Sub-threshold DRG Stimulation vs Sham in Established Responders

NCT07170722 | Completed

• 1 other identifier: DRG-SHAM-2025
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial is to learn if sub-threshold dorsal root ganglion (DRG) stimulation provides pain relief beyond placebo in adults with chronic neuropathic pain who already have an implanted DRG stimulator. The main questions it aims to answer are:

• Does sub-threshold DRG stimulation reduce daily pain intensity compared with sham stimulation?
• How does sub-threshold stimulation affect sleep, mood, and daily activity? Researchers will compare active sub-threshold DRG stimulation to sham (device switched off) to see if stimulation has a genuine effect on pain and wellbeing. Participants will:
• Be randomly assigned to receive either active sub-threshold DRG stimulation or sham stimulation for 5 days, followed by the opposite condition for another 5 days.
• Complete short electronic diaries twice daily about their pain, sleep, mood, and activity.
• Attend study visits for safety checks and assessments.

Conditions

Causalgia; Chronic Pain; Low Back Pain; Pelvic Pain; Neuropathic Pain; Complex Regional Pain Syndromes (CRPS)

Keywords

Dorsal Root Ganglion Stimulation; DRG Stimulation; Sub-threshold Stimulation; Neuromodulation; Sham-controlled Trial; Randomized Controlled Trial; Crossover Trial; Chronic Neuropathic Pain; Complex Regional Pain Syndrome (CRPS); Failed Back Surgery Syndrome (FBSS); Post-surgical Pain; Post-traumatic Pain; Low Back Pain; Chronic Pelvic Pain

Outcome Measures

Primary Outcomes (1)

• Average daily pain intensity (Numeric Rating Scale, 0-10)

  Self-reported pain intensity recorded twice daily (morning and evening) using an 11-point Numeric Rating Scale (0 = no pain, 10 = worst pain imaginable). Daily scores will be averaged across each treatment and washout period.

  Twice daily (morning and evening) from Day 0 through Day 11 (includes both 5-day treatment periods and the two 24-hour washout periods on Day 0 and Day 6).

Secondary Outcomes (4)

• Sleep quality (Patient Global Impression of Change, PGIC)

  Daily in the morning from Day 0 through Day 11.

• Mood (Patient Global Impression of Change, PGIC)

  Daily in the evening from Day 0 through Day 11.

• Daily activity (Patient Global Impression of Change, PGIC)

  Daily in the evening from Day 0 through Day 11.

• Adverse events

  From day 0 through end of study (day 11).

Study Arms (2)

Subtreshhold DRG-S

ACTIVE COMPARATOR

Active Sub-threshold DRG Stimulation Participants receive sub-threshold dorsal root ganglion (DRG) stimulation. Device amplitude is individually titrated to 80% of the perception threshold, ensuring no paresthesia is felt. Frequency and pulse width remain unchanged from each participant's established clinical settings. Stimulation is delivered continuously for 5 days.

Device: Subtreshhold DRG-S

Sham

SHAM COMPARATOR

Sham Stimulation Participants receive sham stimulation. The implanted DRG stimulator is switched off, with device interrogation logs masked to maintain blinding. The sham condition lasts for 5 days.

Other: Sham

Interventions

Subtreshhold DRG-S DEVICE

Continuous electrical stimulation delivered through an implanted DRG neurostimulator. Amplitude is set individually to 80% of each participant's perception threshold, ensuring no paresthesia is produced. Frequency and pulse width remain unchanged from the participant's established therapeutic settings. This sub-threshold programming distinguishes the intervention from suprathreshold (paresthesia-based) DRG stimulation used in earlier studies.

Subtreshhold DRG-S

Sham OTHER

The implanted DRG stimulator remains switched off for the entire 5-day period. Device interrogation logs are masked to maintain blinding. No electrical stimulation is delivered, allowing a placebo-controlled comparison with active sub-threshold stimulation.

