings are consistent with increased variability and reduced efficiency observed in other speech subsystems in PwPD. Further research is recommended to explore the use of laryngeal kinematics in characterizing the pathophysiology of the laryngeal subsystem in PwPD

The Effect of Formant Measurement Methods on Vowel Space in Patients with Parkinson\u27s Disease Before and After Voice Treatment

LSVT-LOUD® has been shown to improve phonatory quality in patients with PD. Previous studies have shown an increase in vowel space area following treatment, but questions remain regarding possible methodological issues in interaction with phonatory factors. This study addresses these questions by comparing multiple formant measurment methods and vowel space metrics. Ten participants were recorded on two separate days before and after treatment. Formants were measured using a human-guided reference (dubbed \u27HGIM\u27), LPC, and two forms of cepstrally-liftered spectrum. Multiple vowel space metrics including the vowel articulation index, F2i/F2u, area of the vowel quadrilateral, and vowel formant dispersion utilized both lax and corner vowels to explore vowel space changes. Analysis revealed no significant change in vowel space following LSVT. High variability in LPC with a fixed coefficient was noted. These results do not support previous claims of increased vowel space but suggest that formant measurement methods may influence results

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

ObjectivesOur 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 designThis is a prospective case–control study.MethodsSixty-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.ResultstVSA 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.ConclusionThis acoustic study identified potential subclinical vowel-related speech biomarkers of dysarthria in speakers with Parkinson’s disease who have not been diagnosed with dysarthria

The effect of concurrent cognitive, linguistic and motor tasks on speech intensity in Parkinson’s disease

This study investigated the effect of concurrent tasks on speech intensity in Parkinson’s disease (PD). Thirteen PD participants and twenty-two controls performed three tasks concurrent with a speech task. The speech task involved a repeated carrier phrase and a target word. The concurrent tasks involved math addition (cognitive), verb generation (linguistic), and manual visuomotor tracking (motor) at three levels of difficulty. All three concurrent tasks were associated with reduced speech intensity relative to the isolated speech task. The concurrent motor task was generally associated with the greatest reduction in speech intensity. Task performance measures were not significantly different for the concurrent and isolated tasks. PD participants demonstrated relatively worse performance on the linguistic task. The results of this study failed to support the energizing hypothesis. Instead, the results appear to support a cognitive/attention resource allocation hypothesis with regard to the effect of concurrent tasks on speech intensity regulation in PD

Speech function in persons with Parkinson\u27s disease: effects of environment, task and treatment

Parkinson’s Disease (PD) is a degenerative neurological disease affecting aspects of movement, including speech. Persons with PD are reported to have better speech functioning in the clinical setting than in the home setting, but this has not been quantified. New methodologies in ambulatory measures of speech are emerging that allow investigation of non-clinical settings. The following questions are addressed: Is speech different between environments in PD and in healthy controls? Can clinical tasks predict speech behaviors in the home? Is treatment proven effective by measures in the home? What can we glean from methods of measurement of speech function in the home? The experiment included 13 persons with PD and 12 healthy controls, studied in the clinical and home environments, and 7 of those 13 persons with PD participated in a treatment study. Major findings included: Spontaneous speech intelligibility, not intensity, was the differentiating factor between persons with PD and healthy controls. Intelligibility and intensity were not related. Both groups presented with higher sentence intensity in the home environment. Spontaneous speech intelligibility in the clinic was related to spontaneous speech intelligibility in the home. The Sentence Intelligibility Test emerged as the best predictor of spontaneous speech intelligibility in the home. Differences between pilot treatment groups measured in the home on intensity and intelligibility were not large enough to make a clinical trial feasible. Individual differences may account for many of these results, for example more severely impaired patients may have shown different data. Drawing conclusions regarding the home environment via measures outside the home should be carefully considered. Ambulatory measures of speech are a viable option for studying speech function in non-clinical settings, and technology is advancing. Further investigation is needed to develop methodologies and normative values for speech in the home