Enhancing Inhibition With tDCS in Low Back Pain

This cross-over study intends to use consecutive days of active versus sham transcranial direct current stimulation (tDCS) to enhance descending inhibition and look at resulting clinical effects in people with low back pain.

Study Overview

• Status: Completed
• Conditions: Low Back Pain
• Intervention / Treatment: Device: High-Definition Transcranial Direct Current Stimulation

• Study Type: Interventional
• Enrollment (Actual): 12
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Denmark
  • Aalborg, Denmark, 9000
    • CNAP, SMI, Aalborg University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 60 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Otherwise healthy men and women
• Aged 18-60 years
• Continuous pain (>3days pain/week) episode lasting at least 3 months, sufficient to limit daily activities
• Pain in the region posteriorly between the inferior border of the 12th rib and the lower gluteal fold (low back pain) at the time of recruitment
• Able to speak, read and understand English

Exclusion Criteria:

• Pregnancy
• Low back pain associated with menstruation
• Currently seeking active treatment for low back pain
• Red flags symptoms (i.e. fever, malaise, progressive neurologic deficit, significant trauma, prolonged corticosteroid use or osteoporosis, pain worst at night, urinary or faecal incontinence, or unintended weight loss)
• Drug addiction defined as the use of cannabis, opioids or other drugs
• Current or previous neurologic, musculoskeletal, mental, or other illnesses which may affect the trial
• Current or previous chronic or recurrent pain condition other than low back pain
• Current regular use of analgesic medication or other medication which may affect the trial
• Lack of ability to cooperate

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Active tDCS; 30s ramp to 2mA with 20 minute session of active High-Definition Transcranial Direct Current Stimulation at 2mA	Device: High-Definition Transcranial Direct Current Stimulation; Device uses an array of electrodes over the scalp, in contact via gel, to provide a weak electrical current.
Placebo Comparator: Sham tDCS; 30s ramp to 2mA with High-Definition Transcranial Direct Current Stimulation, then device stops stimulating for 20 minutes	Device: High-Definition Transcranial Direct Current Stimulation; Device uses an array of electrodes over the scalp, in contact via gel, to provide a weak electrical current.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Conditioned Pain Modulation	Change in cuff pain threshold with contralateral cuff conditioning stimulus	Day 0 (Pre) to Day 3 (Post) in each stimulation phase

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Temporal Summation of Pain	Change in pain intensity ratings (i.e. on an electronic Visual Analogue Scale from 0=no pain to 10=worst pain imaginable) across series of 10 x 1s cuff stimuli at 0.5Hz (scores are normalized to first rating by subtraction and grouped into 3 epochs of 3 inflations with higher change scores indicating higher summation/facilitation)	Day 1 (Pre) to Day 3 (Post) in each stimulation phase
Pressure Pain Thresholds	Handheld algometry over the extensor carpi radialis, upper trapezius, lower back and gastrocnemius muscles	Day 1 (Pre) to Day 3 (Post) in each stimulation phase
Pain Intensity	Visual Analogue Scale from 0=no pain to 10=worst pain imaginable currently at rest and with worst movement, as well as maximum in past week	Day 0 (Pre) to Day 3 (Post) and 2 weeks post for each stimulation phase
Pain Unpleasantness	Visual Analogue Scale from 0=not unpleasant at all to 10=most unpleasant sensation imaginable currently at rest and with worst movement, as well as maximum in past week	Day 0 (Pre) to Day 3 (Post) and 2 weeks post for each stimulation phase
Pain Area	Total number of pixels coloured on an electronic body chart (Navigate Pain)	Day 0 (Pre) to Day 3 (Post) and 2 weeks post for each stimulation phase
Roland-Morris Disability Questionnaire	Measures back-related disability for 24 statements of potentially afflicted tasks with dichotomous responses. Minimum 0 to maximum 24 with higher scores indicating worse disability.	Day 0 (Pre) to Day 3 (Post) and 2 weeks post for each stimulation phase
Back Performance Scale	5 Task scale rated as per performance as a functional measure of back-related disability (each task is rated on a 4 point Likert scale 0-3 and summed to give total), scored from 0-15 with higher scores indicating more pain and dysfunction during task performance. Here will be used to characterize functional disability.	Day 0 (Pre) to Day 3 (Post) and 2 weeks post for each stimulation phase

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Flanker Task Learning	Reaction time to selective attention based computer task	Day 0 (Pre) to Day 3 (Post) and 2 weeks post for each stimulation phase
Affect Manipulation	Effect of image watching on ratings of mood and arousal. Mood and arousal will be measured with the Self Assessment Manikin - a 9 point Likert-type scale with 1 representing most negative/most calm, 5 as neutral, and 9 as most positive/most aroused.	Day 0 (Pre) to Day 3 (Post) and 2 weeks post for each stimulation phase

Collaborators and Investigators

• Sponsor: Aalborg University
• Collaborators: Danish National Research Foundation
• Investigators: Principal Investigator: Megan E McPhee, BPhty MSc, Center for Neuroplasticity and Pain (CNAP), SMI, Aalborg University

Publications and helpful links

General Publications

• McPhee ME, Graven-Nielsen T. Medial Prefrontal High-Definition Transcranial Direct Current Stimulation to Improve Pain Modulation in Chronic Low Back Pain: A Pilot Randomized Double-blinded Placebo-Controlled Crossover Trial. J Pain. 2021 Aug;22(8):952-967. doi: 10.1016/j.jpain.2021.02.012. Epub 2021 Mar 4.

Study record dates

Study Major Dates

• Study Start (Actual): April 29, 2019
• Primary Completion (Actual): October 7, 2020
• Study Completion (Actual): October 7, 2020

Study Registration Dates

• First Submitted: March 1, 2019
• First Submitted That Met QC Criteria: March 5, 2019
• First Posted (Actual): March 6, 2019

Study Record Updates

• Last Update Posted (Actual): December 11, 2020
• Last Update Submitted That Met QC Criteria: December 10, 2020
• Last Verified: December 1, 2020

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Back Pain; Low Back Pain
• Other Study ID Numbers: VN-20170034-v5

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: Data will be shared after study completion and publication in necessary cases on request

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No