Sham

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adults, age 18 years or older
• Implanted with a dorsal root ganglion (DRG) stimulator for chronic neuropathic pain
• Have experienced at least 50% reduction in pain for 3 months or longer on standard DRG therapy
• Stable pain medication regimen for at least 4 weeks before enrollment
• Able and willing to complete electronic diaries and attend study visits

You may not qualify if:

• Active infection or wound complication at the stimulator implant site
• Significant psychiatric illness (for example, uncontrolled depression or psychosis)
• Planned surgery, device reprogramming, or medication changes during the study period
• Currently pregnant or breastfeeding
• Occurrence of any adverse event that meets predefined withdrawal criteria during the study (such as intolerable pain or device-related complications)

Sponsors & Collaborators

• Umeå University: lead

Study Sites (1)

Neurokirurgiska kliniken. Neuromodulationsenheten

Umeå, Västerbotten County, 90185, Sweden

Location

Related Publications (5)

• Huygen FJPM, Kallewaard JW, Nijhuis H, Liem L, Vesper J, Fahey ME, Blomme B, Morgalla MH, Deer TR, Capobianco RA. Effectiveness and Safety of Dorsal Root Ganglion Stimulation for the Treatment of Chronic Pain: A Pooled Analysis. Neuromodulation. 2020 Feb;23(2):213-221. doi: 10.1111/ner.13074. Epub 2019 Nov 15.

  PMID: 31730273 BACKGROUND

• D'Souza RS, Kubrova E, Her YF, Barman RA, Smith BJ, Alvarez GM, West TE, Abd-Elsayed A. Dorsal Root Ganglion Stimulation for Lower Extremity Neuropathic Pain Syndromes: An Evidence-Based Literature Review. Adv Ther. 2022 Oct;39(10):4440-4473. doi: 10.1007/s12325-022-02244-9. Epub 2022 Aug 22.

  PMID: 35994195 BACKGROUND

• Deer TR, Levy RM, Kramer J, Poree L, Amirdelfan K, Grigsby E, Staats P, Burton AW, Burgher AH, Obray J, Scowcroft J, Golovac S, Kapural L, Paicius R, Kim C, Pope J, Yearwood T, Samuel S, McRoberts WP, Cassim H, Netherton M, Miller N, Schaufele M, Tavel E, Davis T, Davis K, Johnson L, Mekhail N. Dorsal root ganglion stimulation yielded higher treatment success rate for complex regional pain syndrome and causalgia at 3 and 12 months: a randomized comparative trial. Pain. 2017 Apr;158(4):669-681. doi: 10.1097/j.pain.0000000000000814.

  PMID: 28030470 BACKGROUND

• Chapman KB, Sayed D, Lamer T, Hunter C, Weisbein J, Patel KV, Dickerson D, Hagedorn JM, Lee DW, Amirdelfan K, Deer T, Chakravarthy K. Best Practices for Dorsal Root Ganglion Stimulation for Chronic Pain: Guidelines from the American Society of Pain and Neuroscience. J Pain Res. 2023 Mar 14;16:839-879. doi: 10.2147/JPR.S364370. eCollection 2023.

  PMID: 36942306 BACKGROUND

• Piedade GS, Gillner S, McPhillips PS, Vesper J, Slotty PJ. Effect of low-frequency dorsal root ganglion stimulation in the treatment of chronic pain. Acta Neurochir (Wien). 2023 Apr;165(4):947-952. doi: 10.1007/s00701-023-05500-1. Epub 2023 Jan 27.

  PMID: 36705762 BACKGROUND

MeSH Terms

Conditions

Neuralgia; Complex Regional Pain Syndromes; Causalgia; Chronic Pain; Low Back Pain; Pelvic Pain; Failed Back Surgery Syndrome; Pain, Postoperative

Interventions

salicylhydroxamic acid

Condition Hierarchy (Ancestors)

Peripheral Nervous System Diseases; Neuromuscular Diseases; Nervous System Diseases; Pain; Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Autonomic Nervous System Diseases; Back Pain; Postoperative Complications; Pathologic Processes

Study Officials

• Pedram Tabatabaei Tabatabaei, M.D, Ph.D

  Univeristy hospital of northern sweden

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Randomised, double blinded, sham study

Study Record Dates

• First Submitted: August 26, 2025
• First Posted: September 12, 2025
• Study Start: September 1, 2025
• Primary Completion: November 30, 2025
• Study Completion: November 30, 2025
• Last Updated: December 5, 2025

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, CSR
• Time Frame: 12 months after publication, with no end date.
• Access Criteria: De-identified individual participant data (IPD) underlying the published results, along with the study protocol, statistical analysis plan, and analytic code, will be made available. Access will be provided to qualified researchers affiliated with academic institutions, healthcare organizations, or non-profit entities. Requests must include a research proposal and be approved by the study investigators. Access will be granted under a data use agreement that ensures compliance with GDPR and institutional policies. Data will be hosted in an open-access repository (OSF) 12 months after publication of the primary results.

Locations

SE (1)