Electromyography findings in radiation-induced unilateral tongue immobility.

BACKGROUND: We used electromyography to characterize hypoglossal nerve function among radiation-treated head and neck cancer survivors with later onset unilateral tongue immobility. METHODS: Patients with unilateral tongue immobility without evidence of recurrent cancer were seen at a tertiary academic institution between February and September 2021. All patients were at least 2 years post-treatment with radiation therapy for head and neck squamous cell carcinoma. Participants were under annual surveillance and displayed no evidence of operative injury to the hypoglossal nerve. RESULTS: The median symptom-free interval for the 10 patients included in this study was 13.2 years (range 2-25 years). Myokymia alone was present in 3 of 10 patients, fibrillation potentials alone were present in 3 of 10 patients, and 1 subject displayed both fibrillation and myokymia. Three out of 10 patients had normal hypoglossal nerve function. DISCUSSION: These findings highlight how disparate mechanisms may underlie similar clinical presentations of radiation-induced neuromuscular dysfunction.

Brain-derived neurotrophic factor overexpression in taste buds diminishes chemotherapy induced taste loss.

Vismodegib is used in patients suffering from advanced basal cell carcinoma (BCC), but 100% of the patients taking it report dysgeusia and 50% discontinue the treatment. Treatment with neurotrophic factors can stimulate neuronal survival and functional improvement in injured organs. Here, we analysed novel transgenic mouse lines in which brain-derived neurotrophic factor (BDNF) is overexpressed in taste buds, to examine whether higher levels of BDNF would reduce or prevent negative side effects of vismodegib in the taste system. BDNF plays crucial roles for development, target innervation, and survival of gustatory neurons and taste buds. The behavioural test in this study showed that vehicle-treated wild-type mice prefered 10 mM sucrose over water, whereas vismodegib treatment in wild-type mice caused total taste loss. Gustducin-BDNF mice had a significantly increased preference for low concentration of sucrose solution over water compared to wild-type mice, and most importantly the transgenic mice were able to detect low concentrations of sucrose following vismodegib treatment. We evaluated taste cell morphology, identity, innervation and proliferation using immunohistochemistry. All drug-treated mice exhibited deficits, but because of a possible functional upcycled priming of the peripheral gustatory system, GB mice demonstrated better morphological preservation of the peripheral gustatory system. Our study indicates that overexpression of BDNF in taste buds plays a role in preventing degeneration of taste buds. Counteracting the negative side effects of vismodegib treatment might improve compliance and achieve better outcome in patients suffering from advanced BCC.

Construction and Quality Evaluation of the Japanese Sarcopenic Dysphagia Database.

OBJECTIVES: To describe the activity and evaluate the quality of the Japanese sarcopenic dysphagia database. DESIGN: Cohort registry study. SETTING: 19 hospitals including 9 acute care hospitals, 8 rehabilitation hospitals, 2 long-term care hospitals, and 1 home visit rehabilitation team. PARTICIPANTS: 467 dysphagic patients, aged 20 years and older. MEASUREMENTS: The following indices were assessed at baseline: age, sex, main disease, sarcopenic dysphagia, whole body sarcopenia, Food Intake Level Scale (FILS), malnutrition diagnosed by the Global Leadership Initiative on Malnutrition criteria, oral status assessed by the Revised Oral Assessment Guide or the Oral Health Assessment Tool, activities of daily living assessed by the Functional Independence Measure (FIM) or the Barthel Index (BI), Charlson comorbidity index, C-reactive protein and serum albumin levels, dysarthria, hoarseness, aphasia, pressure ulcers, bladder, bowel, and kidney function, respiratory status, polypharmacy, number of drugs, and involvement of health care professionals and rehabilitation nutrition team. FILS, FIM or BI, and outcome including discharge destination were assessed at follow-up. A simple comparison of cases and evaluation of the quality of data were performed. RESULTS: The mean age was 80.4 ± 11.4 yr. The variable input error was 0. The number of patients with missing data was high for estimated glomerular filtration rate, C-reactive protein, serum albumin, skeletal mass index, and tongue pressure. The prevalence of either probable, possible, or no sarcopenic dysphagia was 105 (23%), 182 (39%), or 179 (38%), respectively. Doctors including physiatrists, nurses, physical therapists, and registered dietitians were involved with most patients, while the rehabilitation nutrition team was involved in only 16% of patients. CONCLUSIONS: The quality of the database was relatively high. Sarcopenic dysphagia is common in patients with dysphagia.

