Pharyngeal Function Research Articles

Genomic organization of an avermectin receptor subunit from Haemonchus contortus and expression of its putative promoter region in Caenorhabditis elegans.

Avermectins and milbemycins are believed to exert their anthelmintic effects by binding to glutamate-gated chloride channels (GluCls). Two GluCl subunits have been localized in the pharynx in Caenorhabditis elegans, and the pharynx has been implicated as a major target for avermectins in C. elegans. However, in parasitic nematodes, the pharyngeal localization of the GluCl subunits needs to be determined. The HcGluCla gene encoding an alpha-type GluCl subunit has been cloned from Haemonchus contortus previously. To investigate the expression site of the HcGluCla gene we have isolated a 1439bp 5'-flanking region and determined the genomic organization of this gene. The HcGluCla gene is composed of 12 exons separated by 11 introns and spans approximately 7.3kb of genomic DNA. Analysis of the 1439bp 5'-flanking region of the HcGluCla gene revealed that it contained TATA, CCAAT boxes, and several other consensus transcriptional factor recognition sequences. The 1439bp 5'-flanking region and the first exon and intron and part of the second exon of the HcGluCla gene were fused to green fluorescence protein (GFP) reporter gene and microinjected into the gonads of C. elegans. After microinjection of the construct into C. elegans, four stable transformed lines were established and assayed for GFP expression. The transformed animals exhibited fluorescence in the two pairs of MC and M2 pharyngeal neurons, but no expression was detected in the muscle cells. Expression of HcGluCla in pharyngeal neurons suggests a mechanism for the effects of avermectins and milbemycins on pharyngeal function in parasitic nematodes.

Effect of diet variables on the biomechanical measures of swallowing in stroke patients

This study was designed to examine the effect of diet variables, namely: bolus volume and consistency on the biomechanical measures of swallowing in stroke patients for better management of their oro-pharyngeal (O-P) dysphagia. Fifty patients with chronic and acute strokes were selected for the study. All patients were evaluated through an especially designed diagnostic protocol. Each subject was asked to swallow different bolus consistencies (thin and thick liquids; semisolid and solid) in different volumes (3, 5 and 10 ml). The biomechanical measures that were analysed from videofluoroscopic assessment of the patients include the following: (A) degree of impairment of the structural movement and bolus flow; (B) temporal measures of swallowing; (C) percent of O-P residue and percentage of the bolus penetrated/aspirated; (D) penetration/aspiration (P/A) scale; and (E) O-P Swallow Efficiency (OPSE) Score. The results demonstrated that the pharynx adapts itself to the increasing bolus volumes even in an impaired pharyngeal function. However, larger bolus volumes in both thin and thick liquids resulted in an increase in percentage of bolus P/A and higher P/A scale. The results also demonstrated that both thin and thick liquid consistencies were unsafe regarding the airway P/A and might better be avoided in the early stages of restoration of oral feeding in stroke patients. While on the other hand, semisolid consistency was the safest swallowed consistency in both patient groups. Presentation of calibrated bolus sizes and various consistencies should be an integral part of the swallow evaluation protocol. These evaluations will aid in choosing an appropriate nutritional option for patients with O-P dysphagia.

Snoring, sleep apnoea and swallowing dysfunction: a videoradiographic study.

Snoring is associated with subclinical pharyngeal swallowing dysfunction, probably owing to vibration trauma to the pharyngeal tissues caused by snoring. Negative intrathoracic pressure during apnoea causes stretching of the velum and pharynx. The aim of this study was to investigate whether patients with severe sleep apnoea have an increased frequency of videoradiographically diagnosed subclinical pharyngeal swallowing dysfunction compared with snoring patients with or without mild sleep apnoea as well as with non-snoring controls. Eighty consecutive patients referred for sleep apnoea recordings because of snoring were examined. Fourteen of these patients were excluded because they suffered from dysphagia. Fifteen non-snoring, non-dysphagic volunteers served as controls. Videoradiography was performed to examine the oral and pharyngeal swallowing function in patients and controls. Overnight sleep apnoea recordings were used to evaluate the apnoea-hypopnoea index (AHI). Pharyngeal swallowing dysfunction was observed in 34/66 (52%) of the snoring patients and in 1/15 (7%) of the non-snoring controls. Pharyngeal swallowing dysfunction was observed in 50% of patients with an AHI of >or=30, in 61% of patients with an AHI of 5-29 and in 43% of patients with an AHI of <5. There was no significant difference in the frequency of pharyngeal swallowing dysfunction between snoring patients with different AHIs. Snoring patients run an increased risk of developing subclinical pharyngeal swallowing dysfunction independent of concomitant sleep apnoea.

Distribution of glutamate-gated chloride channel subunits in the parasitic nematode Haemonchus contortus.

Glutamate-gated chloride channels (GluCl) are related to gamma-aminobutyric acid-A (GABA(A)) receptors and are the target sites for the avermectin/milbemycin (A/M) anthelmintics, drugs that cause paralysis of the somatic and pharyngeal muscles in nematodes. We have previously identified four GluCl subunits, HcGluClalpha, HcGluClbeta, HcGluClalpha3A, and HcGluClalpha3B from the sheep parasite Haemonchus contortus. We raised specific antisera against all of these subunits and used them in immunofluorescence experiments on adult parasites. All of the subunits were expressed in the motor nervous system, especially motor neuron commissures. Double-immunostaining experiments suggested that HcGluClalpha and HcGluClbeta were expressed on the same commissures; these were also stained with an anti-GABA antibody, suggesting that they may be inhibitory motor neurons. The HcGluClbeta subunit was also detected in lateral and sublateral nerve cords. The HcGluClalpha3A and -B subunits, products of an alternatively spliced gene, were expressed in different neurons. We found HcGluClalphaA in a pair of sensory, possibly amphid, neurons in the head, in addition to the motor neuron commissures. HcGluClalpha3B was detected in three cell bodies, probably of pharyngeal neurons, and to ventral and lateral cords. These results indicate that the GluCl are widely distributed in the H. contortus nervous system and suggest that they have critical roles controlling locomotion, pharyngeal function, and possibly sensory processing in parasitic nematodes. They also provide an explanation for the observed effects of the A/M anthelmintics.

Enzyme activities of pharyngeal jaw musculature in the cichlid Tramitichromis intermedius: implications for sound production in cichlid fishes.

Owing to its high degree of complexity and plasticity, the cichlid pharyngeal jaw apparatus has often been described as a key evolutionary innovation. The majority of studies investigating pharyngeal muscle behavior and function have done so in the context of feeding. Analysis of enzyme activities (citrate synthase, 3-hydroxyacyl-CoA dehydrogenase and L-lactate dehydrogenase) of pharyngeal muscles in the Lake Malawi cichlid Tramitichromis intermedius revealed differences between pharyngeal jaw muscles and between males and females. Therefore, these muscles have different performance characteristics, resulting in different functional characteristics of the muscles within the complex. Furthermore, the differences between muscles of males and females represent fundamental differences in muscular metabolic processes between sexes. This study is the first to demonstrate that the pharyngeal anatomy is not only used for food processing but is possibly responsible for sound production, in turn influencing sexual selection in cichlid fish.

An Fgf8 mouse mutant phenocopies human 22q11 deletion syndrome.

