Solid swallowing versus water swallowing: manometric study of dysphagia

The aim of the study was to investigate whether a soft solid bolus can induce abnormal manometric patterns in patients with dysphagia and normal standard manometry. The study group comprised 12 normal volunteers and 22 patients with dysphagia. Manometry was performed using 10 wet swallows followed by 10 swallows of marshmallow. The results show: (1) in normal subjects the mean contraction amplitude is significantly greater (P<0.035) and the velocity of propagation significantly slower (P<0.003) for soft solid swallows compared with wet swallows; (2) in normal subjects there are fewer abnormal contractions after soft solid swallows than after wet swallows; (3) in 15 patients, soft solid swallows induced nonperistaltic contractions and/or contractions of extreme amplitude and/or duration that were not observed after wet swallows; 94) in patients, the probability of inducing abnormal contractions after soft solid swallows is significantly greater than after wet swallows (P<0.0001). We conclude that soft solid swallowing is useful in the study of patients with dysphagia.Part of this work was presented by Dr. Argaman as a thesis, to the Technion Medical School, for his MD.     

Syncope in the act of swallowing (swallowing syncope)

In a 30-year-old female patient with recurrent syncope during swallowing, intermittent complete AV-block was documented as the underlying mechanism. This phenomenon could be provoked by inflating a balloon positioned in the lower esophagus. The His-bundle electrocardiogram, recorded simultaneously, showed a progressive increase of the normal AH-interval, up to complete block distal to the A-wave. Atropine prevented induction of the block. After implantation of a VVI pacemaker, the symptoms disappeared completely. This very rare phenomenon of swallowing syncope is probably due to a pathologic vago-vagal reflex.     

Volume accommodation during swallowing

Bolus volume is an important modifier of the biomechanical events of the oropharyngeal swallow. The biomechanical events comprising a swallow can be divided into events associated with the reconfiguration of the pharynx into a swallow pathway and events associated with bolus transport from the oropharynx into the esophagus. Volume modification is achieved differently for the events of reconfiguration and propulsion. In the case of reconfiguration, a longer time is allocated to the process, as exemplified by sustained laryngeal elevation and hyoid excursion during larger volume swallows. On the other hand, in the case of bolus expulsion, volume accommodation is accomplished within the same period of time by utilizing increased vigor of expulsion. The result of deglutitive volume accommodation is a remarkably different fluoroscopic appearance of a small vs. a large volume swallow. The larger volume swallow seemingly takes longer and results in much more vigorous bolus expulsion than a small volume. However, this is more related to the bolus than the swallow.     

Neurophysiological basis of swallowing

The neurophysiological control of swallowing involves three functionally distinct divisions: the oral preparatory phase, a pharyngolaryngeal phase and an esophageal phase. Both the pharyngeal and esophageal phases involve control by interneurons in different regions of the reticular formation of the medulla within the brain stem. The central neural control of the brain stem is triggered by specific patterns of sensory or descending cortical input. The threshold that will elicit swallowing depends upon the type of stimuli (i.e., specific fluids, touch, pressure). The threshold is higher if much of the pharyngeal mucosa is anesthetized and if salivation is inhibited. Sensory feedback does change the threshold and intensity of sequential muscle recruitment. Descending pathways that modify swallowing include the prefrontal cortex, the limbic-hypothalamic system, and specific regions of the pons.     

The simple swallowing provocation test as a means of screening for swallowing disorders: a comparison with the water swallowing test]

The sensitivity and specificity of the simple swallowing provocation test (S-SPT) were evaluated in a group of patients who were being examined for aspiration pneumonia (ASP) (ASP group: 72.5 +/- 3.9 years old) and in a group of age-matched control subjects (CTRL group: 69.5 +/- 2.9 years old). The S-SPT was evaluated in terms of the swallowing response and latent time (LT) for swallowing after a bolus injection of 0.4 ml of distilled water at the suprapharynx. Responses to the S-SPT were classified as normal or abnormal, dependent on induction of the swallowing reflex within 3 seconds after bolus injection. The sensitivity and specificity of the S-SPT in detecting ASP were calculated. Of the 40 patients in the ASP group, 18 were given a diagnosis of ASP on the basis of clinical findings and laboratory examinations. The sensitivity and specificity of the S-SPT were 94.4% and 86.4%, respectively, compared to 77.8% and 68.1%, respectively, for the water swallowing test. Because the S-SPT can be performed without any need for special patient effort or cooperation, it should be effective in diagnosing ASP in a wide variety of patients, including those who are bedridden.     

The videoendoscopic swallowing study: An alternative and partner to the videofluoroscopic swallowing study

A new, physical examination-based videoendoscopic method of evaluation can enhance considerably the understanding and efficiency of clinicians working with patients with swallowing difficulties. Using the fiberoptic nasolaryngoscope, evaluation of structure and function of palate, pharynx, and larynx, along with sensation of the laryngopharynx, is carried out. Next, patients' swallowing capabilities are assessed as they ingest various food consistencies. This method, formerly called videoendoscopic evaluation of dysphagia (VEED), but perhaps more appropriately termed videoendoscopic swallowing study (VESS) has particular value for patients who cannot undergo the videofluoroscopic swallowing study (VFSS)—for example, because they are bedfast-or those whose swallowing function is changing so rapidly (after a stroke or surgery) as to call for frequent reassessments. This technique is often useful during the initial consultation with new patients complaining of dysphagia, as a stand alone method of diagnosis and management. Less frequently, VESS findings, along with patient history, will indicate when VFSS should also be obtained. VESS will orient the examiner to the nature and severity of the problem even in this latter circumstance. In follow-up circumstances, VESS is generally more useful than the VFSS. Case presentations are utilized to illustrate the usefulness of VESS as compared to VFSS.     

Dietary management of swallowing disorders

Two major concerns in the dietary management of the dysphagic patient are to maintain adequate nutrition and to ensure safety during oral feeding. Dysphagic patients require modifications of standard hospital diets. Kitchen or nursing staff must remove from standard diet trays solid foods and liquids that pose swallowing hazards. Training kitchen and nursing staff and removing food are time consuming. It is also hazardous if certain foods are served to dysphagic patients through error or lack of knowledge. In addition, there is risk of inadequate nutrition when food is removed from trays. This paper proposes a four-level diet plan for patients who have difficulty swallowing solids and liquids. These diets gradually advance for patients undergoing treatment to improve swallowing function. The proposed diets save time for kitchen and nursing staff, reduce the risk of aspiration among patients, and serve as models for families as they prepare for discharge and meal planning at home. Diet guidelines are based on recommendations of the American Dietetic Association.     

Coordination of mastication and swallowing

The coordination of mastication, oral transport, and swallowing was examined during intake of solids and liquids in four normal subjects. Videofluorography (VFG) and electromyography (EMG) were recorded simultaneously while subjects consumed barium-impregnated foods. Intramuscular electrodes were inserted in the masseter, suprahyoid, and infrahyoid muscles. Ninety-four swallows were analyzed frame-by-frame for timing of bolus transport, swallowing, and phases of the masticatory gape cycle. Barium entered the pharynx a mean of 1.1 s (range −0.3 to 6.4 s) before swallow onset. This interval varied significantly among foods and was shortest for liquids. A bolus of food reached the valleculae prior to swallow onset in 37% of sequences, but most of the food was in the oral cavity at the onset of swallowing. Nearly all swallows started during the intercuspal (minimum gape) phase of the masticatory cycle. Selected sequences were analyzed further by computer, using an analog-to-digital convertor (for EMG) and frame grabber (for VFG). When subjects chewed solid food, there were loosely linked cycles of jaw and hyoid motion. A preswallow bolus of chewed food was transported from the oral cavity to the oropharynx by protraction (movement forward and upward) of the tongue and hyoid bone. The tongue compressed the food against the palate and squeezed a portion into the pharynx one or more cycles prior to swallowing. This protraction was produced by contraction of the geniohyoid and anterior digastric muscles, and occurred during the intercuspal (minimum gape) and opening phases of the masticatory cycle. The mechanism of preswallow transport was highly similar to the oral phase of swallowing. Alternation of jaw adductor and abductor activity during mastication provided a framework for integration of chewing, transport, and swallowing.     

