Sensorimotor tongue evaluation and rehabilitation in patients with sleep-disordered breathing: a novel approach

Comprehensive analysis of orofacial motor skills in children with obstructive sleep apnea

BACKGROUND

The neuromuscular activity has a critical role in the permeability of the upper airways.

OBJECTIVE

The present study aimed to conduct a detailed and comparative investigation of the orofacial musculature and motor skills of children with obstructive sleep apnea (OSA).

MATERIALS AND METHODS

Children aged 7 to 12 years with OSA (OSA group, n = 12) and without OSA (Control group, n = 12) were compared. Orofacial appearance/posture and motor skills were assessed using the orofacial myofunctional evaluation protocol with scores. Bite force, tongue pressure measurements, and surface electromyography of swallowing were also performed.

RESULTS

Compared to the control group, the OSA group obtained lower scores in appearance/posture, mobility, and orofacial functions (P < 0.0001), and lower values of bite force (P = 0.019) and tongue strength in protrusion (P = 0.008) and deglutition (P = 0.004). The OSA group also displayed lower values of maximum speed (P = 0.003) and peak activity (P = 0.0005) during spontaneous swallowing and higher relative energy expenditure (integral) of the muscles in the water swallowing task (50 mL) (P ≤ 0.01). Notably, the effect size ranged from moderate to large for all groups differences.

CONCLUSION

The children with OSA showed impairments in orofacial musculature and motor skills, as evidenced by reduced muscle recruitment capacity and coordination in applying pressure/force and performing orofacial movements and functions.

CLINICAL RELEVANCE

This study contributes to the understanding of non-anatomical factors associated with OSA in children and to the development of therapeutic strategies.

Assessment and rehabilitation of tongue motor skills with myofunctional therapy in obstructive sleep apnea: a systematic review and meta-analysis

STUDY OBJECTIVES

The first objective of this study was to compare tongue motor skills between patients with obstructive sleep apnea (OSA) and healthy participants. Second, the effect of oropharyngeal myofunctional therapy (MFT) on the tongue muscular qualities of patients with OSA was evaluated.

METHODS

Searches were conducted in 5 electronic databases up to July 2023. Risk of bias was assessed via the Joanna Briggs Institute appraisal checklist for cross-sectional studies (aim number 1) and the Physiotherapy Evidence Database (PEDro) scale for randomized controlled trials (aim number 2). Pooled standardized mean differences and 95% confidence intervals were calculated using a random-effects model.

RESULTS

Thirteen studies including 520 adults and one study including 92 children addressed aim number 1. Compared to healthy adults, individuals with OSA had no significant difference in tongue protrusion strength (9 studies, n = 366; standardized mean difference [95% confidence interval], -0.00 [-0.45, 0.44]) or endurance (5 studies, n = 125; 0.31 [-0.26, 0.88]) but presented a lower tongue elevation strength (6 studies, n = 243; 1.00 [0.47, 1.53]) and elevation endurance (3 studies, n = 98; 0.52 [0.11, 0.94]). In children, tongue elevation strength was lower but elevation endurance was higher in those with OSA than in healthy children. Two randomized controlled trials (28 adults, 54 children) addressed aim number 2 and were of poor methodological quality. In these studies, myofunctional therapy improved tongue motor skills in patients with OSA.

CONCLUSIONS

Tongue elevation motor skills are decreased in adults with OSA, whereas tongue protrusion motor skills seem preserved. Very few data are available in children. There are also too few data about the impact of myofunctional therapy on tongue motor skills.

CITATION

Poncin W, Willemsens A, Gely L, Contal O. Assessment and rehabilitation of tongue motor skills with myofunctional therapy in obstructive sleep apnea: a systematic review and meta-analysis. J Clin Sleep Med. 2024;20(9):1535-1549.

