You are in: eMedicine Specialties > Physical Medicine and Rehabilitation > STROKE DysphagiaArticle Last Updated: Jun 25, 2008AUTHOR AND EDITOR INFORMATIONSection 1 of 9
  Author: Nam-Jong Paik, MD, PhD, Chief, Associate Professor of Rehabilitation Medicine, Rehabilitation Medicine, Seoul National University Bundang Hospital Nam-Jong Paik is a member of the following medical societies: American Association of Neuromuscular and Electrodiagnostic Medicine Editors: Milton J Klein, DO, MBA, Consulting Physiatrist, Sewickley Valley Hospital, Allegheny General Hospital, Harmarville Rehabilitation Center, Ohio Valley General Hospital and Aliquippa Community Hospital; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Richard Salcido, MD, Chairman, Erdman Professor of Rehabilitation, Department of Physical Medicine and Rehabilitation, University of Pennsylvania School of Medicine; Kelly L Allen, MD, Consulting Staff, Department of Physical Medicine and Rehabilitation, Lourdes Regional Rehabilitation Center, Our Lady of Lourdes Medical Center; Denise I Campagnolo, MD, MS, Director of Multiple Sclerosis Clinical Research and Staff Physiatrist, Barrow Neurology Clinics, St. Joseph's Hospital and Medical Center; Investigator for Barrow Neurology Clinics; Director, NARCOMS Project for Consortium of MS Centers, Phoenix Author and Editor Disclosure Synonyms and related keywords: dysphagia, swallowing disorders, deglutition disorders, disordered eating, difficulty eating, disrupted swallowing, aphagia, enteral feeding, gastrostomy, percutaneous endoscopic gastrostomy, PEG, nasoenteric tube, NET, nasogastric tube, NGT, oroesophageal tube feeding, cricopharyngeal myotomy, CPM, aspiration pneumonia INTRODUCTIONSection 2 of 9
  Dysphagia is a Greek word that means disordered eating. Dysphagia typically refers to difficulty in eating as a result of disruption in the swallowing process. Dysphagia can be a serious threat to one's health because of the risk of aspiration pneumonia, malnutrition, dehydration, weight loss, and airway obstruction. A number of etiologies have been attributed to dysphagia in populations with neurologic and nonneurologic conditions. Disorders leading to dysphagia may affect the oral, pharyngeal, or esophageal phases of swallowing. Thorough history taking and careful physical examination are important in the diagnosis and treatment of dysphagia. The bedside physical should include examination of the neck, mouth, oropharynx, and larynx. A neurologic examination also should be performed. Several clinical bedside swallowing assessments have been suggested, but videofluoroscopic swallowing studies are accepted as the standard for detecting and evaluating swallowing abnormalities.1 This method not only allows estimation of risks of aspiration and respiratory complications but also helps in determining dietary and compensatory strategies. Fiberoptic endoscopic examination of swallowing may be necessary. Disorders of oral and pharyngeal swallowing are usually amenable to rehabilitation, including dietary modification and training in swallowing techniques and maneuvers. Surgery is rarely indicated for patients with swallowing disorders. In patients with severe disorders, bypassing the oral cavity and pharynx in their entirety and providing enteral nutrition may be necessary. Options include percutaneous endoscopic gastrostomy and intermittent oroesophageal catheterization. For excellent patient education resources, visit eMedicine's Cancer and Tumors Center. Also, see eMedicine's patient education article Cancer of the Mouth and Throat. Normal swallowing physiologyCentral pattern generator During swallowing, muscles are activated in an orderly sequence; they are triggered by volitional cortical drive or peripheral sensory input. Once swallowing is initiated, the cascade of the sequential muscle activation does not essentially alter from the perioral muscles downward. Neural networks that are responsible for this automatic swallowing are called central pattern generator. The brainstem, including the nucleus tractus solitarius and the nucleus ambiguus (with the reticular formation linked to cranial motoneuron pools), is thought to be central pattern generator.2 Three phases of swallowing Deglutition is the act of swallowing, which allows a food or liquid bolus to be transported from the mouth to the pharynx and esophagus, through which it enters the stomach. Normal deglutition is a smooth, coordinated process that involves a complex series of voluntary and involuntary neuromuscular contractions and typically is divided into distinct phases: (1) oral, (2) pharyngeal, and (3) esophageal. Each stage facilitates a specific function; if stages are impaired by pathologic condition, specific symptoms may result. Oral phase The oral preparatory phase refers to the processing of the bolus to render it swallowable; the oral propulsive phase refers to the propelling of food from the oral cavity into the oropharynx. The process begins with contractions of the tongue and striated muscles of mastication. The muscles work in a coordinated fashion to mix the food bolus with saliva and then propel the food from the anterior oral cavity into the oropharynx, where the involuntary swallowing reflex is triggered. The cerebellum controls output for the motor nuclei of cranial nerves V (trigeminal), VII (facial), and XII (hypoglossal). With single swallows of liquid, the entire sequence lasts about 1 second. For swallows of solid foods, a delay of 5-10 seconds may elapse while the bolus accumulates in the oropharynx. Pharyngeal phase The pharyngeal phase is of particular importance, because, without intact laryngeal protective mechanisms, aspiration is most likely to occur during this phase. This phase involves a rapid sequence of overlapping events. The soft palate rises, the hyoid bone and larynx move upward and forward, the vocal folds move to the midline, the epiglottis folds backward to protect the