Changes in tongue-palatal contact during swallowing in patients with skeletal mandibular prognathism after orthognathic surgery.

This study aimed to evaluate improvement of tongue-palatal contact patterns during swallowing after orthognathic surgery in mandibular prognathism patients. Thirty patients with mandibular prognathism treated by orthognathic surgery (average age of 27 years, 3 months) and 10 controls (average age 29 years, 6 months) participated in this study. Tongue-palatal contact patterns of patients before and three months after surgery were evaluated by electropalatography (EPG) as well as controls. Whole total of tongue-palatal contact at 0.3, 0.2, and 0.1 sec before complete tongue-palatal contact during swallowing were evaluated. The duration of swallowing phases was also examined. Complete contact of tongue-tip in the alveolar part of individual artificial EPG plate were shown at 0.3, 0.2, and 0.1 sec before complete tongue-palatal contact in the controls, although incomplete contact in the alveolar part were shown at 0.3 sec in mandibular prognathism patients. Whole total of tongue-palatal contact at 0.3 and 0.2 sec before complete tongue-palatal contact was significantly lower in the patients before surgery than in the controls (p<0.05). However, these values increased after surgery. The duration of oral and pharyngeal phase was significantly longer in the patients before surgery than in the controls and the patients after surgery (p<0.01). This study demonstrated that the tongue-palatal contact pattern improved and the duration of oral and pharyngeal phase was shortened in mandibular prognathism patients during swallowing after orthognathic surgery. It is suggested that changes in maxillofacial morphology by orthognathic surgery can induce normal tongue movement during swallowing. (The data underlying this study have been uploaded to figshare and are accessible using the following DOI: https://doi.org/10.6084/m9.figshare.14101616.v1).

Effect of Electrode Configuration and Impulse Strength on Airway Patency in Neurostimulation for Obstructive Sleep Apnea.

OBJECTIVES/HYPOTHESIS: Hypoglossal nerve stimulation (HNS) has gained increasing interest for the treatment of patients with obstructive sleep apnea (OSA). Drug-induced sleep endoscopy (DISE) can both exclude improper airway collapse patterns and visualize airway changes under stimulation. Stimulation outcome effects depend on the impulse voltage and electric field resulting from the electrode configuration of the implanted device. The effects of various combinations of voltage and electric field on DISE airway patterns in contrast to awake endoscopy are unknown. STUDY DESIGN: Cohort study. METHODS: During therapy adjustment about 6 months after implantation, patients underwent a DISE and awake endoscopy with 100% and 125% of functional voltage in three typical electrode configurations (+ - +, o - o, - - -). All videos were analyzed by two separate persons for the opening of the airway at velum, tongue base, and epiglottis level. RESULTS: Thirty patients showed typical demographic data. The opening effects were visible in all patients, but there were changes between different electrode configurations. Several demographic or therapeutic aspects such as obesity, OSA severity, or prior soft palate surgery were associated with changes arising from different electrode configurations, but none resulted in a consistently better airway opening. CONCLUSIONS: In patients with poor results during the therapy adjustment, electric configuration changes can improve airway patency-an independent variable from increasing voltage. As these effects can only be seen in awake endoscopy or DISE, both endoscopies with live stimulation may be considered in cases with insufficient improvement in apnea-hypopnea index after initiation of HNS therapy. LEVEL OF EVIDENCE: Prospective case series; level 4. Laryngoscope, 131:2148-2153, 2021.

Metabolome and microbiome alterations in tongue coating of gastric precancerous lesion patients.

