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Airway Protective Mechanisms in PD (R01)

Mechanisms of Airway Protection Dysfunction in Parkinson's Disease

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT03321019
Enrollment
119
Registered
2017-10-25
Start date
2017-12-12
Completion date
2023-09-29
Last updated
2024-10-10

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Parkinson Disease

Brief summary

This study will collect data on various aspects of airway sensation and function, and determine how it relates to the development of swallowing and cough dysfunction in Parkinson's disease. Participants will be followed over a 3-year period, with once-per-year visits to collect the data.

Detailed description

Aspiration pneumonia (APn) occurs at a disproportionately hig rate in patients with Parkinson's disease (PD) versus healthy age-matched older adults. This is of particular public health concern given that aspiration pneumonia infection is a leading cause of death in persons with PD. The development of APn is multifactorial with aspiration of material from disordered swallowing (dysphagia) without proper cough response being the main contributing factor. These findings reflect the fact that both swallowing and cough are sensorimotor behaviors, and thus require appropriate detection and scaling of a sensory stimulus in order to produce an appropriate motor response. The long-term goal of this research is to advance the management of airway protection deficits in patients with neurodegenerative disease in order to decrease morbidity and mortality due to aspiration related lung infection. The objective here, which is a critical step in pursuit of that goal, is to further specify the sensory mechanisms associated with airway protection disorders in order to advance the clinical management of these patients. In order to accomplish the objective of this application the study team has identified 3 aims: First, determine relationship(s) between airway somatosensation, reflex cough and swallowing function in people with PD, and how these relationships may change with disease progression, over time. Second, determine whether cortical processing of sensory information is associated with deficits in reflex cough sensitivity or swallowing function in people with PD, and third, to determine how the central neural filtering of airway sensory stimuli may relate to the development of airway protective disorders. The study team will accomplish these aims in 2 experimental studies. First, the study team will test the magnitude of respiratory resistive loads, in people with PD across a range of disease durations, and in a healthy control group. The study team will measure reflex cough, using a cough-inducing irritant (capsaicin), and swallowing function. The study team will perform these tests at 3 time-points, spaced 10-14 months apart, in order to determine the relationships between respiratory sensation, cough sensitivity and effectiveness, and swallowing function, and how they change with advancing disease duration. Next the study team will perform electroencephalographic recordings time-locked to paired respiratory stimuli to determine cortical processing of airway sensory information. The study team will measure the amplitude and latency of the sensory evoked potential peaks, and compute ratios of peak amplitude between the first and second paired stimulus in order to determine the degree of sensory gating. The realization of the proposed aims and studies is significant because it is a necessary step in our program of research that is expected to lead to earlier, more accurate identification, as well as targeted interventions for airway protection deficits in PD. Completion of this research is systematically important for our goal of maintaining adequate airway protective function in PD patients; the results are expected to directly impact reductions in health care costs, morbidity, and mortality related to airway protection deficits.

Interventions

DRUGCapsaicin

Participants will inhale aerosolized capsaicin with the goal of this inducing cough and an urge-to-cough.

DEVICEResistive respiratory loads

Participants will breath through a mouthpiece. Every 3-5 breaths in, a respiratory load will be applied. Participants will be asked to rate the magnitude of the load.

OTHEREvent-related evoked potential using electroencephalography (EEG).

The study team will use EEG time-locked to a respiratory occlusion to measure the brain's response to respiratory sensation.

PROCEDUREFluoroscopic swallow evaluation

Participants will swallow various consistencies of barium under fluoroscopy (moving-picture x-ray) in order to assess swallowing safety and efficiency.

