Task-Specific Lingual Dystonia During Japanese Religious Services

INTRODUCTION

Lingual dystonia is a subtype of oromandibular dystonia characterized by involuntary contractions of the tongue muscles, often provoked by speaking or eating.

METHODS

This study reports six Japanese cases (four female and two male, mean age at onset of 49.5 years) with task-specific lingual dystonia during praying. In the early phase, all patients experienced lingual protrusion exclusively during Japanese religious services. When the patients start speaking, the tongues protrude forward, making it difficult to pronounce words. The patients were treated with multimodal treatment, including muscle afferent block (MAB) therapy comprising local anesthetic injection, botulinum toxin (onabotulinumtoxinA) injection, and a sensory trick splint.

RESULTS

MAB therapy was conducted in five patients (mean time: 5.8), and botulinum toxin injection was administered in four patients (mean time: 8). The injected muscles were the genioglossal muscles and, in one case, the lateral pterygoid muscle. Sensory trick splints were inserted in three patients. After the multimodal therapy, the patients were able to pronounce words smoothly and clearly. Oromandibular Dystonia Rating Scale scores improved significantly (P<0.005) from baseline (187 points) to endpoint (47 points) with a mean follow-up of 4.7 years.

CONCLUSION

Although this entity is rare, medical and dental professionals should be aware of this peculiar symptom. Multimodal therapy is required to ensure effective treatment of praying-induced lingual dystonia.

A Pilot Randomized Controlled Trial of Effect of Genioglossus Muscle Strengthening on Obstructive Sleep Apnea Outcomes

The genioglossus is a major upper airway dilator muscle. Our goal was to assess the efficacy of upper airway muscle training on Obstructive Sleep Apnea (OSA) as an adjunct treatment. Sixty-eight participants with OSA (AHI > 10/h) were recruited from our clinic. They fall into the following categories: (a) Treated with Automatic Positive Airway Pressure (APAP), (n = 21), (b) Previously failed APAP therapy (Untreated), (n = 25), (c) Treated with Mandibular Advancement Splint (MAS), (n = 22). All subjects were given a custom-made tongue strengthening device. We conducted a prospective, randomized, controlled study examining the effect of upper airway muscle training. In each subgroup, subjects were randomized to muscle training (volitional protrusion against resistance) or sham group (negligible resistance), with a 1:1 ratio over 3 months of treatment. In the baseline and the final visit, subjects completed home sleep apnea testing, Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), SF-36 (36-Item Short Form Survey), and Psychomotor Vigilance Test (PVT). Intervention (muscle training) did not affect the AHI (Apnea-Hypopnea Index), (p-values > 0.05). Based on PSQI, ESS, SF-36 scores, and PVT parameters, the changes between the intervention and sham groups were not significant, and the changes were not associated with the type of treatment (p-value > 0.05). The effectiveness of upper airway muscle training exercise as an adjunct treatment requires further study.

Noninvasive electrical stimulation of oropharyngeal muscles in obstructive sleep apnea

Introduction: Continuous positive airway pressure (CPAP) therapy remains the standard treatment for obstructive sleep apnea. However, its proven effect is useless if the patient does not tolerate the treatment. The electrical stimulation approach has been investigated for several decades now and it seems that the implantable devices for invasive electrical stimulation of hypoglossal nerve are viewed as effective with some of them already approved for human use.Areas covered: in this review, we intent to summarize the existing records of noninvasive stimulation in sleep apnea to make the scientific community aware of the details before deciding on its future. We believe that this is a battle still to fight and more could be done bearing in mind the safety of this method.Expertopinion: noninvasive electrical stimulation has been left behind based on few, small and inconsistent studies using different stimulation parameters. These studies are difficult to compare and to draw conclusions.Electrical stimulation is a field for research in the treatment of obstructive sleep apnea, with many aspects still to be discovered, and which may become a therapeutic alternative to the use of CPAP in certain patients.

