A Nonspeech Investigation of Tongue Function in Parkinson's Disease

Tongue strength and clinical correlations in Parkinson's disease

BACKGROUND

Individuals with Parkinson's disease present affected lingual functioning at some stage of the progression of the disease. The objective was to determine the strength and endurance values of the tongue in PD subjects and whether weakness in tongue lift may be an indicator of disease progression.

OBJECTIVE

To determine the strength and endurance values of the tongue in PD subjects and whether weakness in tongue lift may be an indicator of disease progression.

METHODS

Sixty subjects performed tasks of tongue to palate maximum isometric pressure (MIP) and sustained 50% of MIP for endurance. The Iowa Oral Performance Instrument was used as evaluation tool. Selected domains of the Swallowing Quality of Life Questionnaire (SWAL-QOL) related to tongue pressure were considered. Variables of sex, age, disease duration, disease progression (Hoehn & Yahr stage) and body mass index were selected for association analysis.

RESULTS

Tongue MIP ranged from 16 to 48 kPa (mean = 33.43 kPa), which was significantly lower than normal reference values. Likewise, tongue endurance was significantly diminished. Analysis of variance showed differences in tongue strength between stages of disease progression F(3) = 6.503, p = .001, but not for endurance. Subjects in stage IV exhibited the lowest values. No sex effect was found. Tongue strength showed significant correlations with SWAL-QOL domains such as food selection, symptoms frequency and eating duration.

CONCLUSION

Tongue strength and endurance are significantly reduced in Parkinson's disease. Tongue strength is higher in the early stage of the disease and significantly different from that of more severe stages, emerging the notion that tongue strength is a sensitive indicator of disease progression. Selected items regarding swallowing quality of life are strongly associated with tongue strength.

Speech and Nonspeech Parameters in the Clinical Assessment of Dysarthria: A Dimensional Analysis

Nonspeech (or paraspeech) parameters are widely used in clinical assessment of speech impairment in persons with dysarthria (PWD). Virtually every standard clinical instrument used in dysarthria diagnostics includes nonspeech parameters, often in considerable numbers. While theoretical considerations have challenged the validity of these measures as markers of speech impairment, only a few studies have directly examined their relationship to speech parameters on a broader scale. This study was designed to investigate how nonspeech parameters commonly used in clinical dysarthria assessment relate to speech characteristics of dysarthria in individuals with movement disorders. Maximum syllable repetition rates, accuracies, and rates of isolated and repetitive nonspeech oral-facial movements and maximum phonation times were compared with auditory-perceptual and acoustic speech parameters. Overall, 23 diagnostic parameters were assessed in a sample of 130 patients with movement disorders of six etiologies. Each variable was standardized for its distribution and for age and sex effects in 130 neurotypical speakers. Exploratory Graph Analysis (EGA) and Confirmatory Factor Analysis (CFA) were used to examine the factor structure underlying the diagnostic parameters. In the first analysis, we tested the hypothesis that nonspeech parameters combine with speech parameters within diagnostic dimensions representing domain-general motor control principles. In a second analysis, we tested the more specific hypotheses that diagnostic parameters split along effector (lip vs. tongue) or functional (speed vs. accuracy) rather than task boundaries. Our findings contradict the view that nonspeech parameters currently used in dysarthria diagnostics are congruent with diagnostic measures of speech characteristics in PWD.

A Systematic Review and Meta-analysis of Iowa Oral Performance Instrument Measures in Persons with Parkinson's Disease Compared to Healthy Adults

Measures of tongue strength and endurance using the Iowa Oral Performance Instrument (IOPI) may have diagnostic utility during clinical swallowing evaluations for persons with Parkinson's disease (PwPD). Thus, the objective was to systematically analyze the existing literature comparing IOPI values of tongue strength and endurance between age- and sex-match pairs of PwPD and healthy adults as well as across disease stages. A systematic review of 12 databases and Google Scholar identified five peer-reviewed articles published in English (1990-2019) that compared tongue strength and/or endurance between PwPD and controls. Individual-level data were published in two studies and provided by authors for three studies. Study appraisal included the NIH Quality Assessment Tool and STROBE checklists. Limited data for posterior tongue pressures restricted meta-analyses to anterior pressures. Meta-analyses of group means indicated reduced tongue strength across 106 matched pairs (p < .001, I² = 0%) and a trend for reduced endurance across 41 matched pairs (p = .07, I² = 54%). Participant-level analyses found reduced strength (96 pairs, p < .001) and endurance (41 pairs, p = .011) secondary to PD. Tongue strength (n = 68), but not endurance (n = 41), inversely correlated with disease stage when controlling for age (p ≤ .018). Overall, clinicians should be aware that reduced anterior tongue strength and endurance are as follows : expected in approximately one-third and one-fourth of PwPD, respectively, and reduced anterior tongue strength may manifest as early as Hoehn and Yahr stage 2 with continual decline as disease progresses. Further investigation is warranted regarding the relation among tongue strength, tongue endurance, and swallowing physiology as well as applications of tongue pressure training within dysphagia rehabilitation for PwPD.

Objective measures of lingual and jaw function in healthy adults and persons with Parkinson's disease: Implications for swallowing

The study examines the effects of age and Parkinson's disease on lingual and jaw function in neurotypical adults, as well as persons with Parkinson's Disease. Preliminary results provide reference measures in these populations and support the systematic collection of objective data regarding lingual strength, lingual range of motion, and jaw range of motion in clinical populations. The application of this clinically meaningful protocol also provides a means to track physiological changes over time in order to maximize the results of rehabilitative efforts to restore swallow function.

Relationship between tongue pressure and functional oral intake scale diet type in patients with neurological and neuromuscular disorders

INTRODUCTION

Patients with neurological and neuromuscular disorders (NNMD) frequently experience swallowing disorders that increase aspiration pneumonia risk and therefore require specialized diets or tube feeding. Diet type level usually is assessed by video fluoroscopic swallowing study (VFSS). To identify a simpler assessment method, we examined the association between diet type (based on the Functional Oral Intake Scale [FOIS]) diet type and maximum tongue pressure (MTP).

METHODS

From 2011-2020, FOIS diet type level and MTP were assessed in a sample of 927 patients. Of these patients, 186 had Parkinson's disease (PD), 69 had Parkinson-related disease (PRD), 61 had multiple system atrophy (MSA), 42 had spinocerebellar degeneration (SCD), 147 had amyotrophic lateral sclerosis (ALS), 180 had myotonic dystrophy type 1 (DM1), and 242 had Duchenne muscular dystrophy (DMD). VFSS was conducted while patients swallowed water and foods containing barium. MTP measurements were collected the same day. Participants' diet type level was adjusted based on the VFSS, with some participants requiring multiple examinations. Relationships between diet type level and MTP were tested using univariate and Spearman rank correlation analyses.

RESULTS

Mean MTP for the entire NNMD group (25.5 ± 13.1 kPa) was lower than that of healthy elderly individuals, as determined in previous reports. The highest MTP was found in the MSA group (32.2 ± 15.7 kPa) and the lowest in the DM1 group (19.1 ± 9.0 kPa). Diet type level was highest in the MSA group (5.8 ± 1.4) and lowest in the DMD group (5.2 ± 1.7). A significant correlation was observed between diet type level and MTP (R = 0.384, p < 0.001). The optimum MTP cutoff values-detected using ROC curves to predict a requirement to change to a dysphagia diet-was highest in the DMD group (29.0 kPa) and lowest in the ALS group (12.3 kPa).

CONCLUSIONS

The decision to change NNMD patients to a dysphagia diet can be made based on MTP. Modifying a patient's oral diet (FOIS level ≤ 5) should be considered for those with a MTP of 10-25 kPa, with the cutoff value varying by disease.

Tongue Strength in Children With and Without Speech Sound Disorders

Purpose The purpose of this cross-sectional investigation was to expand the comparative database of pediatric tongue strength for children and adolescents with typical development, ages 3-17 years, and compare tongue strength among children with typical development, speech sound delay/disorders (SD), and motor speech disorders (MSDs). Method Tongue strength was measured using the Iowa Oral Performance Instrument in a total of 286 children and adolescents, 228 with typical development, 16 with SD, and 42 with MSDs, including classic galactosemia, a known risk factor for MSD ( n = 33) and idiopathic MSD ( n = 9). Results For all groups, tongue strength increased rapidly from 3 to 6.5 years of age and then continued to increase with age at a slower rate until 17 years of age. Children with SD's tongue strength did not differ from their typically developing (TD) peers. Children and adolescents with MSDs had decreased tongue strength compared to children with typical development or SD. Tongue strength was not related to severity of speech sound disorders in SD or MSD. Conclusion Weak tongue strength does not appear to contribute to speech errors in children with speech sound delays but does appear to be related to speech sound disorders that are neurologic in origin (developmental MSD).