airway, and the tongue pushes backward and downward into the pharynx to propel the bolus downward.3 The tongue is assisted by the pharyngeal walls, which move inward with a progressive wave of contraction from top to bottom. The upper esophageal sphincter relaxes during the pharyngeal phase of swallowing and is pulled open by the forward movement of the hyoid bone and larynx. This sphincter closes after passage of the food, and the pharyngeal structures then return to reference position. The pharyngeal phase of swallowing is involuntary and totally reflexive, so no pharyngeal activity occurs until the swallow reflex is triggered. This swallowing reflex lasts approximately 1 second and involves the motor and sensory tracts from cranial nerves IX (glossopharyngeal) and X (vagus). Esophageal phase In the esophageal phase, the bolus is propelled downward by a peristaltic movement. The lower esophageal sphincter relaxes at initiation of the swallow, and this relaxation persists until the food bolus has been propelled into the stomach. Unlike the upper esophageal sphincter, the lower sphincter is not pulled open by extrinsic musculature. Rather, it closes after the bolus enters the stomach, thereby preventing gastroesophageal reflux. The medulla controls this involuntary swallowing reflex, although voluntary swallowing may be initiated by the cerebral cortex. An interval of 8-20 seconds may be required for contractions to drive the bolus into the stomach. PathophysiologyDisorders of swallowing may be categorized according to the swallowing phase affected. A number of dysphagic problems can be identified during each phase of deglutition. Oral phase Oral-phase disorders affecting the oral preparatory and oral propulsive phases usually result from impaired control of the tongue. Patients may have difficulty chewing solid food and initiating swallows. When drinking a liquid, patients may find it difficult to contain the liquid in the oral cavity before swallowing. As a result, liquid spills prematurely into the unprepared pharynx, often resulting in aspiration. Logemann's Manual for the Videofluorographic Study of Swallowing cites the following oral-phase swallowing symptoms and disorders4:
Pharyngeal phase If pharyngeal clearance is severely impaired, a patient may be unable to ingest sufficient amounts of food and drink to sustain life. In people without dysphasia, small amounts of food commonly are retained in the valleculae or pyriform sinus after swallowing. If there is weakness in or a lack of coordination of the pharyngeal muscles or if there is a poor opening of the upper esophageal sphincter, patients may retain excessive amounts of food in the pharynx and experience overflow aspiration after swallowing. Logemann's Manual for the Videofluorographic Study of Swallowing cites the following pharyngeal-phase swallowing symptoms and disorders4:
Esophageal phase Impaired esophageal function can result in retention of food and liquid in the esophagus after swallowing. This retention may result from a mechanical obstruction, a motility disorder, or an impairment of the opening of the lower esophageal sphincter. Logemann's Manual for the Videofluorographic Study of Swallowing cites the following swallowing symptoms and disorders of the esophageal phase4:
Aspiration Aspiration is the passage of food or liquid through the vocal folds. People who aspirate are at increased risk for pneumonia. People without swallowing abnormalities routinely aspirate microscopic amounts of food and liquid. Gross aspiration, however, is abnormal and may lead to respiratory complications. Several factors influence the effects of aspiration: quantity, depth, physical properties of the aspirate, and pulmonary clearance mechanisms. Aspiration of larger quantities of material is riskier than aspiration of minute quantities of food or liquid. Aspirating material into the distal airways is more dangerous than aspiration into the vocal folds. Solid food may cause fatal airway obstruction. Acidic material is dangerous, because the lungs are highly sensitive to the caustic effects of acid. Aspirating material laden with infectious organisms or even normal mouth flora can cause bacterial pneumonitis. Pulmonary clearance mechanisms include ciliary action and coughing. Aspiration normally provokes a strong reflex cough. If sensation is impaired, silent aspiration may occur. The severity of aspiration can be described by estimating the percentage of the total bolus aspirated or by estimating the depth of bolus invasion into the airway. The Eight-Point Penetration-Aspiration Scale is an example of an estimation tool.6 Frequency Dysphagia, which can be classified as neurologic or nonneurologic, has been reported in several types of disorders. Although dysphagia introduces many confounding variables, it also exerts a large influence on the outcome of rehabilitation (eg, length of hospital stay, mortality/morbidity of the patient). Neurologic swallowing disorders are encountered more frequently in rehabilitation medicine than in most other medical specialties. Stroke is the leading cause of neurologic dysphagia. Approximately 51-73% of patients with stroke have dysphagia, which is the most significant risk factor for the development of pneumonia; this can also delay the patient's functional recovery. Pneumonia accounts for about 34% of all stroke-related deaths and represents the third highest cause of death during the first month after a stroke, although not all of these cases of pneumonia are attributable to the aspiration of food. Therefore, early detection and treatment of dysphagia in patients who have sustained a stroke is very critical. CLINICAL DETAILSSection 3 of 9
Determine how the swallowing process is impaired and what stage is involved by means of careful clinical assessment or bedside evaluation. HistoryPatients who have dysphagia may present with a variety of signs and symptoms. They usually report coughing or choking or the abnormal sensation of food sticking in the back of the throat or upper chest when they are trying to swallow; however, some of these presentations can be quite subtle or even absent (eg, in those with silent aspiration). Signs and symptoms
Causes Careful history taking enables the physician to identify the cause of the patient's dysphagia. Frequent causes of dysphagia in rehabilitation medicine include the following:
Differential diagnosis and other problems to consider Specific questions about the onset, duration, and severity of dysphagia and about a variety of associated symptoms may help to narrow the differential diagnoses to a specific one or to an anatomic or pathophysiologic diagnosis (see Differentials). Review the patient's general health information, including long-term illnesses and current prescription medications. Mucosal injury may be caused by potassium chloride tablets, nonsteroidal anti-inflammatory drugs (NSAIDs), or antibiotics (eg, doxycycline, tetracycline, clindamycin, trimethoprim-sulfamethoxazole). Xerostomia may be caused by anticholinergics, alpha-adrenergic blockers, angiotensin-converting enzyme (ACE) inhibitors, or antihistamines. The patient's history is often useful in identifying esophageal dysphagia. The history also should be directed at eliciting information about symptoms related to gastroesophageal reflux disease (GERD), including heartburn, belching, sour regurgitation, and water brash. Physical examinationThe physical examination for dysphagia includes the following activities:
Differentials
Esophageal dysphagia
Related eMedicine topic: WORKUPSection 4 of 9
Laboratory evaluationInitial laboratory evaluations should be limited to specific studies based on the differential diagnosis. Obtain a complete blood count (CBC) to screen for infectious or inflammatory conditions. Nutritional assessment may aid in determining serum protein and albumin levels. Thyroid function studies may help in detecting dysphagia associated with hypothyroidism or hyperthyroidism. Imaging studiesChest radiography is a simple assessment for pneumonia. Ultrasonography depicts only the region of the tongue posterior to the hyoid and may aid in the evaluation of submucosal and extramural lesions of the esophagus. Computed tomography (CT) scanning and magnetic resonance imaging (MRI) provide excellent definition of structural abnormalities, particularly when used to evaluate patients with suspected CNS causes of dysphagia. Special studiesVideofluoroscopic swallowing study The terms videofluoroscopic swallowing study (VFSS) and modified barium swallow (MBS) often are used interchangeably. Some clinical researchers believe it possible to identify patients with the potential to develop pneumonia by interpreting findings of the bedside test. However, most clinical researchers agree that videofluoroscopy is the standard for identifying patients who have the potential to develop pneumonia and for diagnosing aspiration and swallowing problems from potential discrepancies between findings of bedside tests and videofluoroscopy.9 Splaingard and colleagues reported that using the bedside test, only 42% of patients who had aspiration on videofluoroscopy were identified as having abnormalities.9 This finding indicated that bedside results are not sufficient for evaluating the frequency of aspiration. In general, 40-70% of patients have silent aspiration, which does not manifest specific symptoms. Videofluoroscopy is designed to study the anatomy and physiology of the oral, pharyngeal, and esophageal stages of deglutition and to define treatment strategies to improve swallowing safety or efficiency in patients with dysphagia. If aspiration occurs or if food is retained after the patient swallows, the next step is to evaluate the quantity of retained food, the mechanism of retention or aspiration, and the patient's response. In general, various food consistencies, volumes, postural techniques, and swallowing maneuvers to enhance swallowing efficiency or safety are tested during the study, and clinical decisions (eg, changing food groups, finding appropriate swallowing postures or maneuvers) are made. This study is expensive because of the special expertise, equipment, and facilities required. Fiberoptic endoscopic examination of swallowing A transnasal laryngoscope is used to assess pharyngeal swallowing. The procedure is a sensitive technique for detecting premature bolus loss, laryngeal penetration, tracheal aspiration, and pharyngeal residue. Because pharyngeal contraction obstructs the lumen, the fiberoptic endoscopic examination of swallowing (FEES) does not demonstrate the motion of essential food pathway structures or show the food bolus during the swallow. Swallowing is directly evaluated by using measured quantities of food colored with blue liquid dye. FEES may be helpful when VFSS is not feasible (eg, in critically ill patients unable to tolerate any risk of aspiration, patients in intensive care units who cannot be transferred to the fluoroscopy room, patients who require prompt evaluation). Scintigraphy Scintigraphy has limited value in evaluating pharyngeal swallowing disorders. This test is useful in quantitative and qualitative evaluation of subglottic aspiration, esophageal motility disorders, and gastroesophageal reflux. Oropharyngeal transit time can be measured through time-activity curves constructed from a specific region of interest (ROI) of the mouth, pharynx, and esophagus. Peaks and nadirs of the first derivative curve correspond to peak emptying or filling rates of the respective regions. Reflex cough test For this test, a 20% solution of L-tartaric acid is dissolved in 2 mL of sterile normal saline. Using a nasal nebulizer, the patient inhales the solution, which stimulates cough receptors in the vestibule of the larynx and initiates the laryngeal cough reflex. The laryngeal cough reflex protects the laryngeal aditus from significant aspiration and reduces the risk of respiratory complications (eg, pneumonia). An impaired laryngeal cough reflex may permit laryngeal penetration and increase the risk of aspiration pneumonia. An acute cerebrovascular accident often appears to affect the protective cough reflex. Using a reflex cough test, Addington and colleagues were able to identify in 100% of cases which patients with stroke were unlikely to subsequently develop aspiration pneumonia (specificity of 100%).10 Swallowing electromyography Mechanical upward-downward movement of the larynx is detected by using a piezoelectric sensor while submental integrated electromyography (EMG) activity is recorded during dry and wet swallowing. EMG activity of the cricopharyngeal muscle of the upper esophageal sphincter also can be recorded. In patients with muscular disorders, laryngeal elevators are involved, whereas the cricopharyngeal sphincter is intact. In patients with clinical signs of involvement of the corticobulbar fiber (eg, patients with ALS and pseudobulbar palsy), discoordination between paretic laryngeal elevators and the hyperreflexic cricopharyngeal sphincter is present. EMG can be used for muscle selection and for performing injections of botulinum toxin in patients with dysphagia caused by cricopharyngeus muscle spasm or hypertonicity. Laryngeal EMG Laryngeal EMG can help the clinician to diagnose oropharyngeal dysphagia of peripheral nerve origin (eg, recurrent laryngeal or superior laryngeal nerve injury). Manometry Manometry is performed to assess motor function of the esophagus. A catheter with several electronic pressure probes is passed into the stomach to measure esophageal contractions and to define upper and lower esophageal responses to swallowing. Manometry reveals definitive abnormalities in only 25% of patients with nonobstructive lesions; therefore, its clinical use in oropharyngeal dysphagia is limited. Esophageal pH monitoring Esophageal pH monitoring is the criterion standard for diagnosing reflux disease. A nasogastric probe is inserted into the patient's esophagus to record pH levels. These levels are compared with the patient's record of symptoms over 24 hours to determine whether acid reflux contributes to his/her symptoms. Endoscopy Gastroesophageal endoscopy enables the best assessment of the esophageal mucosa. Endoscopy has the added benefits of permitting the detection of infection and erosions and of enabling biopsy. TREATMENTSection 5 of 9
Various treatments have been suggested for the treatment of oropharyngeal dysphagia in adults. Direct and indirect strategies for treating dysphagia have been described. Direct strategy usually refers to treatment that involves food, whereas indirect strategy refers to an exercise regimen performed without food bolus. Direct techniques include modifications of food consistency; indirect techniques include stimulation of the oropharyngeal structures and the adoption of behavioral techniques, such as those involving postural changes or the swallow maneuver. Our understanding of swallowing physiology and of the effect of swallowing maneuvers and exercises on the underlying physiology has noticeably improved. The literature shows a trend leading from simple descriptive articles to scientific articles, which include the measurement of treatment efficacy. The Dietetics in Physical Medicine and Rehabilitation dietetic practice group conceived the National Dysphagia Diet project in 1996. Growing frustration regarding a lack of standardization for solid-food textures, liquid consistencies, and nomenclature led to the formation of a task force to study the issue and to formulate a new diet based on scientific food properties and clinical swallowing problems. Dietary modificationDietary modification is the key component in the general treatment program of dysphagia. A diet of pureed foods is recommended for patients who have difficulties with the oral preparatory phase of swallowing, who pocket food in the buccal recesses, or who have significant pharyngeal retention of chewed solid foods. As patients' swallowing function improves, their dysphagic diet may be advanced to the next level of soft and semisolid foods with regular consistencies. Recommend to patients that they alternate bites with sips, bite or sip size, and the number of swallows per size. Viscosity and texture If oral feedings are determined to be appropriate, the viscosity and texture of the food should be considered, because patients vary in their ability to swallow thin and thick liquids. Liquids can be thickened with various thickening agents. Many commercially available, starch-based food thickeners are used to increase the consistency of food, and prethickened water, juice, coffee, and other products are available. Food viscosity is defined as frictional resistance to shear. Viscosity of the diet for dysphagia is frequently described in a nonobjective manner. For example, tomato juice, nectar, honey, and pudding have been referred to as fluids. Viscosity can be objectively determined by using a device called a viscometer. A uniform and viscous bolus of food or beverage enables a patient with a delayed swallow reflex to control mastication and transport. It also allows the individual to swallow with less risk of aspirating residue material, because there is a reduced tendency for the material to fall over the base of the tongue before the swallow mechanism is triggered. Viscosity also influences the swallowing reflex and peristaltic activity. Another objective method is a line-spread test.11, 12 Diluted mix is placed on a circle marked on a glass plate and is allowed to stream for 5 minutes. Lengths of the 4 stream directions are measured, and their mean is determined. Food texture is defined as the group of physical properties derived from the structure of the food that can be sensed by touch. Touch usually is performed by elements of the oral and pharyngeal cavities. Food and liquid textures play important roles in the care of patients with dysphagia. Sample classification of dysphagia diet according to viscosity The dysphagia diet can be classified according to viscosity, as follows:
Nutritional supplyThe effect of dysphagia on the patient's nutritional status is profound. As the patient's ability to swallow becomes impaired, adequate dietary intake becomes a challenge, and vice versa. Therefore, early detection and management of dysphagia are critical to halting malnutrition. Malnutrition is a risk factor for pneumonia, because it renders patients susceptible to altered colonization in the oropharynx and because it reduces resistance to infection by depressing the immune system. It may also lead to lethargy, weakness, and reduced alertness, all of which may increase the probability of aspiration. Malnutrition may reduce the strength of cough and the mechanical clearance of the lungs. It also contributes to overall functional decline, muscle breakdown, osteoporosis, osteopenia, iron-deficiency anemia, skin breakdown, and poor wound healing. Therefore, in addition to dysphagia screening, formal nutritional assessment is necessary in high-risk patients. Nutritional needs are determined by means of thorough body composition analysis, clinical examination, and biochemical assessment. Energy, protein, and fluid requirements must also be assessed. In an investigation of the nutritional status of patients admitted to a rehabilitation service, 49% of all patients admitted for stroke were malnourished, and 65% of persons admitted for stroke with dysphagia were malnourished. Many commercial products are available to provide nutritional support. A patient's protein and calorie intake can be enhanced not only with thickening agents but with prethickened beverages, prepacked puree molds, oral liquid supplements, and modular components. When oral nutrition is inadequate, enteral nutrition is indicated. HydrationBecause fluid intake is restricted in most patients with dysphagia, these individuals are at risk of dehydration. Therefore, the patient's hydration status must be closely monitored. Conversely, dehydration may also be a risk factor for pneumonia, because it decreases salivary flow (thus promoting altered colonization of the oropharynx) and may lead to lethargy, mental confusion, and increased aspiration. In addition, dehydration depresses the immune system, making the patient susceptible to infection. The hydration state of a patient can be assessed by using input and output records, laboratory values (eg, serum osmolality), and physical indicators (eg, dry mucous membranes, poor skin turgor, darkened urine). Adequate fluid intake can be achieved through simple interventions, such as systematically offering patients preferred liquids or foods with high fluid content (eg, pureed fruits and vegetables, hot cereals, custards, puddings) and having an adequate number of supervised staff to help patients drink while properly positioned. Intravenous fluids or water boluses given via a feeding tube may be necessary if hydration cannot be maintained. Oral hygiene and dental careOral hygiene and dental care is important. Dried secretions that accumulate on the tongue and palate reduce oral sensitivity and promote bacterial growth. The elderly have an increased incidence of oropharyngeal colonization with respiratory pathogens, a well-known risk factor for pneumonia. Changes in the oral milieu may occur secondary to decreased salivary production and abnormalities in swallowing. These abnormalities may result in the impaired clearance of organisms, allowing for pathogenic colonization. A dependence on oral care is associated with poor oral health, subsequent weight loss and malnutrition, and altered colonization of the oropharynx. The provision of oral care is extremely important when working to prevent pneumonia. Lemon glycerin swabs or a damp washcloth can be used to remove the secretions. Exercise and facilitation techniquesTwo types of exercise can be recommended to the patient with dysphagia: indirect (eg, exercises to strengthen swallowing muscles) and direct (eg, exercises to be performed while swallowing). Exercises designed to facilitate oral motor strength, range of motion (ROM), and coordination usually are performed 5-10 times per day. Sample exercises Lip exercises can facilitate the patient's ability to prevent food or liquid from leaking out of the oral cavity. Tongue exercises are used to facilitate manipulation of the bolus and its propulsion through the oral cavity or to facilitate retraction of the tongue base. Passive ROM and active-assistive ROM exercise concepts also can be applied in this technique. Jaw exercises help to facilitate the rotatory movements of mastication. Respiratory exercises (eg, resistive straw sucking, coughing, incentive spirometer) are recommended to improve respiratory strength. Vocal cord adduction exercises can promote strengthening of weak vocal cords. Tongue-holding maneuvers facilitate compensatory anterior movement of the posterior pharyngeal wall. Head-lift exercises increase anterior movement of the hyolaryngeal complex and opening of the upper esophageal sphincter. Patients lie flat and are instructed to keep their shoulders on the floor as they raise their head high enough to see their toes, maintaining this position for 1 minute. They repeat this activity 3 times, followed by 30 consecutive repetitions of the same action. Patients should perform this exercise 3 times a day for several weeks. Examples of facilitation techniques Electrical stimulation can be applied for dysphagia. Somatosensory input influences motor function, and oral sensory deficit is associated with increased tendency toward aspiration. Somatosensory stimulation in the form of an electrical current applied to the pharynx can change the excitability of the corticobulbar projection and induce cortical reorganization in patients with poststroke