Physiological Flow of Liquids Used in Dysphagia Management (Neuro)
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ClinicalTrials.gov Identifier: NCT03192358 |
Recruitment Status :
Completed
First Posted : June 20, 2017
Results First Posted : July 14, 2022
Last Update Posted : September 15, 2022
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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.
Condition or disease | Intervention/treatment |
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Amyotrophic Lateral Sclerosis Parkinson Disease Dysphagia | Diagnostic Test: Videofluoroscopic Swallowing Examination Other: Tongue Strength Measurement |
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 |
Actual Enrollment : | 40 participants |
Observational Model: | Cohort |
Time Perspective: | Cross-Sectional |
Official Title: | Physiological Flow of Liquids Used in Dysphagia Management |
Actual Study Start Date : | November 1, 2017 |
Actual Primary Completion Date : | December 31, 2020 |
Actual Study Completion Date : | December 31, 2020 |

Group/Cohort | Intervention/treatment |
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Amyotrophic Lateral Sclerosis
We will be recruiting individuals with confirmed or probably ALS, who experience speech or swallowing problems, to attend one data collection session. All participants will undergo the same protocol, including a Videofluoroscopic Swallowing Examination, and Tongue Strength Measurement.
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Diagnostic Test: Videofluoroscopic Swallowing Examination
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. Other: Tongue Strength Measurement 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). |
Parkinson's Disease
We will be recruiting individuals with a diagnosis of Parkinson's disease, who experience speech or swallowing problems, to attend one data collection session. All participants will undergo the same protocol, including a Videofluoroscopic Swallowing Examination, and Tongue Strength Measurement.
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Diagnostic Test: Videofluoroscopic Swallowing Examination
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. Other: Tongue Strength Measurement 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). |
- Number of Participants With Residue of Concern (Observational) [ Time Frame: Single timeframe (baseline only) ]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.
- Maximum Anterior Isometric Tongue Pressure [ Time Frame: Single timeframe (baseline only) ]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.
- Regular Effort Saliva Swallow Tongue Pressure [ Time Frame: Single timeframe (baseline only) ]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.
- Number of Participants With Unsafe Swallows (Observational) [ Time Frame: Baseline (Single timepoint only) ]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.
- Maximum Posterior Isometric Tongue Pressure (Observational). [ Time Frame: Single timeframe (baseline only) ]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.
- Number of Participants With Multiple Swallows Per Bolus (Observational) [ Time Frame: Single timeframe (baseline only) ]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.
- Number of Participants Displaying Prolonged Pharyngeal Bolus Transit (Observational) [ Time Frame: Single timeframe (baseline only) ]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.

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Ages Eligible for Study: | 18 Years to 90 Years (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Sampling Method: | Non-Probability Sample |
Inclusion Criteria:
- Adults (18+) with a confirmed diagnosis of Amyotrophic Lateral Sclerosis (ALS) or Parkinson's disease (PD)
Exclusion Criteria:
- People with a prior medical history of stroke
- People with a prior medical history of acquired brain injury
- People with a prior medical history of spinal or spinal cord injury
- People with a prior medical history of cancer or surgery in the head and neck region
- People who have had radiation to the head and neck for cancer
- People who have a prior history of swallowing problems (e.g., from childhood, medical complication)
- People with significant breathing difficulties (e.g., rely on mechanical ventilation)
- People who rely solely on tube-feeding for all meals and nutrition
- People who have Type I (insulin-dependent) Diabetes
- Women who are pregnant
- People who have allergies to barium, potato starch, corn starch, xanthan gum, milk products, latex or dental glue

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03192358
United States, Florida | |
University of Florida | |
Gainesville, Florida, United States, 32611 |
Principal Investigator: | Catriona M Steele, PhD | University Health Network - Toronto Rehabilitation Institute | |
Principal Investigator: | Emily K Plowman, PhD | University of Florida |
Documents provided by University Health Network, Toronto:
Responsible Party: | University Health Network, Toronto |
ClinicalTrials.gov Identifier: | NCT03192358 |
Other Study ID Numbers: |
17-5421 5R01DC011020-05 ( U.S. NIH Grant/Contract ) CAPCR 17-5421 (NIH_Neuro) ( Other Identifier: University Health Network Research Ethics Board ) IRB201701608 ( Other Identifier: University of Florida Institutional Review Board ) |
First Posted: | June 20, 2017 Key Record Dates |
Results First Posted: | July 14, 2022 |
Last Update Posted: | September 15, 2022 |
Last Verified: | March 2021 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Studies a U.S. FDA-regulated Drug Product: | No |
Studies a U.S. FDA-regulated Device Product: | No |
Thickened Liquids Dysphagia Management Videofluoroscopy Swallowing Physiology |
Deglutition Disorders Parkinson Disease Motor Neuron Disease Amyotrophic Lateral Sclerosis Parkinsonian Disorders Basal Ganglia Diseases Brain Diseases Central Nervous System Diseases Nervous System Diseases Movement Disorders Synucleinopathies |
Neurodegenerative Diseases Neuromuscular Diseases Spinal Cord Diseases TDP-43 Proteinopathies Proteostasis Deficiencies Metabolic Diseases Esophageal Diseases Gastrointestinal Diseases Digestive System Diseases Pharyngeal Diseases Otorhinolaryngologic Diseases |