Nervous System Diseases

All Conditions

Neoplasms

Rare Diseases

Epilepsy

Brain Neoplasms

Brain Tumor, Adult

Marc Slutzky

Electrocortical stimulation (ECS) mapping is a procedure used during brain surgeries, for example when treating diseases like epilepsy or when removing brain tumors. ECS mapping helps surgeons locate areas of the cerebral cortex (the outer part of the brain) that are important for everyday tasks like movement and speech. ECS mapping has been used for decades, and is considered the "gold-standard" tool for locating important areas of cortex. Despite this long history, there is still no clear understanding of exactly how ECS works.

The goal of this study is to learn details about the effects ECS has on the brain. The main questions the study aims to answer are: 1) how ECS affects the neurons of the cortex at the stimulation site; and 2) how ECS impacts brain regions that are critically important for human speech and language. These so-called "critical sites" can be physically distant from one another on the brain's surface, requiring extensive ECS mapping and long surgeries. Critical sites are thought to be part of a speech/language network of brain areas, and so the study's goal is to learn about how they are connected. In some participants, the brain's surface will also be slightly cooled. This is a painless procedure that does not harm the brain's function, but could provide insight as to which parts of the brain (the surface, or deeper parts) are responsible for the effects of ECS.

By improving the understanding of how ECS affects the brain and improving the ability to identify critical sites, this study could potentially lead to shorter surgeries and better outcomes for future individuals who need this care.

Participants will be recruited from among individuals who are undergoing brain surgery for epilepsy treatment or tumor removal. Participants will complete simple tasks like reading words or naming pictures, similar to standard testing that is already performed during their hospital stay.

Electrocortical stimulation (ECS) mapping has been used routinely for many decades to inform surgeons on brain areas to avoid when planning surgical resections for tumors or epilepsy. In particular, those areas that are "critical" for speech and language are important to identify. Yet, despite its long history of clinical use, the precise mechanisms of ECS are poorly understood. For example, it is not known how different cortical layers and cell types respond to ECS. Moreover, it is not even clear whether ECS' behavioral effects are due to affecting the underlying cortex alone, causing trans-synaptic activation of other cortices, or directly affecting both the cortex and underlying white matter.

A primary objective of this project is to determine the effects of ECS on the cortical network and subcortical white matter. This objective will be tested in two ways. First, the study will determine the relationship between ECS' effects and cortical connectivity patterns. This will be accomplished using graph theory metrics to analyze electrocorticography (ECoG) and functional magnetic resonance imaging (fMRI) from people with epilepsy or brain tumors. This will allow the recording of intracranial EEG (ECoG or stereo EEG) without adding substantial extra risk from the planned clinical treatment for these conditions. The study will investigate both static and dynamic network connectivity patterns, defined using static and dynamic graph metrics that measure connectivity at different scales (local, inter-regional, global). The study hypothesizes that structural (a.k.a. anatomical) and functional connectivity patterns of a cortical site determine its significance to the language network. To test this hypothesis, the study will use measures of structural and functional connectivity to predict which nodes are labeled critical by ECS.

Second, the study will test the hypothesis that ECS' behavioral effects also depend on directly perturbing cortico-cortical white matter. The study will use focal cortical cooling as a way to test the respective effects on language function of cooling (which inhibits only the cortex) compared to ECS (which may perturb cortex and underlying white matter), as well as combined ECS and cooling.

Neuronal and Network Mechanisms of Electrocortical Stimulation

Accuracy at decoding critical nodes from network connectivity metrics using machine learning algorithms.

Language or speech errors due to cooling and ECS, assessed by the clinical ECS mapping team in response to ECS and cooling.

Johns Hopkins University

University of Iowa

Indiana University

Northwestern University

Professor

Symptoms and General Pathology

Recurrence

Central Nervous System Neoplasms

Nervous System Neoplasms

Brain Diseases

Central Nervous System Diseases

Patients undergo tumor resection. During surgery, patients also undergo electrocorticography with either the CorTec high resolution hybrid grid, the PMT high-resolution grid, or the Ad-Tech grid followed by direct electrocortical stimulation.

Undergo direct electrocortical stimulation

Direct Electrocortical Stimulation

Electrocorticography

Sujit Prabhu, MD

Sujit S. Prabhu

Sujit S Prabhu

This pilot clinical trial studies how well electrocorticography works in mapping functional brain areas during surgery in patients with brain tumors. Using a larger than the standard mapping grid currently used during brain tumor surgery or a high-definition grid for electrocorticogram brain mapping may help doctors to better identify which areas of the brain are active during specific limb movement and speech during surgery in patients with brain tumors.

PRIMARY OBJECTIVE:

I. To record electrocorticogram (ECoG) data intraoperatively with surface electrode grids during various motor, sensory (tactile) and speech tasks, and identify functional brain areas through the spectral analysis, and compare the preliminary data with our current pre-surgical mapping methods: functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS), and the gold standard, intraoperative direct electrical stimulation (DES).