Use of Ultrasound to Verify the Impact of Telemedicine Myofunctional Therapy on Sleep Apnea Syndrome: Study Protocol Proposal

The anatomy of the upper airways influences the risk of obstructive sleep apnea (OSA). The size of soft tissue structures, such as the tongue, soft palate, and lateral walls of the pharynx, contributes to the pathogenesis of OSA. New lines of treatment for sleep apnea, such as myofunctional therapy (MT), aim to strengthen the oropharyngeal musculature to improve the defining parameters of apnea. The present protocol uses ultrasound imaging to measure the size of the lingual musculature non-invasively and cost-effectively and evaluates the changes in its morphology. Eligible patients include those with OSA who have undergone submental cervical ultrasound and drug-induced sleep endoscopy before starting MT with the AirwayGym app. Follow-up evaluations are conducted at 3 months after beginning treatment. Patients diagnosed with OSA via questionnaires and polysomnography or respiratory polygraphy are evaluated anatomically and functionally using the Iowa Oral Performance Instrument, a tongue digital spoon, somnoscopy, and submental cervical ultrasound to assess their responses to the AirwayGym app. The lingual thickness (mm) and volume (cm3) and the distance between both lingual arteries (mm) are measured. The AirwayGym app helps users and therapists monitor the patient performance of MT. Incorporating submental ultrasound can be a useful non-invasive tool to evaluate OSA and MT.

Assessment of Muscular Weakness in Severe Sleep Apnea Patients: A Prospective Study

OBJECTIVE

There are no official diagnostic tools to evaluate the weakness of the genioglossus muscle. We have developed a protocol for muscular assessment in patients with severe obstructive sleep apnea-hypopnea syndrome (OSAHS) and evaluated its effectiveness.

STUDY DESIGN

Case and controls prospective study.

SETTING

Sleep Unit Hospital Quironsalud Marbella (Spain).

METHODS

Twenty-nine cases and 20 controls were recruited. Patients were examined by a phonoaudiologist that performed biometric measurements and the Orofacial Myofunctional Evaluation With Scores (OMES), Friedman, and Epworth Sleepiness Scale (ESS). In addition, upper airway muscle strength measures were performed using the Iowa Oral Performance Instrument (IOPI) and Tongue Digital Spoon (TDS).

RESULTS

The final cohort consisted of 49 subjects, including 29 cases and 20 controls. According to the univariate and multivariate logistic regression analyses, ESS, OMES protocol, IOPI score, and TDS were associated with severe OSAHS. Multivariate regression revealed an IOPI score below 48 kps with an adjusted odds ratio (OR) of 9.96 (95% confidence interval [CI] 2.5-39.1, p = .001), and a 0.72 specificity (Spe), a 0.79 sensitivity (Sens), and a 0.82 area under the curve (AUC). Similarly, an OMES score lower than 200 had an adjusted risk ratio of 4.02 (95% CI 2-7, p < .001), 1 Spe, 0.79 Sens, and 0.98 AUC; and finally, TDS scores lower than 201 g/cm2 showed an adjusted OR of 27 (95% CI 4.74-153.6, p = .0001), 0.66 Spe, a 0.93 Sens, and a 0.86 AUC.

CONCLUSION

Our findings suggest that severe OSAHS patients present different muscle patterns than controls.

Histological and contractile changes in the genioglossus muscle after nasal obstruction in growing rats

The aim of the study was to address the genioglossus muscle physiological and histological changes after unilateral nasal obstruction in growing rats. Fifty-four 6-day-old male Wistar albino rats were randomly divided into control (n = 27) and experimental (n = 27) groups. Unilateral nasal obstruction was performed at 8 days old. Contractile properties of the genioglossus whole muscle were measured at 5-, 7- and 9-week-old, including the twitch and tetanic forces, contraction time, half-decay time, and fatigue index. The histological characteristics of the genioglossus were also evaluated at 5-, 7- and 9-week-old, analyzing the myosin heavy chain composition of the slow, fast, IIa and IIb muscle fiber type, by measuring the number, rate, diameter and cross-sectional area. The maximal twitch force, and tetanic force at 60 Hz and 80 Hz force was significantly increased at all ages after nasal obstruction. The fatigue index was decreased at 5 weeks-old after nasal obstruction. The diameter and cross-sectional area of the fast, IIa and IIb muscle fiber types were increased at 7 and 9 weeks after nasal obstruction, while only the diameter of IIa type and cross-sectional area of IIb type were increased at 5 weeks-old after nasal obstruction. Nasal obstruction during growth affects the whole genioglossus muscle contractile properties and histological characteristics, increasing its force, the diameter and area of its muscle fibers. These changes in the genioglossus muscle may affect the normal growth, development and function of the craniofacial complex.