Deletion of chromosome 22q11, the most common microdeletion detected in humans, is associated with a life-threatening array of birth defects. Although 90% of affected individuals share the same three megabase deletion, their phenotype is highly variable and includes craniofacial and cardiovascular anomalies, hypoplasia or aplasia of the thymus with associated deficiency of T cells, hypocalcemia with hypoplasia or aplasia of the parathyroids, and a variety of central nervous system abnormalities. Because ablation of neural crest in chicks produces many features of the deletion 22q11 syndrome, it has been proposed that haploinsufficiency in this region impacts neural crest function during cardiac and pharyngeal arch development. Few factors required for migration, survival, proliferation and subsequent differentiation of pharyngeal arch neural crest and mesoderm-derived mesenchyme into their respective cardiovascular, musculoskeletal, and glandular derivatives have been identified. However, the importance of epithelial-mesenchymal interactions and pharyngeal endoderm function is becoming increasingly clear. Fibroblast growth factor 8 is a signaling molecule expressed in the ectoderm and endoderm of the developing pharyngeal arches and known to play an important role in survival and patterning of first arch tissues. We demonstrate a dosage-sensitive requirement for FGF8 during development of pharyngeal arch, pharyngeal pouch and neural crest-derived tissues. We show that FGF8 deficient embryos have lethal malformations of the cardiac outflow tract, great vessels and heart due, at least in part, to failure to form the fourth pharyngeal arch arteries, altered expression of Fgf10 in the pharyngeal mesenchyme, and abnormal apoptosis in pharyngeal and cardiac neural crest. The Fgf8 mutants described herein display the complete array of cardiovascular, glandular and craniofacial phenotypes seen in human deletion 22q11 syndromes. This represents the first single gene disruption outside the typically deleted region of human chromosome 22 to fully recapitulate the deletion 22q11 phenotype. FGF8 may operate directly in molecular pathways affected by deletions in 22q11 or function in parallel pathways required for normal development of pharyngeal arch and neural crest-derived tissues. In either case, Fgf8 may function as a modifier of the 22q11 deletion and contribute to the phenotypic variability of this syndrome.

Dysphagia and aspiration with unilateral vocal cord immobility: incidence, characterization, and response to surgical treatment.

To objectively determine the incidence of dysphagia associated with unilateral vocal cord immobility (UVCI) and to evaluate the potential for response to vocal cord medialization, we made videofluoroscopic swallowing (VFS) recordings of patients with newly diagnosed UVCI and prospectively analyzed them in a blinded fashion using the Penetration-Aspiration Scale (PAS) and pharyngeal transport function measures. A subset of patients underwent vocal cord medialization and were evaluated with a postoperative VFS study. Comparison was made between preoperative and postoperative VFS results to study the effects of vocal cord medialization in this setting. Eighty-seven VFS recordings were studied in 64 adult patients with UVCI; 23 patients underwent VFS testing before and after vocal cord medialization. The UVCI was most commonly left-sided (53 cases) and most commonly resulted from thoracic or cardiac surgery (53.1%), followed by malignancy (15.6%). Overall, the median PAS score was 2.0 (25th-75th percentiles, 1.0-5.0), with 20 patients (31.3%) and 15 patients (23.4%) exhibiting penetration or aspiration, respectively. No significant differences in swallowing function were noted between surgical and nonsurgical causes of paralysis (PAS scores of 2.0 and 2.0, respectively; p = .901). The median PAS score improved from 4.0 to 3.0 (p = .395, Wilcoxon paired samples test) in patients studied after undergoing a vocal cord medialization procedure (6 laryngoplasties and 17 vocal cord injections). Laryngoplasty was not more successful than vocal cord injection in resolving aspiration (p = .27). Radiographically significant penetration or aspiration occurs in approximately one third of patients with UVCI, independent of the cause of paralysis. Vocal cord medialization may not be as effective as thought for eliminating aspiration in these patients.

Prevalence and Predictors of Upper Airway Obstruction in the First 24 Hours After Acute Stroke

The prevalence of sleep-disordered breathing after stroke has been reported to be between 32% and 71%. However, the first 24-hour period, when upper airway obstruction may have a critical effect on the cerebral circulation because of hemodynamic fluctuations and repetitive hypoxia, has not been studied. Furthermore, data on prediction of upper airway obstruction after stroke are limited. This study sought to assess the prevalence of upper airway obstruction in the first 24 hours of stroke and to ascertain whether its occurrence could be predicted. One hundred twenty patients with acute stroke underwent a respiratory variable-only sleep study, started within 24 hours of onset of neurological symptoms. Sleep history and stroke characteristics were recorded on admission. We found that 79%, 61%, and 45% of the patients had a respiratory disturbance index greater than 5, 10, and 15 events per hour, respectively. Patients had a significantly higher respiratory disturbance index when nursed in the supine (29 events per hour), supine left (29 events per hour), and supine right (24 events per hour) positions than in any other position (P<0.0001). On logistic regression analysis, BMI (P=0.025), neck circumference (P=0.026), and limb weakness (P=0.025) independently predicted the occurrence of upper airway obstruction in the first 24 hours after acute stroke. Upper airway obstruction is common in the first 24 hours after stroke, especially if patients are nursed in the supine position, and typical obstructive sleep apnea risk factors (body mass index and neck circumference) appear to be the best predictors of its occurrence. Stroke characteristics (severity, clinical subtype, and clinically assessed pharyngeal function) are not independently associated with upper airway obstruction after stroke.

Lung volume dependence of pharyngeal cross-sectional area by acoustic pharyngometry.

Pharyngeal size and the dynamic behavior of the pharynx may be important factors in the modulation of pharyngeal airflow. There are two measures of pharyngeal function: changes in pharyngeal area with lung volume and changes in pharyngeal area in response to externally applied positive pressure. Both measurements have been used for the assessment of pharyngeal function, and both reflect pharyngeal "floppiness." The aim of the present study was to examine the relationship between pharyngeal cross-sectional area, using acoustic reflection technique, and different lung volumes (tidal volume, inspiratory reserve volume, and expiratory reserve volume), to determine whether there are differences in mechanical properties of the pharynx of normal volunteers in response to changes in intrapharyngeal pressure. The acoustic technique was used to assess the pharyngeal cross-sectional area of 40 healthy volunteers (29 men and 11 women) at tidal volume, inspiratory reserve volume, and expiratory reserve volume. In men, the mean pharyngeal area at tidal volume was 3.191 cm2, the mean pharyngeal area at inspiratory reserve volume was 2.976 cm2, and the mean pharyngeal area at expiratory reserve volume was 2.975 cm2. In women, the corresponding pharyngeal area measurements were 2.832, 2.484, and 2.492 cm2. Statistical analysis of results showed that men have a larger pharyngeal cross-sectional area and the pharyngeal airways of men and women act in a similar manner in response to changes in intrapharyngeal pressure, with men having a greater change. Examination of the pharyngeal compliance by acoustic pharyngometry adds to the potential of this technique as a tool for the evaluation of the pharyngeal airway in terms of area and dynamic behavior assessment. This may be of relevance in promotion of the development of upper airway assessment in patients with obstructive sleep apnea.

Use of reversal agents in day care procedures (with special reference to postoperative nausea and vomiting)

There is some confusion about the contribution of reversal of residual paralysis to the occurrence of postoperative nausea and vomiting. The aim of this review is to discuss whether antagonism of residual paralysis is a cause of postoperative nausea and vomiting, and to assess the risk of residual paralysis if the reversal is omitted. Data from a meta-analysis published before 1998 were considered, along with trials published after that date to assess the influence of reversal of residual paralysis on postoperative nausea and vomiting, and the likelihood of harm when antagonism was omitted. Moreover, an overview of pathophysiological consequences, incidence and clinical consequences of residual paralysis is given and the actual criteria of the adequacy of neuromuscular recovery presented. When emetic outcomes are combined across all trials and all different neostigmine doses, there is no beneficial effect from omitting neostigmine on postoperative nausea and vomiting, but there is some evidence of a dose-responsiveness with neostigmine; higher doses may have emetic properties. However, omitting reversal introduces a non-negligent risk of residual paralysis. An improved understanding of the pathological consequences of residual paralysis (i.e. impaired laryngeal and pharyngeal muscle function, alterations in hypoxic ventilatory control, reduced margin of safety) led to establishment of more rigorous criteria for defining adequacy of neuromuscular recovery. A train-of-four ratio of ≥0.9 is now accepted as the index of adequate recovery of neuromuscular function. Applying this new definition, residual paralysis becomes a frequent adverse side-effect. Neuromuscular recovery should therefore be routinely monitored in ambulatory patients and residual paralysis prevented by reversing neuromuscular block.

