Failed Back Surgery Syndrome (FBSS)ECAP-MED PilotNCT07502612
Evaluation of Medication Tapering on the Sensitivity of the Spinal Cord Using Closed-Loop Spinal Cord Stimulation (Pilot Study)
An observational study of Failed Back Surgery Syndrome (FBSS) and Persistent Spinal Pain Syndrome Type 2 (PSPS-T) Lower Spine, run by Brai²n at 1 site in Belgium.
Trial summary
This pilot study investigates the effects of reducing pain medication including opioids and anticonvulsants, on spinal cord sensitivity during closed-loop spinal cord stimulation (SCS). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Failed Back Surgery Syndrome (FBSS), Persistent Spinal Pain Syndrome Type 2 (PSPS-T) Lower Spine, Neurophysiological Sensitivity to Spinal Cord Stimulation
- What is being tested?
- Spinal Cord Stimulation with Evoke Closed-Loop System
- How many people
- 20 participants
- Where
- 1 siteBelgium
- Study dates
- 8 Jun 2022to 28 Aug 2026
- How long will I take part?
- 6 Months
- Phase
- Observational
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Belgian patients selected for spinal cord stimulation (SCS) with Failed Back Surgery Syndrome ( FBSS )
Who may be able to join
- Candidate for SCS and scheduled for trial with Evoke system.
- Diagnosis of FBSS or FNSS (PSPS-T2).
- Current use of ≥1 qualifying pain medication at or above minimum daily dose:
- Gabapentin ≥150 mg
- Pregabalin ≥75 mg
- Morphine ≥40 mg
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- Hydromorphone ≥10 mg
- Oxycodone ≥20 mg
- Fentanyl ≥25 µg
- Signed informed consent.
- Age ≥18 years.
Who cannot join
- Active disruptive psychiatric disorder or condition impacting pain perception or compliance.
- Progressive neurological disease (MS, CIDP, progressive arachnoiditis, progressive diabetic neuropathy, brain/spinal tumor, severe spinal stenosis).
- Coagulation disorder, platelet dysfunction, progressive vascular disease, or uncontrolled diabetes with procedural risk.
- Active systemic or local infection.
- Pregnancy.
- Significant untreated addiction or substance abuse (within 6 months prior)
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Belgium1 site, 1 recruiting
- Recruiting
Brai²n - ZAS Augustinus
Wilrijk, 2610
Pieter Van Looy, +32 3 443 48 72, pieter.vanlooy@zas.be
Tony Van Havenbergh, MD
About this study
Official title: Neurophysiological Effects of Pain Medication Reduction During Treatment With Closed-Loop Spinal Cord Stimulation: A Pilot Study
This pilot study investigates the effects of reducing pain medication including opioids and anticonvulsants, on spinal cord sensitivity during closed-loop spinal cord stimulation (SCS). Patients with Persistent Spinal Pain Syndrome Type 2 (FBSS/FNSS) will undergo a standard 21-day SCS trial with the Evoke closed-loop system, followed by permanent implantation if successful. Neurophysiological responses (activation plots, conduction velocity, chronaxie, rheobase) and patient-reported outcomes (VAS, activity, sleep, medication intake) will be collected during the trial and up to 6 months after implantation. The goal is to evaluate the relationship between medication tapering and spinal cord sensitivity
Read the detailed description
This is a single-centre, open-label, prospective pilot study in Belgium. Twenty patients scheduled for SCS with the Evoke ECAP-controlled closed-loop system will be enrolled. Eligible patients must use at least one qualifying pain medication at a minimum daily dose (gabapentin ≥150 mg, pregabalin ≥75 mg, morphine ≥40 mg, hydromorphone ≥10 mg, oxycodone ≥20 mg, fentanyl ≥25 µg).
The study includes baseline assessments, a 3-week trial period, permanent implantation if successful, and follow-up visits at 1, 3, and 6 months. Data collected include VAS pain, sleep, activity, medication use, and neurophysiological parameters (activation plots, conduction velocity, chronaxie, rheobase).
The primary endpoint is the effect of medication reduction on spinal cord sensitivity to SCS. Secondary endpoints include changes in pain intensity, medication use, sleep, activity, and additional neurophysiological outcomes.
