Back Pain Lower Back ChronicECAPNCT05704751
EVOKE ECAP-Controlled Lead Placement and Programming in Chronic Pain Patients
An observational study of Back Pain Lower Back Chronic and Spinal Cord Stimulation, run by Barts & The London NHS Trust at 1 site in United Kingdom.
Trial summary
This study is designed to evaluate the feasibility of using intra-operative ECAP and Late-Response (LR) recordings for confirmation of activating the neuronal target of the dorsal column in a single-stage SCS lead placement procedure. Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Back Pain Lower Back Chronic, Spinal Cord Stimulation
- What is being tested?
- spinal cord stimulation
- Type of treatment
- Medical device
- How many people
- 0 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 27 Oct 2023to 12 Aug 2025
- Phase
- Observational
- Are there results?
- None posted in the registry
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 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Patients with chronic predominant back as deemed suitable for SCS treatment
Who may be able to join
- Be 18-75 years of age or older at the time of enrolment.
- Symptoms of chronic predominant back pain for at least 6-months, with a minimum pain intensity of 5/10 in the primary pain area on VAS pain intensity questionnaire.
- Be an appropriate candidate for the surgical procedures required in this study based on the clinical judgment of the implanting physician.
- Be capable of subjective evaluation, able to read and understand English-written questionnaires, and able to read, understand and sign the written inform consent in English.
- Be willing and capable of giving informed consent.
- Be willing and able to comply with study-related requirements, procedures, and visits.
Who cannot join
- Have a medical condition or pain in other area(s), not intended to be treated with SCS, that could interfere with study procedures, accurate pain reporting, and/or confound evaluation of study endpoints, as determined by the Investigator.
- 2. Have evidence of an active disruptive psychological or psychiatric disorder or other known condition significant enough to impact perception of pain, compliance of intervention, and/or ability to evaluate treatment outcomes.
- 3. Subjects with chronic alcohol abuse or currently in rehabilitation. 4. Be benefitting within from an interventional procedure and/or surgery to treat chronic pain (Subjects should be enrolled at least 30 days from last benefit).
- 5. Have prior experience with SCS. 6. Have an existing drug pump and/or another active implantable device such as a pacemaker.
- 7. Have a condition currently requiring or likely to require the use of diathermy.
- 8. Have an active systemic or local infection at the anticipated needle entry site.
Show all 9Show fewer
- 9. Be pregnant (if female and sexually active, subject must be using a reliable form of birth control, be surgically sterile or be at least 2 years post-menopausal).
- 10. Are currently nursing (if female).
- 11. Be concomitantly participating in another clinical study.
Trial locations and contacts
1 site in 1 country.
About this study
This study is designed to evaluate the feasibility of using intra-operative ECAP and Late-Response (LR) recordings for confirmation of activating the neuronal target of the dorsal column in a single-stage SCS lead placement procedure. The collected ECAP and LR data will be analysed post-hoc to further evaluate its utility for determining the laterality of lead placement with respect to the physiologic midline of the dorsal column.
Read the detailed description
The primary objectives of the study will be to evaluate the feasibility of using intra-operative ECAP and LR recordings for confirming the activation of the neural target of the dorsal column in a single-stage SCS lead placement procedure. The collected ECAP and LR data will be analysed post-hoc to further evaluate its utility for determining the laterality of lead placement with respect to the physiologic midline of the dorsal column. Change in pain intensity (Visual Analogue Scale = VAS) will be evaluated after 3-months of the targeted (primary) pain area.
Conventional open-loop SCS devices produce paraesthesia (a tingling sensation) that overlap the pain distribution, with the intent of masking pain perception. It is thought that conventional open-loop SCS success depends on adequacy and durability of paraesthesia coverage as well as patient tolerance of the induced sensations. For the last 40 years, the primary focus of innovation for SCS for chronic pain has been to improve the reliability of overlapping paraesthesia's with distribution of pain. Achieving adequate and stable paraesthesia coverage in the chronic pain region is known to be challenging, making back pain more difficult to treat and limiting application mostly to patients with predominant leg pain. Therefore, the use of neurostimulation for the treatment of chronic pain (especially back) shows mixed results. Declining efficacy over time has been observed in studies using low-frequency SCS programming.