Sponsors

Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
CollaboratorNIH
University of Florida
Lead SponsorOTHER

Study design

Observational model
CASE_CONTROL
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Age
45 Years to 85 Years

Inclusion criteria

1. Between the ages of 45 and 85 years 2. Diagnosis of PD, Hoehn and Yahr stages I - IV, by a fellowship trained neurologist arriving at the diagnosis of PD by applying strict UK brain bank criteria (PD participants only)

Exclusion criteria

1. Neurological disorders other than PD (i.e., stroke, etc.) 2. Difficulty complying due to neuropsychological dysfunction (i.e., severe depression) 3. Allergy to capsaicin or hot peppers 4. History of head or neck cancer 5. History of smoking in the past 5 years 6. Any neurological disorder including PD (Healthy control group only)

Design outcomes

Primary

MeasureTime frameDescription
Respiratory Sensitivity3 years, three time points (assessed at year 1 visit, year 2 visit, and year 3 visit)Slope of perception of resistive load and load resistance: Magnitude estimation of respiratory load (6 - no difficulty inhaling - 20 maximum difficulty inhaling) is plotted on the y-axis and respiratory load (0, 5, 10, 25 & 40 cm H2O loads) is plotted on the x-axis. The slope of the resulting regression line is the measure.
Urge to Cough Sensitivity3 years, three time points (assessed at year 1 visit, year 2 visit, and year 3 visit)Urge to cough sensitivity slope: Slope of the line created by plotting the urge to cough (0 indicating none - 10 indicating maximal) on the y-axis and capsaicin concentration (increasing from 0, 25, 50, 100, 200 micromolar) on the x-axis.
Penetration-aspiration Scale3 years, three time points (assessed at year 1 visit, year 2 visit, and year 3 visit)Rating of airway intrusion of bolus material during swallowing ranging from 1 (best, no airway invasion) to 8 (worst, silent aspiration).

Secondary

MeasureTime frameDescription
Cough Peak Flow Rate3 years, three time points (assessed at year 1 visit, year 2 visit, and year 3 visit)Highest airflow rate (in liters per second; L/s) during cough
Swallowing Timing3 years, three time points (assessed at year 1 visit, year 2 visit, and year 3 visit)Duration from bolus head passing mandible to laryngeal vestibule closure measured in frames. Data are collected at 33 frames per second.

Countries

United States

Participant flow

Recruitment details

Participant recruitment began 12/2017 and ended 2/2022. Participants with Parkinson Disease (PD) were recruited from an IRB-approved clinical database of people with PD. Healthy (non-PD) participants were recruited using advertisement fliers and word-of-mouth. All participants were seen in research space at the outpatient Fixel Institute for Neurological Diseases at the University of Florida.

Participants by arm

ArmCount
Healthy Controls
Men and women between the ages of 45 and 85 years without Parkinson's disease, or any history of neurologic disorder/disease, head or neck cancer, or chronic respiratory illness. Capsaicin: Participants will inhale aerosolized capsaicin with the goal of this inducing cough and an urge-to-cough. Resistive respiratory loads: Participants will breath through a mouthpiece. Every 3-5 breaths in, a respiratory load will be applied. Participants will be asked to rate the magnitude of the load. Event-related evoked potential using electroencephalography (EEG).: The study team will use EEG time-locked to a respiratory occlusion to measure the brain's response to respiratory sensation. Fluoroscopic swallow evaluation: Participants will swallow various consistencies of barium under fluoroscopy (moving-picture x-ray) in order to assess swallowing safety and efficiency.
19
Parkinson's Disease
Men and women between the ages of 45 and 85 years with Parkinson's disease, and without any history of neurologic disorder/disease, head or neck cancer, or chronic respiratory illness. Capsaicin: Participants will inhale aerosolized capsaicin with the goal of this inducing cough and an urge-to-cough. Resistive respiratory loads: Participants will breath through a mouthpiece. Every 3-5 breaths in, a respiratory load will be applied. Participants will be asked to rate the magnitude of the load. Event-related evoked potential using electroencephalography (EEG).: The study team will use EEG time-locked to a respiratory occlusion to measure the brain's response to respiratory sensation. Fluoroscopic swallow evaluation: Participants will swallow various consistencies of barium under fluoroscopy (moving-picture x-ray) in order to assess swallowing safety and efficiency.
100
Total119