Klotho alleviates chronic intermittent hypoxia-induced genioglossus myocyte apoptosis by inhibiting endoplasmic reticulum stress

Chronic intermittent hypoxia (CIH) has been shown to induce cell apoptosis in multiple organs of the human body. The present study aimed to assess the effects of exogenous klotho on CIH-induced genioglossus muscle injury, as well as the involvement of endoplasmic reticulum stress (ERS) in this process. A total of 36 adult C57BL/6 male mice were assigned to normoxia control (NC), CIH and CIH + klotho groups (n=12 mice/group). ELISA was performed to detect the level of klotho protein in the serum and in the genioglossus muscle tissue samples. Apoptosis was evaluated using the TUNEL assay. Reactive oxygen species (ROS) levels were quantified using a dihydroethidium assay kit, and the protein and mRNA levels of ERS-associated proteins (namely, glucoseregulated protein 78, C/EBP homologous protein, cleaved caspase-12 and cleaved caspase-3) in genioglossus samples were assessed using immunoblot assay and reverse transcription-quantitative PCR, respectively. Compared with the NC group, the quantities of klotho protein in the serum and genioglossus muscle tissue samples in the CIH group were significantly decreased, whereas the apoptotic rate, ROS levels and protein and mRNA levels of the ERS-associated proteins in the genioglossus muscle were significantly increased. Following supplementation with exogenous klotho protein, the klotho protein levels in the serum and genioglossus muscle tissue of mice were found to be markedly increased, and the apoptotic rate, ROS levels and protein and mRNA levels of the ERS-associated proteins in the genioglossus muscle were decreased compared with those in the CIH group. Taken together, the results of the present study have demonstrated that exogenous klotho may inhibit apoptosis of genioglossus myocytes in mice by inhibiting ROS-associated ERS.

Electrical stimulation for the treatment of obstructive sleep apnoea: a review of the evidence

INTRODUCTION

Obstructive sleep apnoea is an increasingly prevalent clinical condition with significant impact on individuals and public health. Continuous positive airway pressure therapy is the standard treatment, but adherence is limited and alternative treatments are needed. In this context, non-invasive and invasive methods for the electrical stimulation of upper airway dilator muscles have been demonstrated to be effective in selected patients. Areas covered: This review will cover investigations on the clinical effects, safety, and tolerability of non-invasive and invasive electrical stimulation of the upper airway for the management of obstructive sleep apnoea. Following a search of the relevant literature published on PubMed this review is focused mainly on data obtained from randomized clinical trials and clinical studies. Expert commentary: The available evidence provides a rationale to consider upper airway electrical stimulation as treatment for selected patients with obstructive sleep apnoea, who have poor adherence or experience difficulties with continuous positive airway pressure therapy. Non-invasive stimulation using transcutaneous electrodes and implantable hypoglossal nerve stimulator technologies may provide an alternative to continuous positive airway pressure for the treatment of obstructive sleep apnoea via restoration of neuromuscular tone and improved upper airway patency.

Unilateral Nasal Obstruction during Later Growth Periods Affects Craniofacial Muscles in Rats

Nasal obstruction can occur at different life stages. In early stages of life the respiratory system is still under development, maturing during the growth period. Previous studies have shown that nasal obstruction in neonatal rats alters craniofacial function. However, little is known about the effects of nasal obstruction that develops during later growth periods. The aim of this study was to investigate the effects of nasal obstruction during later periods of growth on the functional characteristics of the jaw-opening reflex (JOR) and tongue-protruding muscles. In total, 102 6-day-old male Wistar rats were randomized into either a control or experimental group (both n = 51). In order to determine the appropriate timing of nasal obstruction, the saturation of arterial oxygen (SpO₂) was monitored at 8 days, and at 3, 5, 7, 9, and 11 weeks in the control group. Rats in the experimental group underwent unilateral nasal obstruction at the age of 5 weeks. The SpO₂ was monitored at 7, 9, and 11 weeks in the experimental group. The electromyographic responses of JOR and the contractile properties of the tongue-protruding muscles were recorded at 7, 9, and 11 weeks. In the control group, SpO₂ decreased until 5 weeks of age, and remained relatively stable until 11 weeks of age. The SpO₂ was significantly lower in the experimental group than in the control. In the experimental group, JOR changes included a longer latency and smaller peak-to-peak amplitude, while changes in the contractile properties of the tongue-protruding muscles included larger twitch and tetanic forces, and a longer half-decay time. These results suggest that nasal obstruction during later growth periods may affect craniofacial function.

Detection of genioglossus myoelectric activity using ICA of multi-channel mandible sEMG

BACKGROUND

Genioglossus myoelectric activity is of great significance in evaluating clinical respiratory function. However, there is a tradeoff in genioglossus EMG measurement with respect to accuracy versus convenience.

OBJECTIVE

This paper presents a way to separate the characteristics of genioglossus myoelectric activity from multi-channel mandible sEMG through independent component analysis.

METHODS

First, intra-oral genioglossus EMGgenioglossus EMG and three-channel mandible sEMG were recorded simultaneously. The FastICA algorithm was applied to three independent components from the sEMG signals. Then the independent components with the intra-oral genioglossus EMG were compared by calculating the Pearson correlation coefficient between them.

RESULTS

An examination of 60 EMG samples showed that the FastICA algorithm was effective in separating the characteristics of genioglossus myoelectric activity from multi-channel mandible sEMG. The results of analysis were coincident with clinical diagnosis through intra-oral electrodes.

CONCLUSIONS

Genioglossus myoelectric activity can be evaluated accurately by multi-channel mandible sEMG, which is non-invasive and easy to record.

Human tongue neuroanatomy: Nerve supply and motor endplates

The human tongue has a critical role in speech, swallowing, and respiration, however, its motor control is poorly understood. Fundamental gaps include detailed information on the course of the hypoglossal (XII) nerve within the tongue, the branches of the XII nerve within each tongue muscle, and the type and arrangement of motor endplates (MEP) within each muscle. In this study, five adult human tongues were processed with Sihler's stain, a whole-mount nerve staining technique, to map out the entire intra-lingual course of the XII nerve and its branches. An additional five specimens were microdissected into individual muscles and stained with acetylcholinesterase and silver staining to study their MEP morphology and banding patterns. Using these techniques the course of the entire XII nerve was mapped from the main nerve to the smallest intramuscular branches. It was found that the human tongue innervation is extremely dense and complex. Although the basic mammalian pattern of XII is conserved in humans, there are notable differences. In addition, many muscle fibers contained multiple en grappe MEP, suggesting that they are some variant of the highly specialized slow tonic muscle fiber type. The transverse muscle group that comprises the core of the tongue appears to have the most complex innervation and has the highest percentage of en grappe MEP. In summary, the innervation of the human tongue has specializations not reported in other mammalian tongues, including nonhuman primates. These specializations appear to allow for fine motor control of tongue shape.

State-dependent and reflex drives to the upper airway: basic physiology with clinical implications

The root cause of the most common and serious of the sleep disorders is impairment of breathing, and a number of factors predispose a particular individual to hypoventilation during sleep. In turn, obstructive hypopneas and apneas are the most common of the sleep-related respiratory problems and are caused by dysfunction of the upper airway as a conduit for airflow. The overarching principle that underpins the full spectrum of clinical sleep-related breathing disorders is that the sleeping brain modifies respiratory muscle activity and control mechanisms and diminishes the ability to respond to respiratory distress. Depression of upper airway muscle activity and reflex responses, and suppression of arousal (i.e., "waking-up") responses to respiratory disturbance, can also occur with commonly used sedating agents (e.g., hypnotics and anesthetics). Growing evidence indicates that the sometimes critical problems of sleep and sedation-induced depression of breathing and arousal responses may be working through common brain pathways acting on common cellular mechanisms. To identify these state-dependent pathways and reflex mechanisms, as they affect the upper airway, is the focus of this paper. Major emphasis is on the synthesis of established and recent findings. In particular, we specifically focus on 1) the recently defined mechanism of genioglossus muscle inhibition in rapid-eye-movement sleep; 2) convergence of diverse neurotransmitters and signaling pathways onto one root mechanism that may explain pharyngeal motor suppression in sleep and drug-induced brain sedation; 3) the lateral reticular formation as a key hub of respiratory and reflex drives to the upper airway.