Objective: This paper seeks to provide mechanistic insight into the pathological transition through the analysis of metabolites and microorganisms in the tongue coating of gastric precancerous lesions (GPL) patients.Methods: GC-TOF-MS and UHPLC-QE-MS metabolomics, combined with 16S rRNA microbiome techniques, were performed to explore the changes in metabolites and microorganisms in the tongue coating of GPL patients.Results: When compared with 15 controls, 133 metabolites were found to be differentially expressed in 60 GPL cases, of which could be divided into ten categories. Among them, most of the differentially expressed metabolites identified were lipids or lipid-like molecules. These metabolites were implicated in 6 metabolic pathways including glycine, serine and threonine metabolism, arginine and proline metabolism, sphingolipid metabolism, valine, leucine and isoleucine degradation, arachidonic acid metabolism, and tyrosine metabolism. The relative abundances of Alloprevotella, Solobacterium, Rothia, Eikenella, and Aggregatibacter in the GPL group increased significantly relative to the controls and were associated with lipids and lipid-like molecules, organic nitrogen compounds, organic oxygen compounds, phenylpropanoids and polyketides, and organoheterocyclic compounds, respectively.Conclusions: Compared with healthy people, the changes of tongue coating metabolites in GPL patients were mainly characterized by alterations in lipid metabolism and were associated with localized changes in the microbiome.

Tendon-like tether formation for tongue-base advancement in an ovine model using a novel implant device intended for the surgical management of obstructive sleep apnoea.

Obstructive sleep apnoea (OSA) is a serious debilitating condition with significant morbidity and mortality affecting almost one billion adults globally. The current gold standard in the non-surgical management of airway collapse is continuous positive airway pressure (CPAP). However, non-compliance leads to a high abandon rate (27-46%). While there are multiple sites of airway obstruction during sleep, the tongue base is recognized as the key player in the pathogenesis of OSA. Poor outcomes of current tongue suspension devices are due to fracture, slippage or migration of devices. Three tongue tethering device groups, namely a polydioxanone/polyurethane combination (PDO + PU) treatment group, a PDO analytical control group, and a polypropylene (PP) descriptive control group, were implanted into 22 sheep (75-85 kg) in a two-phased study. After implant times of 8, 16, and 32 weeks, sheep were serially euthanized to allow for explantation of their tongues and chins. The PDO + PU devices remodeled during the 32-week implant period into a hybrid biological tendon-like tether through the process of gradual degradation of the PDO and collagen deposition as shown by electrophoresis, histology and mechanical testing. The control PDO device degraded completely after 32 weeks and the PP devices remained intact. The hybrid biological tendon-like tether exhibited a break-strength of 60 N, thus exceeding the maximum force to overcome upper airway collapse.

Role of drug-induced sleep endoscopy in evaluation of positional vs non-positional OSA.

BACKGROUND: The study aimed to evaluate the anatomical differences between positional and non-positional OSA, and to identify the potential predictors for distinguishing between these two types of OSA. METHODS: A cross-sectional study of 230 consecutive patients with OSA undergoing DISE (Drug-induced Sleep Endoscopy) was carried out at a tertiary academic medical center. The factors correlating with positional and non-positional OSA were analyzed, including clinical characteristics, polysomnography data, and DISE findings. RESULTS: Univariate analysis revealed that non-positional dependency was correlated with a higher BMI (p < 0.001), neck circumference (p < 0.001), modified Mallampati score (p = 0.003), AHI (p < 0.001), degree of velum concentric collapse (p = 0.004), degree of oropharyngeal lateral wall collapse (p < 0.001), and degree of tongue base anteroposterior collapse (p = 0.004). Multivariate analysis revealed that oropharyngeal lateral wall collapse (OR = 1.90, p = 0.027) was the only anatomical factor significantly predicted non-positional dependency in OSA patients. AHI (OR = 1.04, p < 0.001), although significant, made only a marginal contribution to the prediction of non-positional dependency. CONCLUSIONS: Oropharyngeal lateral wall collapse was identified as the only anatomical predictor for non-positional dependency in OSA patients. Therefore, further treatment modalities should address the distinct anatomical trait between positional and non-positional OSA.

Lingual epilepsia partialis continua: a detailed video-EEG and neuroimaging study.

