Transcranial direct current stimulation reduces food-craving and measures of hyperphagia behavior in participants with Prader-Willi syndrome

Abstract

Prader-Willi syndrome (PWS) is a neurodevelopmental genetic disorder characterized by intellectual disabilities and insatiable appetite with compulsive eating leading to severe obesity with detrimental health consequences. Transcranial direct current stimulation (tDCS) has been shown to modulate decision-making and cue-induced food craving in healthy adults. We conducted a pilot double blind, sham-controlled, multicenter study of tDCS modulation of food drive and craving in 10 adult PWS participants, 11 adult obese (OB) and 11 adult healthy-weight control (HWC) subjects. PWS and OB subjects received five consecutive daily sessions of active or sham tDCS over the right dorsolateral prefrontal cortex (DLPFC), while HWC received a single sham and active tDCS in a crossover design. Standardized psychometric instruments assessed food craving, drive and hyperphagia by self-report and caregiver assessment over 30 days. Robust baseline differences were observed in severity scores for the Three-Factor Eating Questionnaire (TFEQ) and Dykens Hyperphagia Questionnaire (DHQ) for PWS compared to HWC while obese participants were more similar to HWC. Active tDCS stimulation in PWS was associated with a significant change from baseline in TFEQ Disinhibition (Factor II) (Ƶ = 1.9, P < 0.05, 30 days) and Total Scores (Ƶ = 2.3, P < 0.02, 30 days), and participant ratings of the DHQ Severity (Ƶ = 1.8, P < 0.06, 5 days) and Total Scores (Ƶ = 1.9, P < 0.05, 15 days). These findings support sustained neuromodulatory effects and efficacy of tDCS to reduce food drive and behaviors impacting hyperphagia in PWS. Transcranial direct current stimulation may represent a straight-forward, low risk and low cost method to improve care, management and quality of life in PWS.

Keywords: Prader-Willi syndrome; hyperphagia; obesity; transcranial direct current stimulation.

© 2015 Wiley Periodicals, Inc.

Figures

FIG. 1.

Three Factor Eating Questionnaire Total Scores for participants with Prader–Willi syndrome after five days of transcranial direct current stimulation. Significant difference between active and sham treatment arms, Mann–Whitney U, P < 0.05. [Color figure can be seen in the online version of this article, available at http://wileyonlinelibrary.com/journal/ajmgb].

FIG. 2.

(a) Change in Three Factor Eating Questionnaire Total Score in participants with Prader–Willi syndrome after 30 days of transcranial direct current stimulation. Sample medians are indicated by black diamonds and means are indicated by the horizontal lines. Vertical lines show the maximum and minimum values. Active N = 7, Sham N = 3. Significant difference by Mann–Whitney U, P<0.05. (b) Change in Three Factor Eating Questionnaire Disinhibition (Factor II) Score in participants with Prader–Willi syndrome after 30 days of transcranial direct current stimulation. Sample medians are indicated by black diamonds and means are indicated by the horizontal lines. Vertical lines show the maximum and minimum values. Active N = 7, Sham N = 3. Significant difference by Mann–Whitney U, P<0.05. [Color figure can be seen in the online version of this article, available at http://wileyonlinelibrary.com/journal/ajmgb].

FIG. 3.

Dykens Hyperphagia Questionnaire Severity Scores for participants with Prader–Willi syndrome after 5 days of transcranial direct current stimulation. *Significant difference between active and sham treatment arms, Mann–Whitney U, P < 0.05. [Color figure can be seen in the online version of this article, available at http://wileyonlinelibrary.com/journal/ajmgb].

FIG. 4.

(a) Change from baseline Dykens Hyperphagia Questionnaire Severity Scores in participants with Prader–Willi syndrome after transcranial direct current stimulation. Sample medians are indicated by black diamonds and means are indicated by the horizontal lines. Vertical lines show the maximum and minimum values. Active N = 7, Sham N = 3. (b) Change from baseline Dykens Hyperphagia Questionnaire Total Score in participants with Prader–Willi syndrome after transcranial direct current stimulation. Sample medians are indicated by black diamonds and means are indicated by the horizontal lines. Vertical lines show the maximum and minimum values. Active N = 7, Sham N = 3. *Significant difference by Mann–Whitney U, P<0.05. [Color figure can be seen in the online version of this article, available at http://wileyonlinelibrary.com/journal/ajmgb].

FIG. 5.

Numerical Food Craving Rating for participants with Prader–Willi syndrome after 5 days of transcranial direct current stimmulation. One PWS participant with very low reported scores was excluded from the active study arm as an outlier. *Significant difference between active and sham treatment arms, Mann–Whitney U, P < 0.05. [Color figure can be seen in the online version of this article, available at http://wileyonlinelibrary.com/journal/ajmgb].