Lennox Gastaut Syndrome (LGS)CADETNCT06924086
The Children's Adaptive Deep Brain Stimulation for Epilepsy Trial
A study testing Deep Brain Stimulation in people with Lennox Gastaut Syndrome (LGS), run by University College, London at 1 site in United Kingdom.
Trial summary
The CADET Trial will investigate the effectiveness of deep brain stimulation (DBS) to reduce the frequency of seizures in children with Lennox-Gastaut syndrome (LGS). The CADET Trial will use a non-CE/UKCA marked device - the Picostim DBS system. The SMART-DBS study is a sub-study of the CADET Trial. Read more about this study
- Who is it for?
- Ages 5 to 14 years
- Conditions the study is for
- Lennox Gastaut Syndrome (LGS)
- What is being tested?
- Deep Brain Stimulation
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 22 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 24 Mar 2026to 31 Jan 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 5 to 14 years
- All sexes
- No healthy volunteers
- Child
Children enrolled in this study must:
- Be 5-14 years of age at consent.
- Have a diagnosis of LGS, as determined by:
- Slow (<3.0Hz) spike-and-wave pattern and/or fast wave pattern (tonic seizures) detected on EEG at least six-months prior to the enrolment into the baseline period
- History of drop seizures (tonic, atonic, or tonic-clonic) that precedes at least six-months prior to the enrolment into the baseline period
- Have experienced at least 10 seizures in the four weeks prior to enrolment.
- Have tried and not responded to two or more antiseizure medications prior to enrolment.
- Be taking one or more anti-seizure medication(s) at a stable dose for at least the four weeks prior to enrolment.
- Have a carer who is willing for their child's maintenance anti-seizure medications and ketogenic diet (if relevant) to be unaltered for the trial duration.
- Have a carer who is willing and able to comply with all the requirements of the study, including the completion of the seizure diary and periodic device charging.
Children enrolled in this study must not:
- Have received prior deep brain stimulation insertion.
- Have an active ('on') vagus nerve stimulator (or active within the six months prior to the baseline period).
- Have had a change in their anti-seizure medication prescription or stopped their ketogenic diet within the last 4 weeks
- Have started or made changes to the prescription of a ketogenic diet within the last 12-weeks
- Have abnormal thalamic anatomy detected on imaging that would render DBS either unsafe or unfeasible.
- Have a bleeding disorder(s).
- Have a medical condition(s)/factor(s) that would increase their anaesthetic risk to an unacceptable level.
- Have a nickel allergy.
- Be pregnant.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United Kingdom1 site, 1 recruiting
- Recruiting
Great Ormond Street Hospital NHS Foundation Trust
London
Rory Piper, MRCS
Martin Tisdall, FRCS
About this study
Official title: The Children's Adaptive Deep Brain Stimulation for Epilepsy Trial (CADET): a Pivotal, Randomized, Controlled, Double-blinded Multi-site Clinical Trial of Deep Brain Stimulation to Treat Children With Lennox-Gastaut Syndrome
The CADET Trial will investigate the effectiveness of deep brain stimulation (DBS) to reduce the frequency of seizures in children with Lennox-Gastaut syndrome (LGS). The CADET Trial will use a non-CE/UKCA marked device - the Picostim DBS system.
The SMART-DBS study is a sub-study of the CADET Trial. SMART-DBS will investigate the application of adaptive DBS for the treatment of children with LGS. Children will be recruited after they exit from either the prior 'CADET Pilot Study' or 'CADET Trial' - meaning that these children will already be receiving therapy with an already implanted Picostim device.
Read the detailed description
All participants will complete a 4 week baseline assessment phase, then surgical implantation of the Picostim device and then a 4 week recovery phase. The participants will thereafter be randomised (1:1) and double-blinded to either an 'early stimulation' (DBS device switched on) or an 'delayed stimulation' (DBS device switched off) arm. Children allocated to receive early stimulation will complete 36 weeks of immediate active stimulation and children allocated to delayed stimulation will complete 12 weeks of inactive stimulation followed by 24 weeks of active stimulation.
