No differential effects of subthalamic nucleus vs. globus pallidus deep brain stimulation in Parkinson's disease: Speech acoustic and perceptual findings.

Background: Deep Brain Stimulation (DBS) in the Subthalamic Nucleus (STN) or the Globus Pallidus Interna (GPI) is well-established as a surgical technique for improving global motor function in patients with idiopathic Parkinson's Disease (PD). Previous research has indicated speech deterioration in more than 30% of patients after STN-DBS implantation, whilst speech outcomes following GPI-DBS have received far less attention. Research comparing speech outcomes for patients with PD receiving STN-DBS and GPI-DBS can inform pre-surgical counseling and assist with clinician and patient decision-making when considering the neural targets selected for DBS-implantation. The aims of this pilot study were (1) to compare perceptual and acoustic speech outcomes for a group of patients with PD receiving bilateral DBS in the STN or the GPI with DBS stimulation both ON and OFF, and (2) examine associations between acoustic and perceptual speech measures and clinical characteristics. Methods: Ten individuals with PD receiving STN-DBS and eight individuals receiving GPI-DBS were audio-recorded reading a passage. Three listeners blinded to neural target and stimulation condition provided perceptual judgments of intelligibility and overall speech severity. Speech acoustic measures were obtained from the recordings. Acoustic and perceptual measures and clinical characteristics were compared for the two neural targets and stimulation conditions. Results: Intelligibility and speech severity were not significantly different across neural target or stimulation conditions. Generally, acoustic measures were also not statistically different for the two neural targets or stimulation conditions. Acoustic measures reflecting more varied speech prosody were associated with improved intelligibility and lessened severity. Convergent correlations were found between UPDRS-III speech scores and perceptual measures of intelligibility and severity. Conclusion: This study reports a systematic comparison of perceptual and acoustic speech outcomes following STN-DBS and GPI-DBS. Statistically significant differences in acoustic measures for the two neural targets were small in magnitude and did not yield group differences in perceptual measures. The absence of robust differences in speech outcomes for the two neural targets has implications for pre-surgical counseling. Results provide preliminary support for reliance on considerations other than speech when selecting the target for DBS in patients with PD.

Oral diadochokinetic markers of X-linked dystonia-parkinsonism.

INTRODUCTION: X-linked dystonia-parkinsonism (XDP) is a neurodegenerative disorder that may result in severe speech impairment. The literature suggests that there are differences in the speech of individuals with XDP and healthy controls. This study aims to examine the motor speech characteristics of the mixed dystonia-parkinsonism phase of XDP. METHOD: We extracted acoustic features representing coordination, consistency, speed, precision, and rate from 26 individuals with XDP and 26 controls using Praat, MATLAB, and R software. Group demographics were compared using descriptive statistics. A one-way analysis of variance (ANOVA) with Tukey's post hoc test was used to test for acoustic differences between the two groups. RESULTS: The XDP group had significantly lower consistency, speed, precision, and rate than controls (p < 0.05). For coordination, the XDP group had a smaller ratio of pause duration during transitions when compared to controls. DISCUSSION: To our knowledge, this study is the first to describe the motor speech characteristics of the mixed dystonia-parkinsonism phase of XDP. The motor speech of mixed dystonia-parkinsonism XDP is similar to prior characterizations of mixed hyperkinetic-hypokinetic dysarthria with noted differences in articulatory coordination, consistency, speed, precision, and rate from healthy controls. Identifying the motor speech components of all three phenotypes of XDP (i.e., dystonia-dominant phase, parkinsonism-dominant phase, and mixed dystonia-parkinsonism phase) is needed to establish markers of speech impairment to track disease progression.

The association between longitudinal declines in speech sound accuracy and speech intelligibility in speakers with amyotrophic lateral sclerosis.