Programming in the EVOKE Randomized Controlled Trial (RCT) study was performed using objective, neurophysiological feedback i.e., ECAPs for the first time since the advent of SCS to program both the control (open-loop) and test (closed-loop) chronic low back and/or leg pain patients. The trial has shown the superior long-term efficacy and durability of closed-loop SCS in treatment of chronic back and leg pain. Unpublished data collected during the study showed that objective EVOKE ECAP-based programming does not require paraesthesia overlap with pain distribution to achieve successful outcomes in low back (axial or radicular) and leg pain patients. Evaluation of data demonstrated that at 12-months follow-up (EVOKE study), 27% of subjects did not report paraesthesia in the low back region and reported 82% and 72% back pain relief with closed-loop and open-loop SCS, respectively. This is compared to 75% and 69% pain relief, respectively, in subjects who reported paraesthesia. Therefore, no interaction between the treatment effect and paraesthesia (p = 0.775) exist (EVOKE study).
The secondary objective of this observational study is to evaluate the overlap of the dermatomal pain map with the paraesthesia coverage provided by ECAP-based programming by asking the patient to report how much percentage of the primary pain area is covered by paraesthesia.
Additionally, the patients will be followed-up for 12-months and treatment outcomes (Evaluate long-term clinical outcomes (PROMIS 29+2 Profile v2.1, VAS, long-term responders in terms of pain relief, subject satisfaction with asleep lead placement, stimulation programming characteristics, neurophysiological characteristics) will be captured pre-treatment at baseline, at 3-months, 6-months and 12-months post-activation and initial programming of the closed-loop Stimulator (CLS).
- Being tested
- spinal cord stimulation
- Keywords
- closed loop, spinal cord stimulation, chronic back pain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
spinal cord stimulationDevice
EVOKE ECAP-Controlled Lead Placement and Programming in Chronic Pain Patients
What is being measured
The primary outcome is the main question the study is designed to answer.
Visual Analogue Scale (VAS), 0-100 where 0 is no pain and 100 is worst pain.
Evaluate average pain relief using the Visual Analogue Scale (VAS).
Measured: Baseline
Difference in Visual Analogue Scale (VAS), 0-100 where 0 is no pain and 100 is worst pain.
Evaluate average pain relief using the Visual Analogue Scale (VAS). Percentage change in average pain intensity in the primary region of pain on the VAS.
Measured: Baseline and 3 months
Difference in Visual Analogue Scale (VAS), 0-100 where 0 is no pain and 100 is worst pain.
Evaluate average pain relief using the Visual Analogue Scale (VAS).Percentage change in average pain intensity in the primary region of pain on the VAS.
Measured: Baseline, 3 month and 6 months
Difference Visual Analogue Scale (VAS), 0-100 where 0 is no pain and 100 is worst pain.
Evaluate average pain relief using the Visual Analogue Scale (VAS).Percentage change in average pain intensity in the primary region of pain on the VAS.
Measured: Baseline, 3, 6 and 12 months
Secondary outcomes (9)
Pain Symptoms map.
Mapping areas of pain
Measured: Baseline
Pain Symptoms map.
Mapping areas of pain
Measured: Baseline and 3 months
Pain Symptoms map.
Mapping areas of pain
Measured: Baseline and 6 months
Pain Symptoms map.
Mapping areas of pain
Measured: Baseline and 12 months
Paraesthesia coverage dermatomal map for final programming settings.
Patient will be asked to report how much percentage of the primary pain area is covered by paraesthesia.
Measured: 3, 6 and 12 months
Quality of Life and Function change using the PROMIS 29+2 Profile v2.1.
Change in score using the PROMIS 29+2 Profile v2.1. The scale is 1-5 where 1 is unable to do and 5 is without any difficulty.
Measured: baseline to 3-months, 6-months and 12-months
Quality of Life and Function change using Subject Global Impression of Change (PGIC) scale
change in Subject Global Impression of Change (PGIC) scale. The scale is 1-5 where 1 is very unsatisfied and 5 is very satisfied
Measured: baseline to 3-months, 6-months and 12-months
Quality of Life and Function change using Satisfaction scale
change in satisfaction scale. The scale is 1-5 where 1 is very unsatisfied and 5 is very satisfied.
Measured: baseline to 3-months, 6-months and 12-months
Quality of Life and Function change in sleep questionnaire
Patient reports change in sleep quality and disturbance. The scale is 1-5 where 1 is very poor and very good.