Use of reversal agents in day care procedures (with special reference to postoperative nausea and vomiting)

There is some confusion about the contribution of reversal of residual paralysis to the occurrence of postoperative nausea and vomiting. The aim of this review is to discuss whether antagonism of residual paralysis is a cause of postoperative nausea and vomiting, and to assess the risk of residual paralysis if the reversal is omitted. Data from a meta-analysis published before 1998 were considered, along with trials published after that date to assess the influence of reversal of residual paralysis on postoperative nausea and vomiting, and the likelihood of harm when antagonism was omitted. Moreover, an overview of pathophysiological consequences, incidence and clinical consequences of residual paralysis is given and the actual criteria of the adequacy of neuromuscular recovery presented. When emetic outcomes are combined across all trials and all different neostigmine doses, there is no beneficial effect from omitting neostigmine on postoperative nausea and vomiting, but there is some evidence of a dose-responsiveness with neostigmine; higher doses may have emetic properties. However, omitting reversal introduces a non-negligent risk of residual paralysis. An improved understanding of the pathological consequences of residual paralysis (i.e. impaired laryngeal and pharyngeal muscle function, alterations in hypoxic ventilatory control, reduced margin of safety) led to establishment of more rigorous criteria for defining adequacy of neuromuscular recovery. A train-of-four ratio of > or = 0.9 is now accepted as the index of adequate recovery of neuromuscular function. Applying this new definition, residual paralysis becomes a frequent adverse side-effect. Neuromuscular recovery should therefore be routinely monitored in ambulatory patients and residual paralysis prevented by reversing neuromuscular block.

Swallowing physiology of toddlers with long-term tracheostomies: a preliminary study.

This study investigated the swallowing physiology of toddler-aged patients with long-term tracheostomies. Structural movements and motility of the pharyngeal stage of swallowing were studied in four toddlers ranging in age from 1:2 (years:months) to 2:9 with long-term tracheostomies. A patient aged 1:2 years with no tracheostomy served as a toddler model for comparison. Videofluoroscopic recordings of the patients' liquid and puree bolus swallows were analyzed for a) onset times for pharyngeal stage events, laryngeal vestibule closure, and tracheostomy tube movement; b) timeliness of swallow response initiation; and c) pharyngeal transport function. Results found differences in timing of pharyngeal stage movements between the tracheostomized patients and the patient with no tracheostomy. Laryngeal vestibule closure occurred before or within the same 0.033-s video frame as onset of upper esophageal sphincter (UES) opening in the patient with no tracheostomy, but occurred 0.033-.099 s after onset of UES opening in the tracheostomized patients. The time line required to close the laryngeal vestibule once the arytenoids began their anterior movement was longer in the tracheostomized patients than in the patient with no tracheostomy and was associated with laryngeal penetration. The patient with no tracheostomy displayed superior excursion of the arytenoid and epiglottis during the swallowing; the tracheostomized patients did not. No association was found between onset of tracheostomy tube movement and laryngeal vestibule closure. Delayed swallow response initiation was observed across tracheostomized patients at a mean frequency of 45% with associated penetration. Pharyngeal dysmotility was not observed. Findings supported the concept that long-term tracheostomy in toddler-aged patients affects swallowing physiology.

