Trial Outcomes & Findings for Pilot Study of Startle-response Test to Assess Transcranial Direct Current Stimulation-induced Modulation of Hyperphagia in Prader-Willi Syndrome (NCT NCT01863017)

Results Overview

Muscle contractions generated by the orbicularis oculi were recorded by a BIOPAC systems bioamplifier (model EMG 100c) passing 10-500 Hz signals, sampling at a rate of 2000/second and amplified by a factor of 5000. Eyeblink startle-responses were measured in response to food and non-food images at two lead-intervals (2500 ms and 6000 ms) to assess emotional responses (e.g., early and late, respectively) for each picture stimulus. Startle responses were assessed during (e.g., while viewing the food, puppy, etc.) and between (e.g., during washout periods; no-images) visual image-processing. Omnibus amplitudes are presented for sham vs active treatment groups for all participants, individuals with obesity and Prader Willi syndrome relative to lean controls.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

31 participants

Primary outcome timeframe

Amplitude of Eyeblink Startle at Day 30 relative to normal weight controls

Results posted on

2019-04-26

Participant Flow

Participant milestones

Participant milestones
Measure	Sham tDCS Five consecutive sessions of no transcranial direct current stimulation (tDCS). Each session will last approximately 30 minutes. Current will be applied for 20 minutes. Less than 3 minutes of tDCS has been shown to induce no lasting effects. Normal weight control participants will receive one sham session and one active session. tDCS	Active tDCS Five consecutive sessions of tDCS administered. Each session will take about 30 minutes. Normal weight control participants will receive one sham session and one active session. tDCS
Overall Study STARTED	12	19
Overall Study Normal Weight Participants	5	5
Overall Study Obese Participants	4	7
Overall Study Participants With PWS	3	7
Overall Study COMPLETED	12	19
Overall Study NOT COMPLETED	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Race and Ethnicity were not collected from any participant.

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Sham tDCS n=12 Participants Five consecutive sessions of no tDCS. Each session will last approximately 30 minutes. Current will be applied for 20 minutes. Less than 3 minutes of tDCS has been shown to induce no lasting effects. Normal weight control participants will receive one sham session and one active session. tDCS	Active tDCS n=19 Participants Five consecutive sessions of tDCS administered. Each session will take about 30 minutes. Normal weight control participants will receive one sham session and one active session. tDCS	Total n=31 Participants Total of all reporting groups
Age, Categorical <=18 years	0 Participants n=12 Participants	0 Participants n=19 Participants	0 Participants n=31 Participants
Age, Categorical Between 18 and 65 years	12 Participants n=12 Participants	19 Participants n=19 Participants	31 Participants n=31 Participants
Age, Categorical >=65 years	0 Participants n=12 Participants	0 Participants n=19 Participants	0 Participants n=31 Participants
Age, Continuous all patients	33.2 years STANDARD_DEVIATION 13.7 • n=12 Participants	39.3 years STANDARD_DEVIATION 13.6 • n=19 Participants	35.8 years STANDARD_DEVIATION 13.7 • n=31 Participants
Sex: Female, Male Female	7 Participants n=12 Participants	7 Participants n=19 Participants	14 Participants n=31 Participants
Sex: Female, Male Male	5 Participants n=12 Participants	12 Participants n=19 Participants	17 Participants n=31 Participants
Race and Ethnicity Not Collected	—	—	0 Participants Race and Ethnicity were not collected from any participant.
Region of Enrollment United States	12 Participants n=12 Participants	19 Participants n=19 Participants	31 Participants n=31 Participants

PRIMARY outcome

Timeframe: Amplitude of Eyeblink Startle at Day 30 relative to normal weight controls

Population: All participants

Muscle contractions generated by the orbicularis oculi were recorded by a BIOPAC systems bioamplifier (model EMG 100c) passing 10-500 Hz signals, sampling at a rate of 2000/second and amplified by a factor of 5000. Eyeblink startle-responses were measured in response to food and non-food images at two lead-intervals (2500 ms and 6000 ms) to assess emotional responses (e.g., early and late, respectively) for each picture stimulus. Startle responses were assessed during (e.g., while viewing the food, puppy, etc.) and between (e.g., during washout periods; no-images) visual image-processing. Omnibus amplitudes are presented for sham vs active treatment groups for all participants, individuals with obesity and Prader Willi syndrome relative to lean controls.

Outcome measures

Outcome measures
Measure	Sham tDCS n=12 Participants Five consecutive sessions of no tDCS. Each session will last approximately 30 minutes. Current will be applied for 20 minutes. Less than 3 minutes of tDCS has been shown to induce no lasting effects. Normal weight control participants will receive one sham session and one active session. tDCS	Active tDCS n=19 Participants Five consecutive sessions of tDCS administered. Each session will take about 30 minutes. Normal weight control participants will receive one sham session and one active session. tDCS
Amplitude of Eyeblink Startle Responses All Participants	0.006 microvolts Standard Error 0.001	0.001 microvolts Standard Error 0.001
Amplitude of Eyeblink Startle Responses Obese Participants	0.008 microvolts Standard Error 0.002	0.001 microvolts Standard Error 0.001
Amplitude of Eyeblink Startle Responses Participants with PWS	0.004 microvolts Standard Error 0.002	0.001 microvolts Standard Error 0.001

PRIMARY outcome

Timeframe: Total Score Day 30

Population: all participants

The Dykens Hyperphagia Questionnaire is a 13-item instrument that was specifically designed to measure food-related preoccupations and problems, as well as the severity of these concerns. Items on the questionnaire are rated on a five-point scale (1: not a problem to 5: severe and/or frequent problem). Possible scores on the questionnaire range from a minimum score of 0 to a maximum score of 65. Higher scores indicate greater hyperphagia.

Outcome measures

Outcome measures
Measure	Sham tDCS n=12 Participants Five consecutive sessions of no tDCS. Each session will last approximately 30 minutes. Current will be applied for 20 minutes. Less than 3 minutes of tDCS has been shown to induce no lasting effects. Normal weight control participants will receive one sham session and one active session. tDCS	Active tDCS n=19 Participants Five consecutive sessions of tDCS administered. Each session will take about 30 minutes. Normal weight control participants will receive one sham session and one active session. tDCS
Dykens Hyperphagia Questionnaire Normal Weight Participants	19.8 score on a scale Standard Deviation 4.0	22.1 score on a scale Standard Deviation 6.7
Dykens Hyperphagia Questionnaire Obese Participants	15.3 score on a scale Standard Deviation 5.1	24.8 score on a scale Standard Deviation 5.1
Dykens Hyperphagia Questionnaire Participants with PWS	28.3 score on a scale Standard Deviation 6.1	25.3 score on a scale Standard Deviation 6.0

SECONDARY outcome

Timeframe: Total Scores at Day 30

Population: All participants

The Three-Factor Eating Questionnaire is a self-completed, 51-item questionnaire that measures both cognitive and behavioral aspects of eating (dietary restraint, disinhibition, and hunger), and comprises two parts. Part 1 includes 36 true/false questions, and part 2 includes 14 questions on a four point Likert scale (1= rarely, 2 = sometimes, 3 = usually, 4 = always) and 1 question on a five point Likert scale (1 = eat whatever you want, whenever you want it to 5 = constantly limiting food intake, never 'giving in'; other questions). Higher scores indicate more severe pathology.

Outcome measures

Outcome measures
Measure	Sham tDCS n=12 Participants Five consecutive sessions of no tDCS. Each session will last approximately 30 minutes. Current will be applied for 20 minutes. Less than 3 minutes of tDCS has been shown to induce no lasting effects. Normal weight control participants will receive one sham session and one active session. tDCS	Active tDCS n=19 Participants Five consecutive sessions of tDCS administered. Each session will take about 30 minutes. Normal weight control participants will receive one sham session and one active session. tDCS
Three-Factor Eating Questionnaire Normal Weight Participants	19.82 score on a scale Standard Deviation 9.1	20.5 score on a scale Standard Deviation 10.3
Three-Factor Eating Questionnaire Obese Participants	16.3 score on a scale Standard Deviation 8.0	25.1 score on a scale Standard Deviation 10.7
Three-Factor Eating Questionnaire Participants with PWS	32.7 score on a scale Standard Deviation 5.9	27.8 score on a scale Standard Deviation 5.0

Adverse Events

Sham tDCS

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Active tDCS

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Merlin G Butler

University of Kansas Medical Center

Phone: 9135881800

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place