Dysphagia, Stroke
Conditions
Keywords
Brain stimulation
Brief summary
Swallowing difficulties are common after a stroke and can lead to serious complications like pneumonia and malnutrition. Unfortunately, there are no effective treatment for improving swallowing in stroke patients. Previous investigations have shown that recovery of swallowing functions occurs from reorganization (rewiring) of the non-involved cerebral hemisphere. In this study, the investigators propose to investigate a new intervention, which combines, swallowing exercises with brain stimulation targeted to the non-involved cerebral hemisphere, using low intensity current in acute stroke patients. The investigators plan to assess the safety of this technique in this patient population and also assess its effect on improving swallowing functions and swallowing physiology. During this time trial participants will undergo standardized swallowing and neurological assessments as well as brain MRI scans.
Detailed description
Swallowing impairments are a common and a serious complication of stroke but lack effective therapies. The study investigators herein propose to conduct a prospective clinical study using a non-invasive brain stimulation technique, anodal transcranial direct current stimulation (tDCS), in combination with swallowing exercises for improving dysphagia due to an acute-subacute hemispheric infarction, and obtain data on safety and effect of 2 different doses of tDCS, on swallowing physiology and behavior. Dysphagia from hemispheric strokes occurs due to disruption of the cortical projections to the brainstem swallowing centers while recovery of swallowing functions have been shown to be mediated via the reorganization of the swallowing cortex in the unaffected hemisphere. A recent pilot study conducted by the investigators demonstrated the safety and feasibility of applying 5 consecutive daily sessions of anodal tDCS for 30 minutes to the swallowing cortex on the unaffected hemisphere in the acute-subacute stroke phases and showed a promise in improving dysphagia, when combined with swallowing exercises. The proposed research will be used to further confirm safety of this technique in early stroke phases and explore alternative, more effective doses for promoting swallowing recovery prior to its examination in any confirmatory trials. The investigators will use the study cohort to examine important subject specific parameters which influence response to the proposed intervention in dysphagic stroke patients. The overall aim of this study is to gather additional safety data on cumulative sessions of tDCS in acute-subacute phases of stroke, obtain information about effects of this intervention on important physiological and clinically relevant swallowing parameters, examine possible dose effects, and identify candidates who are more likely to benefit from this intervention. The experience gained from this project will guide planning of future confirmatory trials that use relevant clinical outcomes to assess potential benefits of this intervention and utilize important subject specific parameters to refine study inclusion criteria and aid in severity adjusted analysis.
Interventions
DEVICEtDCS
Anodal tDCS will be administered with swallowing exercises
Sponsors
National Institute on Deafness and Other Communication Disorders (NIDCD)
Beth Israel Deaconess Medical Center
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Masking description
Investigators and subjects will be masked to the trail arm assignments at randomization. The investigator reviewing outcome data will also be masked to the trial assignments.
Intervention model description
The trial will randomize subjects to anodal transcranial direct current stimulation (tDCS) versus sham stimulation, both of them carried out in combination with standardized swallowing exercises
Eligibility
Sex/Gender
ALL
Age
21 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* 21 years or older in age since safety of non-invasive cortical stimulation in children. * Between 25 hours (day 2) to 144 (day 6) hours since stroke onset. * Unilateral hemispheric infarction (cortical or subcortical infarction) documented by imaging. * Moderate to severe dysphagia with a score of 4 or more on Penetration and Aspiration Scale (PAS)
Exclusion criteria
* Prior history of swallowing difficulties. * Drowsiness or marked cognitive impairment that interferes with participation in swallowing maneuvers. * Unable to undergo an MRI due to claustrophobia or presence of electrically, magnetically or mechanically activated implant (including cardiac pacemaker), intracerebral vascular clips or any other electrically sensitive support system, metal in any part of the body, including metallic injury to eye, or pregnancy). * History of seizures or unexplained episodes of loss of consciousness.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| To Assess Safety of tDCS in Acute-subacute Stroke Phase: Number of Participants With Swallowing Deterioration in Each of the 3 Groups | Any change between day 1 and day 3 of stimulation session | We will tabulate the number of participants with swallowing deterioration in the High-dose tDCS, Low-dose tDCS and sham groups Swallowing deterioration will be defined as an increase in the score by 2 or more points in the Functional Oral Intake Scale (FOIS). FOIS provides a validated measure of diet level. FOIS is an ordinal scale ranging from 7 (normal diet) to 0 (no oral intake), with lower scores indicating a worse diet. |
| To Assess Changes in Penetration and Aspiration | Scores will be measured before tDCS and after 5 days after completion of stimulation | This will be assessed using the Penetration and Aspiration Scale (PAS) scores, a validated 8 point ordinal scale that quantifies penetration and aspiration events observed during Videofluoroscopic Swallowing Evaluation. PAS ranges from 1 (best score) representing no aspiration or penetration to 8 (worst score) representing severe aspiration. An average PAS score will be computed based on 9 swallows for this outcome. |
| To Assess Safety of tDCS in Acute-subacute Stroke Phase: Number of Participants With Seizures in Each of the 3 Groups | During the 5 days of stimulation sessions | We will tabulate the number of participants who develop seizures in the High-dose anodal tDCS, Low-dose anodal tDCS and Sham stimulation groups. |
| To Assess Safety of tDCS in Acute-subacute Stroke Phase: Number of Deaths in Each of the 3 Groups Attributable to the Direct Effects of Stroke | During the 5 days of stimulation sessions | We will tabulate the number of deaths in High-dose tDCS, Low-dose tDCS and Sham stimulation groups, that are attributable to the direct effects of the qualifying stroke. |
| To Assess Safety of tDCS in Acute-subacute Stroke Phase: Number of Participants With Neurological Deterioration in Each of the 3 Groups | During the 5 days of stimulation sessions | We will tabulate the number of participants who develop neurological deterioration in the High-dose tDCS, Low-dose tDCS and Sham groups. Neurological deterioration will be defined as an increase in the total National Institute of Health Stroke Scale (NIHSS) Score by 4 or more points between each successive day. The NIHSS is a 15-item neurologic examination stroke scale used to evaluate the effect of acute cerebral infarction on the levels of consciousness, language, neglect, visual-field loss, extraocular movement, motor strength, ataxia, dysarthria, and sensory loss. NIHSS ranges from 0 (normal) to 42 (worst possible score). Higher scores mean worse neurological functions. |
| To Assess Safety of tDCS in Acute-subacute Stroke Phase: Number of Participants With Motor Deterioration in Each of the 3 Groups | During the 5 days of stimulation sessions | We will tabulate the number of participants with deterioration in their motor functions in the High-dose tDCS, Low-dose tDCS and Sham groups. Motor deterioration will be defined as an increase in the motor sub-item of the National Institute of Health Stroke Scale (NIHSS) score by 2 or more points between each successive day of stimulation. The motor sub-item of the NIHSS ranges from 0 (normal) to 16 (worst possible score), with higher scores indicating a worse motor exam. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| To Assess Changes in Physiological Measures of Pharyngeal Strength | Variables will be measured at baseline (before starting tDCS) and after 5 days after completion of stimulation | Examining effects of differing doses of anodal tDCS versus sham stimulation on Pharyngeal Constriction Ratio (PCR), derived from videofluoroscopic swallowing studies.PCR is a measure of the pharyngeal area visible in the lateral radiograph view at the point when a bolus is held in the oral cavity divided by the pharyngeal area at the point of maximum pharyngeal constriction during the swallow. A higher PCR indicates a weak swallow leading to increased food residue in the pharynx. |
| To Assess Changes in Physiological Measures of Briskness of Swallow Onset | Variables will be measured at baseline (before starting tDCS) and after 5 days after completion of stimulation | Examining effects of differing doses of anodal tDCS versus sham stimulation on Pharyngeal Delay Time (PDT) , derived from videofluoroscopic swallowing studies. PDT is defined as the time in centiseconds that the bolus is present in the hypopharynx before the swallow is triggered. PDT is a temporal measure of the briskness of the swallow onset. |
| To Assess Changes in Physiological Measures of Laryngeal Excursion | Variables will be measured at baseline (before starting tDCS) and after 5 days after completion of stimulation | Examining effects of differing doses of anodal tDCS versus sham stimulation on measure of actual excursion of the larynx in centimeters from their resting point to maximal excursion, derived from videofluoroscopic swallowing studies. |
| Change in PAS Scores as an Indicator of Dysphagia Recovery After Covariate Adjustment | At day 5 of study participation | We will examine the effects of the intervention in a linear model by using it as a predictor for dysphagia recovery along with other variables of interest \[age, baseline National Institute of Health Stroke Scale and Penetration and Aspiration Scale (PAS) scores\], with a change in PAS scores from baseline to day 5 of the intervention, as being the outcome of interest. |
| To Assess and Compare Changes in Dietary Intake in Each of the Three Groups | At study onset and after 1 month | The durability of any observed effects of the intervention on dietary status will be estimated by changes in Functional Oral Intake Scale (FOIS) score. FOIS is an ordinal scale ranging from 1 (worst) to 7 (normal oral diet) and provides a reliable measure of dietary intake. The change in FOIS scores across each group will be compared. |
Countries
United States
Participant flow
Recruitment details
All subjects were recruited from the inpatient neurology/stroke service at Beth Israel Deaconess Medical Center, Boston, MA. The first subject was recruited on 2/10/2014.
