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Trial registered on ANZCTR


Registration number
ACTRN12614000652673
Ethics application status
Approved
Date submitted
15/06/2014
Date registered
20/06/2014
Date last updated
24/07/2018
Type of registration
Prospectively registered

Titles & IDs
Public title
Investigating the effects of conventional and high-definition transcranial direct current stimulation (tDCS) on working memory and neuroplasticity in healthy volunteers
Scientific title
Enhancing neuroplasticity in the dorsolateral prefrontal cortex using non-invasive brain stimulation: Investigating the effects of conventional and high-definition transcranial direct current stimulation (tDCS) on working memory and neuroplasticity in healthy volunteers
Secondary ID [1] 284536 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Neuroplasticity in healthy volunteers 291800 0
Condition category
Condition code
Mental Health 292161 292161 0 0
Studies of normal psychology, cognitive function and behaviour
Neurological 292561 292561 0 0
Studies of the normal brain and nervous system

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Transcranial direct current stimulation (tDCS) provides a non-invasive means of altering the excitability of cortical neurons, through the application of a weak electric current applied to the scalp.

This study employs a randomised, crossover design where participants take part in three separate treatment sessions at least 72 hours apart. Each session involves administration of either active tDCS (either conventional or 'high-definition' tDCS [HD-tDCS]), or sham tDCS. Conventional tDCS involves the use of sponge electrodes placed in a bipolar array (anode over left prefrontal cortex, cathode over contralateral supraorbital area); HD-tDCS uses five smaller electrodes placed over the left prefrontal cortex in a 4x1 ring configuration in which a central anodal electrode is surrounded by four cathodes.

Specifically, participants will receive:

a) Anodal conventional tDCS (2 mA, 20 minutes)
b) Anodal HD-tDCS (2 mA, 20 minutes)
c) Sham tDCS (20 minutes)
Intervention code [1] 289299 0
Treatment: Devices
Comparator / control treatment
The comparator treatment is: Sham tDCS (20 minutes). In the sham treatment, tDCS stimulation is ramped-up to 2 mA, held at this intensity for several seconds, then ramped down to 0 mA. This technique generates a tingling sensation on the scalp akin to active tDCS, but does not produce any tangible changes in cortical excitability.
Control group
Placebo

Outcomes
Primary outcome [1] 292040 0
N-back task accuracy and reaction time
Timepoint [1] 292040 0
Two separate time-points for each session:
a) directly after tDCS treatment
b) 30 minutes after tDCS treatment
Primary outcome [2] 292041 0
TMS-EEG evoked potential amplitudes
Timepoint [2] 292041 0
a) Immediately after tDCS treatment
b) 30 minutes following tDCS treatment
Secondary outcome [1] 308061 0
EEG oscillations (theta ERS and alpha ERD)
Timepoint [1] 308061 0
Two timepoints for each session. EEG oscilations recorded during n-back task:

a) Immediately after tDCS treatment
b) 30 minutes following tDCS treatment

Eligibility
Key inclusion criteria
1) Right-handed adults who have the capacity to provide informed consent.
2) Have no personal history of psychiatric or neurological illness.
Minimum age
18 Years
Maximum age
60 Years
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
1) Anyone suffering from an unstable medical condition, neurological or psychiatric disorder or any history of a seizure disorder or who are currently pregnant or breastfeeding.

2) Anyone with any metallic implants in the head, a pacemaker, cochlear implant medication pump or other electronic device.

3) Anyone currently taking any psychoactive medications.

4) Professional drivers are not able to participate due to the, albeit relatively low, risk of seizure as this could affect their employment.

