Clinical trial NCT06453759: Thalamic Recordings in Children Undergoing SEEG
Official title: Thalamic Recordings in Children Undergoing SEEG
Study type: INTERVENTIONAL
Overall status: NOT_YET_RECRUITING
Phase: NA
Conditions: Focal Epilepsy
Lead sponsor: Great Ormond Street Hospital for Children NHS Foundation Trust
Sponsor class: OTHER
First posted: 2024-06-12
Enrollment: 30
Sex: ALL
Minimum age (years): 2
Maximum age (years): 20
Standard ages: CHILD
ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: BASIC_SCIENCE

Brief summary: 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.


Eligibility criteria: 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

Primary outcomes:
measure: Ictal thalamic involvement
timeFrame: Hospital discharge (maximum one month from SEEG implantation)
measure: Epileptogenicity index
timeFrame: Hospital discharge (maximum one month from SEEG implantation)
measure: Interictal power distribution
timeFrame: Hospital discharge (maximum one month from SEEG implantation)
measure: Single pulse electrical stimulation (SPES):
timeFrame: Hospital discharge (maximum one month from SEEG implantation)
Secondary outcomes:
measure: Incidence of bleeding
timeFrame: Hospital discharge (maximum one month from SEEG implantation)
Other outcomes:
Locations:
Study officials:
References: