Thalamic Recordings in Children Undergoing SEEG (TRICS)

January 29, 2026 updated by: Great Ormond Street Hospital for Children NHS Foundation Trust

Stereoelectroencephalography (SEEG) forms a key part of the pre-surgical evaluation in children who may be candidates for epilepsy surgery. It can help delineate the location of the putative epileptogenic zone, guiding further treatments including resective, disconnective and ablative epilepsy surgery techniques. However, less than 35% of children undergoing SEEG end up becoming seizure free following further treatment.

Open and closed loop stimulation of thalamic nuclei via deep brain stimulation (DBS) and responsive neurostimulation (RNS) are emerging treatment options for epilepsy. Thalamic target nuclei vary between studies and there are currently no gold standard personalised methods for choosing a target. This stems from the limited systematic neurophysiological recordings from thalamic nuclei; investigators currently do not understand the ictal and interictal thalamic signatures of involvement in epilepsy and do not understand how functional connectivity can be altered within and between patients.

In this prospective study, the investigators aim to recruit 30 patients undergoing SEEG as part of their pre-surgical evaluation for drug resistant epilepsy at Great Ormond Street Hospital over a period of 3 years. Once recruited, the investigators will target 3 nuclei bilaterally in each patient - the anterior, centromedian and pulvinar nuclei - using additional SEEG electrodes. Following clinical recording, the investigators will conduct two stimulation experiments, the first using single pulse electrical stimulation to measure effective connectivity between the thalamus and cortical regions and the second to study the effects of simulated DBS currents on cortical local field potential signatures.

This study will lay the foundation for a personalised approach to thalamic neuromodulation for drug-resistant epilepsy by identifying neurophysiological biomarkers of thalamic involvement in epilepsy, paving the way for closed loop neuromodulation strategies that aim to optimise response using these biomarkers.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
30

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Child
  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. All children undergoing SEEG as part of their pre-surgical evaluation at GOSH
  2. Participants/parents/legal guardian provide informed consent for inclusion

Exclusion Criteria:

1) Lack of informed consent

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Thalamic SEEG
The centromedian, anterior and pulvinar nuclei on each side will be chosen as target for new electrodes.
Procedure: Additional electrodes into bilateral anterior, centromedian and pulvinar thalamic nuclei

The centromedian, anterior and pulvinar nuclei on each side will be chosen as target for new electrodes; up to 6 additional electrodes may be added but, where possible, existing electrode trajectories will be extended to facilitate recording.

At the beginning of the recording process, usually within the first 24-48 hours of implantation, we will conduct 2 study-specific stimulation experiments:

  1. Single pulse electrical stimulation (SPES):
  2. N-of-1 trials of simulated DBS: We will simulate high (130Hz) and low (6Hz) frequency DBS currents from each pair of thalamic nuclei (always bilateral) and record spontaneous interictal neuronal activity in all other cortical contacts for 15 minutes. We will also record SPES from each of the cortical contacts.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Ictal thalamic involvement
Time Frame: Hospital discharge (maximum one month from SEEG implantation)
Experienced neurophysiologists will assess, during ictal activity, whether each of the nuclei are involved in the seizure and, if so, the latency between first cortical contact onset and thalamic nucleus onset.
Hospital discharge (maximum one month from SEEG implantation)
Epileptogenicity index
Time Frame: Hospital discharge (maximum one month from SEEG implantation)
We will quantify ictal involvement by measuring the epileptogenicity index in each nucleus.
Hospital discharge (maximum one month from SEEG implantation)
Interictal power distribution
Time Frame: Hospital discharge (maximum one month from SEEG implantation)
To assess interictal signatures, we will assess power at different frequencies in the nuclei using the 'fitting oscillations & one over f' (FOOOF) method.
Hospital discharge (maximum one month from SEEG implantation)
Single pulse electrical stimulation (SPES):
Time Frame: Hospital discharge (maximum one month from SEEG implantation)
We will systematically conduct SPES from all cortical and thalamic contacts and record responses in all other contacts. This measures the effective connectivity.
Hospital discharge (maximum one month from SEEG implantation)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Incidence of bleeding
Time Frame: Hospital discharge (maximum one month from SEEG implantation)
Radiological evidence of bleeding or clinically new neurological symptoms during SEEG implantation
Hospital discharge (maximum one month from SEEG implantation)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Great Ormond Street Hospital for Children NHS Foundation Trust

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 1, 2025

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 1, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 1, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
May 24, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 5, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 12, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 2, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 29, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 23BI31

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

IPD Plan Description

IPD may not be allowed to be shared by our ethical approvals. We may make anonymised data available based on restrictions of ethical approvals.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Focal Epilepsy

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings