Evaluation of Medication Tapering on the Sensitivity of the Spinal Cord Using Closed-Loop Spinal Cord Stimulation (Pilot Study)

NCT07502612 | Recruiting

• 1 other identifier: GZA-ECAP-01
• Study Type: observational
• Target: 20
• Locations: 1 country
• Sites: 1

Brief 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). 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

Conditions

Persistent Spinal Pain Syndrome Type 2 (PSPS-T) Lower Spine; Neurophysiological Sensitivity to Spinal Cord Stimulation; Failed Back Surgery Syndrome (FBSS)

Keywords

Spinal cord stimulation; Closed-loop stimulation; Evoked Compound Action Potentials (ECAPs); Neurophysiology; Pain medication reduction; Neuromodulation; opioids; anticonvulsants

Outcome Measures

Primary Outcomes (1)

• 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.

  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)

  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

  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.

  From start of SCS trial (baseline) to 6 month after permanent implantation.

• Changes in sleep and activity scores

  From start of SCS trial (baseline) to 6 month after permanent implantation

Study Arms (1)

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.

Other: Spinal Cord Stimulation with Evoke Closed-Loop System

Interventions

Spinal Cord Stimulation with Evoke Closed-Loop System OTHER

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.

Patients with FBSS, taking at least qualifying opioids

Eligibility Criteria

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

Study Population

Belgian patients selected for spinal cord stimulation (SCS) with Failed Back Surgery Syndrome ( FBSS )

You may qualify if:

• 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
• Hydromorphone ≥10 mg
• Oxycodone ≥20 mg
• Fentanyl ≥25 µg
• Signed informed consent.
• Age ≥18 years.

You may not qualify if:

• 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)

Sponsors & Collaborators

• Brai²n: lead

Study Sites (1)

Brai²n - ZAS Augustinus

Wilrijk, 2610, Belgium

RECRUITING

MeSH Terms

Conditions

Failed Back Surgery Syndrome

Interventions

Spinal Cord Stimulation

Condition Hierarchy (Ancestors)

Postoperative Complications; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Back Pain; Pain; Neurologic Manifestations; Signs and Symptoms

Intervention Hierarchy (Ancestors)

Electric Stimulation Therapy; Therapeutics; Physical Therapy Modalities; Rehabilitation

Study Officials

• Tony Van Havenbergh, MD, PhD

  Brai²n / Department of Neurosurgery, ZAS Augustinus, Antwerp, Belgium

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Pieter Van Looy

CONTACT

+32 3 443 48 72; pieter.vanlooy@zas.be

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Target Duration: 6 Months
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Chairman, Department of Neurosurgery (NeurochirurgieGroep); Director, Antwerp Skull Base Team; Director, Brai²n

Study Record Dates

• First Submitted: November 20, 2025
• First Posted: March 31, 2026
• Study Start: June 8, 2022
• Primary Completion: July 28, 2026
• Study Completion (Estimated): August 28, 2026
• Last Updated: March 31, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

BE (1)