EEG Mapping During High Frequency/High Density Spinal Cord Stimulation in Patients With Failed Back Surgery Syndrome

Study Overview
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Brief Summary
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This study is an interventional, observatory single center trial investigating the functional connectivity of the electrical brain activity in high frequency/high density spinal cord stimulation in failed back surgery syndrome patients with back and leg pain.

Detailed Description
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Based on the reimbursement rules in Belgium, a trial implantation of 4 weeks is necessary before implanting the definitive neurostimulator. The definitive neurostimulator will be implanted minimum 4 weeks after the trial implantation, when the patient reports more than 50% pain reduction and/or more than 50% reduction in pain medication. Patients who are included in this study will have four extra study visits at the University Hospital Brussels. The first assessment will take place during the week prior to surgery, the second minimal one month after definitive implantation of the stimulator. The assessments consist of filling in the Pittsburgh Sleep Quality Index (PSQI) and the Pain Catastrophizing Scale (PCS) and recording brain activity before and during the pain protocol. Additionally, patients will wear an Actiwatch for measuring sleep patterns and fill in a VAS diary (back and leg pain separately), one month before the baseline assessment and one month before the second assessment.

Official Title
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EEG Mapping During High Frequency/High Density Spinal Cord Stimulation in Patients With Failed Back Surgery Syndrome

Conditions
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Failed Back Surgery Syndrome

Intervention / Treatment
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* Other: EEG recording + pain protocol


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subject is at least 18 years old. Subject is able and willing to comply with the follow-up schedule and protocol Diagnosis of FBSS with predominant leg pain (VAS) > 5) and non-dominant back pain. Cognitive and language functioning enabling coherent communication between the examiner and the subject; Failed conservative treatments for pain including but not limited to pharmacological therapy and physical therapy Stable neurologic function in the past 30 days In the opinion of the Investigator, the subject is psychologically appropriate for the implantation for an active implantable medical device Subject is able to provide written informed consent Subject speaks Dutch or French. Exclusion Criteria: Female subject of childbearing potential is pregnant/nursing, or plans to become pregnant during the course of the trial Subject has had radiofrequency treatment of an intended target DRG within the past 3 months Subject currently has an active implantable device including ICD, pacemaker, spinal cord stimulator, deep brain stimulator or intrathecal drug pump Subject is unable to operate the device or has no relative available. Subjects with indwelling devices that may pose an increased risk of infection Subjects currently has an active infection Subject has, in the opinion of the Investigator, a medical comorbidity that contraindicates placement of an active medical device Subject has participated in another clinical investigation within 30 days Subject has a coagulation disorder or uses anticoagulants that, in the opinion of the investigator, precludes participation Subject has been diagnosed with cancer in the past 2 years Life expectancy < 6 months Imaging (MRI, CT, x-ray) findings within the last 12 months that, in the Investigator's opinion, contraindicates lead placement Existing extreme fear for entering MRI General contraindication for MRI (pacemaker, etc…) Age male/female patient <18 years

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: spinal cord stimulation<br> | Other: EEG recording + pain protocol<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Functional connectivity | EEG recordings to measure functional connectivity in the brain | The change between baseline and 1 month after definitive implantation of the neurostimulator | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Functioning of the descending inhibitory pathway | Functioning of the descending pathway will be measured with the conditioned pain modulation paradigm by using electrical stimulation and cold water | The change between baseline and 1 month after definitive implantation of the neurostimulator | 
| Visual Analogue Scale (VAS) pain diary |  | Three times every day (morning, afternoon and evening), starting 1 month before baseline measurements up to the second measurement 1 month after definitive implantation of the neurostimulator (at study completion). | 
| Objective sleep quality will be measured using the Actiwatch spectrum plus (Respironics). | This compact and lightweight electronic device similar in size to a wristwatch is worn on the non-dominant hand, and measures and records sleep quality | The difference between 1 month before baseline measurements and 1 month before the second measurement (1 month after definitive implantation). | 
| Pain Catastrophizing | Pain catastrophizing is assess be using the 'pain catastrophizing scale'. | The change between baseline and 1 month after definitive implantation of the neurostimulator | 
| Subjective sleep quality | Subjective sleep quality will be assessed with the Pittsburgh Sleep Quality Index (PSQI). | The change between baseline and 1 month after definitive implantation of the neurostimulator | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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high frequency / high density spinal cord stimulation, EEG, conditioned pain modulation