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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Date data sharing statement initially provided
Date results information initially provided
Type of registration
Prospectively registered

Titles & IDs
Public title
The impact of non-invasive brain stimulation on motor cortex excitability and cognition in chronic lower back pain
Scientific title
In individuals with chronic lower back pain, does anodal transcranial direct current stimulation, compared to sham transcranial direct current stimulation, impact on motor cortex excitability and cognition?
Secondary ID [1] 285872 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Chronic Lower Back Pain 293783 0
Condition category
Condition code
Mental Health 294091 294091 0 0
Studies of normal psychology, cognitive function and behaviour
Neurological 294092 294092 0 0
Studies of the normal brain and nervous system
Musculoskeletal 294297 294297 0 0
Other muscular and skeletal disorders

Study type
Description of intervention(s) / exposure
Transcranial Direct Current Stimulation
20 minutes, 2x week, for 4 weeks
Anodal-tDCS sessions will be delivered by a constant current stimulator (Empi) and involve 20 minutes of constant current 2mA stimulation (equivalent to 0.08 Ma/CM2) over their left dorsal lateral prefrontal cortex, the anode electrode will be placed over F3 according to the 10-20 international system for EEG electrode placement.

The intervention will be administered by PhD (psychology) student Emily Corti, under the supervision of Dr Andrea Loftus. Miss Corti has been trained in the administration and safety procedures regarding the use of tDCS. Dr Loftus has an extensive background in the use of tDCS and is the director of the Curtin University Neuroscience Laboratory.
Intervention code [1] 290853 0
Treatment: Devices
Comparator / control treatment
Sham tDCS provided to control participants

The tDCS machine can be switched to 'sham' condition, where the tDCS will 'ramp up' for the first 30 seconds of the stimulation time. After the 30 seconds the sham participants will experience no stimulation for 20 minutes. At the end of the 20 minutes the participants will again experience some sensation as the tDCS ramps down. This is to ensure participants are unaware they have been placed in the control group. (The control group can be wait-listed at the end of the study if they wish).
The electrodes are placed in the same position as for the anodal stimulation. The tDCS machine is just switched to 'sham'.
Control group

Primary outcome [1] 293885 0
Motor Cortex Excitability (Short intracortical inhibition, intracortical facilitation, and MEP amplitude) as measured using Transcranial Magnetic Stimulation
Timepoint [1] 293885 0
Baseline and after 4 weeks of tDCS intervention
Primary outcome [2] 293886 0
cognitive functioning (executive functioning, working memory/attention, attention, visuospatial and language) measured using 2 tasks for each of the five cognitive domains.
(1) Attention and Working Memory domain: The Letter-Number Sequencing subtest from the Wechsler Adult Intelligence Scale-IV and The Stroop (Colour-Word) Test.
(2) Executive Function domain: The CANTAB Stockings of Cambridge (SOC) subtest and Verbal fluency will be assessed using the Controlled Oral Word Association Task.
(3) Language domain: The Boston Naming Test-Short Form (BNT-Short Form) and the Similarities subtest of the WAIS-IV will be used to assess language.
(4) Memory domain: Hopkins Verbal Learning Test-Revised (HVLT-R) and the Paragraph Recall subtest of the Rivermead Behavioural Memory Test (RMBT) will be used to assess memory.
(5) Visuospatial domain: Judgement of Line Orientation (JLO) and the Hooper Visual Organisation Test (HVOT) will be used to assess visuospatial abilities.
Timepoint [2] 293886 0
baseline and after 4 weeks of tDCS
Primary outcome [3] 293887 0
Chronic lower back pain pain as assessed using the Visual Analog scale and the short-form McGill Pain Questionnaire
Timepoint [3] 293887 0
Baseline, after 4 weeks tDCS intervention
Secondary outcome [1] 312091 0
Depression as measured by the Depression, Anxiety and Stress Scale
Timepoint [1] 312091 0
Baseline and after 4 weeks tDCS intervention
Secondary outcome [2] 312742 0
health related quality of lifes measured by the MOS-36 Health Status Inventory
Timepoint [2] 312742 0
Baseline and after 4 weeks tDCS intervention

Key inclusion criteria
1) Diagnosis of CLBP by a physician and/or physiotherapist
2) Been diagnosed with CLBP for at least 6 months
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
1) A Telephone Interview for Cognitive Status-30 score below 18
2) TMS and tDCS exclusion conditions

Study design
Purpose of the study
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
Who is / are masked / blinded?

Intervention assignment
Other design features
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 290454 0
Self funded/Unfunded
Name [1] 290454 0
Address [1] 290454 0
Country [1] 290454 0
Primary sponsor type
Dr Andrea Loftus
Building 401.210
School of Psychology and Speech Pathology
Curtin University
Kent Street, Bentley, Perth
Western Australia 6102
Secondary sponsor category [1] 289304 0
Name [1] 289304 0
Address [1] 289304 0
Country [1] 289304 0

Ethics approval
Ethics application status
Ethics committee name [1] 292129 0
Curtin University Human Research Ethics Committee
Ethics committee address [1] 292129 0
Ethics committee country [1] 292129 0
Date submitted for ethics approval [1] 292129 0
Approval date [1] 292129 0
Ethics approval number [1] 292129 0

Brief summary
This project will examine motor cortex excitability and cognition in people with chronic low back pain (CLBP). This project will investigate transcranial direct current stimulation (tDCS) for improving motor cortex excitability and cognition in CLBP. Participant’s motor cortex excitability and cognition will be measured before, and after 4-weeks of tDCS. It is predicted CLBP participants will demonstrate abnormal motor cortex excitability and impaired cognitive function, compared with age and gender-matched controls. It is also predicted that tDCS will restore normal motor cortex excitability and improve cognitive functioning in people with CLBP. The findings will provide a better understanding of the relationship between CLBP and the brain and the therapeutic potential of tDCS for CLBP.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 53630 0
Dr Andrea M Loftus
Address 53630 0
Building 401.210
School of Psychology and Speech Pathology
Curtin University
Kent Street, Bentley, Perth
Western Australia 6102
Country 53630 0
Phone 53630 0
+61 8 9266 2308
Fax 53630 0
Email 53630 0
Contact person for public queries
Name 53631 0
Miss Emily Corti
Address 53631 0
Building 401.210
School of Psychology and Speech Pathology
Curtin University
Kent Street, Bentley, Perth
Western Australia 6102
Country 53631 0
Phone 53631 0
+61 431 584 166
Fax 53631 0
Email 53631 0
Contact person for scientific queries
Name 53632 0
Dr Andrea M Loftus
Address 53632 0
Building 401.210
School of Psychology and Speech Pathology
Curtin University
Kent Street, Bentley, Perth
Western Australia 6102
Country 53632 0
Phone 53632 0
+61 8 9266 2308
Fax 53632 0
Email 53632 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
What supporting documents are/will be available?
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary