Intracranial Stimulation Mapping for Epilepsy

Overseen By Matthew Maple

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: University of Minnesota

Disqualifiers: Pregnancy, Cognitive impairment, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Approved in 3 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: Unknown

Duration: Immediate

30 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to create detailed brain maps to better understand how brain regions communicate in people with partial epilepsy. It focuses on using a treatment called Intracranial Stimulation Mapping, which involves electrical stimulation of the brain, to discover how different brain parts connect. The study seeks adults already undergoing special brain monitoring (intracranial EEG) to assist in planning their epilepsy surgery. Participants should be willing to follow all study procedures and be available for the entire study duration. As an unphased trial, this study offers a unique opportunity to contribute to groundbreaking research that could enhance epilepsy treatment strategies.

Do I need to stop taking my current medications for the trial?

The trial information does not specify whether you need to stop taking your current medications. Please consult with the study team for guidance.

What prior data suggests that this intracranial stimulation mapping is safe for epilepsy patients?

Research has shown that brain mapping using intracranial stimulation is generally well-tolerated in people with epilepsy. This technique uses electrical stimulation to identify important brain areas before surgery.

One study found that this method helps locate where seizures begin in the brain by monitoring brain activity with special equipment. Another study confirmed the safety of this approach, noting its use in patients with various brain conditions, such as arteriovenous malformations (a type of blood vessel issue in the brain).

Overall, these findings suggest that intracranial stimulation mapping is safe when performed in controlled settings. However, like any procedure, it carries risks and should be conducted under careful medical supervision. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Intracranial Stimulation Mapping is unique because it offers a new way to pinpoint and understand the functional areas of the brain responsible for triggering epileptic seizures. Unlike traditional treatments like medication or resective surgery, which often aim to prevent or remove the source of seizures, this technique focuses on accurately mapping brain activity. Researchers are excited about this method because it could lead to more precise, personalized treatment plans, potentially improving outcomes for patients with epilepsy by minimizing unnecessary removal of healthy brain tissue.

What evidence suggests that Intracranial Stimulation Mapping is effective for epilepsy?

Research shows that Intracranial Stimulation Mapping (IESM), the method under study in this trial, can help identify where seizures begin in the brain. One study found that using this method reduced seizures by 50% or more in 80% of patients who experienced seizures during the procedure. This technique involves closely monitoring the brain with special equipment, making it easier to locate the exact areas involved in seizures. Studies also indicate that IESM can reveal different levels of brain activity, enhancing understanding of brain reactions. Overall, this approach holds promise for better managing epilepsy by accurately identifying the key brain regions involved in seizures. ^{1 2 3 6 7}

Who Is on the Research Team?

Alexander Herman, MD

Principal Investigator

UMN

Are You a Good Fit for This Trial?

This trial is for adults over 18 with epilepsy who are already getting intracranial EEG monitoring at the University of Minnesota/MINCEP program. They must understand the study, agree to all procedures, and be available throughout. Pregnant individuals or those unable to make independent decisions due to cognitive impairments are excluded.

Inclusion Criteria

Stated willingness to comply with all study procedures and availability for the duration of the study

I am currently being monitored with an EEG at the University of Minnesota for epilepsy surgery.

Written informed consent is obtained from the participant to comply with the requirements of the study

Exclusion Criteria

I am able to understand and make decisions about participating in this study.

Pregnancy ruled out prior to approval for intracranial EEG monitoring

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants undergo intracranial stimulation mapping to generate brain maps for localizing cerebral functions and inter-regional information flow

Immediate

Multiple sessions (in-person)

Follow-up

Participants are monitored for safety and effectiveness after stimulation sessions

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Intracranial Stimulation Mapping

Trial Overview The study is testing a new way to create brain maps in adult patients with partial epilepsy. These maps aim to pinpoint where in the brain seizures start and how different regions communicate during a seizure.

How Is the Trial Designed?

Group I: Research IESM Experimental Treatment 1 Intervention

Functional mapping for research application

Intracranial Stimulation Mapping is already approved in United States, European Union, Canada for the following indications:

Approved in United States as Intracranial Stimulation Mapping for:

• Epilepsy surgery planning
• Localization of cerebral functions
• Inter-regional information flow mapping

Approved in European Union as Electrical Stimulation Mapping (ESM) for:

• Pre-surgical evaluation for epilepsy
• Functional brain mapping

Approved in Canada as Cortical Stimulation Mapping for:

• Epilepsy surgery planning
• Brain function localization

Who Is Running the Clinical Trial?

University of Minnesota

Lead Sponsor

Trials

1,459

Recruited

1,623,000+

Published Research Related to This Trial

Electrical stimulation mapping (ESM) using stereoelectroencephalography (SEEG) is crucial for accurately identifying seizure foci and eloquent brain areas, which is essential for effective surgical planning in epilepsy treatment.

SEEG stimulation has shown positive clinical outcomes in surgical interventions, and future applications may enhance functional mapping and cognitive investigations, potentially improving treatment strategies for epilepsy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Stimulation Mapping Using Stereoelectroencephalography: Current and Future Directions. George, DD., Ojemann, SG., Drees, C., et al.[2020]

Electrical stimulation mapping (ESM) is crucial for locating the seizure onset zone in patients with medically resistant epilepsy, but there is currently no standardized protocol for its implementation.

The study proposes a unified ESM technique using specific parameters, such as a pulse width of 300 µs and stimulation currents of 1-6 mA for depth electrodes, to enhance the reliability of data across different medical centers.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Extraoperative electrical stimulation mapping in epilepsy presurgical evaluation: a proposal and review of the literature. Suller Marti, A., Mirsattari, SM., Steven, DA., et al.[2022]

A survey of 56 epilepsy centers revealed significant variability in extraoperative electrical stimulation mapping (ESM) practices, including stimulation settings and language testing protocols, which could impact surgical outcomes.

Despite following their mapping procedures, 41% of centers reported persistent adverse language outcomes, highlighting the need for standardized guidelines to enhance the safety and efficacy of ESM in epilepsy surgery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Extraoperative neurostimulation mapping: results from an international survey of epilepsy surgery programs. Hamberger, MJ., Williams, AC., Schevon, CA.[2021]

Effective connectivity analysis of intracranially recorded EEG during seizures can objectively localize the ictal-onset zone, showing promise as a reliable method alongside traditional visual analysis by epileptologists.

In a study of eight patients with refractory epilepsy, the electrode contact identified as having the highest connectivity consistently matched the ictal onset zone determined by visual analysis and was located within the resected brain region, indicating the method's accuracy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Ictal-onset localization through connectivity analysis of intracranial EEG signals in patients with refractory epilepsy. van Mierlo, P., Carrette, E., Hallez, H., et al.[2013]

Electrical stimulation mapping is a crucial part of the surgical evaluation process in stereo-EEG (SEEG), helping to identify critical brain areas during epilepsy surgery.

The review highlights important differences between SEEG and electrocorticography techniques, emphasizing the need for clinicians to be aware of specific safety concerns and advantages when using electrical stimulation mapping in SEEG.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Electrical Stimulation Mapping With Stereo-EEG Electrodes. Britton, JW.[2018]

In a study comparing 67 patients using stereoelectroencephalography (SEEG) and 106 patients using subdural electrodes (SDE), SEEG was found to have a higher likelihood of identifying sensory areas while maintaining comparable language and motor response evaluations.

SEEG demonstrated a lower incidence of afterdischarges (ADs) and unwanted electrical stimulation-induced seizures (EISs) compared to SDE, indicating that SEEG may offer superior safety and neurophysiologic validity for functional brain mapping.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparing electrical stimulation functional mapping with subdural electrodes and stereoelectroencephalography. Aungaroon, G., Vedala, K., Byars, AW., et al.[2023]

In a study of 10 patients with intractable epilepsy, intracerebral electrical stimulation (ES) resulted in 213 afterdischarges (ADs), with a higher incidence of ADs occurring from stimulation in the hippocampus compared to other brain areas.

While there was no significant correlation between the location of afterdischarges and the epileptogenic zone (EZ), the afterdischarges were more frequently localized to the irritative zone (IZ), suggesting that IZ may play a key role in the generation of ADs.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Properties of afterdischarges from electrical stimulation in patients with epilepsy. Liu, C., Yu, T., Ren, ZW., et al.[2018]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC7750438/

Electrical Stimulation Mapping of Brain Function This requires chronic monitoring with intracranial electroencephalography (EEG), which facilitates better localization of the seizure onset zone ...

2. sciencedirect.com sciencedirect.com/science/article/pii/S0987705325000024

Cortical Stimulation for brain mapping and seizure ... This study shows individual and sparsely validated approach to CS in pediatric epilepsy. The literature review underscores the urgent need to harmonize ...

3. nature.com nature.com/articles/s41467-025-58187-6

Stimulation mapping and whole-brain modeling reveal ... Our analyses revealed an anatomical gradient of excitability across the cortex, with stronger iES-evoked EEG responses in high-order compared to low-order ...

4. epilepsybehavior.com epilepsybehavior.com/article/S1525-5050(25)00258-6/fulltext

Seizure outcomes after cortical stimulation-induced seizures A 50 % or greater seizure reduction occurred in 80.0 % (4/5) in those with SIS compared to 22.2 % (2/9) of those who did not. Zhao et al.

5. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC5836484/

ELECTRICAL STIMULATION MAPPING of the Brain: Basic ... Any mapping exercise requires electrocorticography (ECoG) to monitor for stimulus-induced ADs that may summate to seizures. Modern stimulator and switching ...

6. acns.org acns.org/UserFiles/file/ACNSESMTechStandards_DRAFT5.14.24_v1.pdf

ACNS Guidelines on Electrical Stimulation with Intracranial ... Electrical stimulation mapping (ESM) to localize cortical areas, sometimes including subcortical tracts, supporting sensorimotor and speech/language functions, ...

7. seizure-journal.com seizure-journal.com/article/S1059-1311(16)30243-6/pdf

Cortical stimulation parameters for functional mapping Functional and epileptogenic areas were assessed in all patients by cortical electrical stimulation and intracranial EEG recordings. Data was collected from the ...