The influence of alcohol on genioglossus single motor units in men and women during wakefulness.

NEW FINDINGS: What is the central question of this study? How does alcohol intake, which worsens obstructive sleep apnoea, alter motor control of the genioglossus muscle, an upper airway dilator, in healthy awake human volunteers, and does alcohol alter genioglossus muscle afterdischarge? What is the main finding and its importance? Alcohol consumption had a very minor effect on the activity of the genioglossus in healthy young individuals studied during wakefulness and did not alter afterdischarge, leaving open the possibility that alcohol worsens obstructive sleep apnoea via other mechanisms. ABSTRACT: Alcohol worsens obstructive sleep apnoea (OSA). This effect is thought to be due to alcohol's depressant effect on upper airway dilator muscles such as the genioglossus, but how alcohol reduces genioglossal activity is unknown. The aim of this study was to investigate the effect of alcohol consumption on genioglossus muscle single motor units (MUs). Sixteen healthy individuals were studied on two occasions (alcohol: breath alcohol concentration ∼0.07% and placebo). They were instrumented with a nasal mask, four intramuscular genioglossal EMG electrodes, and an ear oximeter. They were exposed to 8-12 hypoxia trials (45-60 s of 10% O2 followed by one breath of 100% O2 ) while awake. MUs were sorted according to their firing patterns and quantified during baseline, hypoxia and recovery. For the alcohol and placebo conditions, global muscle activity (mean ± SD peak inspiratory EMG = 119.3 ± 44.1 and 126.5 ± 51.9 µV, respectively, P = 0.53) and total number of MUs recorded at baseline (68 and 67, respectively) were similar. Likewise, the peak discharge frequency did not differ between conditions (21.2 ± 4.28 vs. 22.4 ± 4.08 Hz, P = 0.09). There was no difference between conditions in the number (101 vs. 88, respectively) and distribution of MU classes during hypoxia, and afterdischarge duration was also similar. In this study, alcohol had a very minor effect on genioglossal activity and afterdischarge in these otherwise healthy young individuals studied while awake. If similar effects are observed during sleep, it would suggest that the worsening of OSA following alcohol may be related to increased upper airway resistance/nasal congestion or arousal threshold changes.

Statin-induced autoimmune necrotizing myopathy with pharyngeal muscles involvement.

Statins are widely prescribed in the treatment of hypercholesterolemia. While their efficacy in the secondary prevention of vascular events is proven, their safety profile in older patients with multiple co-morbidities and polypharmacy remains questionable. Although rare, antihydroxy-3-methylglutaryl-coenzyme A reductase (anti-HMGCR) myopathy is a severe adverse effect of statins, manifesting as myalgias, proximal muscle weakness, muscle cell necrosis and rhabdomyolysis. We report an uncommon case of an autopsy-proven anti-HMGCR necrotising myopathy predominately affecting pharyngeal muscles in an older patient, leading to dysphagia, pneumonia and death within 3 weeks from onset. Clinicians should screen for dysphagia in any patient with suspected anti-HMGCR myopathy, order an anti-HMGCR antibody titre and consider prompt immunosupressive therapy.

The effects of sarcopenic dysphagia on the dynamics of swallowing organs observed on videofluoroscopic swallowing studies.

OBJECTIVES: The aim of the present study was (a) to determine the relationship of videofluoroscopic swallowing study (VFSS) findings of the swallowing musculature with the diagnostic criteria for sarcopenic dysphagia and (b) to examine the usefulness of VFSS for diagnosing sarcopenic dysphagia. METHODS: The participants were 132 patients (mean age, 80.4 ± 8.8 years). Their skeletal muscle mass, nutritional status and swallowing functions as assessed by VFSS findings were measured. Also, the relationship between the VFSS findings and sarcopenia was examined. RESULTS: Of all the participants, 20 men (mean age, 83.2 ± 6.9 years) and 27 women (mean age, 85.3 ± 6.9 years) were diagnosed with sarcopenia. In men, the amount of laryngeal upward movement (ALUM) was significantly lower and the pharyngeal area was significantly wider in the sarcopenia group than in the non-sarcopenia group. In women, the pharyngeal area was significantly wider in the sarcopenia group than in the non-sarcopenia group. In a logistic regression model, ALUM (odds ratio [OR] 1.135, 95% confidence interval [CI] 1.037-1.241, P = .006) and pharyngeal area (OR 0.028, 95% CI 0.001-0.670, P = .027) was a significant independent factor for the presence or absence of sarcopenia. CONCLUSIONS: The decline in swallowing function of sarcopenia patients was characterised by lower laryngeal movement and enlargement of the pharyngeal cavity due to decreased skeletal muscle mass and decreased muscle strength. The present study suggested the usefulness of measuring ALUM during swallowing and measuring the pharyngeal area with VFSS as indicators of decreased swallowing muscle function in sarcopenia.

Anatomical Significance of the Spatial Distribution of the Palatopharyngeus With Regard to Velopharyngeal Closure.

OBJECTIVE: Coordination of the various soft palate and pharyngeal muscles should be considered while evaluating velopharyngeal closure. However, it remains unclear whether different muscle bundles have specific functions during velopharyngeal closure. We macroscopically and microscopically examined these muscles in detail and particularly clarified the morphology of the palatopharyngeus (PP) in velopharyngeal closure. DESIGN: Forty halves of 21 heads from Japanese cadavers (average: 83.9 years) were used for analysis; 37 halves of 19 heads were macroscopically examined and 3 halves of 2 heads were histologically examined. RESULTS: The PP consisted of muscle bundles originating from the superior and inferior surfaces of the palatine aponeurosis. The most superior part of the superior constrictor (SC) and most lateral part of PP on the palatine aponeurosis initially ran in parallel and subsequently, in superoposterior and inferoposterior directions, respectively. The PP appeared as a single continuous sheet that was radially spread as a whole. Its medial margins, located superior and inferior to the aponeurosis, formed a fold that established the palatopharyngeal arch. The stylopharyngeus (StP) adjoined the base of this arch. CONCLUSIONS: Since PP consisted of muscle bundles running in various directions, various functions of these bundles should be considered during velopharyngeal closure. The PP can function as a sphincter with SC and as an elevator with StP. In addition, PP forms the medial protrusion in collaboration with StP and SC. Thus, PP plays an important role in velopharyngeal closure with the coordination of various muscles.

The Mendelsohn Maneuver and its Effects on Swallowing: Kinematic Analysis in Three Dimensions Using Dynamic Area Detector CT.

This study investigated the effects of Mendelsohn maneuver with three-dimensional kinematic analysis. Nine female speech-language pathologists (nine females, mean ± SD 27.1 ± 3.5 years old) underwent 320-row area detector scan during swallows of 4-ml nectar-thick liquid using with no maneuvers (control) and with Mendelsohn maneuver (MM). Critical event timing (hyoid, soft palate, epiglottis, laryngeal vestibule, true vocal cords (TVC), UES), hyoid and laryngeal excursion, cross-sectional area of UES, and volume of pharyngeal cavity and bolus were measured and compared between two swallows. In MM, all the events were significantly prolonged with delayed termination time (p < 0.05) except UES opening. The onset, termination, and duration of UES opening were not significantly affected by MM nor was timing of bolus transport. The hyoid bone was positioned significantly higher at maximum displacement (p = 0.011). Pharyngeal constriction ratio was 95.1% in control and 100% of all subjects in MM. Duration of minimum pharyngeal volume was significantly longer in MM than in control (p = 0.007). The MM produces several distinct changes in the kinematics of swallowing in healthy subjects with no dysphagia. The changes in the timing and magnitude of hyoid displacements and prolonged closure of the pharynx during swallowing suggest the utility of MM for improving the safety and efficiency of swallowing in selected cases.

Variability in Ultrasound Measurement of Hyoid Bone Displacement and Submental Muscle Size Using 2 Methods of Data Acquisition.

