Dysphagia is common after sudden-onset neurologic damage such as stroke, head injury, or spinal cord injury. Oropharyngeal swallowing problems are also common in patients with degenerative neurologic disease such as motor neuron disease, amyotrophic lateral sclerosis and postpolio syndrome, myasthenia gravis, multiple sclerosis, or Parkinson’s disease.
I. DYSPHAGIA: DIFFICULTY SWALLOWING
Dysphagia may be the first symptom of neurologic disease. It is critical to identify the presence of a swallowing problem early, define the exact nature of the physiologic or anatomic problem, and institute appropriate compensatory or therapy procedures to prevent costly medical complications (see I.B.4.).
A. Symptoms of oropharyngeal dysphagia.
1. Coughing at meals.
2. Struggling to eat.
3. Taking longer to eat.
4. Chronic excessive secretions including tracheal secretions, chronic bronchitis, and asthma.
5. Weight loss of unexplained origin.
6. Pneumonia, especially recurrent.
7. Gurgly voice quality, especially during or after meals.
8. Recurrent fevers or increased secretions within 1 to 1½ hours after meals.
9. Elimination of some consistencies of foods from the diet.
10. Difficulty managing own saliva.
11. Patient complaint of difficulty swallowing.
B. Effects of dysphagia on health and the health care system.
1. Aspiration pneumonia. A significant positive correlation has been found between the aspiration observed during a modified barium swallow (MBS) test and the development of pneumonia within the next 6 months.
2. Malnutrition.
3. Dehydration.
4. Increased costs of health care including hospitalization for aspiration pneumonia and other costly medical complications, nonoral feeding, nursing care, if dysphagia is not managed properly.
C. Prevention: The reason for the evaluation and treatment of oropharyngeal dysphagia. In patients with neurologic damage or disease, dysphagia cannot be prevented, but the expensive medical complications that result from swallowing disorders can be prevented as a result of appropriate assessment and treatment.
1. Prevent expensive medical complications. Aspiration pneumonia alone is a significant cost to the health care system.
2. Facilitate the patient’s return to safe and efficient oral intake. Nonoral feeding requires greater nursing care and often specially prepared feedings, both of which are more costly than oral feeding.
II. NORMAL SWALLOWING
At all ages, normal swallowing is safe and efficient, moving food or liquid from the mouth, through the pharynx and into the cervical esophagus in 2 seconds or less, and through the esophagus in an additional 8 to 20 seconds.
A. Swallowing stages.
1. Oral preparatory stage (variable duration) includes chewing and other oral manipulations, which reduce food to a consistency appropriate for swallowing and provide taste and pleasure of eating. It does not depend on good dentition. Lip closure, circular and rotary action of the tongue, normal facial tone, and rotary jaw action are included in this stage of swallow. Oral tongue action and fine motor control of the tongue are most important because tongue action controls food in the mouth.
2. Oral stage (lasts approximately 1 second). The oral tongue is responsible for propelling food through the oral cavity and for providing sensory input contributing to triggering the pharyngeal stage of swallow.
3. Pharyngeal triggering (takes half a second or less) involves sensory input from the oral cavity to the cortex and brainstem, which is recognized as a swallow stimulus in the nucleus tractus solitarius in the brainstem. This sensory information is passed to the nucleus ambiguous, which triggers the pharyngeal motor response.
4. Pharyngeal stage (lasts less than 1 second) involves closure of the airway to prevent the entry of food into the airway (aspiration), opening of the upper esophageal sphincter (UES) to allow food to pass into the esophagus, and pressure applied to the bolus by the tongue and pharyngeal walls to clear food efficiently into the esophagus.
5. Esophageal stage (lasts 8–20 seconds) involves sequential contraction of the esophageal muscle fibers from top to bottom, propelling the bolus ahead of the contractile wave into the stomach. This phase also involves relaxation of the lower esophageal sphincter to allow the bolus to pass into the stomach.
B. Neuromuscular components of the normal swallow.
1. Lip closure is maintained from the time food is placed in the mouth until the pharyngeal swallow is completed. If lip closure cannot be maintained, the nasal airway may not be patent.
2. Lingual control. Oral tongue action is required in oral preparation because the tongue controls the food in the mouth during chewing. The tongue also forms the food into a ball or bolus in preparation for the swallow, subdividing the food in the mouth if necessary, to ensure the appropriate size bolus for swallowing. The oral portion of the tongue then propels the food through the oral cavity and into the pharynx.
3. Rotary, lateral jaw motion. Jaw action crushes the food, which is placed on the biting surfaces of the teeth by the tongue.
4. Velar or soft palate elevation and closure of the velopharyngeal port prevent food from entering the nasal cavity.
5. Tongue base posterior motion. Tongue base motion generates pharyngeal pressure on the bolus, as does sequential contraction down the pharyngeal wall.
6. Airway closure prevents aspiration. Airway closure begins at the true vocal folds, proceeds to the level of the airway entrance, that is, the false vocal folds, arytenoids, and base of epiglottis, and ends as the epiglottis is folded over the airway. The most critical level of airway closure is at the entrance, that is, the arytenoid cartilage and the base of epiglottis and false vocal folds. This level of closure prevents food from entering the airway.
7. Opening of the UES involves a complex set of actions including (1) relaxation of the cricopharyngeal muscular portion of the valve, which does not open the sphincter; (2) laryngeal upward and forward motion, which opens the sphincter by carrying the anterior wall of the sphincter, the cricoid cartilage, away from the pharyngeal wall; and (3) arrival of the bolus under pressure, which increases the width of the opening of the upper sphincter.
8. Esophageal peristalsis begins when the tail of the bolus enters the esophagus and follows the bolus through the esophagus.
C. Systematic changes in oropharyngeal swallow with changes in volume and viscosity of the incoming food and voluntary control. Not all swallows are alike. Normal oropharyngeal swallow physiology changes systematically as the volume and viscosity of the food being swallowed increases. A great deal of voluntary control can also be exerted over the oropharyngeal swallow. These systematic changes help to explain why patients have more difficulty with one type of food than another. The swallows are, in fact, different for different foods.
1. As bolus volume increases, the duration of the oral and pharyngeal stages of the swallow increases. The duration of airway closure and cricopharyngeal opening increases systematically.
2. Increasing viscosity of food increases the width of cricopharyngeal opening.
3. Volitional control also changes the characteristics of the oropharyngeal swallow.
a. Breath-holding can extend the duration of airway closure at the vocal folds or at the entrance to the airway. This is often done in anticipation of swallowing a large volume of liquid, as from a cup.
b. Volitional control can open the UES and prolong the duration of UES opening.
c. Volitional control can extend the duration and extent of laryngeal elevation.
d. Increasing effort during swallow will increase oropharyngeal pressures. Voluntary changes can occur spontaneously as patients “work” to swallow or patients can be taught these as compensations for swallowing problems.
D. Effects of normal aging.
1. Oral transit time slows 0.5 to 1.0 seconds with increasing age, probably because older adults most often hold the bolus on the anterior floor of the mouth and must pick it up with their tongue to begin the swallow.
2. Slightly slower shift from the oral to pharyngeal stage in individuals over age 60, probably because of slower neural processing.
3. After age 80, range of motion of pharyngeal structures is reduced, that is, there is less muscle reserve and less flexibility in the swallow. This is particularly true in men.
4. Over age 60, esophageal peristalsis becomes less efficient.
5. Healthy elderly individuals do not aspirate more often than young people. Elderly patients (over age 80) who become generally weak and sick will demonstrate a weak swallow because of their reduced muscular reserve. This can cause aspiration.
E. Efficiency and safety.
1. Normal swallows are efficient, moving food quickly through the mouth and pharynx and into the esophagus (under 2 seconds).
2. Only occasional aspiration occurs, usually when the mechanism is stressed or when both eating and talking in a social situation.
3. Efficiency and safety do not change significantly with age.
III. SWALLOWING DISORDERS
Swallowing disorders can occur in any stage of swallow and may involve one or more of the neuromuscular actions or sensory inputs described earlier as involved in the swallow.
A. Swallowing disorders can be anatomic or physiologic in nature.
B. Effective treatment of swallowing disorders requires identification of the specific anatomic and/or physiologic abnormalities in each patient’s swallow, such as reduced laryngeal elevation, poor airway closure, and reduced tongue base movement.
C. Aspiration and inefficient swallowing causing oral or pharyngeal residue are symptoms of swallowing disorders. They are not disorders. These symptoms will disappear when the patient’s swallowing physiology returns to normal.