Lingual Pressure as a Clinical Indicator of Swallowing Function in Parkinson's Disease

PURPOSE

Swallowing impairment, or dysphagia, is a known contributor to reduced quality of life, pneumonia, and mortality in Parkinson's disease (PD). However, the contribution of tongue dysfunction, specifically inadequate pressure generation, to dysphagia in PD remains unclear. Our purpose was to determine whether lingual pressures in PD are (a) reduced, (b) reflect medication state, or are (c) consistent with self-reported diet and swallowing function.

METHOD

Twenty-eight persons with idiopathic PD (PwPD) and 28 age- and sex-matched controls completed lingual pressure tasks with the Iowa Oral Performance Instrument. PwPD were tested during practically defined ON and OFF dopaminergic medication states. Participants were also stratified into three sex- and age-matched cohorts (7 men, 5 women): (a) controls, (b) PwPD without self-reported dysphagia symptoms or diet restrictions, and (c) PwPD with self-reported dysphagia symptoms with or without diet restrictions.

RESULTS

PwPD exhibited reduced tongue strength and used elevated proportions of tongue strength during swallowing compared with controls (p < .05) without an effect of medication state (p > .05). Reduced tongue strength distinguished PwPD with self-reported dysphagia symptoms from PwPD without reported symptoms or diet restrictions (p = .045) and controls (p = .002).

CONCLUSION

Tongue strength was significantly reduced in PwPD and did not differ by medication state. Tongue strength differentiated between PwPD with and without self-reported swallowing symptoms. Therefore, measures of tongue strength and swallowing pressures may serve as clinical indicators for further dysphagia evaluation and may promote early diagnosis and management of dysphagia in PD.

Visuomotor control of neck surface electromyography in Parkinson's disease

OBJECTIVE

To compare performance of individuals with Parkinson's disease (PD) and age-matched controls on a visuomotor tracking task controlled via surface electromyography (sEMG).

METHODS

Twenty-seven adults with PD and twenty-four older controls produced dry swallows and completed a visuomotor tracking task utilizing both static and dynamic targets. sEMG was recorded at the anterior neck and submental surface during both tasks.

RESULTS

There was no significant difference in visuomotor tracking ability between cohorts. Post hoc analyses indicated that there was no significant difference between participant groups in the strength or duration of swallows as measured by sEMG but that participants with PD showed a trend for decreased swallow durations at the anterior neck (padj = 0.067) whereas controls showed a trend for increased durations at the anterior neck (padj = 0.112), compared to the submental surface. However, there were no significant correlations between swallowing behavior and visuomotor tracking ability.

CONCLUSION

There were no significant differences in visuomotor tracking performance between individuals with PD and controls. Furthermore, there was no relationship between tracking ability and swallowing behavior. We conclude that sEMG-mediated biofeedback may have limited promise as a tool for treating PD-related dysphagia.

Muscle weakness and speech in oculopharyngeal muscular dystrophy

PURPOSE

We documented speech and voice characteristics associated with oculopharyngeal muscular dystrophy (OPMD). Although it is a rare disease, OPMD offers the opportunity to study the impact of myopathic weakness on speech production in the absence of neurologic deficits in a relatively homogeneous group of speakers.

METHODS

Twelve individuals with OPMD and 12 healthy age-matched controls underwent comprehensive assessment of the speech mechanism including spirometry (respiratory support), nasometry (resonance balance), phonatory measures (pitch, loudness, and quality), articulatory measures (diadochokinetic rates, segment duration measures, spectral moments, and vowel space), tongue-to-palate strength measures during maximal isometric and speechlike tasks, quality-of-life questionnaire, and perceptual speech ratings by listeners.

RESULTS

Individuals with OPMD had substantially reduced tongue strength compared to the controls. However, little impact on speech and voice measures or on speech intelligibility was observed except for slower diadochokinetic rates.