Withdrawals & dropouts

PeriodReasonFG000FG001
Overall StudyLost to Follow-up022
Overall StudyWithdrawal by Subject06

Baseline characteristics

CharacteristicHealthy ControlsParkinson's DiseaseTotal
Age, Categorical
<=18 years
0 Participants0 Participants0 Participants
Age, Categorical
>=65 years
13 Participants71 Participants84 Participants
Age, Categorical
Between 18 and 65 years
6 Participants29 Participants35 Participants
Age, Continuous68.1 years
STANDARD_DEVIATION 8.5
69.1 years
STANDARD_DEVIATION 7.3
68.8 years
STANDARD_DEVIATION 7.4
Disease duration (PD only)
11 + years
25 participants25 participants
Disease duration (PD only)
1 - 5 years
49 participants49 participants
Disease duration (PD only)
6 - 10 years
26 participants26 participants
Hoehn &Yahr score (PD only)2 units on a scale2 units on a scale
Race and Ethnicity Not Collected0 Participants
Region of Enrollment
United States
19 participants100 participants119 participants
Sex: Female, Male
Female
12 Participants27 Participants39 Participants
Sex: Female, Male
Male
7 Participants73 Participants80 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 190 / 100
other
Total, other adverse events
0 / 190 / 100
serious
Total, serious adverse events
0 / 190 / 100

Outcome results

Primary

Penetration-aspiration Scale

Rating of airway intrusion of bolus material during swallowing ranging from 1 (best, no airway invasion) to 8 (worst, silent aspiration).

Time frame: 3 years, three time points (assessed at year 1 visit, year 2 visit, and year 3 visit)

Population: For the PD group, the numbers analyzed in years 2 and 3 of the study reflect loss of participants to either withdrawal or loss to follow up. In some cases fluoroscopy was not available in the year 2 or 3 visit, so some participants were not included due to no data for those visits. Not that on the Penetration-Aspiration scale used, higher numbers are worse, with the full range being 1 (normal swallow) to 8 (silent aspiration).

ArmMeasureGroupValue (MEDIAN)
Healthy ControlsPenetration-aspiration ScaleYear 11 score on a scale
Parkinson's DiseasePenetration-aspiration ScaleYear 12 score on a scale
Parkinson's DiseasePenetration-aspiration ScaleYear 2 (PD only)2 score on a scale
Parkinson's DiseasePenetration-aspiration ScaleYear 3 (PD only)2 score on a scale
Comparison: Healthy controls were compared to PD participants across each of the 3 visits. PD participants were compared between visits 1, 2 and 3.p-value: 0.02ANOVA
Primary

Respiratory Sensitivity

Slope of perception of resistive load and load resistance: Magnitude estimation of respiratory load (6 - no difficulty inhaling - 20 maximum difficulty inhaling) is plotted on the y-axis and respiratory load (0, 5, 10, 25 & 40 cm H2O loads) is plotted on the x-axis. The slope of the resulting regression line is the measure.

Time frame: 3 years, three time points (assessed at year 1 visit, year 2 visit, and year 3 visit)

Population: The healthy control group had only 1 visit, whereas the PD group had 3 visits. Thus, the 2nd and 3rd rows in the outcome measure table are pertinent only to the PD participants. The numbers analyzed for the PD group in years 2 and 3 are smaller than year 1 due to participant withdrawals or loss to follow up.

