Tereza Tykalová

Imprecise vowel articulation as a potential early marker of Parkinson's disease: effect of speaking task.

The purpose of this study was to analyze vowel articulation across various speaking tasks in a group of 20 early Parkinsons disease (PD) individuals prior to pharmacotherapy. Vowels were extracted from sustained phonation, sentence repetition, reading passage, and monologue. Acoustic analysis was based upon measures of the first (F1) and second (F2) formant of the vowels /a/, /i/, and /u/, vowel space area (VSA), F2i/F2u and vowel articulation index (VAI). Parkinsonian speakers manifested abnormalities in vowel articulation across F2u, VSA, F2i/F2u, and VAI in all speaking tasks except sustained phonation, compared to 15 age-matched healthy control participants. Findings suggest that sustained phonation is an inappropriate task to investigate vowel articulation in early PD. In contrast, monologue was the most sensitive in differentiating between controls and PD patients, with classification accuracy up to 80%. Measurements of vowel articulation were able to capture even minor abnormalities in speech of PD patients with no perceptible dysarthria. In conclusion, impaired vowel articulation may be considered as a possible early marker of PD. A certain type of speaking task can exert significant influence on vowel articulation. Specifically, complex tasks such as monologue are more likely to elicit articulatory deficits in parkinsonian speech, compared to other speaking tasks.

Automated analysis of connected speech reveals early biomarkers of Parkinson’s disease in patients with rapid eye movement sleep behaviour disorder

For generations, the evaluation of speech abnormalities in neurodegenerative disorders such as Parkinson’s disease (PD) has been limited to perceptual tests or user-controlled laboratory analysis based upon rather small samples of human vocalizations. Our study introduces a fully automated method that yields significant features related to respiratory deficits, dysphonia, imprecise articulation and dysrhythmia from acoustic microphone data of natural connected speech for predicting early and distinctive patterns of neurodegeneration. We compared speech recordings of 50 subjects with rapid eye movement sleep behaviour disorder (RBD), 30 newly diagnosed, untreated PD patients and 50 healthy controls, and showed that subliminal parkinsonian speech deficits can be reliably captured even in RBD patients, which are at high risk of developing PD or other synucleinopathies. Thus, automated vocal analysis should soon be able to contribute to screening and diagnostic procedures for prodromal parkinsonian neurodegeneration in natural environments.

Quantitative assessment of motor speech abnormalities in idiopathic rapid eye movement sleep behaviour disorder

OBJECTIVE Patients with idiopathic rapid eye movement sleep behaviour disorder (RBD) are at substantial risk for developing Parkinsons disease (PD) or related neurodegenerative disorders. Speech is an important indicator of motor function and movement coordination, and therefore may be an extremely sensitive early marker of changes due to prodromal neurodegeneration. METHODS Speech data were acquired from 16 RBD subjects and 16 age- and sex-matched healthy control subjects. Objective acoustic assessment of 15 speech dimensions representing various phonatory, articulatory, and prosodic deviations was performed. Statistical models were applied to characterise speech disorders in RBD and to estimate sensitivity and specificity in differentiating between RBD and control subjects. RESULTS Some form of speech impairment was revealed in 88% of RBD subjects. Articulatory deficits were the most prominent findings in RBD. In comparison to controls, the RBD group showed significant alterations in irregular alternating motion rates (p = 0.009) and articulatory decay (p = 0.01). The combination of four distinctive speech dimensions, including aperiodicity, irregular alternating motion rates, articulatory decay, and dysfluency, led to 96% sensitivity and 79% specificity in discriminating between RBD and control subjects. Speech impairment was significantly more pronounced in RBD subjects with the motor score of the Unified Parkinsons Disease Rating Scale greater than 4 points when compared to other RBD individuals. CONCLUSION Simple quantitative speech motor measures may be suitable for the reliable detection of prodromal neurodegeneration in subjects with RBD, and therefore may provide important outcomes for future therapy trials.

Acoustic investigation of stress patterns in Parkinson's disease.

OBJECTIVES Although reduced stress is thought to be one of the most deviant speech dimensions in hypokinetic dysarthria associated with Parkinsons disease (PD), the mechanisms of stress production in PD have not been thoroughly explored by objective methods. The aim of the present study was to quantify the effect of PD on prosodic characteristics and to describe contrastive stress patterns in parkinsonian speech. METHODS The ability of 20 male speakers with early PD and 16 age- and gender-matched healthy controls (HCs) to signal contrastive stress was investigated. Each participant was instructed to unnaturally emphasize five key words while reading a short block of text. Acoustic analyses were based on the measurement of pitch, intensity, and duration. In addition, an innovative measurement termed the stress pattern index (SPI) was designed to mirror the effect of all distinct acoustic cues exploited during stress production. RESULTS Although PD patients demonstrated a reduced ability to convey contrastive stress, they could still notably increase pitch, intensity, and duration to emphasize a word within a sentence. No differences were revealed between PD and HC stress productions using the measurements of pitch, intensity, duration, and intensity range. However, restricted SPI and pitch range were evident in the PD group. CONCLUSIONS A reduced ability to express stress seems to be the distinctive pattern of hypokinetic dysarthria, even in the early stages of PD. Because PD patients were able to consciously improve their speech performance using multiple acoustic cues, the introduction of speech therapy may be rewarding.

Objective Acoustic Quantification of Phonatory Dysfunction in Huntington's Disease

Purpose Although speech motor changes are reported as a common sign of Huntington’s disease (HD), the most prominent signs of voice dysfunction remain unknown. The aim of the current study was to explore specific changes in phonatory function in subjects with HD. Method 34 subjects with HD and 34 age- and sex-matched healthy controls were examined. Participants performed sustained vowel phonation for subsequent analyses of airflow insufficiency, aperiodicity, irregular vibrations of vocal folds, signal perturbations, increased noise, and articulation deficiency. In total, 272 phonations were collected and 12 voice parameters were extracted. Subsequently, a predictive model was built to find the most salient patterns of voice disorders in HD. The results were also correlated with disease severity according to the Unified HD Rating Scale (UHDRS) motor score. Results Subjects with HD showed deterioration in all investigated phonatory functions. Irregular pitch fluctuations, sudden phonation interruption, increased noise, and misplacement of articulators were found to be most significant patterns of phonatory dysfunction in HD (p<0.001). The combination of these four dysphonia aspects contributed to the best classification performance of 94.1% (sensitivity: 95.1%; specificity: 93.2%) in the separation of HD patients from healthy participants. Our results further indicated stronger associations between sudden phonation interruption and voluntary components of the UHDRS (r = −0.48, p<0.01) and between misplacement of articulators and involuntary components of the UHDRS (r = 0.52, p<0.01). Conclusions Our configuration of phonatory features can detect subtle voice abnormalities in subjects with HD. As impairment of phonatory function in HD was found to parallel increasing motor involvement, a qualitative description of voice dysfunction may be helpful to gain better insight into the pathophysiology of the vocal mechanism.

Distinct patterns of imprecise consonant articulation among Parkinson’s disease, progressive supranuclear palsy and multiple system atrophy

HighlightsDistinctive speech patterns in atypical Parkinsonian syndromes are very rare.We investigated consonant articulation across Parkinsonian and healthy speakers.Voice onset time of voiceless plosives was related to overall dysarthria severity.Duration of pre‐voicing was significantly shorter only in multiple system atrophy.Voiced plosives in multiple system atrophy tended to be misclassified as voiceless. ABSTRACT Distinct speech characteristics that may aid in differentiation between Parkinson’s disease (PD), progressive supranuclear palsy (PSP) and multiple system atrophy (MSA) remain tremendously under‐explored. Here, the patterns and degree of consonant articulation deficits across voiced and voiceless stop plosives in 16 PD, 16 PSP, 16 MSA and 16 healthy control speakers were evaluated using acoustic and perceptual methods. Imprecise consonant articulation was observed across all Parkinsonian groups. Voice onset time of voiceless plosives was more prolonged in both PSP and MSA compared to PD, presumably due to greater severity of dysarthria and slower articulation rate. Voice onset time of voiced plosives was significantly shorter only in MSA, likely as a consequence of damage to cerebellar structures. In agreement with the reduction of pre‐voicing, MSA manifested increased number of voiced plosives misclassified as voiceless at perceptual evaluation. Timing of articulatory movements may provide important clues about the pathophysiology of underlying disease.

Characteristics of motor speech phenotypes in multiple sclerosis

BACKGROUND Motor speech disorders in multiple sclerosis (MS) are poorly understood and their quantitative, objective acoustic characterization remains limited. Additionally, little data regarding relationships between the severity of speech disorders and neurological involvement in MS, as well as the contribution of pyramidal and cerebellar functional systems on speech phenotypes, is available. METHODS Speech data were acquired from 141 MS patients with Expanded Disability Status Scale (EDSS) ranging from 1 to 6.5 and 70 matched healthy controls. Objective acoustic speech assessment including subtests on phonation, oral diadochokinesis, articulation and prosody was performed. RESULTS The prevalence of dysarthria in our MS cohort was 56% while the severity was generally mild and primarily consisted of a combination of spastic and ataxic components. Prosodic-articulatory disorder presenting with monopitch, articulatory decay, excess loudness variations and slow rate was the most salient. Speech disorders reflected subclinical motor impairment with 78% accuracy in discriminating between a subgroup of asymptomatic MS (EDSS < 2.0) and control speakers. Speech disorder severity was related to the severity of neurological involvement. Decreased articulation rate was moderately correlated to EDSS as well as all subtests of the multiple sclerosis functional composite. The strongest correlation was observed between irregular oral diadochokinesis and the 9-Hole Peg Test (r = - 0.65, p < 0.001). Irregular oral diadochokinesis and excess loudness variations significantly separated pure pyramidal and mixed pyramidal-cerebellar MS subgroups. CONCLUSIONS Automated speech analyses may provide valuable biomarkers of disease progression in MS as dysarthria represents common and early manifestation that reflects disease disability and underlying pyramidal-cerebellar pathophysiology.