Pre-assignment details
A total of 328 subjects were screened for the trial, of which 214 did not fulfill all trial criteria and 72 refused consent. A total of 42 subjects were eventually enrolled: 14 subjects in High-Dose tDCS, 13 in Low-Dose tDCS and 15 in Sham arms.
Participants by arm
| Arm | Count |
|---|---|
| High Dose Anodal tDCS High dose tDCS (2 milliamps twice daily) for 5 days will be administered concomitantly with swallowing exercises
tDCS: Anodal tDCS will be administered with swallowing exercises | 14 |
| Low Dose Anodal tDCS This arm will use a low dose of current administered via tDCS (2 milliamps once daily) for 5 days will be administered concomitantly with swallowing exercises
tDCS: Anodal tDCS will be administered with swallowing exercises | 13 |
| Sham Stimulation Twice daily swallowing exercises only
tDCS: Anodal tDCS will be administered with swallowing exercises | 15 |
| Total | 42 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 | FG002 |
|---|---|---|---|---|
| Secondary Analysis-day 30 | Death | 1 | 1 | 1 |
| Secondary Analysis-day 30 | Lost to Follow-up | 1 | 0 | 0 |
Baseline characteristics
| Characteristic | High Dose Anodal tDCS | Low Dose Anodal tDCS | Sham Stimulation | Total |
|---|---|---|---|---|
| Age, Continuous | 68 years STANDARD_DEVIATION 12.6 | 72 years STANDARD_DEVIATION 13.3 | 73 years STANDARD_DEVIATION 14.1 | 71 years STANDARD_DEVIATION 13.2 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 2 Participants | 0 Participants | 1 Participants | 3 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 12 Participants | 13 Participants | 14 Participants | 39 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Penetration and Aspiration Scale Score | 4 units on a scale STANDARD_DEVIATION 1.2 | 4.1 units on a scale STANDARD_DEVIATION 1.1 | 4 units on a scale STANDARD_DEVIATION 1.5 | 4 units on a scale STANDARD_DEVIATION 1.3 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 2 Participants | 0 Participants | 0 Participants | 2 Participants |
| Race (NIH/OMB) Black or African American | 3 Participants | 2 Participants | 0 Participants | 5 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 1 Participants | 1 Participants |
| Race (NIH/OMB) White | 9 Participants | 11 Participants | 14 Participants | 34 Participants |
| Region of Enrollment United States | 14 participants | 13 participants | 15 participants | 42 participants |
| Sex: Female, Male Female | 3 Participants | 8 Participants | 6 Participants | 17 Participants |
| Sex: Female, Male Male | 11 Participants | 5 Participants | 9 Participants | 25 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | 1 / 14 | 1 / 13 | 1 / 15 |
| other Total, other adverse events | 3 / 14 | 2 / 13 | 3 / 15 |
| serious Total, serious adverse events | 1 / 14 | 1 / 13 | 2 / 15 |
Outcome results
Primary
To Assess Changes in Penetration and Aspiration
This will be assessed using the Penetration and Aspiration Scale (PAS) scores, a validated 8 point ordinal scale that quantifies penetration and aspiration events observed during Videofluoroscopic Swallowing Evaluation. PAS ranges from 1 (best score) representing no aspiration or penetration to 8 (worst score) representing severe aspiration. An average PAS score will be computed based on 9 swallows for this outcome.