Does Frenotomy Modify Upper Airway Collapse in OSA Adult Patients? Case Report and Systematic Review

Ankyloglossia (tongue-tie) is a condition of the oral cavity in which an abnormally short lingual frenulum affects the tongue's mobility. Literature on the correlation between ankyloglossia and obstructive sleep apnea (OSA) is scarce. The main objective of this study was to report our preliminary experience in adult OSA patients before and after ankyloglossia treatment, using drug-induced sleep endoscopy (DISE) to evaluate the upper airway modifications resulting after treatment, and to present a systematic review of the impact of ankyloglossia and its treatment on OSA adults. We found that, after frenotomy, regarding the DISE findings, and according to the VOTE classification, two of the three patients showed an improvement in tongue level, from 2A-P (complete anteroposterior collapse) to 1ap (partial anteroposterior collapse). The third patient showed no changes in his UA after frenotomy, neither worsening nor showing improvement. Thus, the results of this study suggest that frenotomy in OSA patients with ankyloglossia could reduce tongue collapse, probably by allowing the tongue to take into the physiological position in the oral cavity. These patients should undergo speech therapy and oropharyngeal exercises prior to any surgical procedure, in order to avoid glossoptosis and to improve the quality of life and sleep apnea results.

Evaluation of the Muscle Strength of the Tongue with the Tongue Digital Spoon (TDS) in Patients with Obstructive Sleep Apnea

Myofunctional therapy (MT) is a recent treatment option for obstructive sleep apnea (OSA). The Iowa Oral Performance Instrument (IOPI) is a useful but expensive tool for measuring tongue strength in patients with OSA. We validated the Tongue Digital Spoon (TDS) to monitor tongue hypotonia in patients with OSA. Measurements with the IOPI and TDS were compared in patients with OSA before and after MT for tongue hypotonia. Baseline mean tongue strength measured with the IOPI in patients with moderate and severe OSA were 35.36 ± 9.05 and 33.83 ± 12.05, respectively, and that with the TDS were 168.55 ± 42.8 and 129.61 ± 53.7, respectively. After MT, mean tongue strength significantly improved: measured with the IOPI in patients with moderate and severe OSA were 53.85 ± 10.09 and 55.50 ± 9.64 (p = 0.8), and that with the TDS were 402.36 ± 52.92 and 380.28 ± 100.75 (p = 0.01), respectively. The correlation between the IOPI and TDS was high (r = 0.74; p = 0.01 pre-treatment, and r = 0.25; p = 0.05 post-treatment). The TDS is a useful tool for monitoring the efficacy of MT in patients with short-term OSA. Future randomized studies will determine the effectiveness of MT for the treatment of OSA.

The effect of tongue elevation muscle training in patients with obstructive sleep apnea: A randomised controlled trial

BACKGROUND

Oropharyngeal myofunctional therapy is a multi-component therapy effective to reduce the severity of obstructive sleep apnoea (OSA). However, existing protocols are difficult to replicate in the clinical setting. There is a need to isolate the specific effectiveness of each component of the therapy.

OBJECTIVE

To assess the effects of a 6 weeks tongue elevation training programme in patients with OSA.

METHODS

We conducted a multicentre randomised controlled trial. Eligible participants were adults diagnosed with moderate OSA who presented low adherence to continuous positive airway pressure therapy (mean use <4 h per night). The intervention group completed a 6 weeks tongue elevation training protocol that consisted in anterior tongue elevation strength and endurance tasks with the Iowa Oral Performance Instrument. The control group completed a 6 weeks sham training protocol that involved expiratory muscle training at very low intensity. Polygraphy data, tongue force and endurance, and OSA symptoms were evaluated pre- and post-intervention. The primary outcome was apneoa-hypopnea index (AHI).

RESULTS

Twenty-seven patients (55 ± 11 years) were recruited. According to modified intention-to-treat analysis (n = 25), changes in AHI and c did not significantly differ between groups. Daytime sleepiness (Epworth Sleepiness Scale) and tongue endurance significantly improved in the intervention group compared to the control group (p = .015 and .022, respectively). In the intervention group, 75% of participants had a decrease in daytime sleepiness that exceeded the minimal clinically important difference.

CONCLUSION

Six weeks of tongue elevation muscle training had no effect on OSA severity.

