Novel Network Analysis of Intracranial Stereoelectroencephalography

NCT03916848 | Unknown

• 1 other identifier: 18NM09
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

Epilepsy is a disorder of the brain which is associated with disabling seizures and affects 100,000 people under 25. Many children with epilepsy also have a learning disability or problems with development. Although better outcomes occur in children who are successfully treated early for their epilepsy, 25% continue to have seizures despite best medical treatment. One potential treatment is a neurosurgical operation to remove parts of the brain that generate seizures. A proportion of these children have electrodes inserted into their brains as part of their clinical assessment, termed stereoelectroencephalography (SEEG), to help localise these regions. Subsequent surgery is not always successful - up to 40% of children will have ongoing seizures 5 years after surgery. The purpose of this study is to assess the utility of specially designed SEEG electrodes which can measure signals from single brain cells. These electrodes record the same clinical information as normal SEEG electrodes and are implanted in the same way, but can give the research team extra information at the same time. The investigators aim to assess whether studying the changes in the firing of individual cells, both during and between seizures, improves our ability to localise seizures and therefore improve outcomes following surgery. As part of this research project, the investigators will not be doing anything that is not already part of the normal investigation and treatment for these children. Children will be recruited to the study during routine outpatient clinic visits. Surgical planning and execution will not be affected. The electrodes are CE licensed for clinical use and do not alter the risks of the operation. Following the period of monitoring, the care of these children would not be altered in any way. The investigators aim to recruit 30 patients over 3 years. In addition to dissemination via scientific publications and presentations, the findings will be shared with participants and the public.

Conditions

Epilepsy in Children; Focal Epilepsy; Epilepsy Intractable; Epilepsy, Focal; Intractable Epilepsy; Refractory Epilepsy; Epilepsies, Partial

Keywords

Stereoelectroencephalography; Single unit recording; Single neuron recording; SEEG; Epilepsy surgery

Outcome Measures

Primary Outcomes (2)

• Analyse single unit behaviour in different brain regions.

  We will assess the abnormalities in single neuron firing behaviour both during and between seizures in children undergoing stereoelectroencephalogaphy (SEEG) as part of work-up for epilepsy surgery. The statistical analysis will include measures of timing coding and population coding of these single units and the investigators will assess these properties in time periods both during and between seizures to assess whether neurons in the seizure onset zone behave differently to those outside the seizure onset zone: 1. Timing coding is evaluated using a generalized linear modeling (GLM) approach. An output of the GLM is called a post-spike filter (PSF), which models the propensity for the same neuron to fire again over the course of the subsequent 0.7 seconds. 2. Population coding is also evaluated using a GLM by calculating coupling filters (the amount of up and down regulation of all other recorded neurons given that an individual neuron has just fired).

  Recording will continue for a period of 5-10 days, as determined by the clinical team. We will therefore use the data collected over the entire recording period for analysis.

• Correlate firing activity of single units to the clinically defined seizure onset zone (SOZ)

  Currently, the seizure onset zone (SOZ) is determined by visual analysis of the SEEG recordings at the end of the monitoring period. We aim to compare the differences in single unit behaviour (as defined above) between and during seizures in neurons inside and outside this clinically defined SOZ to assess if there is a unique behaviour to these neurons.

  Recording will continue for a period of 5-10 days, as determined by the clinical team. We will therefore use the data collected over the entire recording period for analysis.

Study Arms (1)

Combined Micro-Macro SEEG Electrodes

EXPERIMENTAL

Implanting SEEG electrodes with combined micro-macro electrodes capable of recording clinical data and experimental micro electrode single unit data

Procedure: Combined Micro-Macro SEEG Electrodes

Interventions

Combined Micro-Macro SEEG Electrodes PROCEDURE

The novel combined micro-macro electrodes will then be used during the surgical implantation procedure. The use of these novel electrodes will not change the surgical procedure, which is conducted using robotic assistance to ensure optimal accuracy. The macro electrode recordings will be used for routine clinical analysis and the duration of recording and subsequent analysis of the recordings will not be affected by the micro electrode data captured for research purposes. The clinical SEEG also involves electrical stimulation of the brain which will not be affected by the study.

Combined Micro-Macro SEEG Electrodes

Eligibility Criteria

• Age: 3 Years - 18 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• Undergoing SEEG recording as part of the investigation of their epilepsy at Great Ormond Street Hospital for Children
• Aged 3-18

You may not qualify if:

• Lack of informed consent

Sponsors & Collaborators

• Great Ormond Street Hospital for Children NHS Foundation Trust: lead

Study Sites (1)

Great Ormond Street Hospital NHS Foundation Trust

London, WC1N 3JH, United Kingdom

Location

MeSH Terms

Conditions

Epilepsies, Partial; Drug Resistant Epilepsy

Condition Hierarchy (Ancestors)

Epilepsy; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases

Study Officials

• Rod Scott, PhD

  Great Ormond Street Hospital for Children NHS Foundation Trust

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 4, 2019
• First Posted: April 16, 2019
• Study Start: June 16, 2019
• Primary Completion: April 1, 2022
• Study Completion: April 1, 2022
• Last Updated: November 19, 2021

Record last verified: 2021-11

Locations

GB (1)