Chapter 038. Dysphagia (Part 3)

Oropharyngeal motor dysphagia results from impairment of the voluntary effort required in bolus preparation or neuromuscular disorders affecting bolus preparation, initiation of the swallowing reflex, timely passage of food through the pharynx, and prevention of entry of food into the nasal and the laryngeal opening. Paralysis of the suprahyoid muscles leads to loss of opening of the UES and severe dysphagia. Because each side of the pharynx is innervated by ipsilateral nerves, a unilateral lesion of motor neurons leads to unilateral pharyngeal paralysis.Neuromuscular disorders causing dysphagia are listed in Table 38-1. They include a variety of cortical and suprabulbar...
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Chapter 038. Dysphagia (Part 3) Chapter 038. Dysphagia (Part 3) Oropharyngeal motor dysphagia results from impairment of the voluntaryeffort required in bolus preparation or neuromuscular disorders affecting boluspreparation, initiation of the swallowing reflex, timely passage of food through thepharynx, and prevention of entry of food into the nasal and the laryngeal opening.Paralysis of the suprahyoid muscles leads to loss of opening of the UES andsevere dysphagia. Because each side of the pharynx is innervated by ipsilateralnerves, a unilateral lesion of motor neurons leads to unilateral pharyngealparalysis. Neuromuscular disorders causing dysphagia are listed in Table 38-1. Theyinclude a variety of cortical and suprabulbar disorders, lesions of the cranialnerves in their nuclei in the brain stem or their course to the muscles, defects ofneurotransmission at the motor end plates, and muscular diseases. Some of thesedisorders also involve laryngeal muscles and vocal cords, causing hoarseness. Since the oropharyngeal phase of swallowing lasts no more than a second,rapid-sequence videofluoroscopy is necessary to permit detection and analysis ofabnormalities of oral and pharyngeal function. However, such studies can only beperformed in a fully conscious and cooperative patient. A videofluoroscopicswallowing study (VFSS) using barium of different consistencies may revealdifficulties in the oral phase of swallowing. The pharynx is examined to detectstasis of barium in the valleculae and pyriform sinuses and regurgitation of bariuminto the nose and tracheobronchial tree. Pharyngeal contraction waves andopening of UES with a swallow are carefully monitored. Manometric studies maydemonstrate reduced amplitude of pharyngeal contractions and reduced UESpressure without further fall in pressure on swallowing (see Fig. 286-3). Generaltreatment consists of maneuvers to reduce pharyngeal stasis and to enhance airwayprotection under the direction of a trained swallow therapist. Feeding by a naso-gastric tube or an endoscopically placed gastrostomy tube may be necessary fornutritional support; however, these maneuvers do not provide protection againstaspiration of salivary secretions. Gastrostomy tube feeding may actually increasegastroesophageal reflux and lead to more aspiration. Jejunostomy tube feedingmay lessen reflux. Dysphagia resulting from a cerebrovascular accident usually improves withtime, although often not completely. Patients with myasthenia gravis (Chap. 381)and polymyositis (Chap. 383) may respond to treatment of the primary disease.Cricopharyngeal myotomy is usually not helpful. Extensive operative proceduresto prevent aspiration are rarely needed. Death is often due to pulmonarycomplications. A cricopharyngeal bar results from failure of the cricopharyngeus to relaxbut with normal activity of the suprahyoid muscles on swallowing. Bariumswallow shows a prominent projection on the posterior wall of the pharynx at thelevel of the lower part of the cricoid cartilage (see Fig. 286-1). A transient cricopharyngeal bar is seen in up to 5% of individuals withoutdysphagia undergoing upper gastrointestinal studies; it can be produced in normalindividuals during a Valsalva maneuver. A persistent cricopharyngeal bar may becaused by fibrosis in the cricopharyngeus. Cricopharyngeal myotomy may be helpful in severely symptomatic casewith functional evidence of obstruction by the cricopharyngeus muscle, but iscontraindicated in the presence of gastroesophageal reflux because it may lead topharyngeal and pulmonary aspiration. Globus pharyngeus mainly occurs in individuals with emotional disorders,particularly in women. Results of barium studies and manometry are normal.Treatment consists primarily of reassurance. Some patients with globuspharyngeus have associated reflux esophagitis, and they may respond to treatmentof the esophagitis. ESOPHAGEAL DYSPHAGIA In an adult, the esophageal lumen can distend up to 4 cm in diameter. Whenthe esophagus cannot dilate beyond 2.5 cm in diameter, dysphagia to normal solidfood can occur. Dysphagia is always present when the esophagus cannot distendbeyond 1.3 cm. Circumferential lesions produce dysphagia more consistently than dolesions that involve only a portion of circumferences of the esophageal wall, asuninvolved segments retain their distensibility. The esophageal causes of mechanical dysphagia are listed in Table 38-2.Common causes include carcinoma, peptic and other benign strictures, and loweresophageal ring. Esophageal motor dysphagia may result from abnormalities inperistalsis and deglutitive inhibition due to diseases of the esophageal striated orsmooth muscle. ...