Definition

Dysphagia generally refers to any difficulty with swallowing, including occult or asymptomatic impairments. It is a common problem, affecting one third to one half of all stroke patients [1] and about one sixth of elderly individuals [2]. It is frequent in head and neck cancer, traumatic brain injury, degenerative disorders of the nervous system, gastroesophageal reflux disease, and inflammatory muscle disease (Table 129.1). Dysphagia is classified according to the location of the problem as oropharyngeal (localized to the oral cavity or pharynx, not just the oropharynx) or esophageal. It may also be classified as mechanical (due to a structural lesion of the foodway) or functional (caused by a physiologic abnormality of foodway function) [3].

Sudden onset is suggestive of stroke. Concomitant limb weakness suggests a neurologic or neuromuscular disorder. Medication-induced dysphagia is commonly overlooked. Medications that impair level of consciousness (such as sedatives and tranquilizers), have anticholinergic effects (tricyclics, propantheline), or can damage mucous membranes (nonsteroidal anti-inflammatory drugs, aspirin, quinidine) may also cause dysphagia [4].

Symptoms

The most common symptoms of dysphagia are coughing or choking during eating [5] and the sensation of food sticking in the throat or chest. Some of the many symptoms and signs of dysphagia are listed in Table 129.2. A history of drooling, significant weight loss, or recurrent pneumonia suggests that the dysphagia is severe. The history is most useful for identification of esophageal dysphagia; the complaint of food sticking in the chest is usually associated with an esophageal disorder. In contrast, the complaint of food sticking in the throat has little localizing value and is often caused by an esophageal disorder. Coughing and choking during swallowing suggest an oropharyngeal origin and may be precipitated by aspiration (penetration of material through the vocal folds and into the trachea). However, some patients have impaired cough reflexes, resulting in silent aspiration (without cough) [5,6]. Silent aspiration occurs in 28% to 94% of people with dysphagia, depending on the population of patients [7,8]. Patients with neurologic disorder have a higher incidence of silent aspiration. Pain on swallowing (odynophagia) may occur transiently in pharyngitis, but persistent pain is unusual and is suggestive of neoplasia. Heartburn is a nonspecific complaint that is usually not associated with swallowing but occurs after meals. Heartburn may occur in gastroesophageal reflux disease, but a more specific symptom of gastroesophageal reflux disease is regurgitation of sour or bitter-tasting material into the throat after eating.

Physical Examination

An examination of the oral cavity and neck may identify structural abnormalities, weakness, or sensory deficits. The finding of dysarthria (abnormal articulation of speech) or dysphonia (abnormal voice quality) is often associated with oropharyngeal dysphagia. However, the examination is primarily useful for finding evidence of underlying neurologic, neuromuscular, or connective tissue disease. The examination should always include trial swallows of water [9–11]. During the swallow, there should be prompt elevation of the hyoid bone and larynx. Changes in voice quality and spontaneous coughing after swallowing suggest pharyngeal dysfunction. The history and physical examination are limited in their ability to detect and to characterize dysphagia, so instrumental studies are usually necessary [12].

Neurologic examination is important in the evaluation of dysphagic individuals because neurologic disorders commonly cause dysphagia. Disorders of either upper or lower motor neurons may produce dysphagia. The findings of atrophy or fasciculations of the tongue or palate suggest lower motor neuron dysfunction of the brainstem motor nuclei. In contrast to the prevailing wisdom, the gag reflex is not strongly predictive of the ability to swallow. It may be absent in normal individuals and normal in individuals with severe dysphagia and aspiration [13].

Functional Limitations

Functional limitations depend on the nature and severity of the dysphagia. Many individuals modify their diets to eliminate foods that are difficult to swallow; others require special postures or respiratory maneuvers. Some require inordinate amounts of time to consume a meal. In severe cases, tube feeding is necessary. These alterations in the ability to eat a meal can have a profound effect on psychological and social function [14]. Interaction with family and friends often centers on mealtime—family dinners, “going out” for a drink or for dinner, “coming over” for a snack or for dessert. Difficulty in eating a meal may disrupt relationships and result in social isolation. Some patients may require supervision during meals or feel unsafe when they eat alone, causing further disruption of social and vocational function.

Diagnostic Testing

Because the mechanics of swallowing are largely invisible to the naked eye, diagnostic studies are commonly needed. The sine qua non for diagnosis of oropharyngeal swallowing disorders is the videofluorographic swallowing study (VFSS) [15]. In this test, the patient eats and drinks a variety of solids and liquids combined with barium while images are recorded with videofluorography (x-ray videotaping). The VFSS is usually performed jointly by a physician (physiatrist or radiologist) and a speech-language pathologist. A unique benefit of the VFSS is that therapeutic techniques (such as modification of food consistency, body position, or respiration) can be tested and their effects on swallowing observed during the study. A routine barium swallow study is frequently sufficient if the problem is clearly esophageal.