Tongue Fatigue Research Articles

Detection of muscle fatigue caused by repeated posterior tongue lift movement from neck surface EMG: a pilot study.

Fatigue is an important factor for muscle strengthening in rehabilitation medicine. Frequency analysis has been regarded as the gold standard for muscle fatigue assessment in surface electromyography (EMG). However, there are no experiments quantifying fatigue with grouped discharge (GD), which is one of the historical phenomena observed in patients having fatigue, by using high sampling rate recording of EMG. To investigate the effect of fatigue, which is induced by repeated posterior tongue lift movement (TLM), on the occurrence of GD peaks, thus, to provide possible basis as a parameter for future fatigue evaluation. Nineteen healthy adults (9men and 10 women) participated in this study. The muscle fatigue protocol consisted of repetitive posterior TLM and maximum voluntary contractions (MVC). Bilateral N-EMG (Neck surface EMG for measuring the muscle activity of the posterior tongue) was recorded. Subjective tongue fatigue at the end of the protocol was significantly higher than at beginning throughout the muscle fatigue protocol (p<.01). The frequency of occurrence of GD peaks was 0.9±1.2 (per second) at the baseline in 33 of 38subject sides, and significantly increased depending on fatigue progression (p<.01). It was shown that fatigue due to repetitive posterior tongue lifting resulted in significant increase in the frequency of occurrence of GD peaks. Especially, the nature of GD, showing very few occurrences at non-fatigue condition, might work as an advantageous property for its use in future absolute evaluation of fatigue phenomena.

The Influence of Age, Eating a Meal, and Systematic Fatigue on Swallowing and Mealtime Parameters.

Fatigue is widely accepted as a clinically relevant factor in the diagnosis, treatment, and management of dysphagia. Despite the relative importance that is placed on swallowing-related fatigue, the occurrence and effects of fatigue during swallowing is unclear. The goal of this study was to explore effects of eating a meal on measures of tongue strength, endurance, and other parameters of swallowing function under normal conditions compared to when the tongue is intentionally fatigued. Thirty healthy females, 15 "Young" (18-35years old), and 15 "Old" (70 + years old) were seen for two data collection sessions one week apart. On both days, pre-meal measures were collected, then participants consumed a standardized meal based on a previously published protocol (half a bagel with peanut butter and 8 baby carrots) followed by post-meal measures. An additional pre-meal fatigue task was included on one of the test days (counterbalanced), involving maximal tongue presses until participants could not achieve 40% of baseline maximum pressure. Pre- and post-meal measures included anterior and posterior maximum tongue pressures, saliva swallow pressure, tongue endurance, surface electromyography (sEMG), the modified Borg scale, and the Test of Mastication and Swallowing of Solids (TOMASS). Linear mixed effects regressions compared pre- and post-meal outcome measures (1) on the non-fatigue day and (2) between fatigue and non-fatigue days while controlling for participant and age. The fatigue task caused significant reductions in maximum anterior and posterior tongue pressure. After a normal meal (i.e., without fatigue), we found decreased anterior pressures in the older group only. Older participants also had decreased saliva swallow pressures after the meal compared to pre-meal, while this measure increased post-mean in the young participants. When compared to the non-fatigue meal, eating a meal after tongue fatigue resulted in significantly lower post-meal posterior pressures, regardless of age group. The same pattern was observed with posterior functional reserve. Our results demonstrate that a systematic, participant-specific tongue fatigue task induced measurable changes in maximum tongue pressure. A meal by itself was observed to reduce anterior tongue strength and saliva swallow pressures only in older participants. Overall, it appears that older adults may be more vulnerable to fatigue-induced changes in tongue strength, though the relationship between these measures and changes to functional swallowing remains unknown.