Motor epilepsia partialis continua (EPC) is a frequent and widely described variant of simple focal motor status epilepticus. However, lingual EPC is an unusual epileptic condition. We present a case of lingual EPC secondary to low-grade glioma in which the EEG and neuroimaging features were particularly remarkable. The video-EEG showed lateralized periodic discharges with superimposed rhythmic activity and frequent recurrent focal epileptic seizures. Moreover, brain magnetic resonance imaging showed a right temporo-insular cortico-subcortical lesion which was hyperintense on FLAIR, suggestive of low-grade glioma. In addition, diffusion-weighted imaging and arterial spin labelling series showed restricted diffusion in the right temporo-insular and parietal cortex and increased cerebral flow, respectively. All these findings are in keeping with changes related to persistent focal status epilepticus. Finally, we review the literature and discuss the differential diagnosis of this rare epileptic entity. [Published with video sequence].

Reduced genioglossus muscle activity caused by fluid overload in anesthetized rats.

INTRODUCTION: Although the precise cause of obstructive sleep apnea (OSA) remains unknown, various anatomical or structural factors are thought to influence upper airway patency. Recent clinical studies show that OSA is frequently observed among patients with fluid-retaining states, such as heart/renal failure and postsurgery. It is important to note that a cause-effect relationship is not yet established, and our understanding of the effects of fluid overload is limited. The goal of this study was to investigate an animal model that can characterize the physiological changes that occur in response to fluid overload. METHOD: Acute nonsurvival experiments were conducted in 16 Sprague-Dawley rats. Rats were initially anesthetized by inhaled isoflurane, while the femoral vein was cannulated and urethane (1.2-1.5 g/Kg body weight) was gradually delivered intravenously to induce anesthesia. Additional doses of urethane were delivered as necessary to maintain a surgical plane of anesthesia. A surgical incision was made on the cervical area to catheterize carotid artery to measure blood pressure. A pair of stainless-steel wires was injected into the tongue to measure genioglossus muscle activity (GGEMG). All physiological measurements were recorded as intravenous infusion of saline was provided to the rat (infusion rate = 22 ml/kg over 30 min). RESULTS: Acute saline overloading resulted in a 33% decrease in GGEMG, when compared to baseline. There was also a gradual drop in the respiratory rate (13% decrease) that reached statistical significance at 10 min after infusion was stopped. The blood pressure exhibited a 14% increase which subsequently returned to baseline within 40 min stopping infusion. There were no significant changes in the heart rate. CONCLUSION: The results of this study indicate that systemic fluid overload can affect significant changes in different physiological systems including reduction in genioglossus muscle activity, increase in blood pressure, and change autonomic nervous system function.

Effect of tongue-strengthening exercises on tongue strength and swallowing-related parameters in chronic radiation-associated dysphagia.

BACKGROUND: Radiation-associated dysphagia (RAD) is highly prevalent in head and neck cancer (HNC) patients, with insufficient tongue strength (TS) as a characteristic of this disabling complication. The effects of tongue-strengthening exercises (TSE) on TS, swallowing, and quality of life (QoL) have not been studied in this population. METHODS: A prospective phase 2 study using an 8 weeks during TSE protocol was carried out in 15 patients with chronic RAD. Outcome parameters were maximal isometric pressure (MIP), TS during swallowing (Pswal), swallowing function, and QoL. All parameters were evaluated at baseline, after 4 and 8 weeks of training, and 4 weeks after the last training session. RESULTS: MIP increased significantly, without detraining effects. Pswal did not increase significantly, but relevant effect sizes were measured. Swallowing function ameliorated, but did not result in increased functional oral intake, self-reported outcome or QoL. CONCLUSION: TSE in patients with RAD results in increased strength and swallowing function.

Sleep endoscopy findings in children in supine versus left lateral position.

OBJECTIVE: To describe how drug-induced sleep endoscopy (DISE) findings in children with obstructive sleep apnea (OSA) change with lateral positioning. METHODS: Children undergoing DISE for OSA in 2018-19 at a tertiary care children's hospital were positioned first supine and then in left lateral (LL) and findings were compared. RESULTS: 63 children were included, 30 (47.6%) female and 33 (52.4%) male, mean age 4.64 years, and a mean Z-score 0.70. Mean pre-op Apnea Hypopnea Index (AHI) was 6.41 and REM AHI was 15.04. In supine position, 20 had obstruction at the palate (31.7%), 39 (61.9%) had obstruction at each of the base of tongue and the larynx, 17 (27.0%) had obstruction at the tonsils. In LL position, 11 (17.5%) were obstructed at the palate, 21 (33.3%) at the tonsils, 8 (12.7%) at the base of tongue and 7 (11.1%) at the larynx. Larynx and base of tongue were most likely to improve in LL position, as 54% of patients obstructed in supine position were open in LL position. Overall 38 (60.3%) patients improved on LL, 18 (28.6%) had no change, and 7 (11.1%) worsened. 30 (47.6%) patients improved in 1 site while 12 (19.0%) improved in more than 1 site. 16 (25.4%) patients worsened in 1 site and 9 (56.3%) of these had improvement in another site. CONCLUSION: A significant number of patients improved airway patency, particularly at the base of tongue/larynx, during DISE when placed in LL position as compared to standard supine positioning.

Contralateral Tongue Muscle Activation during Hypoglossal Nerve Stimulation.

OBJECTIVE: The effectiveness of upper airway stimulation via hypoglossal nerve stimulation for obstructive sleep apnea depends upon the pattern of tongue muscle activation produced. This study investigated the nature of contralateral tongue muscle activation by unilateral hypoglossal nerve stimulation using intraoperative nerve integrity monitoring in conjunction with electromyography and explored the relationship between contralateral tongue muscle activation and polysomnographic measures of obstructive sleep apnea severity. STUDY DESIGN: Prospective case series. SETTING: Tertiary care medical center. SUBJECTS AND METHODS: Fifty-one patients underwent unilateral (right) hypoglossal nerve stimulator implantation for obstructive sleep apnea. Neurophysiological data included electromyographic responses in ipsilateral (right) and contralateral (left) genioglossus muscles in response to intraoperative bipolar probe stimulation (0.3 mA) of medial hypoglossal nerve branches. Clinical data included pre- and postoperative apnea-hypopnea indices and oxygen desaturation levels. RESULTS: A subset of patients (20/51, 39%) exhibited electromyographic responses in both the ipsilateral and contralateral genioglossus (bilateral), whereas the remaining patients (31/51, 61%) exhibited electromyographic responses only in the ipsilateral genioglossus (unilateral). The baseline characteristics of bilateral and unilateral responders were similar. Both groups exhibited significant and comparable improvements in apnea-hypopnea index and oxygen desaturations after hypoglossal nerve stimulation. Neither the amplitude nor the latency of contralateral genioglossus responses was predictive of clinical outcomes. CONCLUSION: A subset of patients undergoing unilateral hypoglossal nerve stimulation exhibits activation of contralateral genioglossus muscles. Patients with unilateral and bilateral genioglossus responses exhibit comparable, robust improvements in apnea-hypopnea index and oxygen desaturation levels.

Journey towards a personalised medicine approach for OSA: Can a similar approach to adult OSA be applied to paediatric OSA?

The concept of personalised medicine is likely to revolutionise the treatment of adult obstructive sleep apnoea as a result of recent advances in the understanding of disease heterogeneity by identifying clinical phenotypes, pathophysiological endotypes, biomarkers and treatable traits. Children with the condition show a similar level of heterogeneity and paediatric obstructive sleep apnoea would also benefit from a more targeted approach to diagnosis and management. This review aims to summarise the adult literature on the phenotypes and endotypes of obstructive sleep apnoea and assess whether a similar approach may also be suitable to guide the development of new diagnostic and management approaches for paediatric obstructive sleep apnoea.

Tongue symptoms, suspension force and duration during operative laryngoscopy.

PURPOSE: Suspension laryngoscopy is a commonly performed procedure in otolaryngology. During the procedure, the laryngoscope applies direct force to the tongue. Postoperative tongue symptoms include pain, swelling, numbness, taste disturbance, and rarely motor deficits. Duration and magnitude of force applied have previously been associated with post-operative throat and tongue pain, respectively. We sought to correlate postoperative tongue symptoms with magnitude of force applied and/or duration of suspension and investigate any risk factors for tongue morbidity. MATERIALS AND METHODS: A sample of patients undergoing suspension laryngoscopy between 2015 and 2018 were prospectively recruited. Those with preexisting tongue symptoms, disease or surgery were excluded. Patients completed preoperative and postoperative questionnaires evaluating tongue swelling, numbness, motion and taste disturbance. Symptoms were subjectively scored on a visual scale from 0 to 10. Patient demographics, past medical and social history were also recorded. Intraoperative pressures were measured using a spring force scale, positioned between the suspension arm and Mayo stand. Initial and end suspension forces and duration of suspension were recorded. RESULTS: 120 patients met inclusion criteria, of which 63 completed both preoperative and postoperative questionnaires. 6 patients (9.5%) experienced postoperative tongue symptoms. Suspension force and duration of suspension were not significantly predictive of postoperative tongue symptoms. While all symptomatic patients were current or former cigarette smokers, smoking status was not found to be a statistically significant factor. CONCLUSIONS: Neither suspension forces nor duration of suspension were predictive of postoperative tongue morbidity. Further research is needed to evaluate the role of smoking status on postoperative tongue symptoms.

Impairments in Food Oral Processing in Patients Treated for Tongue Cancer.

Patients surgically treated for oral cancer are affected by several underestimated deglutition disorders risk factors. This study aims to characterize the level of these food oral processing (FOP) impairments in a group of patients treated by surgery for tongue cancer. Twenty-seven consecutive patients surgically treated for tongue cancer were evaluated concerning their chewing capacity (Mastication-test), and responded to questions concerning their capacity to bite, chew and manipulate food with their tongue, and their quality of life. According to the Mastication-test, 16 patients suffered total FOP incapacities (TI group), characterized by high tumor stage, invasive carcinological surgery and necessity of reconstructive surgery; 12 patients were partially or not impaired (PI/NI-group). Tongue movement score and number of dental units were lower in the TI group than in the PI/NI-group. Subjective FOP criteria were clearly impaired in the TI group and correlated with a poor oral health-related quality of life. One year after surgery, there is a decrease in BMI for TI group patients while the PI group patients had a significant increase in BMI. All patients surgically treated for oral cancer suffered FOP impairments, but not with the same severity. Totally impaired subjects are at higher risk from long-term malnutrition. Functional evaluation of FOP should form part of the post-operative follow-up for all patients suffering from tongue cancer, using a quick combined evaluation of chewing efficiency, oral health quality of life and nutritional status.

Earlier recovery of lingual dysfunction after middle ear surgery in pediatric versus adult patients.

OBJECTIVES: It is generally thought that the recovery of damaged chorda tympani nerve (CTN) function after middle ear surgery is different in pediatric patients from that in adult patients. The purpose of this study was to investigate the changes and the progress of taste and somatosensory functions of the tongue after middle ear surgery in pediatric patients compared with those of adult patients. STUDY DESIGN: Prospective study. METHODS: Fifty-nine pediatric patients and 106 adult patients underwent middle ear surgery. Taste and somatosensory functions of the anterior tongue, the so-called CTN functions, were assessed using electrogustometry (EGM), a 2-point discriminator, an electrostimulator, and a questionnaire before and 2 weeks and 6 months after surgery. RESULTS: Two weeks after surgery, there was no significant difference in the incidence of dysgeusia and abnormal EGM thresholds between the patient groups. The incidence of tongue numbness was significantly lower in pediatric patients than in adult patients regardless of CTN manipulation. Although the lingual somatosensory thresholds of adult patients were significantly increased, those of pediatric patients were not increased. Six months after surgery, the incidences of dysgeusia and an abnormal EGM threshold were lower in pediatric patients than in adult patients. Tongue numbness disappeared, and the thresholds of lingual somatosensory tests returned to normal in most pediatric patients. CONCLUSION: Not only taste function but also lingual somatosensory function was damaged after middle ear surgery even in pediatric patients. Pediatric patients complained of tongue numbness less frequently and showed earlier recovery than adult patients. LEVEL OF EVIDENCE: 2 Laryngoscope, 130:1016-1022, 2020.