Impact of Galvanic Vestibular Stimulation on Anxiety Level in Young Adults
Authors: Pierre Denise
Gaëlle Quarck
Nicolas Bessot
Florane Pasquier
Antoine Gauthier
Journal: Frontiers in Systems Neuroscience (2019)
Discipline: CLINICAL MEDICINE
Keywords: anxiety; direct current (DC); galvanic vestibular stimulation; motion sickness; vestibular system.
Affiliations: Normandie Université, Unicaen, Inserm, Comete, GIP Cyceron, Caen, France.

Abstract:  Galvanic vestibular stimulation (GVS) is a non-invasive method used to stimulate the vestibular system. The vestibular system includes the sensors, neural pathways, vestibular nuclei and the cortical areas receiving integrated vestibular inputs. In addition to its role in postural control or gaze stabilization, the vestibular system is involved in some cognitive functions and in emotion processing. Several studies have revealed a modulating effect of vestibular stimulation on mood state, emotional control, and anxiety level. Nevertheless, GVS is known to induce motion sickness symptoms such as nausea. The aim of the present study was to evaluate the tolerability and efficacy of a GVS protocol to be used potentially as a treatment for anxiety, and also to test the impact of stimulation parameters (duration) on anxiety. Twenty-two students underwent three stimulation conditions: (1) a sham session (no stimulation); (2) a single-duration session (38 min of GVS); and (3) a double-duration session (76 min of GVS). Before and after each stimulation, participants completed a Graybiel Scale form for motion sickness symptoms evaluation and a visual analog scale form for anxiety. We observed a significant diminution of anxiety level after a 38-min session of GVS, while a low level of motion sickness was only found following a 76-min session of GVS. Our preliminary study confirms the feasibility of using GVS to modulate anxiety and corroborates the involvement of the vestibular system in the emotional process. 

Retracted: No

PubPeer comments:
 The study is described as a prospective research in humans, performed in France: * Taking account of this limitation, the primary objective was to demonstrate the tolerability of our experimental protocol almost similar to the stimulation parameters (intensity, duration) used in tDCS treatment (Utz et al., 2010). The second objective was to test the impact of GVS on anxiety. Considering that stimulation parameters (duration, intensity, electrode placements) contribute to the variability of the therapeutic effects of tDCS (Utz et al., 2010; Bennabi and Haffen, 2018), the third objective was to test whether the impact of GVS on anxiety was duration dependent. * The study has been performed on healthy volunteers and medical parameters were collected and an electric stimulation is done (GVS). It is definitely a prospective research in human (RIPH) According to the [SmartReg tool of GIRCI] helping to define the level of the research in France, this research is at least a RIPH Level 3. RIPH3 requires the approval from a CPP before to start the recruitment of participants. Starting a prospective research in humans in France without a CPP is a serious breach to the Health French Law. The ethic statement of this study is described as follows:  This study was carried out in accordance with the recommendations of CERSTAPS 2019-18-09-37 with written informed consent from all subjects. All subjects gave written informed consent in accordance with the Declaration of Helsinki. The protocol was approved by the CERSTAPS.  The CERSTAPS is not a Comitu00e9 de Protection des Personnes (CPP). As mentioned on the [CERSTAPS website] itself, a prospective research in humans in France MUST obtain an approval from a CPP before to start. The ethics statement do not provide any information related to a CPP approval. Can the authors clarify: - If they obtain a CPP approval before to start the recruitment? - If they request a CPP approval? In this case, what was the answer of the CPP ? If a CPP provide a waiver for the approval, the article should mention it and detail the waiver in order to raise any question on ethics procedure. However, if the CPP approval or a waiver from a CPP has not been obtained, this is a major infringement to the Health French Law and the Declaration of Helsinki (article 23). , 
 The article has been received the 14 December 2018. It means the participants of the prospective study in human were recruited before the 14 December 2018. But the ethics approval from CERSTAPS has a number in 2019 (CERSTAPS #2019-18-09-37). It means the ethics approval is possibly retrospective which is not compliant with the Helsinki Declaration and the editor policies that requires, for a prospective study, an ethics approval prior to the first recruitment of the participants. In addition to comment #1, can the authors explain: - when the first participant was recruited? - when the ethics approval was obtained? If the ethics approval is retrospective, can the Editor explain why they peer-reviewed a prospective study with a retrospective ethics approval, which is not compliant with the Editor policy? ,