The purpose of this study was to examine how neurodegeneration secondary to amyotrophic lateral sclerosis (ALS) impacts speech sound accuracy over time and how speech sound accuracy, in turn, is related to speech intelligibility. Twenty-one participants with ALS read the Bamboo Passage over multiple data collection sessions across several months. Phonemic and orthographic transcriptions were completed for all speech samples. The percentage of phonemes accurately produced was calculated across each phoneme, sound class (i.e. consonants versus vowels), and distinctive feature (i.e. features involved in Manner of Articulation, Place of Articulation, Laryngeal Voicing, Tongue Height, and Tongue Advancement). Intelligibility was determined by calculating the percentage of words correctly transcribed orthographically by naive listeners. Linear mixed effects models were conducted to assess the decline of each distinctive feature over time and its impact on intelligibility. The results demonstrated that overall phonemic production accuracy had a nonlinear relationship with speech intelligibility and that a subset of features (i.e. those dependent on precise lingual and labial constriction and/or extensive lingual and labial movement) were more important for intelligibility and were more impacted over time than other features. Furthermore, findings revealed that consonants were more strongly associated with intelligibility than vowels, but consonants did not significantly differ from vowels in their decline over time. These findings have the potential to (1) strengthen mechanistic understanding of the physiological constraints imposed by neuronal degeneration on speech production and (2) inform the timing and selection of treatment and assessment targets for individuals with ALS.

Improving Perceptual Speech Ratings: The Effects of Auditory Training on Judgments of Dysarthric Speech.

PURPOSE: Auditory training has been shown to reduce rater variability in perceptual voice assessment. Because rater variability is also a central issue in the auditory-perceptual assessment of dysarthria, this study sought to determine if training produces a meaningful change in rater reliability, criterion validity, and scaling magnitude of four features: overall speech impairment, articulatory imprecision, monotony, and slow rate. METHOD: Forty-four nonexperts randomized to training and nontraining listener groups completed a pretest and posttest. Only the former group underwent auditory training between pre- and posttests. For both testing and training, listeners rated samples from speakers with amyotrophic lateral sclerosis (ALS), speakers with Parkinson's disease (PD), and neurologically healthy control speakers using separate visual analog scales (VASs) for each of the four features. Intraclass correlation coefficients were used to compare inter- and intrarater reliability between pre- and posttest for both listener groups. For criterion validity, severity ratings from the two nonexpert listener groups were compared to those of two experienced listeners for all four features. To determine changes in scaling magnitude, raw VAS scores for each feature were compared from pre- to posttest within the two nonexpert listener groups. Scaling changes were also compared between the two listener groups for the pre- and posttest conditions. RESULTS AND CONCLUSIONS: In the training group, a meaningful improvement in interrater reliability was observed for some features in all three speaker groups, but not in the nontraining group. In contrast, for intrarater reliability, in the nontraining group, a meaningful improvement was observed for many features in all three speaker groups, but only for PD monotony and slow rate in the training group. All ratings from the nonexpert listeners were valid except for monotony. Raw VAS scores did not meaningfully change from pre- to posttest for any of the features, but there was a trend toward lower scores posttraining, mainly for the ALS samples. Modifications to the auditory training paradigm to further improve reliability and validity, along with future goals for optimizing training, are discussed.

Lexical Characteristics of the Speech Intelligibility Test: Effects on Transcription Intelligibility for Speakers With Multiple Sclerosis and Parkinson's Disease.

