Current Thinking on Evaluation of Dysphagia

Meaning disordered eating in Greek, dysphagia is typically translated in English to mean difficulty swallowing. Both phrases capture the profound affect that dysphagia can and does have on the many people afflicted by it. Anything that disrupts such a primary human experience as eating or swallowing not only drastically reduces quality of life, but often threatens life itself.

Dysphagia can have multiple etiologies, from neuromuscular disorders to cancer. It is most frequently found in neurologically impaired patients-in particular, stroke patients, in whom the incidence can be as high as 81%. Non-neurologic dysphagia is also common and is frequently found in patients who undergo radiotherapy with or without chemotherapy for head and neck cancer, with a reported incidence ranging between 39% and 89% in these patients.

Because the origin of dysphagia is commonly in the head and neck or cervical esophagus, patients are often referred to otolaryngologists for evaluation. Although detecting the presence of dysphagia can be straightforward for patients who show outward signs such as coughing and choking, other patients may not show such tangible signs and may silently aspirate, said Lori Burkhead, PhD, a speech-language pathologist who is Assistant Professor and Clinical Research Scientist in the Department of Otolaryngology at the Medical College of Georgia in Augusta. This means that they have food, liquid, and/or saliva entering the airway and do not have intact sensation to cough in response to it. Because of the difficulty in detecting silent aspiration, Dr. Burkhead recommends enlisting the services of a speech-language pathologist trained in dysphagia evaluation to assess patients.

Determining the Etiology of Dysphagia

A critical challenging next step to evaluating patients who are found to have dysphagia is to determine the etiology of the dysphagia. This requires a team approach that includes otolaryngologists, speech pathologists, dietitians, radiologists, and gastroenterologists, emphasized Dennis Kraus, MD, Attending Head and Neck Surgeon and Director of the Speech, Hearing, and Rehabilitation Center at Memorial Sloan-Kettering Cancer Center in New York, and his colleagues, Ryan C. Branski, PhD, Assistant Attending Scientist and Associate Director of the Speech, Hearing, and Rehabilitation Center, and Cindy Ganz, MA, a speech pathologist at the center.

The approach this center uses is to first perform a full clinical examination of swallow function in a patient, which involves a cursory head and neck examination, cranial nerve assessment, and observations of swallow physiology. This is done by a speech pathologist.

Often, further evaluation is necessary. Several well-established modalities are available, including transnasal esophageoscopy (TNE); videofluorographic swallowing study (VFSS) or, as it is commonly called, modified barium swallow study (MBSS); and flexible endoscopic evaluation of swallowing (FEES) alone or with the addition of a sensory test (FEESST). Real-time MRI is also being looked at for use in this setting, but to date it remains investigational.

Among these, the most commonly used are the MBSS and FEES exams. A great deal of data and literature is available on the relative merits of each, and a discussion of which exam may be better is still under way, but, to date, data suggest that both are useful tools and in some cases complementary to each other. According to Dr. Burkhead, although past thinking tended to view one exam as better than the other, current opinion tends to see each tool as providing unique information. The choice of exam, therefore, depends largely on the clinical questions to be answered and the presentation of the patient. When both pharyngoesophageal and oropharyngeal symptoms are reported, or when one exam does not answer all the clinical questions, she recommends using both tests.

Modified Barium Swallow Study (MBSS)

Also referred to as VFSS, MBS, rehab swallow study, or cookie swallowexam, the MBSS is a radiologic test done commonly by a speech-language pathologist and radiologist to evaluate esophageal function, and is particularly helpful in looking for motility disorders. Patients swallow a small amount of barium mixed with real food and liquids, which permits assessing all phases of swallowing from when the food enters the mouth until it moves into the stomach.

This test is commonly used by otolaryngologists when an upper aerodigestive tract problem is suspected, said Christine Gourin, MD, Associate Professor in the Department of Otolaryngology-Head and Neck Surgery at Johns Hopkins University in Baltimore, adding that an important aspect of the test is that it can be stopped if the patient starts to aspirate. She cautioned against using this test in patients with gross aspiration.

Overall, she said, the test is superior for evaluating muscular function. MBSS really helps pinpoint which pharyngeal muscles or parts of the tongue are not working, she said. In addition, MBSS identifies trace amounts of aspiration of thin liquids and can identify strictures in the upper esophagus, both of which can be missed using FEES.

Table 1 lists indications for MBSS.

According to Dr. Kraus and his colleagues, a potential disadvantage of this exam is that it is relatively expensive, because it requires the services of a radiologist as well as a speech pathologist.

Flexible Endoscopic Evaluation of Swallowing (FEES)

Newer than the MBSS exam, the FEES allows for the evaluation of laryngeal function, including vocal fold motion or atrophy and laryngeal lesions. The test uses a small scope that is placed through the nose and throat, which is used for visualizing the throat during swallowing. Performed generally by a speech-language pathologist or otolaryngologist, the test also permits evaluation of whether a patient is having trouble with his or her own secretions (unlike MBSS, which evaluates only barium-coated secretions). When sensory testing is added to this test, it is referred to as FEESST.

I prefer the FEES or FEESST for head and neck cancer patients, said Dr. Burkhead, because I can evaluate the structures more clearly and determine the impact of mucositis or edema or tumor bulk on swallowing, something that MBSS cannot fully provide information about.

Other advantages of FEES, said Dr. Gourin, include its ability to assess minor degrees of laryngeal aspiration or residue remaining from ingested material that a patient may not sense or handle effectively. When the sensory part of the test is included, she said, another advantage is the ability to determine if the structures are insensate or respond appropriately to things like residue, as well as seeing if the patient can handle their own secretions.

A further advantage of this exam is that it is office-based, portable, and does not use ionizing radiation. This is beneficial particularly for patients who cannot readily be transported, such as patients in the intensive care unit, or for those who need repeat exams, said Dr. Burkhead.

Table 2 lists indications for FEES (or FEESST).

Reliability of Each Test

Along with recognizing that each test has unique characteristics that suggest its preferred utility to answer specific clinical questions or patient symptoms, it is important to bear in mind that there can be differences in the reliability of the results of each test. For example, compared with MBSS, FEES may overestimate swallowing problems and results must be interpreted in the context of the patient’s underlying condition, said Dr. Gourin. On the other hand, MBSS may underestimate the degree of dysphagia compared with FEES because of problems that won’t be apparent on MBS, such as trouble patients are having with secretions or laryngeal function.

Dr. Kraus and his colleagues emphasized that the reliability of the tests is highly dependent on the clinicians who perform and interpret them.

Specific Issues for Otolaryngologists Managing Head and Neck Cancer Patients

According to Dr. Burkhead, an important issue that otolaryngologists need to recognize and weigh when treating patients with head and neck cancer is the growing trend to treat patients with radiation with or without chemotherapy to avoid surgery and preserve organs. While these regimens seem to hold promise, fatality due to aspiration in those undergoing nonoperative treatment is not uncommon and has been identified as the most life-threatening complication in these patients, she said.

Acknowledging that physicians struggle with balancing tumor ablation with quality of life, and that the primary goal of cancer treatment is survival, Dr. Burkhead emphasized the need to recognize quality of life issues in these patients. Those with tumors in the upper aerodigestive tract are particularly vulnerable to also experience depression, anxiety, social isolation, as well as adverse health risks associated with dysphagia, she said. It is clear that the need for effective intervention to address swallowing disability is great not only for head and neck cancer patients’ quality of life but also for improved survival.

©2009 The Triological Society