吞咽障碍与神经疾病

0引言由神经疾病引起的吞咽障碍可称为神经性吞咽障碍.此种症状多由于原发的神经疾病累及吞咽的口期和咽期的感觉和运动的功能,影响口、咽部肌肉推送食团自口腔经咽至食管的功能.有些神经疾病亦可同时影响食管.本文主要论述口咽部的神经性吞咽障碍.大多数慢性口咽部吞咽障碍属于神经源性,但也有不少是由气管插管后水肿、咽部肿块、憩室等所致[1].1神经性吞咽障碍的表现1.1患者患有已知的神经疾病有口咽部神经性吞咽障碍症状,如咀嚼困难、吞咽起始困难、鼻腔漏溢、流涎、唾液分泌困难、吞咽时呛咳或噎呛、咽喉梗塞等;并有神经性吞咽障碍的并…     

口咽部吞咽障碍的治疗

0引言口咽部吞咽障碍的治疗包括恢复代偿功能疗法、口内矫治疗法、感觉运动协调疗法和吞咽动作演练疗法等,是治疗此项病变的主要方法,有效率可达80%以上[1,2].此类治疗方法有其特殊性.设计和指导此项工作的医师必须熟悉口咽部有关吞咽的生理解剖和口咽部动态造影检查的表现;必须在造影检查中观察吞咽失常的情况,选择和试验较为适合的治疗方法并在造影中观察其效果.但患者在实行代偿功能疗法过程中,却可在不了解生理解剖,“知其然而不知其所以然”的情况下,获得良好疗效.1动态造影是治疗的依据口咽部的吞咽动作非常迅速,约在0.75s内完成.口咽…     

Special swallowing problems in children

As the swallowing process evolves from infantile suckle feeding through transitional feeding to mature function, the process can go awry at many points. Understanding the changes in structure and function of the mouth and pharynx that occur with growth and development is of basic importance. When a child is referred because of unsuccessful feeding or suspicion of aspiration, dynamic imaging of the swallowing mechanism and scrutiny of radiographic abnormalities described in this article can lead to greater understanding of the underlying cause and to more effective treatment.     

Methodology for detecting swallowing sounds

The use of cervical auscultation in the evaluation of the pharyngeal swallow may become a part of the clinical evaluation of dysphagic patients. Though its use is based on subjective evaluation, an acoustic analysis of swallowing sounds might establish more objective criteria in the detection of swallowing disorders. The present study sought to investigate three aspects of the methodology for detecting swallowing sounds: (1) the type of acoustic detector unit suited to an acoustic analysis of the pharyngeal swallow, (2) the type of adhesive suited for the attachement of the detector, and (3) the optimal site for sound detection of the pharyngeal swallow. An accelerometer with double-sided paper tape was selected as the appropriate detector unit because of its wide range of frequency response and small attenuation level. Using this detector unit, swallowing sounds and noise associated with simulated laryngeal elevation and the carotid pulse were acquired at 24 sites on the neck in 14 normal subjects; these signals were acoustically analyzed. The determination of the optimal site for detecting swallowing sounds was based on the signal-to-noise ratio. The site over the lateral border of the trachea immediately inferior to the cricoid cartilage is the optimal site for detection of swallowing sounds because this site showed the greatest signal-to-noise ratio with the smallest variance. The site over the center of the cricoid cartilage and the midpoint between the site over the center of the cricoid cartilage and the site immediately superior to the jugular notch were also considered to be the most appropriate sites.     

Test-retest variability in normal swallowing

The test-retest variability of the modified barium swallow study using videofluoroscopy was analyzed. Sixteen normal subjects (8 men, 8 women) were organized into 2 age groups: middle-aged group (mean, 45 years) and old-aged group (mean, 66 years). Nine durational measures of the swallow were evaluated. There were no statistically significant differences for any of the measures between the initial test and a retest conducted days later. The findings suggest that, on the whole, normal subjects perform similarly on test and a retest. However, the variability displayed by these normal subjects may be clinically significant, indicating that test-retest swallowing duration measures require careful interpretation.