IV. DEFINITIVE ASSESSMENT OF THE OROPHARYNGEAL SWALLOW: THE MBS
A. An MBS is performed by a speech–language pathologist and a radiologist. This radiographic (videofluorographic) test examines the anatomy and physiology of the oral and pharyngeal stages of swallowing. These stages must be examined separately from the esophagus, which is anatomically and physiologically distinct from the oral cavity and pharynx and requires a different technique for assessment (a barium swallow). An MBS assessment examines the ability of the pharynx to manage small to large volumes and thin to thick viscosities of food. An esophageal assessment requires presentation of a large amount of liquid in order to distend the esophagus, which as a collapsed muscular tube cannot be examined adequately unless distended.
1. Purpose.
a. Defines oral and pharyngeal swallow physiology in relation to patient’s swallow symptoms.
b. Defines swallow physiology symptomatic of neurologic disease.
c. Examines effectiveness of management strategies designed to assist patients in continuing to eat safely by mouth or to begin eating safely by mouth.
d. Defines a treatment plan to rehabilitate oropharyngeal swallow physiology and to eliminate symptoms of dysphagia including aspiration, thereby preventing the development of aspiration pneumonia.
e. Defines safest and most efficiently swallowed diet (food consistencies).
2. Procedure (designed to minimize risk of aspiration by presenting calibrated small to larger amounts of liquid, pudding, and masticated material as tolerated by the patient).
a. Patient seated upright initially and examined in the lateral plane to define speed, efficiency, and safety (aspiration) of the swallow.
b. Liquids given in 1-, 3-, 5-, or 10-ml cup drinking amounts (2 swallows each) to observe “dose response” of the pharynx and to define optimal volume for each patient.
c. If and when the patient aspirates or has a highly inefficient swallow, various treatment strategies are provided and their effects observed radiographically, including:
(1) Posture changes.
(2) Increased sensory input.
(3) Therapy procedures (requires normal cognition).
(4) Increased bolus viscosity. Nectar or honey-thickened liquids as needed if thin liquids are aspirated and no other strategy is effective.
d. Pudding (1–2 ml) and a small bite of cookie are given (2 swallows each) as tolerated by patient.
e. The patient is turned and examined in the anteroposterior plane to define symmetry of the swallow.
f. The report contains a description of the oral and pharyngeal anatomy and swallow physiology causing the patient’s dysphagia symptoms, identification of the types and amounts of foods safely swallowed, whether or not partial or full nonoral feeding is possible, and the effectiveness and need for compensatory strategies or swallow therapy.
3. Reevaluation. To ensure patient safety, the patient’s oropharyngeal swallow may need to be reevaluated when the patient appears ready to move to oral intake.
B. Barium swallow is used to examine the esophageal stage of swallowing, particularly esophageal anatomy and any anatomic abnormalities such as stricture and tumors. Because this assessment requires the patient to swallow larger volumes of liquid, it should be completed after an oropharyngeal assessment, that is, the MBS, to be sure the patient can safely tolerate these larger volumes.
1. Assesses esophageal anatomy and peristaltic action.
2. Misses reflux disease 60% to 80% of the time.
V. SCREENING TESTS FOR OROPHARYNGEAL DYSPHAGIA
These tests are not definitive and tend to overidentify patients at risk for swallowing disorders in the pharyngeal stage of swallowing.
A. A bedside or clinical exam usually performed by a speech–language pathologist. A bedside or clinical, noninstrumental assessment of swallowing cannot reliably define swallow physiology or dysphagia symptoms such as aspiration.
1. Complete medical history including history of the swallowing problem.
2. Complete oromotor test of lip, jaw, tongue, pharyngeal, and laryngeal function.
3. Trial swallows of small amounts of food are observed.
B. The Toronto Bedside Swallowing Screening Test. A validated test of the presence of dysphagia in stroke patients. Does not define the nature of the swallowing disorders.
VI. PATIENTS WITH KNOWN NEUROLOGIC DAMAGE OR DISEASE WITH COMPLAINTS OF SWALLOWING PROBLEM(S)
A. Progressive neurologic disease. Dysphagia is frequent in progressive neurologic disease at some point in the patient’s deterioration. Many neurologic diseases can first present with swallowing difficulties including Parkinson’s disease, motor neuron disease, postpolio syndrome, myasthenia gravis, multiple sclerosis, Guillain–Barré’s syndrome, and stroke.
1. Parkinson’s disease.
a. Swallowing problem may come early or later in disease progression.
b. Patient may aspirate silently, that is, there is no cough.
c. Symptoms of swallowing disorder.
(1) Patient may slow down while eating (because of characteristic [pathognomonic] rocking, rolling tongue motion).
(2) Patient may swallow two or three times with each bite of food because the swallow is not efficient and there is residue in the pharynx.
