AnesthesiaNCT03629743
Correlate of Surface Electroencephalogram (EEG) With Implanted EEG Recordings (ECOG)
An observational study of Anesthesia, run by Stanford University at 1 site in United States.
Trial summary
Improve understanding of the correlation between surface EEG and implanted EEG recordings Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Anesthesia
- What is being tested?
- EEG and ECOG
- Type of treatment
- Medical device
- How many people
- 20 participants
- Where
- 1 siteUnited States
- Study dates
- 11 Nov 2019to 9 Aug 2026
- Phase
- Observational
- Are there results?
- None posted in the registry
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
- No healthy volunteers
- Adult, Older adult
Study population: Stanford Health Care and Clinics
Who may be able to join
- Male or Female subjects 18 years of age or older.
- English or Spanish Speaking
- Subjects who have been previously diagnosed with intractable epilepsy and require implantation of invasive electrophysiological recordings as part of their routine clinical presurgical workup.
Who cannot join
- Patients with skin abnormalities at the planned application sites that would interfere with sensor or electrode applications.
- Patients with pre-existing conditions and/or co-morbidities that would prohibit them from participating in the study due to unacceptable risks to their health and well-being, as determined by the Principal Investigator (PI).
- Patients who the PI deems ineligible at the PI's discretion
- Pregnant patients
Trial locations and contacts
1 site in 1 country.
About this study
Improve understanding of the correlation between surface EEG and implanted EEG recordings
- Conditions
- Anesthesia
- Being tested
- EEG, ECOG
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
EEGDevice
EEG will be collected with Brain Product's VAMP-16 channel EEG Monitor using the accompanying software. (Website with further specifications and product details: https://www.brainproducts.com/productdetails.php?id=15)
ECOGDevice
ECOG will be collected with Nihon Kohden acquisition System and accompanying software and depth electrodes.
| Study group | Role | What they receive |
|---|---|---|
| ECOG and EEG Sensor | Study subjects are neurosurgical patients with medically refractory epilepsy who will have implanted with intracranial ECoG electrodes. The electrodes will be used during a period of inpatient monitoring to identify resectable seizure foci. Receives: Device: EEG; Device: ECOG |
What is being measured
The primary outcome is the main question the study is designed to answer.
Electrocardiogram (EEG) change before, during, and after anesthesia.
Patient subjective level of consciousness during and after anesthesia administration will be assessed using response to verbal stimuli, response via button press, reported subjective level of consciousness, and/or response to memory tests (i.e. demonstration of explicit memory recall). Around loss and recovery of consciousness time points (e.g. induction or emergence from anesthesia or when patient falls asleep or wakes up during 24 hour postoperative time points) level of consciousness will be assessed in brief intervals (seconds) until patient no longer responds or begins to respond. Data collected before, after, and during seizure activity if a patient loses consciousness or has diminished consciousness may also be compared.
Measured: Up to 48 hours. Specific time points are dependent on patient clinical events.
Secondary outcomes (2)
Electrocardiogram (EEG) change during any changes in consciousness.
Scalp and cortical electrical activity collected using EEG and ECOG arrays respectively will be analyzed using standard frequency-derived measures (e.g. spectrograms, Fourier analysis), nonlinear dynamical analyses (e.g. correlation dimension, entropy), network dynamics (e.g. connectivity matrices, path length), and/or machine learning. These measures will include all of the data collected from the start of the implant procedure until 24 hours after the implant procedure has ended. Data collected before, after, and during seizure activity if a patient loses consciousness or has diminished consciousness may also be compared. Reports will included characterization of electrophysiological activity before, during, and after variations in behavioral and subjectively reported consciousness.
Measured: Up to 48 hours. Specific time points are dependent on patient clinical events.
Electrocardiogram (EEG) change during any seizures.
Scalp and cortical electrical activity collected using EEG and ECOG arrays respectively will be analyzed using standard frequency-derived measures (e.g. spectrograms, Fourier analysis), nonlinear dynamical analyses (e.g. correlation dimension, entropy), network dynamics (e.g. connectivity matrices, path length), and/or machine learning. Data collected before, after, and during seizure activity if a patient loses consciousness or has diminished consciousness may also be compared. Reports will include characterization and comparison of EEG and ECOG electrophysiological activity and analyses during consciousness transitions and significant time points.
Measured: Up to 48 hours. Specific time points are dependent on patient clinical events.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Aug 2018
- Study start11 Nov 2019
- Primary completion9 Aug 2026
- Study completion9 Aug 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (7)Papers the sponsor has linked to this study.
- Other trials for AnesthesiaStudies of the same condition, open and under way.
- More trials run by Stanford 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 20 participants (actual)
Sponsor and investigators
- Lead sponsor
- Stanford University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, David R. Drover, Stanford University
- Investigators
- David Drover, MD, Principal investigator, Stanford University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03629743
- Sponsor's protocol ID
- 45987
- Status last verified
- Aug 2026
- First submitted
- 29 May 2018
- Last updated
- 11 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- No
Publications
Hashiguchi K, Morioka T, Yoshida F, Miyagi Y, Nagata S, Sakata A, Sasaki T. Correlation between scalp-recorded electroencephalographic and electrocorticographic activities during ictal period. Seizure. 2007 Apr;16(3):238-47. doi: 10.1016/j.seizure.2006.12.010. Epub 2007 Jan 19.
PubMed 17236792Asano E, Brown EC, Juhasz C. How to establish causality in epilepsy surgery. Brain Dev. 2013 Sep;35(8):706-20. doi: 10.1016/j.braindev.2013.04.004. Epub 2013 May 15.
PubMed 23684007Smith EH, Liou JY, Davis TS, Merricks EM, Kellis SS, Weiss SA, Greger B, House PA, McKhann GM 2nd, Goodman RR, Emerson RG, Bateman LM, Trevelyan AJ, Schevon CA. The ictal wavefront is the spatiotemporal source of discharges during spontaneous human seizures. Nat Commun. 2016 Mar 29;7:11098. doi: 10.1038/ncomms11098.
PubMed 27020798Ramantani G, Maillard L, Koessler L. Correlation of invasive EEG and scalp EEG. Seizure. 2016 Oct;41:196-200. doi: 10.1016/j.seizure.2016.05.018. Epub 2016 Jun 10.
PubMed 27324839Hajat Z, Ahmad N, Andrzejowski J. The role and limitations of EEG-based depth of anaesthesia monitoring in theatres and intensive care. Anaesthesia. 2017 Jan;72 Suppl 1:38-47. doi: 10.1111/anae.13739.
PubMed 28044337Fahy BG, Chau DF. The Technology of Processed Electroencephalogram Monitoring Devices for Assessment of Depth of Anesthesia. Anesth Analg. 2018 Jan;126(1):111-117. doi: 10.1213/ANE.0000000000002331.
PubMed 28786839Purdon PL, Sampson A, Pavone KJ, Brown EN. Clinical Electroencephalography for Anesthesiologists: Part I: Background and Basic Signatures. Anesthesiology. 2015 Oct;123(4):937-60. doi: 10.1097/ALN.0000000000000841.
PubMed 26275092
Study at a glance
From the registry record, last updated by the sponsor on 11 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Correlate of Surface Electroencephalogram (EEG) With Implanted EEG Recordings (ECOG)
- ClinicalTrials.gov ID
- NCT03629743
- Acronym / sponsor ID
- 45987
- Conditions
- Anesthesia
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 20 participants (actual)
- Lead sponsor
- Stanford UniversityUniversity, hospital or other
- Study start
- 11 Nov 2019 (actual)
- Primary completion
- 9 Aug 2026 (actual)
- Study completion
- 9 Aug 2026 (actual)
- First posted
- 14 Aug 2018 (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.
Improve understanding of the correlation between surface EEG and implanted EEG recordings
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| ECOG and EEG Sensor | – | Device: EEG, Device: ECOGStudy subjects are neurosurgical patients with medically refractory epilepsy who will have implanted with intracranial ECoG electrodes. The electrodes will be used during a period of inpatient monitoring to identify resectable seizure foci. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Stanford Health Care and Clinics
Key inclusion criteria (3 listed)
- Male or Female subjects 18 years of age or older.
- English or Spanish Speaking
- Subjects who have been previously diagnosed with intractable epilepsy and require implantation of invasive electrophysiological recordings as part of their routine clinical presurgical workup.
Key exclusion criteria (4 listed)
- Patients with skin abnormalities at the planned application sites that would interfere with sensor or electrode applications.
- Patients with pre-existing conditions and/or co-morbidities that would prohibit them from participating in the study due to unacceptable risks to their health and well-being, as determined by the Principal Investigator (PI).
- Patients who the PI deems ineligible at the PI's discretion
- Pregnant patients
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 |
|---|---|---|
| EEGEEG will be collected with Brain Product's VAMP-16 channel EEG Monitor using the accompanying software. (Website with further specifications and product details: https://www.brainproducts.com/productdetails.php?id=15) | Device | ECOG and EEG Sensor |
| ECOGECOG will be collected with Nihon Kohden acquisition System and accompanying software and depth electrodes. | Device | ECOG and EEG Sensor |
Primary outcome
Electrocardiogram (EEG) change before, during, and after anesthesia.
Time frame: Up to 48 hours. Specific time points are dependent on patient clinical events.