PURPOSE: Lexical characteristics of speech stimuli can significantly impact intelligibility. However, lexical characteristics of the widely used Speech Intelligibility Test (SIT) are unknown. We aimed to (a) define variation in neighborhood density, word frequency, grammatical word class, and type-token ratio across a large corpus of SIT sentences and tests and (b) determine the relationship of lexical characteristics to speech intelligibility in speakers with multiple sclerosis (MS), Parkinson's disease (PD), and neurologically healthy controls. METHOD: Using an extant database of 92 speakers (32 controls, 30 speakers with MS, and 30 speakers with PD), percent correct intelligibility scores were obtained for the SIT. Neighborhood density, word frequency, word class, and type-token ratio were calculated and summed for each of the 11 sentences of each SIT test. The distribution of each characteristic across SIT sentences and tests was examined. Linear mixed-effects models were performed to assess the relationship between intelligibility and the lexical characteristics. RESULTS: There was large variability in the distribution of lexical characteristics across this large corpus of SIT sentences and tests. Modeling revealed a relationship between intelligibility and the lexical characteristics, with word frequency and word class significantly contributing to the model. CONCLUSIONS: Three primary findings emerged: (a) There was considerable variability in lexical characteristics both within and across the large corpus of SIT tests; (b) there was not a robust association between intelligibility and the lexical characteristics; and (c) findings from a study demonstrating an effect of neighborhood density and word frequency on intelligibility were replicated. Clinical and research implications of the findings are discussed, and three exemplar SIT tests systematically controlling for neighborhood density and word frequency are provided.

Clear Speech Variants: An Investigation of Intelligibility and Speaker Effort in Speakers With Parkinson's Disease.

PURPOSE: This study investigated the effects of three clear speech variants on sentence intelligibility and speaking effort for speakers with Parkinson's disease (PD) and age- and sex-matched neurologically healthy controls. METHOD: Fourteen speakers with PD and 14 neurologically healthy speakers participated. Each speaker was recorded reading 18 sentences from the Speech Intelligibility Test in their habitual speaking style and for three clear speech variants: clear (SC; given instructions to speak clearly), hearing impaired (HI; given instructions to speak with someone with a hearing impairment), and overenunciate (OE; given instructions to overenunciate each word). Speakers rated the amount of physical and mental effort exerted during each speaking condition using visual analog scales (averaged to yield a metric of overall speaking effort). Sentence productions were orthographically transcribed by 50 naive listeners. Linear mixed-effects models were used to compare intelligibility and speaking effort across the clear speech variants. RESULTS: Intelligibility was reduced for the PD group in comparison to the control group only in the habitual condition. All clear speech variants significantly improved intelligibility above habitual levels for the PD group, with OE maximizing intelligibility, followed by the SC and HI conditions. Both groups rated speaking effort to be significantly higher for both the OE and HI conditions versus the SC and habitual conditions. DISCUSSION: For speakers with PD, all clear speech variants increased intelligibility to a level comparable to that of healthy controls. All clear speech variants were also associated with higher levels of speaking effort than habitual speech for the speakers with PD. Clinically, findings suggest that clear speech training programs consider using the instruction "overenunciate" for maximizing intelligibility. Future research is needed to identify if high levels of speaking effort elicited by the clear speech variants affect long-term sustainability of the intelligibility benefit.

Acoustic and Kinematic Assessment of Motor Speech Impairment in Patients With Suspected Four-Repeat Tauopathies.

PURPOSE: The aim of this study was to use acoustic and kinematic speech measures to characterize type of motor speech impairment-apraxia of speech (AOS) versus dysarthria-in individuals with four-repeat tauopathy (4RT)-associated syndromes, including nonfluent variant primary progressive aphasia (nfvPPA), primary progressive AOS (PPAOS), corticobasal syndrome (CBS), and progressive supranuclear palsy syndrome (PSPs). METHOD: Twenty patient participants were recruited and stratified into two groups: (a) a motor-speech-impaired group of individuals with nfvPPA, PPAOS, CBS, or PSPs and suspected 4RT pathology ("MSI+") and (b) a non-motor-speech-impaired group of individuals with logopenic variant primary progressive aphasia ("MSI-"). Ten healthy, age-matched controls also participated in the study. Participants completed a battery of speech tasks, and 15 acoustic and kinematic speech measures were derived. Quantitative speech measures were grouped into feature categories ("AOS features," "dysarthria features," "shared features"). In addition to quantitative speech measures, two certified speech-language pathologists made independent, blinded auditory-perceptual ratings of motor speech impairment. A principal component analysis (PCA) was conducted to investigate the relative contributions of quantitative features. RESULTS: Quantitative speech measures were generally concordant with independent clinician ratings of motor speech impairment severity. Hypothesis-driven groupings of quantitative measures differentiated predominantly apraxic from predominantly dysarthric presentations within the MSI+ group. PCA results provided additional evidence for differential profiles of motor speech impairment in the MSI+ group; heterogeneity across individuals is explained in large part by varying levels of overall severity-captured by the shared feature variable group-and degree of apraxia severity, as measured by the AOS feature variable group. CONCLUSIONS: Quantitative features reveal heterogeneity of MSI in the 4RT group in terms of both overall severity and subtype of MSI. Results suggest the potential for acoustic and kinematic speech assessment methods to inform characterization of motor speech impairment in 4RT-associated syndromes. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.21401778.