ArmMeasureGroupValue (MEAN)Dispersion
Healthy ControlsRespiratory SensitivityYear 1 visit0.22 scores on a scale / CmH2OStandard Deviation 0.08
Parkinson's DiseaseRespiratory SensitivityYear 1 visit0.22 scores on a scale / CmH2OStandard Deviation 0.07
Parkinson's DiseaseRespiratory SensitivityYear 2 visit (PD only)0.21 scores on a scale / CmH2OStandard Deviation 0.07
Parkinson's DiseaseRespiratory SensitivityYear 3 visit (PD only)0.22 scores on a scale / CmH2OStandard Deviation 0.06
Comparison: Healthy controls were compared to PD participants across each of the 3 visits. PD participants were compared between visits 1, 2 and 3.p-value: <0.0001ANOVA
Primary

Urge to Cough Sensitivity

Urge to cough sensitivity slope: Slope of the line created by plotting the urge to cough (0 indicating none - 10 indicating maximal) on the y-axis and capsaicin concentration (increasing from 0, 25, 50, 100, 200 micromolar) on the x-axis.

Time frame: 3 years, three time points (assessed at year 1 visit, year 2 visit, and year 3 visit)

Population: For the PD group, the numbers analyzed in years 2 and 3 of the study reflect loss of participants to either withdrawal or loss to follow up.

ArmMeasureGroupValue (MEAN)Dispersion
Healthy ControlsUrge to Cough SensitivityYear 10.31 scores on a scale / micromolar capsaicinStandard Deviation 0.08
Parkinson's DiseaseUrge to Cough SensitivityYear 10.22 scores on a scale / micromolar capsaicinStandard Deviation 0.08
Parkinson's DiseaseUrge to Cough SensitivityYear 2 (PD only)0.21 scores on a scale / micromolar capsaicinStandard Deviation 0.09
Parkinson's DiseaseUrge to Cough SensitivityYear 3 (PD only)0.20 scores on a scale / micromolar capsaicinStandard Deviation 0.09
Comparison: Healthy controls were compared to PD participants across each of the 3 visits. PD participants were compared between visits 1, 2 and 3.p-value: 0.72ANOVA
Secondary

Cough Peak Flow Rate

Highest airflow rate (in liters per second; L/s) during cough

Time frame: 3 years, three time points (assessed at year 1 visit, year 2 visit, and year 3 visit)

Population: For the PD group, the numbers analyzed in years 2 and 3 of the study reflect loss of participants to either withdrawal or loss to follow up. The measure (L/s) is airflow - higher is better (indicating more airflow out per second), a measure of cough effectiveness.

ArmMeasureGroupValue (MEAN)Dispersion
Healthy ControlsCough Peak Flow RateYear 13.17 Liters of air per second (L/s)Standard Deviation 1.31
Parkinson's DiseaseCough Peak Flow RateYear 13.67 Liters of air per second (L/s)Standard Deviation 1.31
Parkinson's DiseaseCough Peak Flow RateYear 2 (PD only)3.27 Liters of air per second (L/s)Standard Deviation 1.2
Parkinson's DiseaseCough Peak Flow RateYear 3 (PD only)3.01 Liters of air per second (L/s)Standard Deviation 1.18
Comparison: Healthy controls were compared to PD participants across each of the 3 visits. PD participants were compared between visits 1, 2 and 3.p-value: 0.034ANOVA
Secondary

Swallowing Timing

Duration from bolus head passing mandible to laryngeal vestibule closure measured in frames. Data are collected at 33 frames per second.

Time frame: 3 years, three time points (assessed at year 1 visit, year 2 visit, and year 3 visit)

Population: For the PD group, the numbers analyzed in years 2 and 3 of the study reflect loss of participants to either withdrawal or loss to follow up.

ArmMeasureGroupValue (MEAN)Dispersion
Healthy ControlsSwallowing TimingYear 16.10 FramesStandard Deviation 7.24
Parkinson's DiseaseSwallowing TimingYear 3 (PD only)8.14 FramesStandard Deviation 5.32
Parkinson's DiseaseSwallowing TimingYear 16.70 FramesStandard Deviation 10.22
Parkinson's DiseaseSwallowing TimingYear 2 (PD only)8.85 FramesStandard Deviation 6.63
Comparison: Healthy controls were compared to PD participants across each of the 3 visits. PD participants were compared between visits 1, 2 and 3.p-value: 0.022ANOVA

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026