Measured: baseline to 3-months, 6-months and 12-months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Jan 2023
- Study start27 Oct 2023
- Primary completion12 Aug 2025
- Study completion12 Aug 2025
Why it stopped: We were unable to recruit any patients for this study. There were processes to add an additional site but due to site capacity, unfortunately we were unable to recruit or transfer.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Back Pain Lower Back ChronicStudies 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
- Case-control
- Time perspective
- Prospective
- Enrolment
- 0 participants (actual)
Sponsor and investigators
- Lead sponsor
- Barts & The London NHS Trust
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05704751
- Sponsor's protocol ID
- 322831
- Acronym
- ECAP
- Status last verified
- Sep 2026
- First submitted
- 13 Jan 2023
- Last updated
- 22 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- No: We will follow the policies laid by the local information governance team at Barts Health NHS Trust and NHS code of Confidentiality in accordance to the data protection act.
Study at a glance
From the registry record, last updated by the sponsor on 22 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- EVOKE ECAP-Controlled Lead Placement and Programming in Chronic Pain Patients
- ClinicalTrials.gov ID
- NCT05704751
- Acronym / sponsor ID
- ECAP / 322831
- Keywords
- closed loop, spinal cord stimulation, chronic back pain
- Study type
- Observational
- Recruitment status
- WithdrawnReason stopped: We were unable to recruit any patients for this study. There were processes to add an additional site but due to site capacity, unfortunately we were unable to recruit or transfer.
- Enrolment
- 0 participants (actual)
- Lead sponsor
- Barts & The London NHS TrustUniversity, hospital or other
- Study start
- 27 Oct 2023 (actual)
- Primary completion
- 12 Aug 2025 (actual)
- Study completion
- 12 Aug 2025 (actual)
- First posted
- 30 Jan 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study is designed to evaluate the feasibility of using intra-operative ECAP and Late-Response (LR) recordings for confirmation of activating the neuronal target of the dorsal column in a single-stage SCS lead placement procedure. The collected ECAP and LR data will be analysed post-hoc to further evaluate its utility for determining the laterality of lead placement with respect to the physiologic midline of the dorsal column.
Detailed description
The primary objectives of the study will be to evaluate the feasibility of using intra-operative ECAP and LR recordings for confirming the activation of the neural target of the dorsal column in a single-stage SCS lead placement procedure. The collected ECAP and LR data will be analysed post-hoc to further evaluate its utility for determining the laterality of lead placement with respect to the physiologic midline of the dorsal column. Change in pain intensity (Visual Analogue Scale = VAS) will be evaluated after 3-months of the targeted (primary) pain area.
Conventional open-loop SCS devices produce paraesthesia (a tingling sensation) that overlap the pain distribution, with the intent of masking pain perception. It is thought that conventional open-loop SCS success depends on adequacy and durability of paraesthesia coverage as well as patient tolerance of the induced sensations. For the last 40 years, the primary focus of innovation for SCS for chronic pain has been to improve the reliability of overlapping paraesthesia's with distribution of pain. Achieving adequate and stable paraesthesia coverage in the chronic pain region is known to be challenging, making back pain more difficult to treat and limiting application mostly to patients with predominant leg pain. Therefore, the use of neurostimulation for the treatment of chronic pain (especially back) shows mixed results. Declining efficacy over time has been observed in studies using low-frequency SCS programming.
Programming in the EVOKE Randomized Controlled Trial (RCT) study was performed using objective, neurophysiological feedback i.e., ECAPs for the first time since the advent of SCS to program both the control (open-loop) and test (closed-loop) chronic low back and/or leg pain patients. The trial has shown the superior long-term efficacy and durability of closed-loop SCS in treatment of chronic back and leg pain. Unpublished data collected during the study showed that objective EVOKE ECAP-based programming does not require paraesthesia overlap with pain distribution to achieve successful outcomes in low back (axial or radicular) and leg pain patients. Evaluation of data demonstrated that at 12-months follow-up (EVOKE study), 27% of subjects did not report paraesthesia in the low back region and reported 82% and 72% back pain relief with closed-loop and open-loop SCS, respectively. This is compared to 75% and 69% pain relief, respectively, in subjects who reported paraesthesia. Therefore, no interaction between the treatment effect and paraesthesia (p = 0.775) exist (EVOKE study).
The secondary objective of this observational study is to evaluate the overlap of the dermatomal pain map with the paraesthesia coverage provided by ECAP-based programming by asking the patient to report how much percentage of the primary pain area is covered by paraesthesia.