Validity of Off-the-Shelf Automatic Speech Recognition for Assessing Speech Intelligibility and Speech Severity in Speakers With Amyotrophic Lateral Sclerosis.

PURPOSE: There is increasing interest in using automatic speech recognition (ASR) systems to evaluate impairment severity or speech intelligibility in speakers with dysarthria. We assessed the clinical validity of one currently available off-the-shelf (OTS) ASR system (i.e., a Google Cloud ASR API) for indexing sentence-level speech intelligibility and impairment severity in individuals with amyotrophic lateral sclerosis (ALS), and we provided guidance for potential users of such systems in research and clinic. METHOD: Using speech samples collected from 52 individuals with ALS and 20 healthy control speakers, we compared word recognition rate (WRR) from the commercially available Google Cloud ASR API (Machine WRR) to clinician-provided judgments of impairment severity, as well as sentence intelligibility (Human WRR). We assessed the internal reliability of Machine and Human WRR by comparing the standard deviation of WRR across sentences to the minimally detectable change (MDC), a clinical benchmark that indicates whether results are within measurement error. We also evaluated Machine and Human WRR diagnostic accuracy for classifying speakers into clinically established categories. RESULTS: Human WRR achieved better accuracy than Machine WRR when indexing speech severity, and, although related, Human and Machine WRR were not strongly correlated. When the speech signal was mixed with noise (noise-augmented ASR) to reduce a ceiling effect, Machine WRR performance improved. Internal reliability metrics were worse for Machine than Human WRR, particularly for typical and mildly impaired severity groups, although sentence length significantly impacted both Machine and Human WRRs. CONCLUSIONS: Results indicated that the OTS ASR system was inadequate for early detection of speech impairment and grading overall speech severity. While Machine and Human WRR were correlated, ASR should not be used as a one-to-one proxy for transcription speech intelligibility or clinician severity ratings. Overall, findings suggested that the tested OTS ASR system, Google Cloud ASR, has limited utility for grading clinical speech impairment in speakers with ALS.

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 × âˆš2 × 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.

Longitudinal Recovery of Speech Motor Function Following Facial Transplantation: A Prospective Observational Study.

OBJECTIVES: Although facial transplantation is considered effective for restoring facial appearance, research on speech outcomes following surgery is limited. More research is critically needed to inform patients of expected rates and extent of recovery, and to develop interventions aimed at improving speech outcomes. METHODS: Four patients in early recovery (3 weeks-24 months postsurgery) and three patients in late recovery (36-60 months postsurgery) were included. Clinical measures of speech recovery, including speech intelligibility measured using the Sentence Intelligibility Test, a lip strength testing device (Iowa Oral Performance Instrument), and kinematic measures of lip and jaw function measured using high-resolution 3D optical motion capture were used to describe the rate and extent of functional speech and lip recovery, describe and compare the rate of functional speech recovery and kinematic lip and jaw changes in early and late stages of recovery, and explore the association between kinematic measures and functional speech. RESULTS: Speech intelligibility, speaking rate, and lip strength were below normative values in the first 2 years of postsurgery. Participants in the first 2 years of recovery demonstrated steeper slopes of improvement in clinical and kinematic measures than participants in the later stages of recovery (36-64 months). Gains in jaw range of movement and gains in lip speed and range of movement were significantly correlated with rates of sentence intelligibility improvement. Gains in lip strength were not associated with functional speech improvement. CONCLUSIONS: These findings motivate ongoing work aimed at developing interventions for improving motor speech function in this population. LEVEL OF EVIDENCE: 3 Laryngoscope, 132:2359-2367, 2022.