OBJECTIVE: This study compares variability in measures of hyoid bone displacement and submental muscle size using 2 methods of ultrasound transducer placement: fixed and hand-held. PATIENTS AND METHODS: Twenty-four healthy participants (11 males, 13 females) aged between 51 and 84 years were scanned using both methods. Repeated measures were collected within and across 3 sessions. RESULTS: A nonlinear mixed effects model was used to estimate the effects of the method, trial, and session. The fixed transducer produced greater within- and across-session variability on several measures compared to the hand-held method. Fixed-transducer measurements of hyoid bone displacement were 9.4% smaller compared to hand-held measurements (F[1, 24.34] = 3.58, p = 0.07). CONCLUSION: Results suggest that using a fixed transducer does not necessarily improve measurement accuracy of swallowing outcomes in a healthy system. The wide variability in individual measures indicates that further research is required before ultrasound is used for outcome measurement in rehabilitation.

Swallowing Outcomes in 7 Patients Following Endoscopic Cricopharyngeal Myotomy With Primary Closure.

Cricopharyngeal spasm and pharyngeal pouch can result in severe dysphagia symptoms that can have a significant impact on a patient's quality of life. Several surgical interventions have been demonstrated including balloon dilatation, botox injection, and open and endoscopic cricopharyngeal myotomy. The aim of this case series is to describe our technique for endoscopic cricopharyngeal myotomy and compare pre- and postoperative swallowing outcomes using objective swallowing questionnaires in a small series of patients. Seven patients diagnosed with cricopharyngeal spasm or grade 1 pharyngeal pouch on barium swallow were prospectively observed. MD Anderson Dysphagia inventory (MDADI) and Dysphagia handicap index (DHI) were given to patients before and after their operation. All patients underwent the same surgical technique with the cricopharyngeal bar divided and the defect closed with dissolvable sutures. Mean inpatient stay was 7 days (range 1-8) and mean time to resumption of soft diet was 4 (range 1-7) days. All patients resumed oral diet before discharge. MDADI scores showed improvement across all domains, however only the emotional score achieved statistical significance (P = .04). Dysphagia handicap index scores showed a statistically significant improvement across functional, emotional, and total domains. Postoperative chest infection treated with oral antibiotics occurred in 3 patients (43%) and no other complications were documented. In conclusion, endoscopic cricopharyngeal myotomy with primary sutured endoscopic closure can result in a significant benefit to patient's swallowing symptoms, emotional well-being, and quality of life.

Influence of head and neck positions on oropharyngeal seal pressure with Baska mask® versus I-gel™; A randomised clinical study.

BACKGROUND AND AIMS: Oropharyngeal seal pressure (OSP) achieved by a supraglottic airway device holds due importance as it indicates the feasibility of positive pressure ventilation, the degree of airway protection from supra-cuff soiling and also relates to postoperative morbidity. The primary outcome measure was to assess and compare OSP in different head and neck positions with Baska mask® and I-gel™. Secondary outcome measures were to compare peak inspiratory pressure (PIP), exhaled tidal volume (ETV), ease of insertion, time taken for insertion, number of attempts, intraoperative manipulations, and postoperative airway morbidity with both the devices. MATERIALS AND METHODS: Seventy consenting adults scheduled for a variety of surgical procedures under general anesthesia were allocated to Group B and Group G using Baska mask® and I-gel™ respectively. All statistical calculations were done using SPSS (Statistical Package for the Social Science). The comparison of quantitative variables between the study groups was done using Student t-test and within the variables was done by paired t-test. For comparing categorical data, Chi-square (χ2) test was performed. RESULTS: OSP was significantly higher in group B than in group G in all head and neck positions (neutral 33 ± 2.8 vs. 23.2 ± 1.8, flexion 35.5 ± 2.5 vs. 25.2 ± 1.6, extension 30.6 ± 2.7 vs. 21.4 ± 1.7, right lateral 32.6 ± 2.8 vs. 23.0 ± 1.5. left lateral 32.6 ± 2.7 vs. 23.1 ± 1.7 cm H2O, respectively) (P = 0.000). PIP increased significantly in group G as compared to group B in flexion. (P = 0.009). Baska mask® had significantly higher ETV in flexion compared to I-gel™. (P = 0.009). CONCLUSION: Baska mask® may provide a useful alternative to I-gel™ where the glottic seal has precedence over ease of insertion.

Anatomical variations of the stylopharyngeus and superior constrictors in relation to their function.

The aims of this study were to clarify the topography and variations stylopharyngeus (STP) and superior constrictor (SC) muscles, and to examine what role they play in the pharyngeal movement. Forty-four specimens (22 right and 22 left sides) from embalmed Korean adult cadavers (13 males, 9 females; age range, 46-89 years; mean age, 69.2 years) were used in this study. The accessory bundle of STP and petropharyngeus was found in 18.2% (8/44) and 25.0% (11/44) of cases, respectively. A variation of the STP, in which it ran transversely and merged with the SC muscle, was found in 2.3% (1/44) of cases while a variation of the SC muscle, in which it ran longitudinally and merged with the contralateral constrictors, was found in 11.4% (5/44). The variant muscle bundles play their own role in pharyngeal movement according to their morphology. These results provide information that will help a comprehensive understanding of the effects of pharyngeal muscles on movement.

Submental Muscle Activity and Its Role in Diagnosing Sarcopenic Dysphagia.

PURPOSE: The objectives of this study were two-fold: 1) to investigate differences in activity duration and amplitude of the submental muscles during swallowing measured with surface electromyography (sEMG) in older patients with sarcopenic dysphagia compared to those without dysphagia and 2) to examine the diagnostic accuracy of submental sEMG signals for sarcopenic dysphagia. PATIENTS AND METHODS: Patients (n = 60) aged ≥65 years participated in this cross-sectional study. The submental muscle activity duration parameters were the duration from the onset of swallowing to the maximum amplitude (duration A), duration from the maximum amplitude to the end of the swallowing activity (duration B), and total duration. The amplitude parameters were mean and maximum amplitude. Maximum lingual pressures were also measured for comparison with sEMG parameters. RESULTS: Duration A was not significantly different between the groups (p = 0.15), but duration B (p < 0.001) and total duration (p < 0.001) were significantly different between the non-dysphagic and sarcopenic dysphagic groups. The mean (p = 0.014) and maximum (p < 0.001) amplitudes were significantly different between the groups. The area under the receiver operating characteristic curve (AUC) was 0.94 (95% confidence interval (CI) 0.87-0.98) for duration B, 0.95 (95% CI 0.89-0.99) for total duration, 0.76 (95% CI 0.63-0.87) for maximum amplitude, and 0.61 (95% CI 0.47-0.75) for mean amplitude. The AUC of the total duration was significantly greater than that of lingual pressure (p = 0.02). CONCLUSION: Patients with sarcopenic dysphagia had longer submental muscle activity duration and higher amplitude during swallowing as assessed using sEMG. The findings of this study can be useful in elucidating the underlying pathophysiology of sarcopenic dysphagia and in diagnosing sarcopenic dysphagia.

The Changes in Pharyngeal Constrictor Muscles Related to Head and Neck Radiotherapy: A Systematic Review.

It is well known that radiation damage of the pharyngeal constrictor muscles, the glottic larynx, and the supraglottic larynx may lead to dysphagia, an unwanted effect of head and neck radiotherapy. The reduction of radiotherapy-induced dysphagia might be achieved by adaptive radiotherapy. Although the number of studies concerning adaptive radiotherapy of head and neck cancer is continuously increasing, there are only a few studies concerning changes in dysphagia-related structures during radiotherapy.The goal of this review is to summarize the current knowledge about volumetric, dosimetric, and other changes of the pharyngeal constrictor muscles associated with head and neck radiotherapy. A literature search was performed in the MEDLINE database according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The conclusions of 8 studies that passed the criteria indicate a significant increase in the volume and the thickness of the pharyngeal constrictor muscles during radiotherapy. Moreover, the changes in magnetic resonance imaging signal intensity of the pharyngeal constrictor muscles correlate with the absorbed dose (typically higher than 50 Gy) and also with the grade of dysphagia. This systematic review presents 2 variables, which are suitable for estimation of radiotherapy-related pharyngeal constrictor muscles changes-magnetic resonance imaging signal intensity and the thickness. In the case of the thickness, there is no consensus in the level of the measurement-C2 vertebra, C3 vertebra, and the middle of the craniocaudal axis are used. It seems that reference to a position associated with a vertebral body could be more reproducible and beneficial for future research. Although late pharyngeal toxicity remains a challenge in head and neck cancer treatment, better knowledge of radiotherapy-related changes in the pharyngeal constrictor muscles contributes to adaptive radiotherapy development and thus improves the treatment results.