Studies of the histomorphology and function of the uvula

Alternations in pharyngeal structure and function are considered fundamental in the pathogenesis of snoring or obstructive sleep apnea (OSA). The physiological function of the uvula as a dynamic sealing of the nasopharynx prevents a "craniocaudal aspiration" during deglutition. The oropharyngeal soft tissues and the uvula are known to play an important role in affecting the oropharyngeal airflow resistance but studies about alterations in the histomorphological uvula structure are controversial. We studied the histomorphological tissue composition of the uvula (midsagittal and transversal sections) in 142 patients who underwent uvulopalatopharyngoplasty (UPPP) or uvulopalatoplasty (UPP) for snoring and by autopsy in 30 normal subjects not known to have been snoring. Statistical comparisons were controlled for differences caused by age and body mass index. The uvula was found to be significantly longer in patients with snoring than in control subjects. Patients with snoring had a significantly greater percentage of fat content and connective tissue in combination with a muscle atrophy in the uvula than did normal subjects. The disturbance of the specific muscular composition and formation causes a reduction of muscular tonus and a loss of muscular contraction. The uvula is destabilized on the basis of a missing skeletal and cartilaginous brace. The uvula destabilization causes a narrowing of the pharyngeal airway that could lead to an increased oropharyngeal airflow resistance with an intensified passive uvula movement and vibration during mouth breathing.

Swallowing Dysfunction Related to Snoring: A Videoradiographic Study

Biopsy studies of the soft palatal and oropharyngeal tissues in habitual snorers and patients suffering from obstructive sleep apnoea have shown signs of neurogenic lesions. These lesions might affect the pharyngeal swallowing function, which is dependent on adequate sensitivity. The objective of the present study was to test the hypothesis that snoring is associated with aberrant pharyngeal swallowing function. Forty-one consecutive patients without dysphagia, seeking medical attention because of heavy snoring and various degrees of daytime sleepiness, were prospectively selected. Fifteen non-snoring volunteers without dysphagia served as controls. Patients and volunteers were videoradiographically examined in lateral and posteroanterior views during the oral and pharyngeal phases of swallowing. The hypothesis was verified. Snoring patients demonstrated deviant pharyngeal swallowing function seven times more frequently than did the non-snoring volunteers. Deviant pharyngeal swallowing function was observed in 22 (54%) of the snorers compared with 1 (7%) of the non-snoring volunteers. Impaired bolus control with premature leakage of bolus into the pharynx and a delayed evocation of the swallowing reflex was the most common finding, followed by bolus residual in the pharynx and laryngeal penetration. The conclusion was that snoring is associated with subclinical pharyngeal swallowing dysfunction.

Pharyngeal dysfunction during exercise

Summary Pharyngeal dysfunction in the horse during exercise has been poorly understood. Endoscopic examinations of these animals as they exercised on high-speed treadmills has allowed direct observation of many of these dysfunctions. There is still considerable variation in the interpretation of these findings. The existence and function of the oropharyngeal seal (OPS) is discussed as are several etiological bases for inappropriate pharyngeal function.

舌癌術後等の咽頭への送り込み障害に対する摂食補助具の検討と工夫

Some patients who have had their oropharyngeal organs resected due to malignant tumors (especially tongue carcinoma) suffer from a disorder involving transport of a bolus to the oropharynx. Similarly, some of nuromuscular disorders do not impair the pharyngeal swallowing function as much as the oral function. However, devices to aid in disorders of transporting food to the oropharyngeal cavity have not been developed.Devices that can enable adequate control as to transporting point, direction, and feeding rate with ease are needed. They must be useable not only by the patients, but also by their helpers when patients can not use the devices by themselves. From this view point, we examined and improved on some new devices with our patients.

Persisting dysphagia after uvulopalatoplasty performed with steel scalpel.

The aim of the present study was to determine the incidence of postoperative persisting dysphagia after uvulopalatoplasty performed with conventional steel scalpel (UPP) and to videoradiographically evaluate the oral and pharyngeal phases of swallowing in patients reporting persisting dysphagia. The hypothesis to be tested was that patients treated with UPP would demonstrate a lower incidence of persisting dysphagia than previously found after uvulopalatoplasty performed with laser technique (LUPP). Retrospective. Sixty-eight of 76 consecutive patients treated with UPP answered a questionnaire concerning outcome and late complications after the operation. The patients who reported postoperative dysphagia were additionally interviewed at a minimum of 1 year postoperatively, and the oral and pharyngeal phases of swallowing were videoradiographically examined in those with persisting dysphagia. The incidence of persisting dysphagia after UPP was 29%. Videoradiographically 71% of the dysphagic patients showed a deviant pharyngeal swallowing pattern. The incidence of persisting dysphagia after UPP did not differ from that reported after laser uvulopalatoplasty. Dysphagia after UPP was mostly associated with videoradiographic signs of deviant pharyngeal swallowing function. Patients should be informed that there is a risk of developing dysphagia after uvulopalatoplasty.