- Conditions
- Failed Back Surgery Syndrome (FBSS), Persistent Spinal Pain Syndrome Type 2 (PSPS-T) Lower Spine, Neurophysiological Sensitivity to Spinal Cord Stimulation
- Being tested
- Spinal Cord Stimulation with Evoke Closed-Loop System
- Keywords
- Spinal cord stimulation, Closed-loop stimulation, Evoked Compound Action Potentials (ECAPs), Neurophysiology, Pain medication reduction, Neuromodulation, opioids, anticonvulsants
- Medical subject headings
- Failed Back Surgery Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Spinal Cord Stimulation with Evoke Closed-Loop SystemOther
All patients undergo a 21-day trial with Evoke closed-loop SCS. If successful, patients receive a permanent implant. Assessments include activation plots, conduction velocity, chronaxie, rheobase, VAS pain, sleep, activity, and medication intake.
| Study group | Role | What they receive |
|---|---|---|
| Patients with FBSS, taking at least qualifying opioids | Patients with FBSS, taking at least one qualifying pain medication at or above the minimum daily dose. Receives: Other: Spinal Cord Stimulation with Evoke Closed-Loop System |
What is being measured
The primary outcome is the main question the study is designed to answer.
Spinal cord sensitivity expressed in ECAP amplitude (µV) as a function of the SCS stimulation amplitude (mA).
Spinal cord sensitivity to spinal cord stimulation (SCS), will be assessed using activation plots describing the relationship between SCS stimulation current (mA) and the resultant Evoked Compound Action Potential (ECAP) amplitude (µV). Change is spinal cord sensitivity (µV/mA) will be compared between the SCS trial phase and at 1 month after permanent implantation across the different medication groups.
Measured: From start of SCS trial (baseline) to 6 month after permanent implantation.
Secondary outcomes (4)
Change in pain intensity measured using a 10 cm Visual Analog Scale (VAS)
Participants will be required report their pain intensity using a 10 cm visual analog scale (VAS) where 0 refers to no pain at all and 10 refers to worst possible pain. The resultant VAS score, expressed in cm, will be compared across study visits.
Measured: From start of SCS trial (baseline) to 6 month after permanent implantation.
Change in pain medication intake measured via Belgian Pain Platform (BPP) and clinical verification
Reduction in analgesic medication dose (standardized daily dose or milligram equivalents, if applicable) will be documented using daily/weekly BPP entries and verified by clinical staff. Data will be compared between baseline, end of SCS trial, and 1 month after permanent implantation.
Measured: From start of SCS trial (baseline) to 6 month after permanent implantation.
Change in neurophysiological parameters such as conduction velocity (m/sec), rheobase (mA) and chronaxie (µs), measured using the Evoke system's neurophysiological assessment tools.
The following neurophysiological parameters will be measured using the Evoke system's neurophysiological assessment tools.
- Conduction velocity (meter/sec): Changes in SCS neural conduction velocity (m/sec) will be compared across baseline, during the SCS trial phase, and 1 month after permanent implantation.
- Rheobase (mA): This is the lowest electrical current amplitude (mA) that can stimulate a nerve or muscle. Changes in rheobase will be compared across baseline, during the SCS trial phase, and 1 month after permanent implantation.
- Chronaxie (µs): The minimum pulse duration (µs) needed to excite a nerve or muscle when the current strength is set to double the rheobase. Changes in chronaxie will be compared across baseline, during the SCS trial phase, and 1 month after permanent implantation.
Measured: From start of SCS trial (baseline) to 6 month after permanent implantation.
Changes in sleep and activity scores
Participants will be required report their sleep and activity scores using a 10 cm visual analog scale (VAS) where 0 refers to no sleep and no activity at all and 10 refers to sleeping very well through the night and being very active. The resultant VAS score, expressed in cm, will be compared across study visits.
Measured: From start of SCS trial (baseline) to 6 month after permanent implantation
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 Mar 2026
- Study start8 Jun 2022
- Primary completion28 Jul 2026 (estimated)
- Study completion28 Aug 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Failed Back Surgery Syndrome (FBSS)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 20 participants (estimated)
- Target duration
- 6 Months
Sponsor and investigators
- Lead sponsor
- Brai²n
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Dr. Tony Van Havenbergh, Brai²n
- Investigators
- Tony Van Havenbergh, MD, PhD, Principal investigator, Brai²n / Department of Neurosurgery, ZAS Augustinus, Antwerp, Belgium
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07502612
- Sponsor's protocol ID
- GZA-ECAP-01
- Acronym
- ECAP-MED Pilot
- Status last verified
- Mar 2026
- First submitted
- 20 Nov 2025
- Last updated
- 31 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: The international committee of medical journal editors believes there is an ethical obligtion to share data generated by interventional clinical trials. This is not considered an interventional clinical trial