EpilepsyNCT06391294
Neuronal and Network Mechanisms of Electrocortical Stimulation
A study testing Focal cortical cooling in people with Epilepsy and Brain Tumor Adult, run by Northwestern University at 3 sites in United States.
Trial summary
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… Read more about this study
- Who is it for?
- Ages 18 to 80 years
- Conditions the study is for
- Epilepsy, Brain Tumor Adult
- What is being tested?
- Focal cortical cooling
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 65 participants
- Where
- 3 sitesUnited States
- Study dates
- 17 May 2024to 30 Jun 2030
- 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 18 to 80 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Requiring awake, cortical mapping for brain tumor resection or implantation of intracranial electrodes for extraoperative monitoring for epilepsy
- For extraoperative patients: Planned electrode coverage including at least parts of frontal and temporal or parietal lobes, preferably both anterior (inferior frontal gyrus) and posterior language areas (superior temporal gyrus) in the language dominant hemisphere
- For intraoperative patients: Planned craniotomy including parts of both frontal and temporal anterior and posterior language areas in the language dominant hemisphere.
Who cannot join
- Significant language or speech impairment, including but not limited to aphasia, dysarthria, and apraxia of speech, consistently preventing patient from speaking words
- Non English-speaking (because this is a study of language networks, and second language could be encoded differently)
- Impaired cognitive function, as determined by neurological testing, such that the patient cannot follow test instructions or provide written informed consent
- Tumor infiltrating, or within 1 cm of, multiple of the cortical or subcortical areas studied in this proposal (inferior frontal gyrus, precentral gyrus, superior temporal gyrus)
- Ferromagnetic implants that are MRI incompatible or other contraindications to MRI
- Pregnancy
Trial locations and contacts
3 sites in 1 country. Contact the study team or a site near you to ask about taking part.
United States3 sites
Johns Hopkins University
Baltimore, Maryland, 21218
Northwestern University
Chicago, Illinois, 60611
University of Iowa
Iowa City, Iowa, 52242
About this study
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.
Read more
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.
Read the detailed description
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.
- Conditions
- Epilepsy, Brain Tumor Adult
- Being tested
- Focal cortical cooling
- Keywords
- Electrocortical Stimulation, Electrocorticography
- Medical subject headings
- Epilepsy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Focal cortical coolingProcedure or surgery
Focal cortical cooling will be applied
| Study group | Role | What they receive |
|---|---|---|
| Experimental group | Experimental | Single arm of the study Receives: Procedure: Focal cortical cooling |
What is being measured
The primary outcome is the main question the study is designed to answer.
Critical node decoding performance
Accuracy at decoding critical nodes from network connectivity metrics using machine learning algorithms.
Measured: Up to 1 week during ECoG recording
Secondary outcomes (1)
Language function
Language or speech errors due to cooling and ECS, assessed by the clinical ECS mapping team in response to ECS and cooling.
Measured: Up to 4 hours during ECoG recording
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Apr 2024
- Study start17 May 2024
- Primary completion30 Jun 2029 (estimated)
- Study completion30 Jun 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for EpilepsyStudies of the same condition, open and under way.
- More trials run by Northwestern UniversityThe 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
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 65 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Northwestern University
- Sponsor type
- University, hospital or other
- Collaborators
- Johns Hopkins University, University of Iowa, Indiana University
- Responsible party
- Principal investigator, Marc Slutzky, Northwestern University
- Investigators
- Marc Slutzky, Principal investigator, Northwestern University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06391294
- Sponsor's protocol ID
- STU00219749
- Status last verified
- Aug 2026
- First submitted
- 5 Apr 2024
- Last updated
- 7 Aug 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 7 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Neuronal and Network Mechanisms of Electrocortical Stimulation
- ClinicalTrials.gov ID
- NCT06391294
- Acronym / sponsor ID
- STU00219749
- Conditions
- Epilepsy, Brain Tumor Adult
- Keywords
- Electrocortical Stimulation, Electrocorticography
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 65 participants (estimated)
- Lead sponsor
- Northwestern UniversityUniversity, hospital or other
- Collaborators
- Johns Hopkins University, University of Iowa, Indiana University
- Study start
- 17 May 2024 (actual)
- Primary completion
- 30 Jun 2029 (estimated)
- Study completion
- 30 Jun 2030 (estimated)
- First posted
- 30 Apr 2024 (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.
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.
Detailed description
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.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Experimental group | Experimental | Procedure: Focal cortical coolingSingle arm of the study |
Who may qualify
- Ages
- 18 to 80 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Requiring awake, cortical mapping for brain tumor resection or implantation of intracranial electrodes for extraoperative monitoring for epilepsy
- For extraoperative patients: Planned electrode coverage including at least parts of frontal and temporal or parietal lobes, preferably both anterior (inferior frontal gyrus) and posterior language areas (superior temporal gyrus) in the language dominant hemisphere
- For intraoperative patients: Planned craniotomy including parts of both frontal and temporal anterior and posterior language areas in the language dominant hemisphere.
Key exclusion criteria (6 listed)
- Significant language or speech impairment, including but not limited to aphasia, dysarthria, and apraxia of speech, consistently preventing patient from speaking words
- Non English-speaking (because this is a study of language networks, and second language could be encoded differently)
- Impaired cognitive function, as determined by neurological testing, such that the patient cannot follow test instructions or provide written informed consent
- Tumor infiltrating, or within 1 cm of, multiple of the cortical or subcortical areas studied in this proposal (inferior frontal gyrus, precentral gyrus, superior temporal gyrus)
- Ferromagnetic implants that are MRI incompatible or other contraindications to MRI
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 |
|---|---|---|
| Focal cortical coolingFocal cortical cooling will be applied | Procedure or surgery | Experimental group |
Primary outcome
Critical node decoding performance
Time frame: Up to 1 week during ECoG recording
Accuracy at decoding critical nodes from network connectivity metrics using machine learning algorithms.
1 secondary outcome
Language function
Time frame: Up to 4 hours during ECoG recording
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 Aug 2026.
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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.
Marc Slutzky principal investigator
Northwestern University
3 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Focal cortical cooling in people with Epilepsy and Brain Tumor Adult, run by Northwestern University at 3 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 6 exclusion criteria. 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: enrolling by invitation, as of the sponsor's last update on 7 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in United States. 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. 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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Critical node decoding performance (time frame: Up to 1 week during ECoG recording). 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 Aug 2026.