Age-related changes in rat genioglossus, geniohyoid and masseter muscles

OBJECTIVES

The aim of this study was to elucidate age-related changes from adult to middle age in the contractile properties of the masseter, genioglossus and geniohyoid muscles of the rat.

MATERIALS AND METHODS

We analysed the expressions of myosin heavy chain (MyHC) mRNAs and proteins as indicators of the contractile properties in these muscles obtained from rats at 6, 12, 18 and 24 months of age using real-time PCR and SDS-PAGE.

RESULTS

We found no marked age-related changes in the expressions of MyHC mRNAs and proteins in rat masseter and geniohyoid muscles, suggesting that the biological ageing process does not affect contractile properties in these muscles. However, we found a decrease in the expression of MyHC IIb mRNA with ageing in the rat genioglossus muscle, suggesting that biological ageing process induces at least some fast-to-slow myofibre phenotype transition.

CONCLUSION

The biological ageing process from adult to middle age appears to differentially affect different types of craniofacial muscles.

Treating obstructive sleep apnea with hypoglossal nerve stimulation

BACKGROUND

Reduced upper airway muscle activity during sleep is fundamental to obstructive sleep apnea (OSA) pathogenesis. Hypoglossal nerve stimulation (HGNS) counteracts this problem, with potential to reduce OSA severity.

STUDY OBJECTIVES

To examine safety and efficacy of a novel HGNS system (HGNS, Apnex Medical, Inc.) in treating OSA.

PARTICIPANTS

Twenty-one patients, 67% male, age (mean ± SD) 53.6 ± 9.2 years, with moderate to severe OSA and unable to tolerate continuous positive airway pressure (CPAP).

DESIGN

Each participant underwent surgical implantation of the HGNS system in a prospective single-arm interventional trial. OSA severity was defined by apnea-hypopnea index (AHI) during in-laboratory polysomnography (PSG) at baseline and 3 and 6 months post-implant. Therapy compliance was assessed by nightly hours of use. Symptoms were assessed using the Epworth Sleepiness Scale (ESS), Functional Outcomes of Sleep Questionnaire (FOSQ), Calgary Sleep Apnea Quality of Life Index (SAQLI), and the Beck Depression Inventory (BDI).

RESULTS

HGNS was used on 89% ± 15% of nights (n = 21). On these nights, it was used for 5.8 ± 1.6 h per night. Nineteen of 21 participants had baseline and 6-month PSGs. There was a significant improvement (all P < 0.05) from baseline to 6 months in: AHI (43.1 ± 17.5 to 19.5 ± 16.7), ESS (12.1 ± 4.7 to 8.1 ± 4.4), FOSQ (14.4 ± 2.0 to 16.7 ± 2.2), SAQLI (3.2 ± 1.0 to 4.9 ± 1.3), and BDI (15.8 ± 9.0 to 9.7 ± 7.6). Two serious device-related adverse events occurred: an infection requiring device removal and a stimulation lead cuff dislodgement requiring replacement.

CONCLUSIONS

HGNS demonstrated favorable safety, efficacy, and compliance. Participants experienced a significant decrease in OSA severity and OSA-associated symptoms.

CLINICAL TRIAL INFORMATION

NAME: Australian Clinical Study of the Apnex Medical HGNS System to Treat Obstructive Sleep Apnea.

REGISTRATION NUMBER

NCT01186926. URL: http://clinicaltrials.gov/ct2/show/NCT01186926.