Additionally, the patients will be followed-up for 12-months and treatment outcomes (Evaluate long-term clinical outcomes (PROMIS 29+2 Profile v2.1, VAS, long-term responders in terms of pain relief, subject satisfaction with asleep lead placement, stimulation programming characteristics, neurophysiological characteristics) will be captured pre-treatment at baseline, at 3-months, 6-months and 12-months post-activation and initial programming of the closed-loop Stimulator (CLS).
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Patients with chronic predominant back as deemed suitable for SCS treatment
Key inclusion criteria (6 listed)
- Be 18-75 years of age or older at the time of enrolment.
- Symptoms of chronic predominant back pain for at least 6-months, with a minimum pain intensity of 5/10 in the primary pain area on VAS pain intensity questionnaire.
- Be an appropriate candidate for the surgical procedures required in this study based on the clinical judgment of the implanting physician.
- Be capable of subjective evaluation, able to read and understand English-written questionnaires, and able to read, understand and sign the written inform consent in English.
- Be willing and capable of giving informed consent.
Key exclusion criteria (9 listed)
- Have a medical condition or pain in other area(s), not intended to be treated with SCS, that could interfere with study procedures, accurate pain reporting, and/or confound evaluation of study endpoints, as determined by the Investigator.
- 2. Have evidence of an active disruptive psychological or psychiatric disorder or other known condition significant enough to impact perception of pain, compliance of intervention, and/or ability to evaluate treatment outcomes.
- 3. Subjects with chronic alcohol abuse or currently in rehabilitation. 4. Be benefitting within from an interventional procedure and/or surgery to treat chronic pain (Subjects should be enrolled at least 30 days from last benefit).
- 5. Have prior experience with SCS. 6. Have an existing drug pump and/or another active implantable device such as a pacemaker.
- 7. Have a condition currently requiring or likely to require the use of diathermy.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| spinal cord stimulationEVOKE ECAP-Controlled Lead Placement and Programming in Chronic Pain Patients | Device | – |
Primary outcome
Visual Analogue Scale (VAS), 0-100 where 0 is no pain and 100 is worst pain.
Time frame: Baseline
Evaluate average pain relief using the Visual Analogue Scale (VAS).
Difference in Visual Analogue Scale (VAS), 0-100 where 0 is no pain and 100 is worst pain.
Time frame: Baseline and 3 months
Evaluate average pain relief using the Visual Analogue Scale (VAS). Percentage change in average pain intensity in the primary region of pain on the VAS.
Difference in Visual Analogue Scale (VAS), 0-100 where 0 is no pain and 100 is worst pain.
Time frame: Baseline, 3 month and 6 months
Evaluate average pain relief using the Visual Analogue Scale (VAS).Percentage change in average pain intensity in the primary region of pain on the VAS.
Difference Visual Analogue Scale (VAS), 0-100 where 0 is no pain and 100 is worst pain.
Time frame: Baseline, 3, 6 and 12 months
Evaluate average pain relief using the Visual Analogue Scale (VAS).Percentage change in average pain intensity in the primary region of pain on the VAS.
9 secondary outcomes
Pain Symptoms map.
Time frame: Baseline
Pain Symptoms map.
Time frame: Baseline and 3 months
Pain Symptoms map.
Time frame: Baseline and 6 months
Pain Symptoms map.
Time frame: Baseline and 12 months
Paraesthesia coverage dermatomal map for final programming settings.
Time frame: 3, 6 and 12 months
Quality of Life and Function change using the PROMIS 29+2 Profile v2.1.
Time frame: baseline to 3-months, 6-months and 12-months
Quality of Life and Function change using Subject Global Impression of Change (PGIC) scale
Time frame: baseline to 3-months, 6-months and 12-months
Quality of Life and Function change using Satisfaction scale
Time frame: baseline to 3-months, 6-months and 12-months
Quality of Life and Function change in sleep questionnaire
Time frame: baseline to 3-months, 6-months and 12-months
Results and safety
The study was withdrawn before enrolling participants, so there are no results.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 Sep 2026.
- Individual participant dataSharing planned: No. We will follow the policies laid by the local information governance team at Barts Health NHS Trust and NHS code of Confidentiality in accordance to the data protection act.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Back Pain Lower Back Chronic and Spinal Cord Stimulation, run by Barts & The London NHS Trust at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: withdrawn, as of the sponsor's last update on 22 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study was withdrawn before enrolling participants, so there are no results.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Visual Analogue Scale (VAS), 0-100 where 0 is no pain and 100 is worst pain. (time frame: Baseline). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Sep 2026.