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


Intervention assignment
Crossover
Other design features
Participants will receive both active and sham stimulation in a cross-over design employing a 72 hour wash out period.
Phase
Type of endpoint/s
Efficacy
Statistical methods / analysis
As there is limited data on which to base meaningful power analyses we will aim to recruit 30 participants. However, we will conduct interim analyses at N=20.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
23/06/2014
Actual
16/10/2014
Date of last participant enrolment
Anticipated
Actual
21/04/2015
Date of last data collection
Anticipated
Actual
21/04/2015
Sample size
Target
30
Accrual to date
Final
20
Recruitment in Australia
Recruitment state(s)
VIC

Funding & Sponsors
Funding source category [1] 289168 0
University
Name [1] 289168 0
Monash University
Country [1] 289168 0
Australia
Primary sponsor type
University
Name
Monash Univeristy
Address
Wellington Road,
Clayton, VIC 3168
Country
Australia
Secondary sponsor category [1] 287837 0
None
Name [1] 287837 0
Address [1] 287837 0
Country [1] 287837 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 290943 0
Alfred Health Human Ethics Commiittee
Ethics committee address [1] 290943 0
Alfred Hospital
Commercial Rd
Prahran
3181 VIC
Ethics committee country [1] 290943 0
Australia
Date submitted for ethics approval [1] 290943 0
07/05/2014
Approval date [1] 290943 0
24/06/2014
Ethics approval number [1] 290943 0
193/14

Summary
Brief summary
There is growing scientific evidence of the clinical efficacy of transcranial direct current stimulation (tDCS) in treating a number of neurological and psychiatric conditions. Although the exact mechanism of action underlying tDCS remains to be fully elucidated, its ability to promote lasting neuroplastic changes within the brain appears central to its therapeutic effects. tDCS involves the application of a very weak electrical current to the scalp, which acts to modulate the excitability of underlying cortical neurons, thereby altering their function. Importantly, tDCS is both safe and painless, and can induce changes in brain function which are measurable up to an hour after the cessation of stimulation. In order for tDCS to be optimally utilised, however, research which directly compares the different stimulation methods available is greatly needed.

This project specifically aims to compare two methods of administering tDCS to a region of the brain known as the dorsolateral prefrontal cortex, an important area for cognitive processing. The first is a conventional method, which applies the stimulus to the head using two large sponge electrodes, while the second method, which has been more recently developed, is referred to as high definition tDCS (HD-tDCS) and uses several smaller electrodes to deliver the stimulation to a more confined region of the brain. It is currently unclear which of these two methods of stimulation is the most efficacious. Therefore, the aim of this study is to directly compare, using both behavioural and neurophysiological outcome measures, the effect that each of these stimulation methods has on brain neuroplasticity.
Trial website
Trial related presentations / publications
Hill, A. T., Rogasch, N. C., Fitzgerald, P. B., & Hoy, K. E. (2017). Effects of prefrontal bipolar and high-definition transcranial direct current stimulation on cortical reactivity and working memory in healthy adults. Neuroimage, 152, 142-157. doi:10.1016/j.neuroimage.2017.03.001
Public notes

Contacts
Principal investigator
Name 48094 0
Mr Aron Hill
Address 48094 0
Monash Alfred Psychiatry Research Centre, Level 4, 607 St Kilda Rd Melbourne, VIC 3004
Country 48094 0
Australia
Phone 48094 0
+61 (0)3 9076 6564
Fax 48094 0
Email 48094 0
[email protected]
Contact person for public queries
Name 48095 0
Aron Hill
Address 48095 0
Monash Alfred Psychiatry Research Centre, Level 4, 607 St Kilda Rd Melbourne, VIC 3004
Country 48095 0
Australia
Phone 48095 0
+61 (0)3 9076 6564
Fax 48095 0
Email 48095 0
[email protected]
Contact person for scientific queries
Name 48096 0
Aron Hill
Address 48096 0
Monash Alfred Psychiatry Research Centre, Level 4, 607 St Kilda Rd Melbourne, VIC 3004
Country 48096 0
Australia
Phone 48096 0
+61 (0)3 9076 6564
Fax 48096 0
Email 48096 0
[email protected]

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No Supporting Document Provided



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