The primary endpoint for all participants in the trial will be following 24 weeks of active stimulation. Secondary outcomes will be compared between the early and delayed stimulation arms following the first 12 weeks of the controlled phase.
The SMART-DBS study will recruit participants from the CADET Trial and the preceding CADET Pilot study. In both the CADET Trial and CADET Pilot studies, participants were fitted with the Picostim device and the device remains active. Participants who potentially meet the eligibility criteria will be provided with the PIS to consider participation in the adaptive DBS study.
- Conditions
- Lennox Gastaut Syndrome (LGS)
- Being tested
- Deep Brain Stimulation
- Keywords
- epilepsy, deep brain stimulation, Lennox-Gastaut Syndrome, pediatric, paediatric, children
- Medical subject headings
- Lennox Gastaut Syndrome, Epilepsy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Deep Brain StimulationDevice
Picostim DBS Device
| Study group | Role | What they receive |
|---|---|---|
| Early stimulation | Active comparator | Active stimulation Receives: Device: Deep Brain Stimulation |
| Delayed stimulation | Sham comparator | Inactive stimulation Receives: Device: Deep Brain Stimulation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Seizure frequency reduction
Seizure frequency reduction measured on carer-recorded seizure diaries
Measured: 24 weeks of active stimulation compared to baseline
Secondary outcomes (6)
Seizure frequency
Seizure frequency reduction measured on carer-recorded seizure diaries
Measured: 8-12 weeks following randomisation between the active and inactive stimulation arms
Seizure frequency
Seizure frequency reduction measured on scalp EEG
Measured: 24 weeks of active stimulation compared to baseline
Seizure frequency
Seizure frequency reduction measured on scalp EEG
Measured: 8-12 weeks following randomisation between the active and inactive stimulation arms
Seizure severity
Seizure severity (according to the Hague Seizure Severity Scale). The HSSS scores range from 13 (least severe) and to 53 (most severe).
Measured: 24 weeks of active stimulation relative to baseline and comparison 12 weeks following randomisation between the active and inactive arms
Quality of life (PedsQL)
The PedsQL (Pediatric Quality of Life Inventory) questionnaire provides a quantitative score ranging from 0 (worst possible QoL) to 100 (best possible QoL) (https://www.pedsql.org/).
Measured: After 24-weeks of active stimulation, and 12 weeks following randomisation between the active and inactive stimulation arms
Quality of life (IPES)
The Impact of Pediatric Epilepsy Scale (IPES) is a 12-item questionnaire that is answered by the carers of children with epilepsy that, as titled, aims to objectively measure the burden that epilepsy has on the child's life. The IPES scores range from 0 (lowest impact of epilepsy on the participant) to 33 (highest impact of epilepsy on the participant).
Measured: After 24-weeks of active stimulation, and 12 weeks following randomisation between the active and inactive stimulation arms
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Apr 2025
- Study start24 Mar 2026
- Primary completion31 Jan 2028 (estimated)
- Study completion31 Jan 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Lennox Gastaut Syndrome (LGS)Studies of the same condition, open and under way.
- More trials run by University College, LondonThe sponsor's other registered studies.
- 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 22 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University College, London
- Sponsor type
- University, hospital or other
- Collaborators
- Great Ormond Street Hospital for Children NHS Foundation Trust, King's College Hospital NHS Trust, University of Oxford, King's College London
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06924086
- Sponsor's protocol ID
- 141268
- Acronym
- CADET
- Status last verified
- Apr 2026
- First submitted
- 28 Mar 2025
- Last updated
- 7 Apr 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 7 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Children's Adaptive Deep Brain Stimulation for Epilepsy Trial (CADET): a Pivotal, Randomized, Controlled, Double-blinded Multi-site Clinical Trial of Deep Brain Stimulation to Treat Children With Lennox-Gastaut Syndrome
- ClinicalTrials.gov ID
- NCT06924086
- Acronym / sponsor ID
- CADET / 141268
- Conditions
- Lennox Gastaut Syndrome (LGS)
- Keywords
- epilepsy, deep brain stimulation, Lennox-Gastaut Syndrome, pediatric, paediatric, children
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 22 participants (estimated)
- Lead sponsor
- University College, LondonUniversity, hospital or other
- Collaborators
- Great Ormond Street Hospital for Children NHS Foundation Trust, King's College Hospital NHS Trust, University of Oxford, King's College London
- Study start
- 24 Mar 2026 (actual)
- Primary completion
- 31 Jan 2028 (estimated)
- Study completion
- 31 Jan 2028 (estimated)
- First posted
- 11 Apr 2025 (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.
