Enhancing Acupuncture Treatment Effect Through Non-invasive Neuromodulation

In this study, investigators will examine the brain mechanism behind the synergistic effects of combining acupuncture and transcranial direct current stimulation (tDCS) treatments. Specifically, chronic low back pain (cLBP) patients will be recruited and randomized to one of four groups (30 per group, one month of treatment): 1) verum acupuncture + real tDCS, 2) sham acupuncture + real tDCS, 3) verum acupuncture + sham tDCS, and 4) sham acupuncture + sham tDCS. Investigators will study 1) the longitudinal (one-month) effects of different treatments as indicated by changes in resting state functional connectivity (rsFC), cerebral blood flow (CBF), clinical outcomes of low back pain, and quantitative sensory test (QST) and 2) the association between these changes.

Study Overview

• Status: Completed
• Conditions: Chronic Pain
• Intervention / Treatment: Device: verum acupuncture; Device: real tDCS; Device: sham acupuncture; Device: sham tDCS

• Study Type: Interventional
• Enrollment (Actual): 116
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Massachusetts
    • Charlestown, Massachusetts, United States, 02129-2020
      • Massachusetts General Hospital

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• volunteers 18-60 years of age
• meet the classification criteria of chronic low back pain (having low back pain for more than 6 months), as determined by the referring physician
• at least 4/10 clinical pain on the 11-point Low Back Pain Numeric Rating Scale (LBP NRS)
• at least a 10th grade English-reading level; English can be a second language provided that the patients understand all questions used in the assessment measures

Exclusion Criteria:

• history of epilepsy or loss consciousness (LOC)
• specific causes of back pain (e.g. cancer, fractures, spinal stenosis, infections)
• complicated back problems (e.g. prior back surgery, medicolegal issues)
• the intent to undergo surgery during the time of involvement in the study
• history of cardiac, respiratory, or nervous system disease that, in the investigator's judgment, precludes participation in the study because of a heightened potential for adverse outcomes. For example: asthma or claustrophobia
• presence of any contraindications to magnetic resonance imaging (MRI) scanning. For example: cardiac pacemaker, metal implants, claustrophobia, pregnancy, inability to remain still in MRI scanner
• history of medical or psychiatric illness as determined by the investigator
• history of substance abuse or dependence

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Factorial Assignment
• Masking: Double

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: verum acupuncture + real tDCS	Device: verum acupuncture; Participants will receive real acupuncture treatment.; Device: real tDCS; Participants will receive real transcranial direct current stimulation.
Experimental: sham acupuncture + real tDCS	Device: real tDCS; Participants will receive real transcranial direct current stimulation.; Device: sham acupuncture; Participants will receive sham acupuncture treatment.
Experimental: verum acupuncture + sham tDCS	Device: verum acupuncture; Participants will receive real acupuncture treatment.; Device: sham tDCS; Participants will receive sham transcranial direct current stimulation.
Sham Comparator: sham acupuncture + sham tDCS	Device: sham acupuncture; Participants will receive sham acupuncture treatment.; Device: sham tDCS; Participants will receive sham transcranial direct current stimulation.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Periaqueductal Gray (PAG) Resting State Functional Connectivity (rsFC) Changes	We investigated whether tDCS and acupuncture treatments modulate resting-state functional connectivity (rsFC) of the periaqueductal gray (PAG). This was evaluated by comparing pre- and post-treatment MRI scans. In this report, we focused on the rsFC between the PAG and the rostral anterior cingulate cortex (rACC, peak MNI coordinate (2, 38, 12) with a 2-mm radius sphere). Functional connectivity values were computed as Pearson's correlation coefficients between the mean time series of predefined regions of interest (ROIs). To improve normality and enable parametric statistical analysis, these correlation coefficients (r) were converted to Fisher z values using the transformation z = 0.5 × ln[(1 + r) / (1 - r)]. Higher Fisher z values indicate stronger positive connectivity, whereas lower values indicate weaker or negative connectivity. Changes in Fisher z values from baseline to post-intervention reflect the degree and direction of connectivity modulation.	difference between Day 1 (pre-intervention); post-intervention at Week 4 (pre-intervention - Post-intervention)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Clinical Outcomes as Measured by LBP Intensity Scores	The Low Back Pain Numeric Rating Scale (LBP NRS) is a standardized adaptation of the Pain Numeric Rating Scale for assessing pain intensity specifically related to the lower back. It uses an 11-point scale from 0 ("no low back pain") to 10 ("worst low back pain imaginable"), allowing patients to rate their pain over the past week.	Difference between the Day 1 (pre-intervention) and post-intervention at Week 4 (post-intervention - pre-intervention)
Cerebral Blood Flow (CBF) Differences Before and After Treatments	Investigators will examine Cerebral blood flow (CBF) changes before and after treatment in several pain-related brain areas. Cerebral blood flow represents the volume of blood delivered to brain tissue per unit time, CBF data will be collected during arterial spin labeling (ASL) scans that will take place before the first treatment and after the last treatment. Images from these scans will be aggregated to an average CBF-weighted image to be used for analysis. In this report, we focused on bilateral postcentral Gyrus (MNI coordinate: +/-18, -34, 56, 2 mm sphere)	Day 1 (pre-intervention); post-intervention at Week 4
Quantitative Sensory Testing (QST) Differences	Participants' quantitative sensory testing (QST) ratings were analyzed before and after all treatments. Here, we report the heat pain threshold measured around the affected lower back area.	Day 1 (pre-intervention); post-intervention at Week 4 (pre-intervention - post-intervention)
Primary Motor Cortex (M1) rsFC Changes Before and After 4-week Treatments	We investigated whether tDCS and acupuncture treatments modulate resting-state functional connectivity (rsFC) of the M1. This was evaluated by comparing pre- and post-treatment MRI scans. In this report, we focused on the rsFC between the PAG and the rostral anterior cingulate cortex (rACC), using a seed defined by the rACC peak MNI coordinate (0, 34, 20) with a 2-mm radius sphere. Functional connectivity values were computed as Pearson's correlation coefficients between the mean time series of predefined regions of interest (ROIs). To improve normality and enable parametric statistical analysis, these correlation coefficients (r) were converted to Fisher z values using the transformation z = 0.5 × ln[(1 + r) / (1 - r)]. Higher Fisher z values indicate stronger positive connectivity, whereas lower values indicate weaker or negative connectivity. Changes in Fisher z values from baseline to post-intervention	Day 1 (pre-intervention); post-intervention at Week 4 (pre-intervention - post-intervention)

Collaborators and Investigators

• Sponsor: Massachusetts General Hospital

Study record dates

Study Major Dates

• Study Start (Actual): November 7, 2020
• Primary Completion (Actual): January 31, 2025
• Study Completion (Actual): March 31, 2025

Study Registration Dates

• First Submitted: October 18, 2018
• First Submitted That Met QC Criteria: October 22, 2018
• First Posted (Actual): October 23, 2018

Study Record Updates

• Last Update Posted (Estimated): November 5, 2025
• Last Update Submitted That Met QC Criteria: October 21, 2025
• Last Verified: October 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Chronic Pain
• Other Study ID Numbers: 2018P001970

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No