A swallow study, formally known as a deglutition study, is a diagnostic procedure used to assess dysphagia, which is difficulty or discomfort in swallowing. This specialized test identifies the precise nature and location of the swallowing impairment. The process is typically overseen by a Speech-Language Pathologist (SLP), often working alongside a radiologist, to analyze the movements of the mouth, throat, and esophagus. The main goal is to determine if food or liquid is safely passing into the stomach or if it is entering the airway, helping to pinpoint the underlying functional issue.
Symptoms That Require Assessment
A medical professional may order a swallow study if a patient exhibits signs indicating a breakdown in the complex swallowing process. Difficulties in the oral phase, which involves chewing and moving food, may manifest as drooling, excessive chewing time, or food pocketing in the cheeks. Problems in the pharyngeal phase, involving the throat, often present as coughing or choking during or immediately following a meal.
A change in vocal quality, such as a wet or gurgly sound after swallowing, signals that material has been left in the throat or has entered the airway. Recurring respiratory infections, particularly unexplained pneumonia, can be a consequence of chronic swallowing problems. Other signs include unexplained weight loss, dehydration, or requiring multiple swallows to clear a single mouthful. These symptoms collectively suggest an impairment requiring instrumental visualization for an accurate diagnosis.
Comparing the Primary Study Methods
The two primary instrumental methods used to assess swallowing function are the Modified Barium Swallow (MBS) and the Fiberoptic Endoscopic Evaluation of Swallowing (FEES). The MBS, also called a Videofluoroscopic Swallow Study (VFSS), uses fluoroscopy (X-ray technology) to capture a continuous video of the swallowing mechanism. During this exam, the patient swallows various foods and liquids coated with barium, a contrast agent that appears white on the X-ray. This allows the clinician to observe the entire swallow from the mouth through the upper esophagus. The primary advantage of the MBS is its ability to visualize all four phases of the swallow, including the oral, pharyngeal, and initial esophageal phases.
The FEES procedure uses a thin, flexible endoscope passed through the patient’s nose to position a camera above the voice box (larynx). This provides a direct, superior view of the throat structures. The patient swallows test materials, often mixed with a colored dye to make them easier to see on the camera feed. A benefit of the FEES is that it can be performed at the patient’s bedside, making it highly portable and suitable for those who are medically fragile or unable to travel to a radiology suite. Unlike the MBS, FEES uses no radiation, allowing for longer or repeated examinations to assess the effects of fatigue on swallowing.
What to Expect During the Examination
For either type of instrumental swallow study, the patient is seated upright, often in a specialized chair, to simulate a typical eating posture. The SLP guides the patient and administers the test materials, ensuring the procedure is dynamic and responsive to the patient’s reactions. Depending on the specific test, the patient may be asked to fast for a few hours beforehand, especially before an MBS, to ensure a clear view of the swallowing path.
The examination involves swallowing a small, controlled amount of different food and liquid consistencies. The SLP systematically tests thin liquids (such as water), followed by liquids thickened to different viscosities (such as nectar-thick or honey-thick). They also present pureed foods, like pudding, and potentially solid foods. The patient is given precise instructions, such as, “Hold this in your mouth and swallow when I tell you,” to capture specific moments of the swallowing process. The entire test is recorded, allowing the professional team to analyze the video frame-by-frame after the examination.
Understanding the Findings and Treatment Plan
The analysis focuses on identifying issues that compromise the safety and efficiency of the swallow. A primary finding is aspiration, which occurs when food or liquid passes below the vocal folds and enters the trachea, posing a risk for aspiration pneumonia. A related issue is penetration, where material enters the laryngeal area but remains above the vocal folds. The study also measures residue, which is any food or liquid remaining in the mouth or throat after the swallow, suggesting weak muscle function or poor timing.
Based on these findings, the SLP develops a treatment plan addressing the specific deficits observed. This often includes dietary modifications, such as changing the thickness of liquids or the texture of solid foods, to make them safer to swallow. Compensatory strategies may also be introduced, such as the chin-tuck posture, which physically redirects the food bolus away from the airway during the swallow. Specific swallowing therapy exercises are prescribed to strengthen the muscles involved in the swallow, aiming to improve the underlying physiological function.