Book Review

Deglutition and Its Disorders: Anatomy, physiology, clinical diagnosis, and management

N Engl J Med 1997; 337:798September 11, 1997

Article

Deglutition and Its Disorders: Anatomy, physiology, clinical diagnosis, and management
Edited by Adrienne L. Perlman and Konrad S. Schulze-Delrieu. 522 pp. San Diego, Calif., Singular Publishing Group, 1997. $75. ISBN: 1-56593-621-3

Our understanding of swallowing has been much like the description of the elephant provided by the blind men. In our narrow, specialty-oriented arenas, the neurologist sees neuromuscular sequences, and the endoscopist sees structural anomalies; the dietitian opines on malnutrition, and the radiologist interprets shadows representing aspiration. The speech pathologist, gastroenterologist, internist, and surgeon also bring their tunneled views to the description of deglutition. Although each professional holds a limited piece of the truth, each has difficulty understanding the larger conceptual, methodologic, diagnostic, and therapeutic tools of other disciplines. Disorders of deglutition are summarily lumped into a diagnostic wastebasket called dysphagia (abnormal swallowing). Definitions are blurry, and therapies parochial. Furthermore, outcome criteria for the surgeon treating dysphagia may have little meaning to the neurologist, and vice versa:

Deglutition disorders receive short shrift in medical school curricula because they are not “owned” by any one department or division. There is no gold standard for, or even consensus about, what is normal. Consequently the call arises for the creation of a deglutition specialist, one who has mastered the array of skills other specialties bring on a part-time basis to the field.

Such specialists, who formerly found research data strewn through many specialty journals, would find their textbook in Deglutition and Its Disorders.

The editors have assembled a group of contributors who appear to have been handpicked from a Who's Who of deglutition specialists. The contributors represent fields as diverse as pediatrics, speech pathology, radiology, gastroenterology, otolaryngology and head and neck surgery, internal medicine, geriatrics, and dentistry. They have accomplished the formidable task of keeping the text readable for the student without compromising its value to the specialist. The editors have established a basis for a common language among clinicians in different disciplines and have produced a comprehensible body of information about normal and disordered swallowing. The gap between research and clinical care is skillfully bridged as the book pinpoints information that has been missing from the literature and specifies areas of ongoing controversy.

The editors assume that the reader already understands basic nutrition, since they present no information about nutrition. The early chapters provide an excellent distillation of the anatomy and neurophysiology of swallowing. The pharmacology of neurotransmitter activity is concisely reviewed, with discussions of excitatory amino acids, acetylcholine, γ-aminobutyric acid, somatostatin, serotonin, catecholamines, opioid peptides, and other putative neuromediators. The complex counterfunctioning of respiration and deglutition is thought to be controlled by brain-stem nuclei in the medulla, with interneurons connecting the two centers. Jeffrey Curtis and Susan Langmore differentiate penetration and aspiration, defining the latter as the delivery of material into the distal lung. They note that four syndromes should be distinguished: aspiration of large solids, leading to acute upper-airway obstruction, or of a large volume of liquids, leading to drowning or near drowning; aspiration of toxic fluids, including gastric or other acids and basic mineral oils or hydrocarbons; aspiration of contaminated oral secretions or debris, leading to infectious pneumonia, frequently from anaerobic organisms; and chronic aspiration of small amounts of food or organic substances, leading to pulmonary fibrosis due to a granulomatous response. The authors correctly note the difficulty in extrapolating experimental or clinical data to answer the manifold questions about aspiration. It is this kind of concise defining that gives currency to the interdisciplinary approach.

The midsection of the book provides an outstanding treatise on the evaluation of dysphagia with the use of the clinical assessment, radiographic examinations with the administration of contrast material, fiberoptic endoscopy, and newer imaging methods such as ultrasonography and scintigraphy. The roles of electromyography, esophagoscopy, and manometry are succinctly presented in reference to assessing the distal deglutitive structures, as well as impedance planimetry and monitoring of esophageal pH. The strategies for medical, surgical, and rehabilitational interventions are elucidated in the final sections by Jeri Logemann and others. These discussions are thorough without being encyclopedic. The surgical discussions are not technically oriented and are quite readable. The average house-staff member would be well informed that tracheostomy is not indicated or effective in every case of aspiration, nor is percutaneous gastrostomy universally cost effective.

Two other valuable features of Deglutition and Its Disorders are the multiple-choice questions and comprehensive reference list at the end of each chapter. These features help the reader focus on the most pertinent information in each section and point the way to further reading. In this manner, the editors hope to provide sight to the blind.

Brian F. Humphreys, M.D.
Shannon Health Systems, San Angelo, TX 76903