EpilepsyNCT04266041

High-density EEG in Neurological Disorders

A study testing High-density electroencephalogram (HD-EEG) in people with Epilepsy and Tumor, run by Dartmouth-Hitchcock Medical Center at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record

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Trial summary

The purpose of the study is to use a new method of high-density electroencephalogram (HD-EEG) recording to map brain areas important for movement, sensation, language, emotion, and cognition. Read more about this study

Who is it for?: Ages 18 years and olderHealthy volunteers can take part
Conditions the study is for: Epilepsy, Tumor, Healthy
What is being tested?: High-density electroencephalogram (HD-EEG)
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 122 participants
Where: 1 siteUnited States
Study dates: 9 Feb 2018to 13 Dec 2024
Phase: Interventional
Are there results?: Yes, posted in the registrySummary in the doctors' view

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 years and older
All sexes
Healthy volunteers accepted
Adult, Older adult

Who may be able to join

Able to perform the tasks
Able to give own consent

Who cannot join

Any neurologic or psychiatric diagnosis such as stroke, tumor, or psychosis judged to interfere with high-density EEG.

Trial locations and contacts

1 site in 1 country.

United States1 site

Dartmouth-Hitchcock Medical Center
Lebanon, New Hampshire, 03756

Other trials in United States

About this study

The purpose of the study is to use a new method of high-density electroencephalogram (HD-EEG) recording to map brain areas important for movement, sensation, language, emotion, and cognition.

Read the detailed description

This study will measure brain waves using high-density EEG. Participants will be asked wear a cap with electrodes attached to it. During the recording, participants may be asked to rest, sleep, or complete a task. The tasks involve viewing pictures, answering questions, speaking, or moving an arm or leg. Recordings generally last between 60-120 minutes.*

Conditions: Epilepsy, Tumor, Healthy
Being tested: High-density electroencephalogram (HD-EEG)
Keywords: Electroencephalogram (EEG), Epilepsy, Lesion, Brain, Language, Movement, Sensation, Mapping, Dense-array EEG, High-density EEG, HD-EEG, stroke, Electrical Impedance Tomography
Medical subject headings: Epilepsy, Neoplasms, Language, Stroke

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

High-density electroencephalogram (HD-EEG)Diagnostic test
This study will focus on obtaining a special type of high-density scalp electroencephalography (HD-EEG) recordings in patients with neurological disorders (i.e., epilepsy, brain tumor, stroke, etc.) and appropriately matched controls. HD-EEG is a scalp EEG which uses up to 256 channels compared to the standard 21 channels used for routine clinical applications. The reason for using more channels to record is for more precise localization of epileptogenic foci and/or more precise mapping of brain functions. This type of EEG requires the use of patient's own MRI scan to precisely localize activity. Therefore, all patients and controls getting an HD-EEG will require a structural MRI scan.

Study groups in NCT04266041
Study group	Role	What they receive
High-density EEG localization in epilepsy	Experimental	High-density EEG will be used for brain localization in epilepsy patients Receives: Diagnostic Test: High-density electroencephalogram (HD-EEG)
High-density EEG localization in healthy controls	Active comparator	High-density EEG will be used for brain localization in healthy controls Receives: Diagnostic Test: High-density electroencephalogram (HD-EEG)
High-density EEG localization in tumor patients	Experimental	High-density EEG will be used for brain localization in tumor patients Receives: Diagnostic Test: High-density electroencephalogram (HD-EEG)
High-density EEG localization in peripheral nerve patients	Experimental	High-density EEG will be used for brain localization in patients with peripheral nerve dysfunction Receives: Diagnostic Test: High-density electroencephalogram (HD-EEG)
High-density EEG localization in stroke patients	Experimental	High-density EEG will be used for brain localization in patients who have recently experienced a stroke Receives: Diagnostic Test: High-density electroencephalogram (HD-EEG)

What is being measured

The primary outcome is the main question the study is designed to answer.

Localizing Brain Regions That Generate Interictal Spikes
The frequency of detecting interictal spikes in HD-EEG The distance between the source location determined by electrical source imaging and the spike locations determined by SEEG studies
Measured: From 30-60 min HD-EEG recording, pre-operatively

Secondary outcomes (5)

Localize Brain Functions in Patients and Healthy Controls
Localize brain functions using high-density EEG recordings
Measured: At baseline for approximately 60 - 90 minutes
Localize Brain Areas Involved in Language
Localize brain areas involved in language using high-density EEG recordings
Measured: At baseline for approximately 60 - 90 minutes
Localize Brain Areas Involved in Movement
Localize brain areas involved in movement using high-density EEG recordings
Measured: At baseline for approximately 60 - 90 minutes
Localize Brain Areas Involved in Sensation
Localize brain areas involved in sensation using high-density EEG recordings
Measured: At baseline for approximately 60 - 90 minutes
Localize Brain Areas Associated With Lesions
Localize brain areas associated with lesions using high-density EEG recordings
Measured: At baseline for approximately 60 - 90 minutes

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

9 Feb 201813 Dec 2024

First posted12 Feb 2020
Study start9 Feb 2018
Primary completion31 May 2024
Study completion13 Dec 2024

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Other trials for EpilepsyStudies of the same condition, open and under way.
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: Diagnosis
Allocation: Non-randomised
Intervention model: Parallel groups
Masking: None (open label)
Enrolment: 122 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT04266041
Sponsor's protocol ID: D18111 30813
Status last verified: Nov 2025
First submitted: 10 Feb 2020
Last updated: 12 Dec 2025
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: No
FDA-regulated drug: No
FDA-regulated device: Yes

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

RecruitingObservational study
Tumor Related Epilepsy
Epilepsy, Cancer
Enrolling by invitation
An Examination of Cognitive and Sensorimotor Processes in Patients With Epilepsy
Epilepsy
RecruitingObservational study
Investigating Epilepsy: Screening and Evaluation
Seizures, Epilepsy
RecruitingPhase 3
Study Evaluating the Efficacy and Safety of RAP-219 in Adult Participants With Focal Seizures FOCUS-1
Focal Seizure, Epilepsy
Enrolling by invitationObservational study
Neurophysiological Intraoperative or Epilepsy Monitoring
Patients Operated on at the Neurosurgery Department

All Epilepsy trials

Study at a glance

From the registry record, last updated by the sponsor on 12 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: High-density EEG in Neurological Disorders
ClinicalTrials.gov ID: NCT04266041
Acronym / sponsor ID: D18111 30813
Conditions: Epilepsy, Tumor, Healthy
Keywords: Electroencephalogram (EEG), Epilepsy, Lesion, Brain, Language, Movement, Sensation, Mapping
Study type: Interventional
Recruitment status: Completed
Enrolment: 122 participants (actual)
Lead sponsor: Dartmouth-Hitchcock Medical CenterUniversity, hospital or other
Study start: 9 Feb 2018 (actual)
Primary completion: 31 May 2024 (actual)
Study completion: 13 Dec 2024 (actual)
First posted: 12 Feb 2020 (actual)
Results: Posted 12 Dec 2025

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

The purpose of the study is to use a new method of high-density electroencephalogram (HD-EEG) recording to map brain areas important for movement, sensation, language, emotion, and cognition.

Detailed description

Study design

Primary purpose: Diagnosis
Allocation: Non-randomised
Intervention model: Parallel groups
Masking: None (open label)
Number of arms: 5

Arm	Type	Receives
High-density EEG localization in epilepsy	Experimental	Diagnostic Test: High-density electroencephalogram (HD-EEG)High-density EEG will be used for brain localization in epilepsy patients
High-density EEG localization in healthy controls	Active comparator	Diagnostic Test: High-density electroencephalogram (HD-EEG)High-density EEG will be used for brain localization in healthy controls
High-density EEG localization in tumor patients	Experimental	Diagnostic Test: High-density electroencephalogram (HD-EEG)High-density EEG will be used for brain localization in tumor patients
High-density EEG localization in peripheral nerve patients	Experimental	Diagnostic Test: High-density electroencephalogram (HD-EEG)High-density EEG will be used for brain localization in patients with peripheral nerve dysfunction
High-density EEG localization in stroke patients	Experimental	Diagnostic Test: High-density electroencephalogram (HD-EEG)High-density EEG will be used for brain localization in patients who have recently experienced a stroke

Who may qualify

Ages: 18 years and older
Sex: All
Healthy volunteers: Accepted
Age groups: Adult, Older adult

Key inclusion criteria (2 listed)

Able to perform the tasks
Able to give own consent

Key exclusion criteria (1 listed)

Any neurologic or psychiatric diagnosis such as stroke, tumor, or psychosis judged to interfere with high-density EEG.

