For individuals with neurodegenerative conditions, such as Amyotrophic Lateral Sclerosis and Parkinson disease, swallowing impairment (i.e., dysphagia) is a common and serious symptom. Dysphagia places the affected individual at risk for secondary health consequences, including malnutrition and aspiration pneumonia, and negatively affects quality of life. Thickened liquids are commonly recommended for individuals with dysphagia, as they flow more slowly and reduce the risk of entry into the airway. However, there is limited understanding about how changes in liquid thickness modulate swallowing physiology in individuals with neurodegenerative conditions, and previous reports have shown that increased liquid thickness may contribute to the accumulation of residue in the throat. The purpose of this study is to explore swallowing physiology and function in individuals with neurodegenerative conditions, across five levels of liquid thickness (thin, slightly-thick, mildly-thick, moderately-thick, and extremely-thick), and to identify boundaries of "optimal liquid thickness", which maintain airway safety, without contributing to the accumulation of significant residue. Results from this study will help guide the clinical recommendations for thickened liquids in dysphagia management.
This observational research study will measure swallowing function in individuals with Amyotrophic Lateral Sclerosis or Parkinson's disease. The aims of this study are to (1) identify parameters of swallowing physiology that are associated with impaired swallowing safety and efficiency, and (2) explore how liquid thickness influences swallowing function. Participation in this research study involves a single appointment at the University of Florida Swallowing Systems Core laboratory located at Shands Hospital, Gainesville. The appointment will last approximately 1 hour, and will involve tasks to measure tongue-strength, and a dynamic swallowing x-ray (known as videofluoroscopy) to evaluate swallowing function. A selection of demographic information (e.g., age, onset of symptoms) will also be recorded. To measure tongue strength, participants will be given a disposable air-filled bulb and asked to perform a series of tongue presses, and swallow their saliva. Next, during the videofluoroscopy, participants will take sips of various liquids ranging in thickness from thin (like water), to extremely-thick (similar to the consistency of pudding or yogurt). The liquids will be mixed with a safe substance called barium, to make them visible on x-ray images. After the videofluoroscopy has been completed, each participant will have their tongue strength measured again, which will conclude their participation in the study. Swallowing physiology will be measured from the videofluoroscopy images, post-hoc, by an experienced team of blinded raters.
Study Type
OBSERVATIONAL
Enrollment
40
During the videofluoroscopy, subjects will take up to 21 sips of liquid, ranging in thickness from thin (like water), to extremely-thick (like pudding or custard). The liquids will be mixed with E-Z-Paque barium sulfate, to allow it to be visible on the x-ray.
We will measure tongue strength using a tongue pressure measurement system called the Iowa Oral Performance Instrument (IOPI). A small disposable bulb filled with air will be placed in the mouth, just behind the front teeth. Participants will be asked to press their tongue upwards against the bulb as hard as they can, three (3) times at the front of the tongue and three (3) times at the back of the tongue (i.e., total of six (6) maximum isometric tongue presses). Participants will also be asked to swallow their saliva with the bulb placed in their mouth, three (3) times. Tongue pressure measurement will be completed twice in the data collection session - once at the beginning, and once at the end (following the videofluoroscopy).
University of Florida
Gainesville, Florida, United States
Number of Participants With Residue of Concern (Observational)
Residue is material remaining behind in the pharynx after the swallow. We measured residue by tracing the area of barium visible on a lateral view x-ray (in pixels, using ImageJ software) and dividing that area by the squared length C2-C4 cervical spine. This cervical spine scalar provides a common anatomical reference that is a proxy for pharyngeal size, and enables the comparison of residue severity across different people with different neck length and pharynx size. Smaller values are considered better. The 75th percentile healthy reference values for this measure are 1.7% on thin liquids, 1.9% on slightly thick liquids, 2.2% on mildly thick liquids, 1.6% on moderately thick liquids and 1.5% on extremely thick liquids. Values above these thresholds are considered atypical and of clinical concern. We report the number of participants who display atypical total pharyngeal residue measures per consistency.
Time frame: Single timeframe (baseline only)
Maximum Anterior Isometric Tongue Pressure
Tongue strength was measured using a tongue pressure measurement system called the Iowa Oral Performance Instrument (IOPI). A small disposable bulb filled with air was placed in the mouth, just behind the front teeth. Participants were asked to press the front of their tongue upwards against the bulb as hard as possible. This task was repeated 3 times. The maximum value obtained across 3 repetitions was recorded as "maximum anterior isometric pressure". Higher values represent greater tongue strength. We report group mean values and standard deviations for this measure.
Time frame: Single timeframe (baseline only)
Regular Effort Saliva Swallow Tongue Pressure
Tongue strength was measured using a tongue pressure measurement system called the Iowa Oral Performance Instrument (IOPI). A small disposable bulb filled with air was placed in the mouth, just behind the front teeth. Participants were asked to swallow their saliva with the bulb in this position. This task was repeated 3 times. The mean value obtained across 3 repetitions was recorded as "regular effort saliva swallow tongue pressure". Higher values represent greater tongue strength. We report group mean values and standard deviations for this measure.
Time frame: Single timeframe (baseline only)
Number of Participants With Unsafe Swallows (Observational)
Swallowing safety was measured using the 8-point Penetration-Aspiration Scale, an 8-point categorical scale which captures the depth to which any material enters the airway and whether or not the material is ejected. Levels 1 and 2 on the scale are considered safe, while levels \> 2 are considered unsafe. Actual scale scores (1-8) were recorded and then converted to binary categorical scores (\< 3 vs \>/= 3). We report the frequency (count) of participants showing scores \> 2 by bolus consistency.
Time frame: Baseline (Single timepoint only)
Maximum Posterior Isometric Tongue Pressure (Observational).
Tongue strength was measured using a tongue pressure measurement system called the Iowa Oral Performance Instrument (IOPI). A small disposable bulb filled with air was placed in the mouth, with the front margin of the sensor aligned with the first molar tooth. Participants were asked to press the back of their tongue upwards against the bulb as hard as possible. This task was repeated 3 times. The maximum value obtained across 3 repetitions was recorded as "maximum posterior isometric pressure". Higher values represent greater tongue strength. We report group mean values and standard deviations for this measure. There was no statistical analysis comparing group values for this parameter.
Time frame: Single timeframe (baseline only)
Number of Participants With Multiple Swallows Per Bolus (Observational)
The number of swallows needed to clear a single bolus will be counted. A single swallow is considered efficient, while 2+ swallows for one bolus is considered atypical. We will report the number of participants with \> 1 swallow per bolus.
Time frame: Single timeframe (baseline only)
Number of Participants Displaying Prolonged Pharyngeal Bolus Transit (Observational)
The time interval from the first frame showing the bolus entering the pharynx (passing the shadow of the ramus of the mandible) until the first frame showing the bolus entering the upper esophageal sphincter was calculated (in milliseconds) for each bolus. The 75th percentile healthy reference values for this measure are 533 ms on thin liquids, 567 ms on slightly thick liquids, 701 ms on mildly thick liquids, 867 ms on moderately thick liquids and 1001 ms on extremely thick liquids. Pharyngeal transit durations above these values are considered prolonged and atypical. We will report the number of participants who present with atypical pharyngeal transit duration above these 75th percentile reference value thresholds per consistency.
Time frame: Single timeframe (baseline only)
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.