CONCLUSIONS

Despite having less than half the maximal tongue strength of healthy controls, the individuals with OPMD exhibited minimal speech deficits. The threshold of weakness required for noticeable speech impairment may not have been reached by this group of adults with OPMD.

Speech-related fatigue and fatigability in Parkinson's disease

This study tested the assumption that speech is more susceptible to fatigue than normal in persons with dysarthria. After 1 h of speech-like exercises, participants with Parkinson's disease (PD) were expected to report increased perceptions of fatigue and demonstrate fatigability by producing less precise speech with corresponding acoustic changes compared to neurologically normal participants. Twelve adults with idiopathic PD and 13 neurologically normal adults produced sentences with multiple lingual targets before and after six 10-min blocks of fast syllable or word productions. Both groups reported increasing self-perceived fatigue over time, but trained listeners failed to detect systematic differences in articulatory precision or speech naturalness between sentences produced before and after speech-related exercises. Similarly, few systematic acoustic differences occurred. These findings do not support the hypothesis that dysarthric speakers are particularly susceptible to speech-related fatigue; instead, speech articulation generally appears to be resistant to fatigue induced by an hour of moderate functional exercises.

Reliability of measurements of tongue and hand strength and endurance using the Iowa Oral Performance Instrument with elderly adults

PURPOSE

This study investigated the reliability of tongue and hand strength and endurance measurements in old adults using the Iowa Oral Performance Instrument (IOPI).

METHOD

Thirty aged-care residents (6 males and 24 females) aged 79-97 years were tested on four occasions two weeks apart to determine test-retest reliability. The primary outcome measures were isometric anterior and posterior tongue and hand strength (best of three trials) and isometric tongue and hand endurance time at 50% of maximal strength.

RESULTS

Changes in the mean between sessions for tongue and hand strength indicated acceptable (< 10%) reliability particularly with familiarisation. The within-subject variation (mean-typical error expressed as a coefficient of variation, CV) indicated higher than acceptable variation for anterior and posterior tongue and hand strength. Intra-class correlations (ICC) indicated moderate to strong reliability for anterior (ICC 0.58-0.77) and posterior (ICC 0.77-0.84) tongue strength and hand strength (ICC 0.79-0.96). No tongue or hand endurance measures were regarded as reliable.

CONCLUSION

These findings indicate that overall tongue and hand strength values demonstrate acceptable reliability in the elderly, especially where familiarisation with the IOPI is provided. Further investigation to reduce sources of variability in tongue endurance measurements is warranted.

Protrusive tongue strength in people with severely weak tongues

The purpose of the study was to quantify tongue protrusion force and compare its characteristics between participants with severely weak tongues and those with normal lingual strength. The sample consisted of 11 participants with severe lingual strength deficits and 11 age- and sex-matched participants with normal lingual strength. Tongue force was evaluated quantitatively using the Forling instrument, and the average force, maximum force, average force application rate, and area under the graphic curve were analysed. These parameters were compared between the groups. In the participants with severely weak tongues, the average and the maximum forces in N (Newton) were 2.03 ± 1.17 and 3.56 ± 1.77, respectively. The average force application rate in N/s (Newton per second) was 1.25 and the area under the graphic curve in Ns (Newton times second) was 18.6. The values of the participants with normal lingual strength were, respectively, 13.27 ± 6.15 N, 18.91 ± 7.95 N, 10.46 N/s, and 108.08 Ns. All parameters analysed differed significantly between the groups. The data collected could aid speech-language pathologists in diagnosing problems related to tongue force.

Aging effects on sensorimotor integration: a comparison of effector systems and feedback modalities

Research on motor aging has focused on visuomotor effects in limb musculature, with few comparisons across effectors or feedback modalities. The authors examined steady fine force control in oral and manual effectors under visual and auditory feedback in 13 young (19-23 years old) and 13 older (60-77 years old) participants, hypothesizing that force variability would increase with aging (a) more in the finger than the lip and (b) for both feedback modalities. The magnitude of variability increased with age for both visuomotor and audiomotor tasks but age-related differences were greater in the lip than the finger. These results point to increased variability as a potential early marker of changing motor function (prior to loss of strength) that extends beyond the visuomotor system.