The Relationship Between Single-Word Speech Severity and Intelligibility in Childhood Apraxia of Speech.

PURPOSE: The purpose of this study was to investigate the association between perceived single-word speech severity and intelligibility in children with childhood apraxia of speech (CAS), with and without comorbid language impairment (LI), and to investigate the contribution of different CAS signs to perceived single-word speech severity and single-word intelligibility. METHOD: Thirty children with CAS, 18 with comorbid LI, completed the Goldman-Fristoe Test of Articulation-Second Edition (GFTA-2). Trained judges coded children's responses for signs of CAS and percent phonemes correct. Nine listeners, blind to diagnoses, rated speech severity using a visual analog scale. Intelligibility was assessed by comparing listeners' orthographic transcriptions of children's responses to target responses. RESULTS: Measures of speech severity (GFTA-2 standard score, number of unique CAS signs, total CAS signs, and mean severity rating) were significantly correlated with measures of intelligibility (GFTA-2 raw score, percent phonemes correct, and mean intelligibility score). Speech severity and intelligibility did not differ significantly between children with and without LI. Only consonant errors contributed significant variability to speech severity. Consonant errors and stress errors contributed significant variability to intelligibility. CONCLUSIONS: Findings suggest that visual analog scale ratings are a valid and convenient measure of single-word speech severity and that GFTA-2 raw score is an equally convenient measure of single-word intelligibility. The result that consonant errors were by far the major contributor to single-word speech severity and intelligibility in children with CAS, with stress errors also making a small contribution to intelligibility, suggests that consonant accuracy and appropriate lexical stress should be prime therapeutic targets for these children in the context of treatment addressing motor planning/programming, self-monitoring, and self-correcting. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.19119350.

Effects of low-frequency repetitive transcranial magnetic stimulation in adductor laryngeal dystonia: a safety, feasibility, and pilot study.

PURPOSE: The effects of neuromodulation are virtually unexplored in adductor laryngeal dystonia (AdLD), a disorder characterized by involuntary contraction of intrinsic laryngeal muscles. Recent findings indicated that intracortical inhibition is reduced in people with AdLD. Low-frequency repetitive transcranial magnetic stimulation (rTMS) induces prolonged intracortical inhibition, but the effects in AdLD are unexplored. This pilot and feasibility study aimed to examine the safety, feasibility, and effects of a single session 1 Hz rTMS over the laryngeal motor cortex (LMC) in people with AdLD and healthy individuals. METHODS: The stimulation location was individualized and determined through TMS-evoked responses in the thyroarytenoid muscles using fine-wire electrodes. 1200 pulses of 1 Hz rTMS were delivered to the left LMC in two groups: Control (n = 6) and AdLD (n = 7). Tolerance, adverse effects, intracortical inhibition, and voice recordings were collected immediately before and after rTMS. Voice quality was assessed with acoustic-based and auditory-perceptual measures. RESULTS: All participants tolerated the procedures, with no unexpected adverse events or worsening of symptoms. No significant effects on intracortical inhibition were observed. In the AdLD group, there was a large-effect size after rTMS in vocal perturbation measures and a small-effect size in decreased phonatory breaks. CONCLUSIONS: One rTMS session over the LMC is safe and feasible, and demonstrated trends of beneficial effects on voice quality and phonatory function in AdLD. These preliminary findings support further investigation to assess clinical benefits in a future randomized sham-controlled trial. CLINICALTRIALS.GOV: NCT02957942, registered on November 8, 2016.

"You Say Severe, I Say Mild": Toward an Empirical Classification of Dysarthria Severity.

PURPOSE: The main purpose of this study was to create an empirical classification system for speech severity in patients with dysarthria secondary to amyotrophic lateral sclerosis (ALS) by exploring the reliability and validity of speech-language pathologists' (SLPs') ratings of dysarthric speech. METHOD: Ten SLPs listened to speech samples from 52 speakers with ALS and 20 healthy control speakers. SLPs were asked to rate the speech severity of the speakers using five response options: normal, mild, moderate, severe, and profound. Four severity-surrogate measures were also calculated: SLPs transcribed the speech samples for the calculation of speech intelligibility and rated the effort it took to understand the speakers on a visual analog scale. In addition, speaking rate and intelligible speaking rate were calculated for each speaker. Intrarater and interrater reliability were calculated for each measure. We explored the validity of clinician-based severity ratings by comparing them to the severity-surrogate measures. Receiver operating characteristic (ROC) curves were conducted to create optimal cutoff points for defining dysarthria severity categories. RESULTS: Intrarater and interrater reliability for the clinician-based severity ratings were excellent and were comparable to reliability for the severity-surrogate measures explored. Clinician severity ratings were strongly associated with all severity-surrogate measures, suggesting strong construct validity. We also provided a range of values for each severity-surrogate measure within each severity category based on the cutoff points obtained from the ROC analyses. CONCLUSIONS: Clinician severity ratings of dysarthric speech are reliable and valid. We discuss the underlying challenges that arise when selecting a stratification measure and offer recommendations for a classification scheme when stratifying patients and research participants into speech severity categories.

Validation of an Acoustic-Based Framework of Speech Motor Control: Assessing Criterion and Construct Validity Using Kinematic and Perceptual Measures.

PURPOSE: This study investigated the criterion (analytical and clinical) and construct (divergent) validity of a novel, acoustic-based framework composed of five key components of motor control: Coordination, Consistency, Speed, Precision, and Rate. METHOD: Acoustic and kinematic analyses were performed on audio recordings from 22 subjects with amyotrophic lateral sclerosis during a sequential motion rate task. Perceptual analyses were completed by two licensed speech-language pathologists, who rated each subject's speech on the five framework components and their overall severity. Analytical and clinical validity were assessed by comparing performance on the acoustic features to their kinematic correlates and to clinician ratings of the five components, respectively. Divergent validity of the acoustic-based framework was then assessed by comparing performance on each pair of acoustic features to determine whether the features represent distinct articulatory constructs. Bivariate correlations and partial correlations with severity as a covariate were conducted for each comparison. RESULTS: Results revealed moderate-to-strong analytical validity for every acoustic feature, both with and without controlling for severity, and moderate-to-strong clinical validity for all acoustic features except Coordination, without controlling for severity. When severity was included as a covariate, the strong associations for Speed and Precision became weak. Divergent validity was supported by weak-to-moderate pairwise associations between all acoustic features except Speed (second-formant [F2] slope of consonant transition) and Precision (between-consonant variability in F2 slope). CONCLUSIONS: This study demonstrated that the acoustic-based framework has potential as an objective, valid, and clinically useful tool for profiling articulatory deficits in individuals with speech motor disorders. The findings also suggest that compared to clinician ratings, instrumental measures are more sensitive to subtle differences in articulatory function. With further research, this framework could provide more accurate and reliable characterizations of articulatory impairment, which may eventually increase clinical confidence in the diagnosis and treatment of patients with different articulatory phenotypes.

Psychometric Analysis of an Ecological Vocal Effort Scale in Individuals With and Without Vocal Hyperfunction During Activities of Daily Living.