0564 Assessment of Tongue and Soft Palate Muscles Mechanical Properties in Patients with OSA

Abstract Introduction Soft palate muscles are crucial in the maintenance of UA patency. Different contraction tasks have been used to investigate tongue mechanical properties, but not to soft palate muscles. This study aimed to investigate the mechanical consequences of tongue and soft palate muscles fatigue in moderate-severe OSA patients. Methods 12 moderate and 8 severe patients with OSA were enrolled. Measurements include strength, endurance, and fatigue indices. During the soft palate fatiguing protocol, subjects were asked to develop repetitive intra-oral positive pressure during cheek-bulging maneuvers while wearing a mouth piece to keep the jaw opened. Tongue mechanical properties were also assessed using protrusion tasks with similar protocol. Subjects were encouraged to develop sustained maximal bulging pressure or tongue protrusion force for 5 sec every 10 sec until the peak pressure did not reach 85% of baseline maximal pressure for 2 consecutive times. The influence of age and BMI were also investigated. Results The sex, age were not significantly different between the 2 OSA groups. BMI was significantly higher in severe OSA patients (p&amp;lt;0.05). Overall, the tongue maximal voluntary contraction force (MVC), endurance time and total muscle work were respectively positively associated with the ones obtained from the soft palate fatiguing task (rs=0.51, 0.43, 0.66, respectively). The MVC of both tongue and soft palate muscles were positively correlated with BMI in all subjects (rs=0.43, 0.5 respectively). The recovery time from soft palate fatigue was significantly longer in moderate than severe OSA patients (270s ± 192.3s and 120s ± 0, p =0.02). Interestingly, the recovery time was positively correlated with AHI in tongue fatiguing task, while negatively correlated with supine AHI and age in soft palate fatiguing task (p&amp;lt;0.05). In both tasks, MVC was negatively correlated with the endurance time (p&amp;lt;0.05). Conclusion Moderate patients are less likely to recover from soft palate muscle fatigue. A more severe apneic disease is associated with longer recovery time from tongue fatigue, but with shorter recovery time from soft palate fatigue. Our results suggest that alteration in tongue and velopharyngeal muscles function may differ according to the severity of disease. Support SBD from IUCPQ Foundation.

0562 Assessment of Mandibular Advancement Treatment Success According to Upper Airway Muscle Mechanical Properties in Obstructive Sleep Apnea Patients

Mandibular advancement device (MAD) is a valid treatment for obstructive sleep apnea (OSA). However there is no reliable criteria predicting treatment efficacy. Upper airway muscle mechanical properties (UAMP) are important pathophysiological determinants of the occurrence of OSA that could be involved in MAD treatment response. The aim of this study was to investigate UAMP in the response to MAD in OSA patients. 9 subjects were recruited to perform either a soft palate fatigue protocol (SPFP, n=4) or a tongue fatigue protocol (TFP, n=5) before initiating MAD treatment. In SFPF, subjects were asked to develop sustained maximal bulging pressure for 5 seconds every 10 seconds until the peak pressure failed to reach 85% of baseline maximal pressure for 2 consecutive times. In TFP, subjects had to press an air filled bulb with the tongue against the hard palate. Endurance time, recovery time, and mean maximum pressure were measured. Sleep studies were performed before the beginning of MAD treatment and after the titration period. Characteristics of subjects for SFPF group were 1 female, age 54 ± 8 y, BMI 29.1 ± 3.1 kg/m2. Characteristics of TFP were 1 female, age 62 ± 2, BMI 26.8 ± 2.8 kg/m2. Baseline AHI was 22.8 ± 8.7/h for SPFP and 36.7 ± 13.1/h for TFP. MAD AHI was 10.4 ± 8.2/h for SFPF and 18.2 ± 12.8/h for TFP. 2 TFP and 2 SPFP subjects were responders (AHI decrease greater than 50% with a final MAD AHI < 15/h). No difference was found in endurance time and recovery time between responders (5.1 ± 6.8 and 4.0 ± 2.8 min respectively) and non-responders (11.2 ± 6.1 and 6.8 ± 4.6 min), but difference in mean maximum pressure was borderline significant (34.8±13.6 and 60.0±10.7 kPa respectively, p=0.07). Our pilot results suggest that mechanical strength but not fatigue may differentiate MAD responders/non-responders. Supported by Le fonds de recherche et enseignement sur les troubles respiratoires du sommeil de la Fondation IUCPQ.