The CADET Trial will investigate the effectiveness of deep brain stimulation (DBS) to reduce the frequency of seizures in children with Lennox-Gastaut syndrome (LGS). The CADET Trial will use a non-CE/UKCA marked device - the Picostim DBS system.
The SMART-DBS study is a sub-study of the CADET Trial. SMART-DBS will investigate the application of adaptive DBS for the treatment of children with LGS. Children will be recruited after they exit from either the prior 'CADET Pilot Study' or 'CADET Trial' - meaning that these children will already be receiving therapy with an already implanted Picostim device.
Detailed description
All participants will complete a 4 week baseline assessment phase, then surgical implantation of the Picostim device and then a 4 week recovery phase. The participants will thereafter be randomised (1:1) and double-blinded to either an 'early stimulation' (DBS device switched on) or an 'delayed stimulation' (DBS device switched off) arm. Children allocated to receive early stimulation will complete 36 weeks of immediate active stimulation and children allocated to delayed stimulation will complete 12 weeks of inactive stimulation followed by 24 weeks of active stimulation.
The primary endpoint for all participants in the trial will be following 24 weeks of active stimulation. Secondary outcomes will be compared between the early and delayed stimulation arms following the first 12 weeks of the controlled phase.
The SMART-DBS study will recruit participants from the CADET Trial and the preceding CADET Pilot study. In both the CADET Trial and CADET Pilot studies, participants were fitted with the Picostim device and the device remains active. Participants who potentially meet the eligibility criteria will be provided with the PIS to consider participation in the adaptive DBS study.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Early stimulation | Active comparator | Device: Deep Brain StimulationActive stimulation |
| Delayed stimulation | Sham comparator | Device: Deep Brain StimulationInactive stimulation |
Who may qualify
- Ages
- 5 to 14 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
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 |
|---|---|---|
| Deep Brain StimulationPicostim DBS Device | Device | Delayed stimulation, Early stimulation |
Primary outcome
Seizure frequency reduction
Time frame: 24 weeks of active stimulation compared to baseline
Seizure frequency reduction measured on carer-recorded seizure diaries
6 secondary outcomes
Seizure frequency
Time frame: 8-12 weeks following randomisation between the active and inactive stimulation arms
Seizure frequency
Time frame: 24 weeks of active stimulation compared to baseline
Seizure frequency
Time frame: 8-12 weeks following randomisation between the active and inactive stimulation arms
Seizure severity
Time frame: 24 weeks of active stimulation relative to baseline and comparison 12 weeks following randomisation between the active and inactive arms
Quality of life (PedsQL)
Time frame: After 24-weeks of active stimulation, and 12 weeks following randomisation between the active and inactive stimulation arms
Quality of life (IPES)
Time frame: After 24-weeks of active stimulation, and 12 weeks following randomisation between the active and inactive stimulation arms
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Apr 2026.
- Individual participant dataSharing planned: Undecided
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Deep Brain Stimulation in people with Lennox Gastaut Syndrome (LGS), run by University College, London 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?
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: looking for participants now, as of the sponsor's last update on 7 Apr 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. Some participants in this study may receive a placebo. 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Rory J Piper, MRCS, PhD (+44 20 7405 9200, Rory.Piper@ucl.ac.uk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Seizure frequency reduction (time frame: 24 weeks of active stimulation compared to baseline). 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 7 Apr 2026.