Objective The purpose of this study was to examine the psychometric properties of an ecological vocal effort scale linked to a voicing task. Method Thirty-eight patients with nodules, 18 patients with muscle tension dysphonia, and 45 vocally healthy control individuals participated in a week of ambulatory voice monitoring. A global vocal status question was asked hourly throughout the day. Participants produced a vowel-consonant-vowel syllable string and rated the vocal effort needed to produce the task on a visual analog scale. Test-retest reliability was calculated for a subset using the intraclass correlation coefficient, ICC(A, 1). Construct validity was assessed by (a) comparing the weeklong vocal effort ratings between the patient and control groups and (b) comparing weeklong vocal effort ratings before and after voice rehabilitation in a subset of 25 patients. Cohen's d, the standard error of measurement (SEM), and the minimal detectable change (MDC) assessed sensitivity. The minimal clinically important difference (MCID) assessed responsiveness. Results Test-retest reliability was excellent, ICC(A, 1) = .96. Weeklong mean effort was statistically higher in the patients than in controls (d = 1.62) and lower after voice rehabilitation (d = 1.75), supporting construct validity and sensitivity. SEM was 4.14, MDC was 11.47, and MCID was 9.74. Since the MCID was within the error of the measure, we must rely upon the MDC to detect real changes in ecological vocal effort. Conclusion The ecological vocal effort scale offers a reliable, valid, and sensitive method of monitoring vocal effort changes during the daily life of individuals with and without vocal hyperfunction.

The effects of continuous oromotor activity on speech motor learning: speech biomechanics and neurophysiologic correlates.

Sustained limb motor activity has been used as a therapeutic tool for improving rehabilitation outcomes and is thought to be mediated by neuroplastic changes associated with activity-induced cortical excitability. Although prior research has reported enhancing effects of continuous chewing and swallowing activity on learning, the potential beneficial effects of sustained oromotor activity on speech improvements is not well-documented. This exploratory study was designed to examine the effects of continuous oromotor activity on subsequent speech learning. Twenty neurologically healthy young adults engaged in periods of continuous chewing and speech after which they completed a novel speech motor learning task. The motor learning task was designed to elicit improvements in accuracy and efficiency of speech performance across repetitions of eight-syllable nonwords. In addition, transcranial magnetic stimulation was used to measure the cortical silent period (cSP) of the lip motor cortex before and after the periods of continuous oromotor behaviors. All repetitions of the nonword task were recorded acoustically and kinematically using a three-dimensional motion capture system. Productions were analyzed for accuracy and duration, as well as lip movement distance and speed. A control condition estimated baseline improvement rates in speech performance. Results revealed improved speech performance following 10 min of chewing. In contrast, speech performance following 10 min of continuous speech was degraded. There was no change in the cSP as a result of either oromotor activity. The clinical implications of these findings are discussed in the context of speech rehabilitation and neuromodulation.

Speech and swallowing deficits in X-Linked Dystonia-Parkinsonism.

INTRODUCTION: X-linked Dystonia-Parkinsonism (XDP) is a progressive, disabling disease characterized by the devastating impairment of bulbar function, including speech and swallowing. Despite these detrimental impacts, bulbar impairments in this population are not well characterized. OBJECTIVES: To identify impairments in the bulbar system measured by oromotor performance in individuals with XDP relative to healthy controls. Secondarily, to detect diagnostic bulbar markers that are sensitive and specific to the initial years of XDP. METHODS: This case-control study included 25 healthy controls and 30 participants with XDP, divided into two subgroups based on the median of their disease length. Multiple clinical and instrumental oromotor tasks and measures were used to evaluate bulbar motor function. RESULTS: Differences were found between both the subgroups with XDP and healthy controls on almost all measures, including maximum performance tasks such as tongue strength, alternating motion rate (AMR), and sequential motion rate (SMR) (p < 0.05). Differences were found between the XDP subgroups and the control group for the percentage of pause time during the speech, a rating of speech severity, and a swallowing task (ps < 0.05). Scores on self-reported questionnaires, tongue strength, the number of repetitions produced during an AMR, percent pause, and speech severity demonstrated good sensitivity and specificity to differentiate the initial years of XDP onset from healthy controls. CONCLUSIONS: Our findings revealed impairments across bulbar functions in participants within the first 7 years of the XDP onset. Highly sensitive and specific bulbar impairment measures were detected in instrumental and self-reported measures that are fundamental for monitoring disease.