Patient subjective level of consciousness during and after anesthesia administration will be assessed using response to verbal stimuli, response via button press, reported subjective level of consciousness, and/or response to memory tests (i.e. demonstration of explicit memory recall). Around loss and recovery of consciousness time points (e.g. induction or emergence from anesthesia or when patient falls asleep or wakes up during 24 hour postoperative time points) level of consciousness will be assessed in brief intervals (seconds) until patient no longer responds or begins to respond. Data collected before, after, and during seizure activity if a patient loses consciousness or has diminished consciousness may also be compared.
2 secondary outcomes
Electrocardiogram (EEG) change during any changes in consciousness.
Time frame: Up to 48 hours. Specific time points are dependent on patient clinical events.
Electrocardiogram (EEG) change during any seizures.
Time frame: Up to 48 hours. Specific time points are dependent on patient clinical events.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Aug 2026.
- Background: PubMed 17236792Hashiguchi K, Morioka T, Yoshida F, Miyagi Y, Nagata S, Sakata A, Sasaki T. Correlation between scalp-recorded electroencephalographic and electrocorticographic activities during ictal period. Seizure. 2007 Apr;16(3):238-47. doi: 10.1016/j.seizure.2006.12.010. Epub 2007 Jan 19.
- Background: PubMed 23684007Asano E, Brown EC, Juhasz C. How to establish causality in epilepsy surgery. Brain Dev. 2013 Sep;35(8):706-20. doi: 10.1016/j.braindev.2013.04.004. Epub 2013 May 15.
- Background: PubMed 27020798Smith EH, Liou JY, Davis TS, Merricks EM, Kellis SS, Weiss SA, Greger B, House PA, McKhann GM 2nd, Goodman RR, Emerson RG, Bateman LM, Trevelyan AJ, Schevon CA. The ictal wavefront is the spatiotemporal source of discharges during spontaneous human seizures. Nat Commun. 2016 Mar 29;7:11098. doi: 10.1038/ncomms11098.
- Background: PubMed 27324839Ramantani G, Maillard L, Koessler L. Correlation of invasive EEG and scalp EEG. Seizure. 2016 Oct;41:196-200. doi: 10.1016/j.seizure.2016.05.018. Epub 2016 Jun 10.
- Background: PubMed 28044337Hajat Z, Ahmad N, Andrzejowski J. The role and limitations of EEG-based depth of anaesthesia monitoring in theatres and intensive care. Anaesthesia. 2017 Jan;72 Suppl 1:38-47. doi: 10.1111/anae.13739.
- Background: PubMed 28786839Fahy BG, Chau DF. The Technology of Processed Electroencephalogram Monitoring Devices for Assessment of Depth of Anesthesia. Anesth Analg. 2018 Jan;126(1):111-117. doi: 10.1213/ANE.0000000000002331.
- Background: PubMed 26275092Purdon PL, Sampson A, Pavone KJ, Brown EN. Clinical Electroencephalography for Anesthesiologists: Part I: Background and Basic Signatures. Anesthesiology. 2015 Oct;123(4):937-60. doi: 10.1097/ALN.0000000000000841.
- Individual participant dataSharing planned: No
Related trials for Anesthesia
Not yet recruitingObservational study
"Comparison of Oxygen Reserve Index (ORI), End-Tidal Oxygen, and Time-Based Preoxygenation Targets With Arterial Blood Gas During Preoxygenation
Preoxygenation Adequacy Assessed by Oxygen Reserve Index, End-tidal Oxygen and Arterial Blood Gas
RecruitingObservational study
Comparison of Hemodynamic Responses During Anesthesia Induction Using Eleveld and Schnider
Spinal (Fusion) Surgery, Total Intravenous Anesthesia
Not yet recruiting
A Randomized Controlled SaCo-VLM Trial
General Anaesthesia Using Supraglotic Airway
Not yet recruiting
Bispectral Index-Guided Propofol Sedation During Endoscopic Retrograde Cholangiopancreatography
Deep Sedation, Endoscopic Retrograde Cholangiopancreatography
RecruitingPhase 4
Comparison of Hemodynamics and Respiratory Function Between Ciprofol and Propofol in Elderly Patients Undergoing Non-intubated General Anesthesia
Comparison of Hemodynamics and Respiratory Function Between Ciprofol and Propofol in Elderly Patients Undergoing Non-intubated General Anesthesia
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.
David Drover, MD principal investigator
Stanford University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Anesthesia, run by Stanford University 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 3 inclusion and 4 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 11 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 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Electrocardiogram (EEG) change before, during, and after anesthesia. (time frame: Up to 48 hours. Specific time points are dependent on patient clinical events.). 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 NCT03629743, which also lists 7 linked publications.
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 11 Aug 2026.