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
High-density electroencephalogram (HD-EEG)This study will focus on obtaining a special type of high-density scalp electroencephalography (HD-EEG) recordings in patients with neurological disorders (i.e., epilepsy, brain tumor, stroke, etc.) and appropriately matched controls. HD-EEG is a scalp EEG which uses up to 256 channels compared to the standard 21 channels used for routine clinical applications. The reason for using more channels to record is for more precise localization of epileptogenic foci and/or more precise mapping of brain functions. This type of EEG requires the use of patient's own MRI scan to precisely localize activity. Therefore, all patients and controls getting an HD-EEG will require a structural MRI scan.	Diagnostic test	High-density EEG localization in epilepsy, High-density EEG localization in healthy controls, High-density EEG localization in peripheral nerve patients, High-density EEG localization in stroke patients, High-density EEG localization in tumor patients

Primary outcome

Localizing Brain Regions That Generate Interictal Spikes
Time frame: From 30-60 min HD-EEG recording, pre-operatively
The frequency of detecting interictal spikes in HD-EEG The distance between the source location determined by electrical source imaging and the spike locations determined by SEEG studies

5 secondary outcomes

Localize Brain Functions in Patients and Healthy Controls
Time frame: At baseline for approximately 60 - 90 minutes
Localize Brain Areas Involved in Language
Time frame: At baseline for approximately 60 - 90 minutes
Localize Brain Areas Involved in Movement
Time frame: At baseline for approximately 60 - 90 minutes
Localize Brain Areas Involved in Sensation
Time frame: At baseline for approximately 60 - 90 minutes
Localize Brain Areas Associated With Lesions
Time frame: At baseline for approximately 60 - 90 minutes

Results and safety

Results posted to the registry on 12 Dec 2025, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
High-density EEG Localization in Epilepsy	95	95
High-density EEG Localization in Healthy Controls	12	12
High-density EEG Localization in Tumor Patients	1	1
High-density EEG Localization in Peripheral Nerve Patients	4	4
High-density EEG Localization in Stroke Patients	7	7

Primary outcome: Localizing Brain Regions That Generate Interictal Spikes

Time frame: From 30-60 min HD-EEG recording, pre-operatively. Count of participants. Unit: Participants

Measure	High-density EEG Localization in Epilepsy n = 87
Value	52

Population analysed: 95 adult patients were enrolled in this study. Five subjects have already got neurostimulator (RNS or DBS) implanted before the study, of whom the HD-EEG data were excluded for further analysis. Two other subjects' recordings were excluded due to excessive electrical noise or faulty bulk connector. Therefore, 87 subjects with decent resting-state HD-EEG recordings were processed for spike detection. Interictal spikes were detected in the HD-EEG recordings of nearly 60% of subjects (n = 52).

5 secondary outcomes are reported in the full results.

Adverse events

Time frame: Adverse event data were collected from the consent through the end of participation for each subject (typically one day).. Other adverse events reported at 0% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
High-density EEG Localization in Epilepsy	0 of 95 (0%)	0 of 95 (0%)	0 of 95
High-density EEG Localization in Healthy Controls	0 of 12 (0%)	0 of 12 (0%)	0 of 12
High-density EEG Localization in Tumor Patients	0 of 1 (0%)	0 of 1 (0%)	0 of 1
High-density EEG Localization in Peripheral Nerve Patients	0 of 4 (0%)	0 of 4 (0%)	0 of 4
High-density EEG Localization in Stroke Patients	2 of 7 (28.6%)	1 of 7 (14.3%)	1 of 7

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 12 Dec 2025.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.

Related trials for Epilepsy

RecruitingObservational study
Tumor Related Epilepsy
Epilepsy, Cancer
Enrolling by invitation
An Examination of Cognitive and Sensorimotor Processes in Patients With Epilepsy
Epilepsy
RecruitingObservational study
Investigating Epilepsy: Screening and Evaluation
Seizures, Epilepsy
RecruitingPhase 3
Study Evaluating the Efficacy and Safety of RAP-219 in Adult Participants With Focal Seizures FOCUS-1
Focal Seizure, Epilepsy
Enrolling by invitationObservational study
Neurophysiological Intraoperative or Epilepsy Monitoring
Patients Operated on at the Neurosurgery Department

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. This study is not recruiting at the moment.

The record lists no contact. Use the official record to reach the sponsor.

1 site in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A study testing High-density electroencephalogram (HD-EEG) in people with Epilepsy and Tumor, run by Dartmouth-Hitchcock Medical Center at 1 site 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 2 inclusion and 1 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: finished, as of the sponsor's last update on 12 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site 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?

Yes. Results are posted in the registry (first posted 12 Dec 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

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?

Localizing Brain Regions That Generate Interictal Spikes (time frame: From 30-60 min HD-EEG recording, pre-operatively). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04266041.

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 12 Dec 2025.