Two Distinct Clinical Phenotypes of Bulbar Motor Impairment in Amyotrophic Lateral Sclerosis.

Objective: Understanding clinical variants of motor neuron diseases such as amyotrophic lateral sclerosis (ALS) is critical for discovering disease mechanisms and across-patient differences in therapeutic response. The current work describes two clinical subgroups of patients with ALS that, despite similar levels of bulbar motor involvement, have disparate clinical and functional speech presentations. Methods: Participants included 47 healthy control speakers and 126 speakers with ALS. Participants with ALS were stratified into three clinical subgroups (i.e., bulbar asymptomatic, bulbar symptomatic high speech function, and bulbar symptomatic low speech function) based on clinical metrics of bulbar motor impairment. Acoustic and lip kinematic analytics were derived from each participant's recordings of reading samples and a rapid syllable repetition task. Group differences were reported on clinical scales of ALS and bulbar motor severity and on multiple speech measures. Results: The high and low speech-function subgroups were found to be similar on many of the dependent measures explored. However, these two groups were differentiated on the basis of an acoustic measure used as a proxy for tongue movement. Conclusion: This study supports the hypothesis that high and low speech-function subgroups do not differ solely in overall severity, but rather, constitute two distinct bulbar motor phenotypes. The findings suggest that the low speech-function group exhibited more global involvement of the bulbar muscles than the high speech-function group that had relatively intact lingual function. This work has implications for clinical measures used to grade bulbar motor involvement, suggesting that a single bulbar measure is inadequate for capturing differences among phenotypes.

Biomechanical Biomarkers of Tongue Impairment During Swallowing in Persons Diagnosed with Amyotrophic Lateral Sclerosis.

BACKGROUND: The impact of tongue dysfunction on deglutition in persons diagnosed with amyotrophic lateral sclerosis (ALS) is not well understood. This information is needed to improve our understanding of the mechanisms of swallowing impairment, for identifying risk factors of dysphagia, and for establishing impairment-specific treatments aimed at slowing the loss of swallow function. OBJECTIVES: The goals of this study were to determine the relation between biomechanical measures of oral tongue movements using electromagnetic articulography (EMA) and measures of swallow physiology, swallow safety and efficiency, and self-reported swallowing function. METHODS: Participants were diagnosed with ALS by a neurologist following the El Escorial Criteria from the World Federation of Neurology. Twelve participants underwent (1) EMA to derive biomechanical measures of the tongue, (2) videofluoroscopic evaluation to measure swallow physiology, safety, and efficiency, and (3) maximal tongue strength testing using the Iowa Oral Pressure Instrument (IOPI). Participants completed self-reported functional assessments. Spearman's rank correlations assessed for associations between lingual biomechanics and swallowing physiology, swallow safety and efficiency, and self-reported bulbar function. RESULTS: Results demonstrated strong associations between biomechanical and swallowing physiology, swallow safety, and self-reported measures. Notably, swallowing safety during thin liquid intake was associated with tongue speed (r = - 0.7, p < 0.05) and range of motion (r = - 0.71, p < 0.05), and swallowing safety during puree intake was associated with tongue strength (r = - 0.69, p < 0.05). CONCLUSIONS: Our findings underscore the importance of tongue movements on swallowing physiology and safety, help improve our understanding of mechanisms of swallowing impairment, and highlight a potential clinical tool to index bulbar impairment.