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Trial registered on ANZCTR


Registration number
ACTRN12616001604493p
Ethics application status
Submitted, not yet approved
Date submitted
15/11/2016
Date registered
21/11/2016
Date last updated
21/11/2016
Type of registration
Prospectively registered

Titles & IDs
Public title
The effects of non-invasive brain stimulation of the tongue muscle cortical representation on tobacco addiction.
Scientific title
The effect of non-invasive brain stimulation of the tongue muscle cortical representation on tobacco addiction in chronic smokers (CS) under nicotine withdrawal.
Secondary ID [1] 290540 0
None
Universal Trial Number (UTN)
None
Trial acronym
BSTAT (Brain stimulation Tobacco Addiction Trial)
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Tobacco Addiction 300968 0
Condition category
Condition code
Mental Health 300770 300770 0 0
Addiction

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Material
Transcranial direct current stimulation
In this project we propose to modulate the excitability of the cortical representation of the tongue muscle through a non-invasive brain stimulation method, namely transcranial direct current stimulation (tDCS), to explore effects on reward-related behaviours. tDCS is an established investigative tool in the cognitive neurosciences and psychiatry permitting safe and non-invasive stimulation of the subjacent cortex. tDCS modulates cortical excitability using small direct electrical currents (1 ~ 2 mA) passed through the brain (e.g., Nitsche & Paulus, 2000, J Physiol) via two electrodes with opposite polarities (i.e., anodal and cathodal) placed on the scalp. Anodal (A) stimulation increases cortical excitability, whereas cathodal (C) stimulation decreases it (Stagg and Nitsche, 2011, Neuroscientist). These effects can last for up to 90 min after a single stimulation session of 13 ~ 20 min (Nitsche and Paulus, 2001, Neurology), and can be further extended by repeated stimulation (i.e., cumulative effects) (Monte-Silva et al. 2013). In the present projects, a direct current of 2 mA intensity will be delivered for 20 minutes per session by a battery-driven, constant-current stimulator through two saline-soaked surface sponge electrodes. Previous studies have shown that this intensity of stimulation is safe in healthy volunteers (Nitsche et al., 2003, Clin Neurophysiol).

Procedures
Participants
15 participants will be recruited from the University of Tasmania. All participants will be assigned, in separate sessions to one of three stimulation conditions: Cathodal, Anodal, Sham. The stimulation order will be counterbalanced across participants.



Measures
During a baseline session, carbonmonoxide (CO) in expired air will be taken as an objective measure of recent smoking, and a level > 15 ppm will be considered as consistent with recent smoking, and will serve as further exclusion criterion. Before and after the tDCS session participants will be submitted to a craving assessment, including the completion of the Fagerstrom Test for Nicotine Dependence, Urge to Smoke (UTS) Scale and a self-report rating via Visual Analogue Scale (VAS). Moreover, they will be submitted to the Profile of Mood States (POMS), questionnaires for smoking history and demographic information. To induce craving, participants will be also asked to watch 25 pictures of smoking cue immediately before each craving assessment session. As further measure for tobacco consumption, participants will be tested for urinary cotinine concentrations.

Who will deliver the intervention?
The intervention will be delivered by Dr. Carmelo Vicario. Carmelo is Research Fellow at the University of Tasmania. He has extensive research experience (i.e., 12 years) in the field of Cognitive, Clinical and Social neuroscience. He has a PhD in Neuroplasticity and rehabilitation of Cognitive functions and in the use of non-invasive brain stimulation methods. In the last 4 years Dr. Vicario has conducted a successful research programs for the study of tobacco addiction and reward system in healthy humans through the use of a non-invasive brain stimulation method such as the Transcranial magnetic stimulation. In particular, he has studied the contribution of the Tongue motor cortex neurons in detecting changes in the activity of reward system. These results suggest that this pool of motor neurons is sensitive to changes in the activity of reward system. The results of this research program have been published in important scientific journals (i.e., The Journal of psychiatry and Neuroscience) and represent the key platform for the proposed trial, which intend to test the effects of non-invasive stimulation of the cortical representation of the tongue muscle on tobacco addiction.

The mode of delivery
All participants will be tested under nicotine abstinence. A direct current will be delivered by a battery-driven, constant-current stimulator (Neuroconn) through two saline-soaked surface sponge electrodes. Each participant will be tested in two sessions, at least 48h apart. They will be stimulated at a different types of stimulation in each session with the order of stimulation counterbalanced across sessions. The MTA [(a scalp region located 1.5 cm posteriorly to the area 44, as suggested by Uozumi et al. (2004) Neurology] will be identified via EEG 10-20 International system; The tDCS will be applied over the target scalp regions for 20 minutes. The return electrode will be placed over the left shoulder. We will compare the participants’ craving symptoms before and immediately after each single session of tDCS. Participants will be asked to smoke their last cigarette at least 10 hours before the experimental session. Each session will consist of the following steps: i) we will collect (daily) urine sample to quantify the urinary cotinine concentrations which would provide a more reliable measure of the tobacco consumption in the 48 hours following each tDCS session; ii) we will confirm that the participant has not smoked for at least 10 hours by measuring breath carbon monoxide (Micro Smokerlyzer); iii) exposure to smoking cues; iv) Questionnaires for smoking history and demographic information will be completed to quantify subjective craving and other related parameters; v) tDCS session; vi) The previous questionnaire will be repeated.

The location where the intervention occurs:
University of Tasmania, Division of Psychology, School of Medicine, Psychology research center, Sandy Bay, Hobart, 7005, TAS.
Intervention code [1] 296400 0
Treatment: Devices
Comparator / control treatment
As control condition participants will receive sham stimulation. A brief initial stimulation to produce a tingling sensation followed by decreasing the administration to zero. The duration of this stimulation will be 30 seconds.
Control group
Placebo

Outcomes
Primary outcome [1] 300194 0
Tobacco desire, assessed using a 100 mm visual analogue scale (VAS).
Timepoint [1] 300194 0
Comparing the smoking desire rating in the baseline condition (i.e., pre-intervention session) with the smoking desire rating immediately after having received tDCS/sham treatment (i.e., post intervention session).
Primary outcome [2] 300229 0
Tobacco desire, assessed using the Questionnaire on Smoking Urges (QSU-Brief; for reference see Cox et al.,, 2001, Nicotine and Tobacco Research).
Timepoint [2] 300229 0
Comparing the smoking desire rating in the baseline condition (i.e., pre-intervention session) with the smoking desire rating immediately after having received tDCS/sham treatment (i.e., post intervention session).
Primary outcome [3] 300230 0
Tobacco desire, assessed using the Factor structure of Tobacco Craving Questionnaire–Short Form (Reference: Heishman et al., 2008, Nicotine Tob Research).
Timepoint [3] 300230 0
Comparing the smoking desire rating in the baseline condition (i.e., pre-intervention session) with the smoking desire rating immediately after having received tDCS/sham treatment (i.e., post intervention session).
Secondary outcome [1] 329434 0
Using Fagerstrom Test for Nicotine Dependence (Heatherton et al., 1991, Br J Addict) to assess the intensity of physical addiction to nicotine.
Timepoint [1] 329434 0
Collecting the Fagerstrom Test for Nicotine Dependence in the baseline condition (i.e., pre-intervention section).

Eligibility
Key inclusion criteria
Participants must be aged between 18-45 yrs. The inclusion criteria are good general health, more than 10 cigarettes per day for at least 2 years, no current illicit drug use at all sessions. All participants will be tested under nicotine abstinence. In particular, they will be asked to smoke their last cigarette 10 hours before the experimental session, as in previous works (i.e. Grundey et al., 2012). Written informed consent.
Minimum age
18 Years
Maximum age
45 Years
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Presence of any current psychiatric conditions or psychiatric history; Pregnancy or breastfeeding (to avoid hormonal confounds); Severe medical condition; History of brain injury or blow to the head that resulted in loss of consciousness minutes, or neurological condition. Subjects who have a severe impediment in vision or hearing. Self-report of learning disability or dyslexia, current use of psychotropic drugs, or self-report of TB or HIV positive. Subjects who in the opinion of the investigators are unable or unlikely to comprehend and follow the study procedures. Any form of metal implant and pacemaker.

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s


The people analysing the results/data
Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
A repeated measures ANOVA will include, as a within subject factor, the stimulation conditions (i.e., Cathodal, Anodal and Sham stimulations) and the tDCS session (before and after tDCS).

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
TAS

Funding & Sponsors
Funding source category [1] 294969 0
University
Name [1] 294969 0
The University of Tasmania
Country [1] 294969 0
Australia
Primary sponsor type
University
Name
The University of Tasmania
Address
Sandy Bay, Churchill Ave, Hobart TAS 7005
Country
Australia
Secondary sponsor category [1] 293789 0
None
Name [1] 293789 0
Address [1] 293789 0
Country [1] 293789 0

Ethics approval
Ethics application status
Submitted, not yet approved
Ethics committee name [1] 296329 0
Health and Medical Ethics
Ethics committee address [1] 296329 0
Office of Research Services
University of Tasmania
Private Bag 01
Hobart TAS 7001
Ethics committee country [1] 296329 0
Australia
Date submitted for ethics approval [1] 296329 0
15/11/2016
Approval date [1] 296329 0
Ethics approval number [1] 296329 0

Summary
Brief summary
The goal of the proposed research is testing the hypothesis that the non-invasive electrical stimulation of the tongue muscle cortical neurons may reduce the desire for nicotine addiction. This hypothesis has been suggested according to a recent evidence (Vicario et al., 2014, The Journal of Psychiatry and Neuroscience) documenting altered electrical activity of this neurons in chronic smokers during tobacco abstinence. Thus, we propose to test the impact of a single session non-invasive electrical stimulation of the tongue muscle cortical representation in one group of chronic smokers (CS) under nicotine withdrawal. This research goal will be pursued by using medical device named transcranial direct current stimulation (Tdcs).
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 70470 0
Dr Carmelo M Vicario
Address 70470 0
Room 124C, Psychology research Center, University of Tasmania, Sandy Bay Campus, Hobart, TAS 7005
Country 70470 0
Australia
Phone 70470 0
+61 3 6226 6396
Fax 70470 0
Email 70470 0
Contact person for public queries
Name 70471 0
Dr Carmelo M Vicario
Address 70471 0
Room 124C, Psychology research Center, University of Tasmania, Sandy Bay Campus, Hobart, TAS 7005
Country 70471 0
Australia
Phone 70471 0
+61 3 6226 6396
Fax 70471 0
Email 70471 0
Contact person for scientific queries
Name 70472 0
Dr Carmelo M Vicario
Address 70472 0
Room 124C, Psychology research Center, University of Tasmania, Sandy Bay Campus, Hobart, TAS 7005
Country 70472 0
Australia
Phone 70472 0
+61 3 6226 6396
Fax 70472 0
Email 70472 0

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No Supporting Document Provided



Results publications and other study-related documents

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