dysphagia.13, 14, 15 Electrical stimulation is administered by using a modified, handheld, battery-powered electrical stimulator connected to a pair of electrodes positioned on the neck. This technique is comparable to neuromuscular stimulation or functional electrical stimulation applied to the limb. Deep pharyngeal neuromuscular stimulation (DPNS) is a therapeutic program that uses the afferent-efferent cycle (ie, sensory stimulation–motor response) to improve pharyngeal swallow. DPNS focuses on stimulating 3 reflex sites with frozen lemon-glycerin swabs. The first site—the bitter taste buds and tongue base—is used to improve tongue-base retraction. The second site is the soft palate, which is stimulated to improve palatal elevation. The therapy is applied to the third site, the superior and medial pharyngeal constrictor, to improve pharyngeal peristalsis and cricopharyngeal opening. Tactile-thermal stimulation (TTS) can be used to increase the speed of swallow. TTS involves the application of cold by rubbing the bilateral anterior facial arch with a laryngeal mirror that has been placed in ice. The purpose is to sensitize the area of the oral cavity where the swallow is triggered. The bite reflex can be inhibited by applying sustained pressure to the tongue with a rubber seizure stick, in the chin-tuck position. A hypoactive gag reflex can be facilitated by applying a tongue depressor or a quick tap to the arch of the soft palate. A hyperactive gag can be desensitized by using firm pressure with a tongue depressor, which is advanced farther back in the mouth. Compensatory techniquesMaintaining oral feeding often requires compensatory techniques to reduce aspiration or improve pharyngeal clearance. Several examples of compensatory techniques are as follows:
ManeuversVoluntary maneuvers to protect the airway The supraglottic swallow is a technique designed to close the airway voluntarily before and during the swallow, protecting the trachea from aspiration. This technique can be useful for patients who have reduced laryngeal closure. Most patients can master this technique. Advise the patient to practice the following steps:
The extended supraglottic swallow is helpful for patients with severe reductions in tongue mobility or severely reduced tongue bulk due to surgical procedures for oral cancer, because these persons essentially have little or no oral transit. Advise these patients to learn the following technique:
The supersupraglottic swallow incorporates the supraglottic swallow with Valsalva effect. This technique is designed to close the airway entrance voluntarily by tilting the arytenoid cartilage anteriorly to the base of the epiglottis before and during swallow. This strategy is used in patients with reduced closure of the airway entrance, particularly those who have undergone supraglottic laryngectomy. Voluntary maneuvers to improve clearance of the bolus The effortful swallow is designed to improve posterior tongue-base movement and thus to improve clearance of the bolus from the valleculae. Patients are instructed to swallow hard. The Mendelson maneuver is used to improve laryngeal elevation and cricopharyngeal opening during the swallow. Patients are instructed to swallow, to hold the swallow for 2-3 seconds, and then to complete the swallow and relax when the pharynx is in the uppermost stage. Repeated swallow and washing food through the pharynx may be helpful to patients who have excessive residue in the pharynx after the swallow. Other maneuvers The Shaker exercise is a head lift designed to increase anterior movement of the hyolaryngeal complex and opening of the upper esophageal sphincter. The Heimlich maneuver is used to dislodge food that the patient cannot cough out of the airway. The maneuver consists of wrapping one's arms around the upper abdomen of the victim from behind and squeezing mightily and quickly in a brief, fervent hug. Other techniquesBiofeedback Biofeedback can be useful for oral motor and facial exercises. The patient also receives feedback on the actual swallow. Enteral feeding methods In some patients, enteral feeding may be necessary in order to bypass the oral cavity and pharynx. In general, enteral feeding is indicated in any patient who is unable to achieve adequate alimentation and hydration by mouth. Patients with an impaired level of consciousness, massive aspiration, silent aspiration, esophageal obstruction, or recurrent respiratory infections fall into this category. There has been some controversy regarding the most appropriate mode and method of administering enteral feeding (e.g., continuous or intermittent, intestinal or gastric) Nasogastric tube feeding Nasogastric tube feeding is a commonly used method of enteral feeding. In patients with a short-term life expectancy, nasogastric feeding is a more appropriate route for enteral nutrition. Insertion of a nasogastric tube is easy, quick, relatively noninvasive, requires little training, and is associated with negligible mortality. However, many patients find the nasogastric tube uncomfortable and repeatedly pull the tube out, which results in interrupted feeding and potential malnutrition. Percutaneous endoscopic gastrostomy (PEG) has several advantages over surgical gastrostomy, including reduced procedure time, cost, and recovery time, as well as the fact it requires no general anesthesia. However, PEG also requires the invasive insertion of the feeding tube through the anterior abdominal wall, which can be complicated by bleeding, peritonitis or perforation of other abdominal organs, chest infections, and local infection around the insertion site, as well as by tubes being pulled out. Relative contraindications for PEG are aspiration pneumonia due to gastroesophageal reflux, significant ascites, and morbid obesity. Prospective, randomized trials have shown increased compliance, convenience, and continuity of feeding with PEG tubes compared with nasogastric intubation.
Campbell-Taylor and colleagues introduced oroesophageal tube feeding in 1988.16 Patients who refuse nasogastric or gastrostomy tubes can use this method. The patient is taught to insert the 14F urethral tube into the mouth and past the side of the tongue, pushing slowly until the catheter end reaches the lips. Food supplements and liquid are administered by means of a 500-mL syringe at a rate of approximately 50 mL/min. The absence of a gag reflex indicates the possible need for oroesophageal tube feeding. The patient must be cooperative and alert but need not be completely cognitively intact. This method is relatively contraindicated in patients with a hyperexaggerated gag reflex, esophagitis, Zenker diverticulum, or anteriorly directed cervical osteophytes. This method has several advantages. First, oroesophageal tube feeding may prevent the harmful effects of continuous nasogastric tube feeding. Second, the speed of pouring liquids can be faster than with nasogastric tube feedings. Third, oroesophageal tube feeding provides training for facilitating the swallowing reflex. A couple of disadvantages should be noted. First, performance of this procedure requires skillful technique. Second, the need for frequent manipulation (6 times per day) may be troublesome for the assistant. Adaptive equipment Adaptive equipment for patients who have difficulty with the motor or perceptual components of feeding compensates for decreased upper extremity functions, accommodating limited grasp, incoordination, decreased ROM, and hemiparesis. Rocker knives, swivel utensils, built-up handles on utensils, scoop dishes, nonskid mats, and large-handled cups are examples. Surgical interventionSurgery rarely is indicated in patients with oral or pharyngeal dysphagia, but it can be effective in selected patients. Surgical gastrostomy Surgical placement of a gastrostomy tube requires a laparotomy under general or local anesthesia. This procedure is more expensive and is associated with greater morbidity than is PEG. Cricopharyngeal myotomy Cricopharyngeal myotomy (CPM) is a procedure designed to decrease pressure on the pharyngoesophageal sphincter (PES) by incising the main muscular component of the PES. However, no means of precisely determining the underlying PES dysfunction exists. For this reason, no rational guidelines have been compiled for recommending CPM. Even less certain is the advisability of performing a CPM in patients with neurogenic dysphagia, such as patients with stroke. The fact that neurogenic causes of dysphagia usually involve a lack of coordination of the swallow rather than any intrinsic or extrinsic muscle dysfunction probably explains this consideration. The injection of botulinum toxin injection into the PES has been introduced as a replacement for CPM. Surgery for chronic aspiration Surgery for chronic aspiration may involve tracheostomy, medialization, laryngeal suspension, laryngeal closure, and/or laryngotracheal separation-diversion. A tracheostomy tube worsens dysphagia by tethering the trachea to the skin and decreasing laryngeal elevation over time. Medialization helps to restore glottic closure and subglottic pressure during the swallow. With laryngeal suspension, the larynx is in a relatively protected position under the tongue base. Laryngeal closure may be performed to close the glottis off, in this way protecting the airway at the expense of phonation. Laryngotracheal separation-diversion may be done to separate the airway from the alimentary tract. In the acute setting, when the need to decrease the aspiration of secretions is urgent, a tracheostomy is a simple and effective choice. However, in a chronic situation in which the patient has no likelihood of recovering a safe swallow and voice, laryngectomy is the most effective choice. In patients for whom recovery of voice and swallowing function is uncertain but aspiration of secretions is life threatening, temporary laryngeal closure by diversion procedure can be used. Medical issuesAspiration pneumonia Dysphagia is a risk factor, directly and indirectly, for pneumonia. However, only 9-13% of patients who aspirated in an instrumental swallow study developed pneumonia. Dysphagia and aspiration are necessary, but not sufficient, conditions for pneumonia. Malnutrition and dehydration are other established risk factors for pneumonia. Malnutrition Patients who have had a stroke are likely to decrease their dietary intake, which increases their risk of malnutrition or exacerbates existing malnourishment. In an investigation of the nutritional status of patients with stroke who were admitted to a rehabilitation service, 49% had malnutrition, and 65% of those with dysphagia were malnourished. In another study, no differences were found in the nutritional parameters of patients admitted for stroke with or without dysphagia on admission. However, after 1 week, 48.3% of the patients with dysphagia were malnourished, but only 13.6% of those without dysphagia were malnourished. Malnutrition is a risk factor for pneumonia because it renders the person susceptible to altered colonization in the oropharynx and reduced resistance to infection by depressing the immune system. Malnutrition may also lead to lethargy, weakness, and reduced alertness, all of which may increase the probability of aspiration. In addition, malnutrition may reduce the strength of cough and mechanical clearance in the lungs. Dehydration Dysphagia can potentially lead to dehydration. Conversely, dehydration also may be a risk factor for pneumonia for several reasons. First, it decreases salivary flow, which promotes altered colonization of the oropharynx. Second, it may lead to lethargy, mental confusion and increased aspiration. Third, it makes the person susceptible to infection by depressing the immune system. FOLLOW-UPSection 6 of 9
Stroke patients recover swallowing function gradually, and therapeutic interventions for dysphagia generally are successful. In one prospective investigation of 128 patients admitted because of acute stroke, a swallowing abnormality was detected in 51% on clinical examination and in 64% on videofluoroscopy at initial presentation.17 At 6 months after stroke, 87% of patients had returned to their prestroke diet. In a study of 124 patients with acute stroke, 39% of them had failing results on initial swallow screening.18 However, because of early management (eg, altered dietary texture) of their dysphagia, no patients developed aspiration pneumonia. Early swallow screening and dysphagia management in patients with acute stroke reduces their risk of aspiration pneumonia, it is cost effective, and it helps to ensure good-quality care with optimal outcomes. Recovery from dysphagia is associated with increased pharyngeal representation in the brain, suggesting brain reorganization in recovery. Several scales have been suggested to determine patients' functional outcomes.1, 19, 20 One of them is the Swallowing Rating Scale, which the American Speech-Language-Hearing Association (ASHA) has suggested as a means of systematically describing the functional severity of dysphagia. The categories are as follows:
SPECIAL CONCERNSSection 7 of 9
Patients with a tracheostomy The frequency of aspiration in patients with a tracheostomy is 50-83%. The tracheostomy tube affects airway protection and swallowing in many ways. It impairs the glottic closure reflex, reduces subglottic pressure and laryngeal elevation, impairs hypopharyngeal and laryngeal sensation, and leads to disuse muscle atrophy. Tracheostomy alters the essence of normal respiratory flow by diverting air through the neck instead of the pharynx, especially when an inflated tracheostomy tube cuff is present. The previous belief that an inflated tracheostomy tube cuff prevents aspiration of food has been refuted. An inflated cuff causes secretions to stagnate and collect above it, and these secretions can trickle down past the cuff and potentially lead to infection. Increasing the pressure of the cuff may lead to malacia, stenosis, fistula of the tracheal wall, or dragging of the cuff on the larynx as the larynx elevates during a swallow (laryngeal excursion). Subglottic airway pressure is disrupted in patients with open tracheostomy tubes. The expiratory phase is shortened because the function of the normal vocal folds to maintain lung volumes throughout the physiologic prolongation of the expiratory phase is impaired. Furthermore, reduced subglottic pressure precludes effective coughing. Superior and anterior laryngeal excursion during swallowing facilitates vertical closure of the laryngeal vestibule, assisting in airway protection and opening of the upper esophageal sphincter. The tracheostomy tube may attach the larynx to the surrounding neck tissue, anchoring it in position and reducing laryngeal elevation. The tracheostomy desensitizes laryngeal and hypopharyngeal receptors, delaying onset of the laryngeal adductor reflex response and leading to aspiration. The sensory response, and hence the organization of the swallowing mechanism, can be improved by restoring the transglottic airflow by downsizing the tracheostomy tube, placing a fenestrated tube, or occluding the tracheostomy tube with a cap or with a 1-way speaking valve. Endotracheal intubation also affects swallowing function, directly and indirectly. The direct effect of the endotracheal tube on laryngeal structures is caused by laryngeal trauma, which manifests as vocal-fold and supraglottic edema, granulation tissue in the posterior larynx, subluxation of 1 or both arytenoid cartilages, and permanent or temporary palsy of the recurrent laryngeal nerve. Supraglottic and glottic edema reduces the patient's ability to sense the presence of secretions in the larynx or hypopharynx, which in turn can inhibit the timely triggering of the pharyngeal swallow response, causing aspiration. Indirect effects on swallowing caused by endotracheal intubation relate to the coordination required between respiration and the swallowing function. An increased respiratory rate in patients with suboptimal oxygenation can disrupt the regular swallowing and respiration pattern and predispose the patient to aspiration of saliva and secretions. For example, continuous, positive airway pressure delays the latency of the swallow response and reduces the number of swallows, because it alters the peripheral sensory receptors that assist with the triggering of a pharyngeal swallow. To restore glottic closure, subglottic pressures, and transglottic airflow, 1-way speaking valves are used. The value of the occlusion of the tracheostomy tube may be related to the provision of a closed aerodigestive tract, which enables the patient to effectively react to aspiration. Other important benefits include improved communication, improved olfaction, and assistance with decannulation. Restoration of glottic function can also be accomplished by downsizing the standard cuffed tracheostomy tube toward stepwise decannulation. Patients receiving mechanical ventilation often cannot control the duration of inspiratory and expiratory airflow. Therefore, ventilator settings, such as tidal volume and flow rate, may need to be adjusted during meals. (Tidal volume may need to be increased, and flow rate may need to be reduced.) The patient may have to relearn the inspiratory and expiratory phases of the breathing cycle for optimal coordination with swallowing. Dysphagia in pediatric patients Certain factors make dysphagia in children unique. Successful oral feeding and growth in infants and children depend not only on functional deglutition but also on a broad range of neurodevelopmental skills involving sensory systems, cognition, communication, and gross and fine motor behaviors. Prematurity by itself and neurologic impairment (eg, cerebral palsy) are common causes of dysphagia in young patients. Children with cerebral palsy typically manage solid boluses more easily than they do liquid boluses, and small liquid boluses more easily than large liquid boluses. Congenital structural lesions (eg, choanal atresia, cleft lip and palate, craniofacial syndromes) can interfere with normal anatomic transport of a bolus. Prosthetic devices or adaptive feeding equipment may be necessary. GERD is a common problem in children. Choking, food refusal, and food "getting stuck" are nonspecific symptoms that may arise because of reflux and esophagitis. Childhood achalasia appears to be more common in boys than in girls. Regurgitation of food and dysphagia are the most common symptoms. In about 18% of patients, symptoms begin during infancy. Management of pediatric dysphagia requires a special approach. Cognitive, developmental, and behavioral issues can affect the treatment options. Treatment does not necessarily imply feeding therapy. Tone abnormalities, postural control, adverse behavior, and primitive reflexes should be managed. Hypoxemia can occur while a child with dysphagia eats, so pulse oximetry during mealtime can be useful. Dysphagia in geriatric patients The prevalence of dysphagia increases with age, and dysphagia is a major healthcare problem in elderly patients. Normal aging alters some aspects of the swallowing function. Problems include increased oral and pharyngeal transit times, poor bolus control and coordination, increased magnitude and duration of pharyngeal pressures, and increased incidence of pharyngeal residue after swallowing. Other factors (eg, poor dentition, atrophy of the tongue and alveolar ridge, diminished taste and smell sensitivity, decreased muscle tone, increased ligamentous laxity, limited laryngeal elevation) can cause a predisposition to dysphagia or can aggravate the condition. MULTIMEDIASection 8 of 9
REFERENCESSection 9 of 9
Article Last Updated: Jun 25, 2008 | |||||||||||||||||||||||||||||||||||||||||||||||||