Influence of height, weight and body mass index in the axial tongue force

PURPOSE

To analyze the influence of weight, height and body mass index in the axial tongue force.

METHODS

Medical records with data from 44 subjects aged between 20 and 37 years, 11 (25%) males and 33 (75%) female, were analyzed. The investigated information were weight, height, result of clinical evaluation for tongue force (lingual tonus) and instrumental assessment of axial tongue force, which was accomplished by using the FORLING. Data was statistically analyzed.

RESULTS

No differences were observed between the force values regarding the variables body mass index classification and clinical classification of tongue force. Body mass index and weight had positive correlation with mean tongue force. There was a strong positive correlation between the variables mean force, maximum force and highest maximum force.

CONCLUSION

Although body mass index and weight correlated positively with the mean axial tongue force, there was no association between body mass index classification and the axial tongue forces.

Métodos quantitativos para avaliação da força de língua

Por muitos anos, pesquisadores têm procurado métodos para quantificar a força da língua e muitos instrumentos foram construídos para este fim. O objetivo deste trabalho é apresentar uma revisão crítica da literatura sobre instrumentos para quantificar a força de língua. Os 30 aparelhos encontrados foram agrupados em quatro diferentes categorias: bocal contendo sensores (n=9), sensores fixados nos dentes, palato ou em placas palatais (n=8), bulbos preenchidos com fluidos e conectados a sensores de pressão (n=7) e outras tecnologias (n=8). Esses instrumentos podem, potencialmente, auxiliar o fonoaudiólogo na avaliação miofuncional orofacial, fazendo com que o diagnóstico de força da língua seja mais preciso. Alguns aparelhos apresentam desvantagens, tais como não serem sensíveis a pequenas mudanças de força, dificuldades na reprodutibilidade do posicionamento e outros pontos específicos. A grande variação de valores de força/pressão máxima e média encontrados relaciona-se à grande diversidade dos métodos, que empregam diferentes tecnologias.

Axial force of the tongue in different age groups

PURPOSE

To analyze the maximum axial force, the mean axial force, the amount of energy accumulated by the tongue, and the time taken to reach the maximum axial force, in different age ranges.

METHODS

The records of 92 individuals - students, staff and visitors at an university -, 29 (32.6%) men and 63 (67.4%) women, with ages between 14 and 53 years old, were analyzed. Subjects were divided into four age groups: 14 to 18 years, 19 to 23 years, 24 to 28 years, and 29 to 53 years. Each subject underwent clinical and instrumental assessment of the tongue. Instrumental assessment used FORLING. Data were statistically analyzed.

RESULTS

Regarding the maximum force, the mean force and the tongue's accumulated energy, no differences were observed between groups. Regarding the time taken to reach the maximum force, the greatest values were obtained at the age range from 14 to 18 years (4.5 s), and the shortest values, at the age range from 19 to 23 years (3.1 s), with significant difference between the groups (p=0.001).

CONCLUSION

Only the time taken to reach the tongue's maximum force is influenced by age range, indicating that teenagers are not able to reach the maximum lingual force as fast as young adults.

Kinematic analysis of lingual function in dysarthric speakers with Parkinson's disease: An electromagnetic articulograph study

Dysarthria in people with Parkinson's disease (PD) has been widely studied. However, a limited number of studies have investigated lingual function during speech production in this population. This study aimed to investigate lingual kinematics during speech production using electromagnetic articulography (AG-200 EMA). The PD group consisted of eight dysarthric speakers with PD and was matched with a group of eight controls. The tongue tip and tongue back movements of all participants during sentence production were recorded by EMA. Results showed that, perceptually, the participants with PD were mildly dysarthric. Kinematic results documented comparable (for alveolar sentence production) and increased (for velar sentence production) range of lingual movement in the PD group when compared to the control group. Lingual movement velocity, acceleration, and deceleration were also increased in the PD group, predominantly for the release phase of consonant production during sentence utterances. The PD group had longer duration in the production of alveolar consonant and comparable duration in the production of velar consonant. The results of the present study suggest the presence of impaired lingual control in individuals with PD. Increased range of articulatory movement, primarily in the release phase of consonant production, may account for articulatory imprecision in this population.