Time frame: Scores will be measured before tDCS and after 5 days after completion of stimulation
Population: Analysis of participant was based on an intention to treat principle.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Dose Anodal tDCS | To Assess Changes in Penetration and Aspiration | -0.4 score on a scale | Standard Deviation 1.2 |
| Low Dose Anodal tDCS | To Assess Changes in Penetration and Aspiration | -0.8 score on a scale | Standard Deviation 1.5 |
| Sham Stimulation | To Assess Changes in Penetration and Aspiration | -0.8 score on a scale | Standard Deviation 1.6 |
Primary
To Assess Safety of tDCS in Acute-subacute Stroke Phase: Number of Deaths in Each of the 3 Groups Attributable to the Direct Effects of Stroke
We will tabulate the number of deaths in High-dose tDCS, Low-dose tDCS and Sham stimulation groups, that are attributable to the direct effects of the qualifying stroke.
Time frame: During the 5 days of stimulation sessions
Population: Analyzed on an intention to treat as well as per protocol analysis
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| High Dose Anodal tDCS | To Assess Safety of tDCS in Acute-subacute Stroke Phase: Number of Deaths in Each of the 3 Groups Attributable to the Direct Effects of Stroke | 0 Participants |
| Low Dose Anodal tDCS | To Assess Safety of tDCS in Acute-subacute Stroke Phase: Number of Deaths in Each of the 3 Groups Attributable to the Direct Effects of Stroke | 0 Participants |
| Sham Stimulation | To Assess Safety of tDCS in Acute-subacute Stroke Phase: Number of Deaths in Each of the 3 Groups Attributable to the Direct Effects of Stroke | 0 Participants |
Primary
To Assess Safety of tDCS in Acute-subacute Stroke Phase: Number of Participants With Motor Deterioration in Each of the 3 Groups
We will tabulate the number of participants with deterioration in their motor functions in the High-dose tDCS, Low-dose tDCS and Sham groups. Motor deterioration will be defined as an increase in the motor sub-item of the National Institute of Health Stroke Scale (NIHSS) score by 2 or more points between each successive day of stimulation. The motor sub-item of the NIHSS ranges from 0 (normal) to 16 (worst possible score), with higher scores indicating a worse motor exam.
Time frame: During the 5 days of stimulation sessions
Population: Analyzed on an intention to treat as well as per protocol analysis
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| High Dose Anodal tDCS | To Assess Safety of tDCS in Acute-subacute Stroke Phase: Number of Participants With Motor Deterioration in Each of the 3 Groups | 0 Participants |
| Low Dose Anodal tDCS | To Assess Safety of tDCS in Acute-subacute Stroke Phase: Number of Participants With Motor Deterioration in Each of the 3 Groups | 0 Participants |
| Sham Stimulation | To Assess Safety of tDCS in Acute-subacute Stroke Phase: Number of Participants With Motor Deterioration in Each of the 3 Groups | 0 Participants |
Primary
To Assess Safety of tDCS in Acute-subacute Stroke Phase: Number of Participants With Neurological Deterioration in Each of the 3 Groups
We will tabulate the number of participants who develop neurological deterioration in the High-dose tDCS, Low-dose tDCS and Sham groups. Neurological deterioration will be defined as an increase in the total National Institute of Health Stroke Scale (NIHSS) Score by 4 or more points between each successive day. The NIHSS is a 15-item neurologic examination stroke scale used to evaluate the effect of acute cerebral infarction on the levels of consciousness, language, neglect, visual-field loss, extraocular movement, motor strength, ataxia, dysarthria, and sensory loss. NIHSS ranges from 0 (normal) to 42 (worst possible score). Higher scores mean worse neurological functions.
Time frame: During the 5 days of stimulation sessions
Population: Analyzed on an intention to treat as well as per protocol analysis
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| High Dose Anodal tDCS | To Assess Safety of tDCS in Acute-subacute Stroke Phase: Number of Participants With Neurological Deterioration in Each of the 3 Groups | 0 Participants |
| Low Dose Anodal tDCS | To Assess Safety of tDCS in Acute-subacute Stroke Phase: Number of Participants With Neurological Deterioration in Each of the 3 Groups | 0 Participants |
| Sham Stimulation | To Assess Safety of tDCS in Acute-subacute Stroke Phase: Number of Participants With Neurological Deterioration in Each of the 3 Groups | 0 Participants |
Primary
To Assess Safety of tDCS in Acute-subacute Stroke Phase: Number of Participants With Seizures in Each of the 3 Groups
We will tabulate the number of participants who develop seizures in the High-dose anodal tDCS, Low-dose anodal tDCS and Sham stimulation groups.
Time frame: During the 5 days of stimulation sessions
Population: Analyzed on an intention to treat as well as per protocol analysis
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| High Dose Anodal tDCS | To Assess Safety of tDCS in Acute-subacute Stroke Phase: Number of Participants With Seizures in Each of the 3 Groups | 0 Participants |
| Low Dose Anodal tDCS | To Assess Safety of tDCS in Acute-subacute Stroke Phase: Number of Participants With Seizures in Each of the 3 Groups | 0 Participants |
| Sham Stimulation | To Assess Safety of tDCS in Acute-subacute Stroke Phase: Number of Participants With Seizures in Each of the 3 Groups | 0 Participants |
Primary
To Assess Safety of tDCS in Acute-subacute Stroke Phase: Number of Participants With Swallowing Deterioration in Each of the 3 Groups
We will tabulate the number of participants with swallowing deterioration in the High-dose tDCS, Low-dose tDCS and sham groups Swallowing deterioration will be defined as an increase in the score by 2 or more points in the Functional Oral Intake Scale (FOIS). FOIS provides a validated measure of diet level. FOIS is an ordinal scale ranging from 7 (normal diet) to 0 (no oral intake), with lower scores indicating a worse diet.
Time frame: Any change between day 1 and day 3 of stimulation session
Population: Analyzed on an intention to treat as well as per protocol analysis
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| High Dose Anodal tDCS | To Assess Safety of tDCS in Acute-subacute Stroke Phase: Number of Participants With Swallowing Deterioration in Each of the 3 Groups | 0 Participants |
| Low Dose Anodal tDCS | To Assess Safety of tDCS in Acute-subacute Stroke Phase: Number of Participants With Swallowing Deterioration in Each of the 3 Groups | 0 Participants |
| Sham Stimulation | To Assess Safety of tDCS in Acute-subacute Stroke Phase: Number of Participants With Swallowing Deterioration in Each of the 3 Groups | 0 Participants |
Secondary
Change in PAS Scores as an Indicator of Dysphagia Recovery After Covariate Adjustment
We will examine the effects of the intervention in a linear model by using it as a predictor for dysphagia recovery along with other variables of interest \[age, baseline National Institute of Health Stroke Scale and Penetration and Aspiration Scale (PAS) scores\], with a change in PAS scores from baseline to day 5 of the intervention, as being the outcome of interest.
Time frame: At day 5 of study participation
| Arm | Measure | Value (MEDIAN) | Dispersion |
|---|---|---|---|
| High Dose Anodal tDCS | Change in PAS Scores as an Indicator of Dysphagia Recovery After Covariate Adjustment | -0.34 score on a scale | Standard Error 0.35 |
| Low Dose Anodal tDCS | Change in PAS Scores as an Indicator of Dysphagia Recovery After Covariate Adjustment | -0.81 score on a scale | Standard Error 0.36 |
| Sham Stimulation | Change in PAS Scores as an Indicator of Dysphagia Recovery After Covariate Adjustment | -0.96 score on a scale | Standard Error 0.33 |
Comparison: The aim for this analysis was to assess for effect modification of the trial intervention across the novel radiological variable corticobulbar tract-lesion load.p-value: 0.1162-way analysis of variance with interact
Secondary
To Assess and Compare Changes in Dietary Intake in Each of the Three Groups
The durability of any observed effects of the intervention on dietary status will be estimated by changes in Functional Oral Intake Scale (FOIS) score. FOIS is an ordinal scale ranging from 1 (worst) to 7 (normal oral diet) and provides a reliable measure of dietary intake. The change in FOIS scores across each group will be compared.