Mechanical effects of pharyngeal constrictor activation on pharyngeal airway function.

The mechanical effects of pharyngeal constrictor (PC) muscle activation on pharyngeal airway function were determined in 20 decerebrate, tracheotomized cats. In 10 cats, a high-compliance balloon attached to a pressure transducer was partially inflated to just occlude the pharyngeal airway. During progressive hyperoxic hypercapnia, changes in pharyngeal balloon pressure were directly related to phasic expiratory hyopharyngeus (middle PC) activity. In two separate protocols in 10 additional cats, the following measurements were obtained with and without bilateral electrical stimulation (0.2-ms duration, threshold voltage) of the distal cut end of the vagus nerve's pharyngeal branch supplying PC motor output: 1) pressure-volume relationships in an isolated, sealed upper airway at a stimulation frequency of 30 Hz and 2) rostrally directed axial force over a stimulation frequency range of 0-40 Hz. Airway compliance determined from the pressure-volume relationships decreased with PC stimulation at and below resting airway volume. Compared with the unstimulated condition, PC stimulation increased airway pressure at airway volumes at and above resting volume. This constrictor effect progressively diminished as airway volume was brought below resting volume. At relatively low airway volumes below resting volume, PC stimulation decreased airway pressure compared with that without stimulation. PC stimulation generated a rostrally directed axial force that was directly related to stimulation frequency. The results indicate that PC activation stiffens the pharyngeal airway, exerting both radial and axial effects. The radial effects are dependent on airway volume: constriction of the airway at relatively high airway volumes, and dilation of the airway at relatively low airway volumes. The results imply that, under certain conditions, PC muscle activation may promote pharyngeal airway patency.

Evaluation of pharyngeal and laryngeal structure and function in patients with oculo-auriculo-vertebral spectrum.

This study described the occurrence and expression of pharyngeal and laryngeal anomalies in a population of patients with oculo-auriculo-vertebral spectrum (OAVS). Cross-sectional study using chart review, physical examination, and endoscopic evaluation of the pharynx and larynx, and perceptual and aerodynamic evaluation of speech for assessment of vocal tract function. Academic tertiary referral center. Chart review of 41 patients with a diagnosis of OAVS and clinical evaluation of 23 of the patients identified in the initial chart review, ranging in age from 9 months to 17 years. Data from chart review pertaining to airway and speech symptoms. Physical examination and endoscopic studies of pharyngeal and laryngeal structure and function and perceptual and aerodynamic evaluation of speech, resonance, and voice. Chart review showed a high occurrence of indicators of pharyngeal and laryngeal abnormalities such as velopharyngeal inadequacy and airway obstruction. Clinical evaluations documented a variety of abnormalities in pharyngeal and laryngeal structure and function as well as impairment in speech articulation, resonance, and voice. Presence and severity of pharyngeal and laryngeal abnormalities were not correlated with the severity of expression of the spectrum based on mandibular morphology. Oculo-auriculo-vertebral spectrum appears to be associated with a high occurrence of structural and functional abnormalities of the pharynx and larynx that may contribute to increased risk of airway obstruction, communication impairment, and morbidity.

Evaluation of Pharyngeal and Laryngeal Structure and Function in Patients with Oculo-Auriculo-Vertebral Spectrum

Evaluation of Pharyngeal and Laryngeal Structure and Function in Patients with Oculo-Auriculo-Vertebral Spectrum