Lateral-Expansion Pharyngoplasty: Combined Technique for the Treatment of Obstructive Sleep Apnea Syndrome.

Introduction Obstructive sleep apnea syndrome (OSAS) is a multifactorial disease characterized by episodes of partial or complete collapse during sleep of different regions of the upper airway. Surgery for OSAS evolved with the introduction of different techniques, considering new surgical concept of reconstruction of the upper airway. Objective To retrospectively evaluate the effectiveness of a new approach aimed at reducing pharyngeal collapse by combining two surgical techniques: lateral and expansion pharyngoplasty. Methods We reviewed the medical records of 38 patients with OSAS undergoing lateral/expansion pharyngoplasty from January 2012 to December 2016. The following data were collected: patient age, gender, and pre- and postoperative body mass index (BMI), Epworth sleepiness scale (ESS) scores, snoring visual analogue scale (VAS) scores, and polysomnography (PSG) results. Results The PSG results showed a significant reduction in the apnea/hypopnea index (AHI) from 22.4 ± 27.3 events/h preoperatively to 13.6 ± 17.9 events/h postoperatively ( p = 0.009), with postoperative AHI reduction greater than 50% in 63.2% of the patients. There was also a significant reduction in the microarousal index (19.5 ± 22.6 vs 11.0 ± 13.4 events/h; p = 0.001) and in the minimum oxygen saturation (82.6 ± 10.3 vs 86.9 ± 11.1; p = 0.007). Conclusions Lateral-expansion pharyngoplasty represents a new surgical strategy for the treatment of OSAS in patients with palatal collapse by combining two different techniques: lateral and expansion pharyngoplasty. The two techniques, performed as a one-stage procedure, led to improvements in excessive daytime sleepiness, snoring, and PSG respiratory parameters by acting on lateral and retropalatal collapse, producing favorable results with good applicability in otolaryngology clinical practice.

Effects of Inhaled Corticosteroids and Particle Size on Risk of Obstructive Sleep Apnea: A Large Retrospective Cohort Study.

Background: Inhaled corticosteroids (ICS) produce local effects on upper airway dilators that could increase the risk of developing obstructive sleep apnea (OSA). Given that the particle size of ICS changes their distribution, the particle size of ICS may impact the risk of developing OSA. Objectives: In this large retrospective study, we explore the relationship of ICS use and OSA in patients with asthma. In addition, we seek to determine if this relationship is affected by the particle size of ICS. Methods: Using electronic health records, we established a cohort of 29,816 asthmatics aged 12 and older with a diagnosis of asthma documented by ICD-9 or ICD-10 codes between January 2011 and August 2016. We performed analyses of variance and multivariate logistic regression analysis to determine the effects ICS on the diagnosis of OSA with sub-analysis by particle size of ICS. Results: Uncontrolled asthmatics showed increased odds of receiving a diagnosis of OSA whether when looking at ACT scores (adjusted odds ratio (aOR) 1.60, 95% CI 1.32-1.94) or PFT results (aOR 1.45, 95% CI 1.19-1.77). Users of ICS also had increased odds of OSA independent of asthma control (aOR 1.58, 95% CI 1.47-1.70). Notably, users of extra-fine particle ICS did not have significantly increased odds of having OSA compared to non-users of ICS (aOR 1.11, 95% CI 0.78-1.58). Conclusions: Use of ICS appears to be an independent risk factor for OSA. Notably, extra-fine particle size ICS do not appear to be associated with an increased risk of OSA.

Why do Zenker's diverticulae occur more often on the left than the right side?