(3) Increased chest secretions, “bronchitis” with chronic cough, which are actually signs of chronic aspiration.
(4) Gurgly voice quality because of residual food remaining at the top of the airway.
d. Referrals.
(1) MBS.
(2) Swallowing therapy as indicated by MBS.
e. Progression is slow and may worsen very slowly over 10, 20, or more years.
f. Parkinson medications may improve swallowing disorder in some patients.
g. Swallow therapy. The patient responds moderately well.
2. Amyotrophic lateral sclerosis.
a. A swallowing or speech disorder may be first symptom and usually affects oral stage of swallow first with reduced tongue strength and fine control so that chewing is increasingly difficult.
b. Symptoms of swallowing disorders.
(1) Diet change. The patient eliminates foods from their diet requiring chewing, thicker foods requiring more muscle effort to swallow.
(2) Weight loss.
(3) Coughing usually occurs when swallowing liquids, which are not controlled well by the tongue and splash into the pharynx and into the open airway.
(4) There may be some aspiration.
c. Referrals. MBS at regular intervals (3 to 4 months) for patients with brainstem involvement to define best eating strategies. Direct exercise fatigues muscles.
d. Progression.
(1) Often rapid in predominantly brainstem involved patients. Patient may be advised to stop eating and accept gastrostomy when within 1½ to 2 years of diagnosis because of chronic aspiration.
(2) Very slow in patients with predominantly spinal involvement. It may be 10 to 15 years before dysphagia is severe enough to cause weight loss or chronic aspiration.
3. Postpolio syndrome.
a. Dysphagia may begin as patients reach their 40s or 50s, particularly patients with a history of bulbar polio.
b. The patient may have reduced awareness of the swallow problem.
c. Symptoms of a swallowing disorder.
d. Referrals. An MBS is indicated to define optimum eating strategies. Often the problem is unilateral weakness in the pharynx and head rotation toward the damaged side of the pharynx during eating facilitates improved clearance of food. Direct exercise fatigues the mechanism.
e. Progression is slow, worsening over years.
4. Myasthenia gravis.
a. A swallow or speech disorder may be the first symptom.
b. Symptoms may include the following:
(1) Fatigue in selected muscles of mouth or pharynx as eating progresses. May become severe enough so that no swallowing is possible.
(2) Increasing nasality, hoarseness, imprecision in speech sounds as the patient continues to talk.
c. Referrals. An MBS is used to define involved musculature and extent of fatigue.
d. Progression. Slow worsening of symptoms. Medication may significantly improve swallowing.
5. Multiple sclerosis.
a. Swallowing problem may be first symptom, but is more likely to occur as the disease progresses. The patient is often unaware of the swallowing problem.
b. Wide range of swallowing disorders as various parts of the nervous system are affected.
c. Symptoms may include the following:
(1) Difficulty swallowing liquids with coughing because of pharyngeal swallow delay.
(2) Complaint of food “stuck in the throat” because of reduced strength of tongue base and pharyngeal wall movement.
d. Responds well to swallowing therapy.
e. Referrals.
(1) MBS.
(2) Swallowing therapy, if indicated by results of MBS.
B. Sudden onset neurologic disorders. Stroke, head injury, and spinal cord injury may cause dysphagia from which the patient has potential for recovery with appropriate management. The focus of management should be early radiographic assessment (MBS) with swallowing therapy to prevent medical complications from occurring. The more medical problems and complications the patient sustains, the longer the recovery.
1. Stroke. Single or multiple strokes can cause swallowing problems.
a. A single infarct in the cortex, subcortical region, or brainstem can cause swallowing problems to worsen within the first week post stroke. By 3 weeks post stroke, patients usually will be functional swallowers unless they are taking medications that may affect swallow or have additional medical complications that slow swallowing recovery.
b. Brainstem stroke patients are at greatest risk for dysphagia. Some brainstem stroke patients, particularly those with lateral medullary syndrome, will need intensive swallowing therapy.
c. Patients with multiple strokes often exhibit more severe swallowing problems and require more rehabilitation, but usually do recover to full oral intake.
d. Referrals.
(1) An MBS when the patient is alert and awake (3 to 4 days post stroke) to determine need for nonoral feeding and swallowing therapy. Repeat study at 3 weeks post stroke to determine progress and discontinue nonoral feeding if no longer needed.
(2) Swallowing therapy, if indicated by MBS.