ACC Research Agenda Conference 2018: Peer Reviewer Acknowledgments and Abstracts of Proceedings

ACC Research Agenda Conference 2018: Peer Reviewer Acknowledgments and Abstracts of Proceedings

Quantitative and comparative assessment of learning in a tongue-operated computer input device--part II: navigation tasks.

Tongue drive system (TDS) is a novel tongue-operated assistive technology (AT) for the mobility impaired, to empower them to access computers and drive powered wheelchairs (PWC) using their free voluntary tongue motion. We have evaluated the TDS performance in five sessions over 5-8 weeks to study the learning process in different tasks of computer access and PWC navigation on nine able-bodied subjects who already had tongue piercing and used our magnetic tongue studs throughout the trial. Computer access tasks included on-screen maze navigation and issuing random commands to measure the TDS information transfer rate. PWC navigation included driving through a ~50-m obstacle course using three control strategies. Some of the qualitative aspects of using the TDS were also evaluated based on the two Likert scale questionnaires, one of which was short (eight questions) and asked at the end of each session and the other one (46 questions) at the end of the trial. Included in this study was also a task to measure the tongue fatigue as a result of using the TDS continuously for a few hours. All performance measures showed significant improvement from the first to the second session as well as further gradual improvements throughout the rest of the sessions, suggesting a rapid learning process.

Assessment of tongue weakness and fatigue

Assessment of nonspeech tongue function is common in speech-language pathology. This paper reviews techniques used to determine tongue strength and endurance, and describes a constant-effort task. These techniques are intended to reveal and quantify the presence of weakness or fatigue of the tongue. The consequences of performing these tasks with and without a bite block, used to fix jaw position, are considered. Whether nonspeech tongue impairment is associated with speech dysfunction in Parkinson’s disease is another topic of interest. Past studies indicated reduced tongue strength and endurance in Parkinson’s disease, but these measures did not correlate with speech measures. It was hypothesized that weakness and fatigue need to be impaired to a “critical” level before speech is perceptibly affected. To examine whether experimentally induced tongue fatigue affects speech, normal speakers performed prolonged strenuous tongue exercise. Speech deteriorated following these exercises. A new investigation examines whether 1 hour of speech-like tongue exercise (rapid syllable repetitions) affects dysarthric speech. Preliminary data from 6 participants with Parkinson’s disease, 1 person with bulbar ALS, and 6 neurologically normal control subjects indicate that sentences sound more precise but less natural after the exercises. Surprisingly, results did not differ significantly between the groups. Continued collection of data and refinement of tasks will contribute to our understanding of the potential relationships between weakness, fatigue, and speech.

Changes in normal speech after fatiguing the tongue.

Detrimental effects of tongue fatigue on speech have been assumed to exist based on neuromotor speech disorders. However, to address whether fatigue is a contributing cause to impaired speech requires an experimental protocol with an uncomplicated population. This study induced tongue fatigue in eight neurologically normal persons and examined changes in speech perceptually and acoustically. The fatigue task consisted of repeated cycles of 6 s of sustained maximum voluntary contraction and 4 s of rest until 50% of maximum strength could not be achieved for three consecutive cycles. Participants then produced speech that was weighted heavily with lingual-palatal consonants. Perceptual analyses of the speech revealed a statistically significant deleterious effect of induced tongue fatigue on speech precision and an incomplete reversal of this effect after a recovery period. Acoustically, the first and third spectral moments (mean and skewness) of the spectral energy for /see text/, /see text/, and /see text/ differed significantly after fatigue but in directions opposite to a priori predictions. Tendencies were found for decreased stop-closure duration and increased voice onset time for /see text/ after fatigue. Supplemental analyses revealed decreased second formant (F2) frequency for /see text/ and /see text/ and flattened F2 transition for the diphthong /see text/ after fatigue. These results indicate disruption of tongue positioning and transitioning for lingual-palatal consonants during speech after prolonged strenuous tongue exercises.