SECONDARY OBJECTIVE:

I. To perform a preliminary assessment of the utility of using ECoG data in these patients to quantify new neurological deficits in the short term (24 hours) and long-term (1 and 3 months), and achieve a safe maximal tumor resection.

OUTLINE:

Patients undergo tumor resection. During surgery, patients also undergo electrocorticography with either the CorTec high resolution hybrid grid, the PMT high-resolution grid, or the Ad-Tech grid followed by direct electrocortical stimulation.

Following completion of study, patients are followed up within 24 hours from surgery and at 1 and 3 months.

Electrocorticography in Mapping Functional Brain Areas During Surgery in Patients With Brain Tumors

Pilot Investigation of Using Electrocorticogram (ECoG) in Predicting Eloquent Cortex and Post-Operative Functional Outcomes in Patients With Brain Tumors

Will be assessed by cortical electrical activity based on individual hand muscle function. ECoG will be compared to direct electrical stimulation (DES), navigated transcranial magnetic stimulation (nTMS), and functional magnetic resonance imaging (fMRI). The data obtained using ECoG will be correlated with the fMRI and TMS data acquired preoperatively and intraoperative DES. The categorical variables would be preoperative Karnofsky performance status and functional status, tumor location, fMRI, TMS, ECoG, and DES data points. Other variables involved in the analysis would be extent of resection and neurological outcome. The Chi-square or Fisher's exact tests will be used to explore associations between categorical variables. Additional analysis may be performed.

National Cancer Institute (NCI)

University of Houston

M.D. Anderson Cancer Center

Glioma

Neoplasms, Neuroepithelial

Neuroectodermal Tumors

Neuroectodermal Tumors, Primitive

Neoplasms, Germ Cell and Embryonal

Neoplasms by Histologic Type

Neoplasms, Glandular and Epithelial

Neoplasms, Nerve Tissue

Neuroepithelioma

Central Nervous System Depressants

All Drugs and Chemicals

Anesthetics

The skull and the dura are opened under general anesthesia and the two grids of 64 cortical electrodes will be applied to the cortex, one facing the glial lesion, and the other at a distance from the glial lesion in the so-called area. "Healthy" (non-tumor), before the patient wakes up. They consist of 8 recording slides each comprising 8 electrodes of 2 mm in diameter each spaced 0.5 mm (DispoMed®, USA).

ECoG : electrocorticography

This study proposes to analyze data from intraoperative ECoG recordings acquired during wakefulness interventions in order to identify the connection networks involved in cognitive functions. This study also proposes to correlate the ECoG data with the imaging data and to analyze the disturbances of the electrophysiological signals induced by the cortical and subcortical brain lesions: this will make it possible to establish a more detailed mapping of the tumor areas and to compare disturbances recorded to those recorded in healthy areas. Thus, this approach should make it possible to improve the quality of excision of glial lesions located in eloquent areas, while reducing the risk of neurological sequelae and thus improve the survival and quality of life of patients.

Assessment of Awake Surgery With Electrocorticographic Recordings in the Management of Gliomas and Correlation With Imaging Data (ECoG)

Assessment of Awake Surgery With Electrocorticographic Recordings in the Management of Gliomas and Correlation With Imaging Data

Intraoperative ECoG recordings (raw signals) acquired during awake surgery which in clinical practice couples cortical stimulation and simultaneous ECoG recordings with behavioral tests. The regions defined as electrophysiologically "connected" to the stimulated region will be those for which an afterdischarge is recorded (short-duration rhythmic activity following the stimulation) and/or a cortico-cortical evoked potential is obtained after a average of 5 successive stimulations.

Study title	NCT ID	Conditions	Interventions	Eligibility	Organization
Neuronal and Network Mechanisms of Electrocortical Stimulation	NCT06391294	Epilepsy Brain Tumor Adu...		18 Years - 80 Years	Northwestern University
Electrocorticography in Mapping Functional Brain Areas During Surgery in Patients With Brain Tumors	NCT02754544	Brain Neoplasm Metastatic Mali... Recurrent Brain...	Direct Electroc... Electrocorticog...	18 Years -	M.D. Anderson Cancer Center
Assessment of Awake Surgery With Electrocorticographic Recordings in the Management of Gliomas and Correlation With Imaging Data (ECoG)	NCT05875935	Electrocorticog... Karnofski Index Glioma	ECoG : electroc...	18 Years -	Ramsay Générale de Santé
Electrocorticography in Mapping Functional Brain Areas During Surgery in Patients With Brain Tumors	NCT02754544	Brain Neoplasm Metastatic Mali... Recurrent Brain...	Direct Electroc... Electrocorticog...	18 Years -	M.D. Anderson Cancer Center
Assessment of Awake Surgery With Electrocorticographic Recordings in the Management of Gliomas and Correlation With Imaging Data (ECoG)	NCT05875935	Electrocorticog... Karnofski Index Glioma	ECoG : electroc...	18 Years -	Ramsay Générale de Santé

Spots Global Cancer Trial Database for electrocorticography