BACKGROUND: Zenker's diverticulum is a pharyngoesophageal outpouching of mucosa and submucosa through Killian's dehiscence. OBJECTIVE: To investigate the propensity for Zenker's diverticulum to occur on the left side by examining muscle thickness in Killian's dehiscence, and to explore correlations between muscle thickness, sex, height and age. METHODS: The study included 109 Caucasian cadavers, 52 male and 57 female. The mean thickest and thinnest measurements of left medial, left lateral, right medial and right lateral aspects of Killian's dehiscence were calculated. The paired student's t-test was used to determine significance. RESULTS: The average left muscle layer was significantly thinner than the right muscle layer, in both medial and lateral aspects. Furthermore, medial muscle thickness was significantly thinner than its respective lateral aspect for both the left and right sides. No correlations were found between muscle thickness and cadavers' sex, length or stature, or age. CONCLUSION: There was a significant difference in muscle thickness between the left and right sides of Killian's dehiscence. The findings suggest there is a reason why Zenker's diverticulum occurs predominantly on the left side. The study also showed a significant difference in muscle thickness between the medial and lateral aspects of Killian's triangle.

Swallowing outcomes after cricopharyngeal myotomy: A systematic review.

BACKGROUND: No practice guidelines have been established for swallowing outcomes after cricopharyngeal myotomy (CPM). The purpose of this systematic review was to summarize evidence for swallowing outcomes in patients undergoing CPM to treat symptomatic cricopharyngeal dysfunction, in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) protocol. METHODS: Swallowing outcomes examined included penetration/aspiration ratings, manometric measures, patient-rated dysphagia scales, clinician-rated dysphagia scales, diet level, and weight. RESULTS: Three databases were queried for studies published between January 1995 and July 2015, resulting in a total of 122 full-text eligible records. Studies were screened and reviewed, culminating in 10 studies meeting inclusion criteria. Critical appraisal of study design, swallowing outcomes measures, and statistical analysis were summarized. CONCLUSION: This systematic review revealed insufficient evidence for guiding clinical practice. Future investigations should use validated patient-rated and clinician-rated instruments as well as detailed high-resolution manometry measures to optimally capture postoperative swallowing outcomes.

Intraoral electrical muscle stimulation in the treatment of snoring.

The tone of the intraoral und pharyngeal muscles of the upper airway is of particular importance for the development of snoring. By increasing the tone with electrical stimulation, a reduction in snoring may be achieved. The aim of the study was to record the effects of intraoral muscle stimulation during the day on snoring at night. The prospective bi-centric study included 16 patients with snoring and mild obstructive sleep apnoea (Apnoea Hypopnoea Index [AHI] < 15, BMI < 32). After initial polygraphy, snoring was monitored over 2 weeks (baseline) using a visual analogue scale (VAS; 0-10). This was followed by a 6-week treatment phase (2â€¯× 20 min daily) with an intraoral electrical stimulation device. During and up to 2 weeks after therapy, snoring intensity in addition to use and potential side effects were documented on a daily basis. Three patients discontinued therapy because of technical problems. The 13 remaining patients (11 male/2 female, BMI 26.9 ± 3.2, AHI 9.3 ± 4.6) underwent per-protocol analysis. The mean snoring score was reduced from 5.6 ± 1.1 (baseline) to 3.2 ± 2.7 (after therapy) and remained stable until 2 weeks after treatment (3.3 ± 2.4). In 7 patients (53.9%) the score was reduced by more than 50%. Patients with an AHI < 10 responded better to therapy. No unexpected events occurred. In the present pilot study, the first signs of the effectiveness of intraoral muscle stimulation in snoring patients were shown. In addition to a technical improvement of the stimulator, carrying out controlled trials and assessing potential influencing factors on the success of therapy are necessary.

Simultaneously occurring Zenker's diverticulum and Killian-Jamieson diverticulum: case report and literature review.

BACKGROUND: Pharyngoesophageal diverticula have many subtypes, with Zenker's diverticulum being the most common. First described in 1983, a Killian-Jamieson diverticulum is an outpouching in the anterolateral wall at the pharyngoesophageal junction. This is located inferiorly to the cricopharyngeus muscle, unlike Zenker's diverticula which occur superiorly. Killian-Jamieson diverticula are rare and are commonly misdiagnosed as Zenker's diverticula. Less than 30 reports of Killian-Jamieson diverticula have been described in the literature. CASE REPORT: A 69-year-old man presented with a 2-year symptomatic history, and was found to have simultaneous Zenker's diverticulum and Killian-Jamieson diverticulum. He was treated successfully with open surgical excision of both pouches. CONCLUSION: Zenker's diverticulum and Killian-Jamieson diverticulum are diagnosed using radiological studies and endoscopy. Their differentiation is important, as surgical management differs. This paper reviews the literature on Killian-Jamieson diverticula and the management options available.

The Influence of CO2 on Genioglossus Muscle After-Discharge Following Arousal From Sleep.

Objectives: Ventilatory after-discharge (sustained elevation of ventilation following stimulus removal) occurs during sleep but not when hypocapnia is present. Genioglossus after-discharge also occurs during sleep, but CO2 effects have not been assessed. The relevance is that postarousal after-discharge may protect against upper airway collapse. This study aimed to determine whether arousal elicits genioglossus after-discharge that persists into sleep, and whether it is influenced by CO2. Methods: Twenty-four healthy individuals (6 female) slept with a nasal mask and ventilator. Sleep (EEG, EOG, EMG), ventilation (pneumotachograph), end-tidal CO2 (PETCO2), and intramuscular genioglossus EMG were monitored. NREM eucapnia was determined during 5 minutes on continuous positive airway pressure (4 cmH2O). Inspiratory pressure support was increased until PETCO2 was ≥2 mm Hg below NREM eucapnia. Supplemental CO2 was added to reproduce normocapnia, without changing ventilator settings. Arousals were induced by auditory tones and genioglossus EMG compared during steady-state hypocapnia and normocapnia. Results: Eleven participants (4 female) provided data. Prearousal PETCO2 was less (p < .05) during hypocapnia (40.74 ± 2.37) than normocapnia (43.82 ± 2.89), with differences maintained postarousal. After-discharge, defined as an increase in genioglossus activity above prearousal levels, occurred following the return to sleep. For tonic activity, after-discharge lasted four breaths irrespective of CO2 condition. For peak activity, after-discharge lasted one breath during hypocapnia and 6 breaths during normocapnia. However, when peak activity following the return to sleep was compared between CO2 conditions no individual breath differences were observed. Conclusions: Postarousal genioglossal after-discharge may protect against upper airway collapse during sleep. Steady-state CO2 levels minimally influence postarousal genioglossus after-discharge.

Pharyngeal pouch management: an historical review.

BACKGROUND: Management of the pharyngeal pouch has evolved enormously since the first description by Ludlow in 1764 and the first case series by Zenker and Von Ziemssen in 1877. With the introduction of antibiotics, and the advancement of surgical technique with the advent of endoscopic surgery and lasers, current management is vastly different to that in the nineteenth century. OBJECTIVES: This paper traces the history of pharyngeal pouch management, and discusses the various treatment options and opinions recorded during the nineteenth and twentieth centuries, comparing these with techniques popular today. RESULTS AND CONCLUSION: Pharyngeal pouch surgery has been associated with significant morbidity, both because of the elderly age of patients typically affected by the condition and because of the surgery itself and potential post-operative complications encountered. The historical development of pharyngeal pouch management and the understanding of pharyngeal pouch pathophysiology are discussed.

Management of isolated cricopharyngeal dysfunction: systematic review.

OBJECTIVE: A systematic review was performed to evaluate the safety and efficacy of different therapeutic interventions available for the management of isolated cricopharyngeal dysfunction. METHODS: Studies were identified using the following databases: Ovid (Medline, Embase), the Cochrane Library, PubMed and Google Scholar. An initial search identified 339 articles. All titles and abstracts were reviewed. Fifty-six relevant articles were inspected in more detail; of these, 47 were included in the qualitative analysis. RESULTS: No relevant randomised trials were found. A range of case series were used to perform a qualitative analysis. Botulinum toxin A injection and cricopharyngeal dilatation were associated with a higher risk of recurrence, but appear to be more suitable in elderly and co-morbid patients. In those patients requiring formal myotomy, endoscopic approaches appear to be as effective but less morbid when compared with classical open surgery. CONCLUSION: There is good evidence for the safety and efficacy of the different therapeutic options for isolated cricopharyngeal dysfunction. However, further studies are required to compare the efficacy of the various treatment modalities.