Time frame: At study onset and after 1 month
Population: Analyzed on an intention to treat analysis
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Dose Anodal tDCS | To Assess and Compare Changes in Dietary Intake in Each of the Three Groups | 2.9 score on a scale | Standard Deviation 1.2 |
| Low Dose Anodal tDCS | To Assess and Compare Changes in Dietary Intake in Each of the Three Groups | 2.5 score on a scale | Standard Deviation 1.7 |
| Sham Stimulation | To Assess and Compare Changes in Dietary Intake in Each of the Three Groups | 2.1 score on a scale | Standard Deviation 1.7 |
Secondary
To Assess Changes in Physiological Measures of Briskness of Swallow Onset
Examining effects of differing doses of anodal tDCS versus sham stimulation on Pharyngeal Delay Time (PDT) , derived from videofluoroscopic swallowing studies. PDT is defined as the time in centiseconds that the bolus is present in the hypopharynx before the swallow is triggered. PDT is a temporal measure of the briskness of the swallow onset.
Time frame: Variables will be measured at baseline (before starting tDCS) and after 5 days after completion of stimulation
Population: Analyzed on an intention to treat as well as per protocol analysis
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Dose Anodal tDCS | To Assess Changes in Physiological Measures of Briskness of Swallow Onset | 5.2 centiseconds | Standard Deviation 21.3 |
| Low Dose Anodal tDCS | To Assess Changes in Physiological Measures of Briskness of Swallow Onset | -7.3 centiseconds | Standard Deviation 43.4 |
| Sham Stimulation | To Assess Changes in Physiological Measures of Briskness of Swallow Onset | 0.83 centiseconds | Standard Deviation 20.6 |
Secondary
To Assess Changes in Physiological Measures of Laryngeal Excursion
Examining effects of differing doses of anodal tDCS versus sham stimulation on measure of actual excursion of the larynx in centimeters from their resting point to maximal excursion, derived from videofluoroscopic swallowing studies.
Time frame: Variables will be measured at baseline (before starting tDCS) and after 5 days after completion of stimulation
Population: Analyzed on an intention to treat as well as per protocol analysis
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Dose Anodal tDCS | To Assess Changes in Physiological Measures of Laryngeal Excursion | 0.07 centimeters | Standard Deviation 0.81 |
| Low Dose Anodal tDCS | To Assess Changes in Physiological Measures of Laryngeal Excursion | 0.17 centimeters | Standard Deviation 1.4 |
| Sham Stimulation | To Assess Changes in Physiological Measures of Laryngeal Excursion | 0.14 centimeters | Standard Deviation 0.67 |
Secondary
To Assess Changes in Physiological Measures of Pharyngeal Strength
Examining effects of differing doses of anodal tDCS versus sham stimulation on Pharyngeal Constriction Ratio (PCR), derived from videofluoroscopic swallowing studies.PCR is a measure of the pharyngeal area visible in the lateral radiograph view at the point when a bolus is held in the oral cavity divided by the pharyngeal area at the point of maximum pharyngeal constriction during the swallow. A higher PCR indicates a weak swallow leading to increased food residue in the pharynx.
Time frame: Variables will be measured at baseline (before starting tDCS) and after 5 days after completion of stimulation
Population: Analyzed on an intention to treat as well as per protocol analysis
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Dose Anodal tDCS | To Assess Changes in Physiological Measures of Pharyngeal Strength | -0.01 Ratio | Standard Deviation 0.09 |
| Low Dose Anodal tDCS | To Assess Changes in Physiological Measures of Pharyngeal Strength | -0.1 Ratio | Standard Deviation 0.12 |
| Sham Stimulation | To Assess Changes in Physiological Measures of Pharyngeal Strength | -0.02 Ratio | Standard Deviation 0.06 |