Effects of dining on tongue endurance and swallowing-related outcomes

PURPOSE

The purpose of this study was to test the hypothesis that eating a meal reduces tongue strength and endurance in healthy old and young adults. It was predicted that older adults would show greater declines in tongue endurance while demonstrating higher perceived effort, longer meal durations, and clinical signs of swallowing difficulty.

METHOD

Twenty-two healthy adults were enrolled into 2 groups (ages 20-35 years and ages 65-82 years; 5 males and 6 females each). Maximum tongue strength (Pmax) and endurance (duration 50% of Pmax could be maintained) were measured twice at baseline and once postmeal. Subjects consumed half of a bagel with peanut butter, carrot sticks, and milk between measures.

RESULTS

All subjects demonstrated reduced tongue strength and endurance postmeal. Young adults showed a greater decline in anterior tongue endurance compared with older adults (p=.05). There was no evidence that changes in tongue strength, perceived effort, or meal duration varied by age or gender. The 3 oldest subjects reported the highest effort and displayed signs of difficulty swallowing while dining.

CONCLUSIONS

Young and old adults demonstrated reduced tongue strength and endurance after dining, but younger subjects showed greater declines in anterior tongue endurance, whereas older adults exhibited signs of swallowing difficulty.

Translating principles of neural plasticity into research on speech motor control recovery and rehabilitation

PURPOSE

To review the principles of neural plasticity and make recommendations for research on the neural bases for rehabilitation of neurogenic speech disorders.

METHOD

A working group in speech motor control and disorders developed this report, which examines the potential relevance of basic research on the brain mechanisms involved in neural plasticity and discusses possible similarities and differences for application to speech motor control disorders. The possible involvement of neural plasticity in changes in speech production in normalcy, development, aging, and neurological diseases and disorders was considered. This report focuses on the appropriate use of functional and structural neuroimaging and the design of feasibility studies aimed at understanding how brain mechanisms are altered by environmental manipulations such as training and stimulation and how these changes might enhance the future development of rehabilitative methods for persons with speech motor control disorders.

CONCLUSIONS

Increased collaboration with neuroscientists working in clinical research centers addressing human communication disorders might foster research in this area. It is hoped that this article will encourage future research on speech motor control disorders to address the principles of neural plasticity and their application for rehabilitation.

Age-related changes in orolingual motor function in F344 vs F344/BN rats

Normal aging is associated with both locomotor and orolingual motor deficits. Preclinical studies of motor function in normal aging, however, have focused primarily on locomotor activity. The purpose of this study was to measure age-related changes in orolingual motor function and compare these changes between two rat strains commonly used in aging studies: Fischer 344 (F344) and Fischer 344/Brown Norway hybrid (F344/BN) rats. Rats (6-, 12-, 18- and 24-months of age) were trained to lick water from an isometric force-sensing operandum so that the number of licks per session, licking rhythm (licks/second) and lick force could be measured. In both strains, the number of licks per session was greatest in the oldest group, while this measure was greater for F344/BN rats at all ages. Peak tongue force increased with age in F344/BN rats, did not change with age in the F344 rats, and was greater for the F344/BN rats at all ages. Both strains exhibited an age-related slowing of licking rhythm beginning with the 18-month-old group. These findings suggest that despite lifespan differences between these two rat strains, diminished tongue motility emerges at the same age.

What is orofacial fatigue and how does it affect function for swallowing and speech?

Speech-language pathologists are likely to encounter patients who report symptoms of fatigue, but there are few clinical procedures to assess this phenomenon. Furthermore, it is difficult to determine whether fatigue contributes to a patient's dysphagia or dysarthria. This article reviews orofacial muscles, including the muscles of the tongue, lips, and cheeks, highlighting in particular their role in swallowing and speaking. It provides definitions of fatigue and describes assessment procedures. The author's research has focused on assessing fatigue, especially of the tongue, and elucidating the effects of exercising the tongue on speech and nonspeech tasks. Most of this work involves people who have Parkinson's disease and neurologically normal adults; results generally support heightened fatigue in Parkinson's disease. However, the effect of fatigue on functional activities remains unclear. Literature regarding the effects of orofacial fatigue on swallowing and speaking is notably sparse, but preliminary evidence indicates that these functions are rather robust.