Quantitative Measurement of Swallowing Performance Using Iowa Oral Performance Instrument: A Systematic Review and Meta-Analysis

Swallowing is a complex but stereotyped motor activity aimed at serving two vital purposes: alimentary function and the protection of upper airways. Therefore, any impairment of the swallowing act can represent a significant clinical and personal problem that needs an accurate diagnosis by means of reliable and non-invasive techniques. Thus, a systematic review and meta-analysis was performed to investigate the reliability of the Iowa Oral Pressure Instrument (IOPI) in distinguishing healthy controls (HC) from patients affected by swallowing disorders or pathologies and conditions that imply dysphagia. A comprehensive search was conducted following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines and using PubMed, Scopus, Web of Science, Cochrane, and Lilacs databases. Overall, 271 articles were identified and, after a three-step screening, 33 case-control and interventional studies reporting IOPI measurements were included. The methodological quality of the retrieved studies resulted in being at a low risk of bias. The meta-analysis on case-control studies showed that maximum tongue pressure (MIP) values were always higher in HC than in patients, with an overall effect of the MIP difference of 18.2 KPa (17.7–18.7 KPa CI). This result was also confirmed when the sample was split into adults and children, although the MIP difference between HC and patients was greater in children than in adults (21.0 vs. 15.4 KPa in the MIP mean difference overall effect, respectively). Tongue endurance (TE) showed conflicting results among studies, with an overall effect among studies near zero (0.7 s, 0.2–1.1 s CI) and a slight tendency toward higher TE values in HC than in patients. Among the intervention studies, MIP values were higher after treatment than before, with a better outcome after the experimental tongue training exercise than traditional treatments (the MIP mean difference overall effect was 10.8 and 2.3 KPa, respectively). In conclusion, MIP values can be considered as a reliable measure of swallowing function in adults and in children, with a more marked MIP difference between HC and patients for the children population. MIP measures in patients are also able to detect the best outcome on the tongue function after the training exercise compared to traditional training.

Obstructive Sleep Apnea and Role of the Diaphragm

Obstructive sleep apnea (OSA) causes multiple local and systemic pathophysiological consequences, which lead to an increase in morbidity and mortality in patients suffering from this disorder. OSA presents with various nocturnal events of apnoeas or hypopneas and with sub-clinical airflow limitations during wakefulness. OSA involves a large percentage of the population, particularly men, but the estimate of OSA patients could be much broader than data from the literature. Most of the research carried out in the muscle field is to understand the causes of the presence of chronic nocturnal desaturation and focus on the genioglossus muscle and other muscles related to dilating the upper airways. Sparse research has been published regarding the diaphragm muscle, which is the main muscle structure to insufflate air into the airways. The article reviews the functional anatomy of the muscles used to open the upper respiratory tract and the non-physiological adaptation that follows in the presence of OSA, as well as the functional anatomy and pathological adaptive aspects of the diaphragm muscle. The intent of the text is to highlight the disparity of clinical interest between the dilator muscles and the diaphragm, trying to stimulate a broader approach to patient evaluation.

Improving Adherence to Myofunctional Therapy in the Treatment of Sleep-Disordered Breathing

Myofunctional therapy (MT) is used to treat sleep-disordered breathing. However, MT has low adherence-only ~10% in most studies. We describe our experiences with MT delivered through a mobile health app named Airway Gym®, which is used by patients who have rejected continuous positive airway pressure and other therapies. We compared ear, nose, and throat examination findings, Friedman stage, tongue-tie presence, tongue strength measured using the Iowa oral performance instrument (IOPI), and full polysomnography before and after the 3 months of therapy. Participants were taught how to perform the exercises using the app at the start. Telemedicine allowed physicians to record adherence to and accuracy of the exercise performance. Fifty-four patients were enrolled; 35 (64.8%) were adherent and performed exercises for 15 min/day on five days/week. We found significant changes (p < 0.05) in the apnoea-hypopnoea index (AHI; 32.97 ± 1.8 to 21.9 ± 14.5 events/h); IOPI score (44.4 ± 11.08 to 49.66 ± 10.2); and minimum O2 saturation (80.91% ± 6.1% to 85.09% ± 5.3%). IOPI scores correlated significantly with AHI after the therapy (Pearson r = 0.4; p = 0.01). The 19 patients who did not adhere to the protocol showed no changes. MT based on telemedicine had good adherence, and its effect on AHI correlated with IOPI and improvement in tongue-tie.