Dualistic effect of pallidal deep brain stimulation on motor speech disorders in dystonia

BACKGROUND Although pallidal deep brain stimulation (GPi-DBS) is an effective treatment for dystonia, it may cause important stimulation-induced side-effects such as hypokinetic dysarthria or stuttering. However, the reasons behind the occurrence of these side-effects remain unknown. OBJECTIVE To objectively investigate the impact of GPi-DBS on patients with dystonia on speech fluency, intelligibility, and key aspects of hyperkinetic and hypokinetic dysarthria. METHODS Speech was systematically evaluated in 19 dystonic patients with GPi-DBS. Each patient was tested twice within one day in both the GPi-DBS ON and GPi-DBS OFF stimulation conditions. A control sample of 19 matched healthy speakers underwent the same speech assessment. RESULTS We observed an improvement of hyperkinetic dysarthria symptoms in 47% and an aggravation of hypokinetic dysarthria symptoms in 26% of patients with the GPi-DBS switched ON. A higher stimulus intensity was found in a group of patients in whom the hypokinetic dysarthria worsened with the GPi-DBS ON when compared to other dystonic patients (p = 0.02). Furthermore, we revealed a significant increase of dysfluent words in the GPi-DBS ON when compared to OFF condition (p = 0.001) associated with the shorter distance of the active contact localization along the medio-lateral direction (r = -0.70, p = 0.005). CONCLUSION This study provides evidence of dualistic effects of GPi-DBS on speech in dystonia manifested as an improvement of hyperkinetic or a deterioration of hypokinetic dysarthria. Our findings suggest that lower stimulation parameters and placement of active contacts more laterally in the internal globus pallidus should be preferred to avoid the possible side effects of hypokinetic dysarthria and dysfluency.

High-Accuracy Voice-Based Classification Between Patients With Parkinson’s Disease and Other Neurological Diseases May Be an Easy Task With Inappropriate Experimental Design

Recently, based on voice cepstral analysis, (Benba et al, 2016) have reported discrimination between patientswith Parkinson’s disease and different neurological disorderswith high classificationaccuracyup to 90%. Using the same approach, wewere able to experimentally separate two groups of normal healthy speakers with 96% classification accuracy and showed that the method proposed by Benba et al. may not be appropriate for discrimination between different neurological diseases. In particular, voice cepstral analysis appears to be sensitive to specific speakers’ characteristics such as gender or age. Our findings emphasize several assumptions that can be considered as basic necessary conditions for research reporting speech data in progressive neurodegenerative diseases.

C16 Hoarseness can be found in vocalisations of both human as well as genetically modified minipig model of huntington’s disease

Background Voice quality of patients with Huntington’s disease is commonly perceived as harsh, hoarse, or breathy. Digital signal analysis allows to quantify the degree of hoarseness objectively by harmonic-to-noise ratio. Such a simple automated acoustic measurement could provide cheap, non-invasive, and effective biomarker of Huntington’s disease. Aims The aim of this study is to explore, whether the hoarseness is presented in human as well as in a genetically modified minipig animal model of Huntington’s disease. Methods Data were digitally recorded using head-set microphone with linear frequency response. Sustained phonations of the vowel/a/and vowel/i/were recorded from 20 patients with Huntington’s disease (mean duration of disease 6.4 years, standard deviation 3.0 years) and 23 matched healthy controls. Vocalisations were acquired from 14 Huntington’s disease transgenic minipigs (mean age 45.9 months, standard deviation 14.5 months), and 12 matched healthy siblings. Harmonic-to-noise ratio was analysed only on voiced segments of phonations and grunt-like vocalisations. Results Harmonic-to-noise ratio was significantly decreased between patients with Huntington’s disease (mean 19.3 dB, standard deviation 5.4 dB) when compared to healthy control speakers (mean 22.4 dB, standard deviation 3.1 dB) (p < 0.05) as well as between transgenic minipigs (mean 3.26 dB, standard deviation 1.9 dB) as compared to healthy siblings (mean 4.3 dB, standard deviation 1.3 dB) (p < 0.05). Conclusions Our results demonstrate that hoarseness is presented in both human as well as animal pig model of Huntington’s disease. Although dissimilarities of vocal apparatus between human and minipig are obvious, our findings suggest that pathophysiology mechanisms of Huntington’s disease influence voice in both human and minipig model similarly. More complex vocal assessment may be beneficial for monitoring of Huntington’s disease onset in transgenic minipigs.