2. Head injury. Approximately one-third of the patients with head injury exhibit swallowing problems. Dysphagia may result from the neurologic injury, from other injuries to the head or neck, such as laryngeal fractures, and from acute care procedures, such as long-term intubation. Usually, neuromuscular damage is present in both the oral and pharyngeal phases of swallowing.
a. Referrals.
(1) MBS.
(2) Swallowing therapy, if indicated by MBS.
b. Most patients regain oral intake with therapy. Some patients who are severely head injured will require maintenance therapy from a caregiver to maintain safe and adequate oral intake.
3. Cervical spinal cord injury. Patients with cervical spinal cord injuries who undergo anterior spinal fusions are at greatest risk for dysphagia. The pharyngeal swallow is usually impaired.
a. Referrals.
(1) MBS.
(2) Swallowing therapy.
b. Most often swallowing problems are in the pharyngeal phase of the swallow.
c. With swallowing therapy, most patients will recover. The length of time in recovery will depend on the extent of physical damage and the number of medical complications sustained.
VII. PATIENTS WITH COMPLAINTS OF SWALLOWING DISORDER(S) (DYSPHAGIA) BUT NO MEDICAL DIAGNOSIS
A. Most often these patients have a progressive neurologic disease, have had a stroke, or have a brain tumor. Rarely does the dysphagia indicate a head or neck cancer. Rarely is dysphagia a psychogenic problem. Anatomic or physiologic disorders should be ruled out first before psychogenic etiology considered.
B. Testing Needed.
1. History. A complete medical and swallowing history should be taken, including:
a. Pattern of difficulty.
(1) Fatigue at the end of the meal could indicate myasthenia gravis.
(2) Foods that the patient finds difficult.
(3) Gradual or sudden onset. If gradual onset, usually indicates neurologic disease. Sudden onset may indicate a stroke.
b. Family history of any swallowing problem.
2. Symptoms. Asking the patient to describe their symptoms is helpful.
a. Food remains in mouth—indicates oral stage problem.
b. Food hesitates at the top of neck—may indicate difficulty triggering pharyngeal stage.
c. Food remains in throat—may indicate pharyngeal stage problems.
d. A feeling of pressure at the base of the neck or a feeling that food remains at base of neck—usually indicates an esophageal stage problem.
e. Pressure, feeling of food caught in chest—usually indicates esophageal stage problem(s).
3. Other motor signs.
a. Gait changes.
b. Tremor in the tongue, jaw, pharynx, or larynx. Tremor at rest may indicate Parkinson’s disease.
c. Speech or voice changes. Many patients with neurologic disease may exhibit speech and/or voice changes and swallowing problems.
VIII. SUMMARY
Early MBS assessment by a speech–language pathologist can reduce the medical complications from dysphagia and thereby reduce costs to the health care system. One hospitalization for aspiration pneumonia can equal the cost of MBSs and follow-up swallowing therapy for 3 to 5 patients for 3 months. Careful and aggressive management of dysphagia can save the health care system significant costs in hospitalization and other medical costs.
Recommended Readings
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Horner J, Massey EW, Riski JE, et al. Aspiration following stroke: clinical correlates and outcomes. Neurology. 1988;38:1359–1362.
Lazarus CL, Logemann JA, Rademaker AW, et al. Effects of bolus volume, viscosity and repeated swallows in normals and stroke patients. Arch Phys Med Rehabil. 1993;74:1066–1070.
Logemann JA. Head and neck diseases in the elderly: effects of aging on the swallowing mechanism. Otolaryngol Clin North Am. 1990;23(6):1045–1056.
Logemann JA. The dysphagia diagnostic procedure as a treatment efficacy trial. Clin Commun Disord. 1993;3(4):1–10.
Logemann JA. A Manual for Videofluoroscopic Evaluation of Swallowing. 2nd ed. Austin, TX: Pro-Ed; 1993.
Logemann JA. Evaluation and Treatment of Swallowing Disorders. 2nd ed. Austin, TX: Pro-Ed; 1998.
Logemann JA, Kahrilas P, Kobara M, et al. The benefit of head rotation on pharyngoesophageal dysphagia. Arch Phys Med Rehabil. 1989;70(10):767–771.
Logemann JA, Pauloski BR, Rademaker AW, et al. Temporal and biomechanical characteristics of oropharyngeal swallow in younger and older men. J Speech Lang Hear Res. 2000;43:1264–1274.
Martino R, Silver F, Teasell R, et al. The Toronto Bedside Swallowing Screening Test (TOR-BSST): development and validation of a dysphagia screening tool for patients with stroke. Stroke. 2009;40(2):555–561.