Epilepsy IntractablemultiHFONCT05332990
Multicenter Comparison of Interictal HFO as a Predictor of Seizure Freedom
An observational study of Epilepsy Intractable, run by University of Zurich at 1 site in Switzerland.
Trial summary
In drug-resistant focal epilepsy, interictal high frequency oscillations (HFO) recorded from intracranial EEG (iEEG) may provide clinical information for delineating epileptogenic brain tissue. Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Epilepsy Intractable
- What is being tested?
- HFO analysis
- How many people
- 300 participants
- Where
- 1 siteSwitzerland
- Study dates
- 1 May 2022to 1 May 2024
- 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 Any age
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Study population: We include patients with drug-resistant focal epilepsy of all ages who 1) underwent invasive EEG recordings with subdural and/or depth electrodes as part of their pre-surgical evaluation 4, 2) underwent epilepsy surgery aiming at seizure freedom after resection of a single focus, and 3) and the postsurgical seizure outcome was determined by follow-up visits at ≥ 2 y 32. According to the International League Against Epilepsy (ILAE) Classification 3 we classify outcome into seizure freedom (ILAE 1) or recurrent seizures (ILAE 2-6). Outcome data that are assessed with the Engel scale are mapped to ILAE 1 or ILAE 2-6 respectively.
Data as provided from the participating center
Trial locations and contacts
1 site in 1 country.
Switzerland1 site
University Hospital Zurich, Neurosurgery
Zurich, Canton of Zurich, 8091
About this study
Official title: Multicenter Comparison of Interictal High Frequency Oscillations as a Predictor of Seizure Freedom
In drug-resistant focal epilepsy, interictal high frequency oscillations (HFO) recorded from intracranial EEG (iEEG) may provide clinical information for delineating epileptogenic brain tissue. The iEEG electrode contacts that contain HFO are hypothesized to delineate the epileptogenic zone; their resection should then lead to postsurgical seizure freedom.
We test whether our prospective definition of clinically relevant HFO is in agreement with postsurgical seizure outcome. The algorithm is fully automated and is equally applied to all datasets. The aim is to assess the reliability of the proposed detector and analysis approach.
Read the detailed description
We use an automated data-independent prospective definition of clinically relevant HFO that has been validated in data from two independent epilepsy centers. In this study, we combine retrospectively collected datasets from 9 independent epilepsy centers. The analysis is blinded to clinical outcome. We use iEEG recordings during NREM sleep with a minimum of 12 epochs of 5 minutes of NREM sleep. We automatically detect HFO in the ripple (80-250 Hz) and in the fast ripple (250-500 Hz) band. There is no manual rejection of events in this fully automated algorithm. The type of HFO that we consider clinically relevant is defined as the simultaneous occurrence of a fast-ripple and a ripple. We calculate the temporal consistency of each patient's HFO rates over several data epochs within and between nights. Patients with temporal consistency < 50% are excluded from further analysis. We determine whether all electrode contacts with high HFO rate are included in the resection volume and whether seizure freedom (ILAE 1) was achieved at ≥2 y follow-up.
Applying a previously validated algorithm to a large cohort from several independent epilepsy centers may advance the clinical relevance and the generalizability of HFO analysis as essential next step for use of HFO in clinical practice.
- Conditions
- Epilepsy Intractable
- Being tested
- HFO analysis
- Medical subject headings
- Drug Resistant Epilepsy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
HFO analysisDiagnostic test
We use an automated data-independent prospective definition of clinically relevant HFO that has been validated in data from two independent epilepsy centers.
What is being measured
The primary outcome is the main question the study is designed to answer.
seizure freedom
ILAE grade 1
Measured: 2 years after surgery
seizure recurrence
ILAE grade 2-6
Measured: within 2 years after surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Apr 2022
- Study start1 May 2022
- Primary completion1 May 2024 (estimated)
- Study completion1 May 2024 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (4)Papers the sponsor has linked to this study.
- Other trials for Epilepsy IntractableStudies of the same condition, open and under way.
- More trials run by University of ZurichThe 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
- Case-control
- Time perspective
- Retrospective
- Enrolment
- 300 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Zurich
- Sponsor type
- University, hospital or other
- Collaborators
- McGill University, University of Michigan, University of Calgary, Cook Children's Health Care System, St. Anne's University Hospital Brno, Czech Republic, Mayo Clinic, Thomas Jefferson University, UMC Utrecht, Schweizerisches Epilepsie Zentrum
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05332990
- Sponsor's protocol ID
- multiHFO
- Acronym
- multiHFO
- Status last verified
- Nov 2023
- First submitted
- 10 Apr 2022
- Last updated
- 7 Dec 2023
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Dimakopoulos V, Gotman J, Stacey W, von Ellenrieder N, Jacobs J, Papadelis C, Cimbalnik J, Worrell G, Sperling MR, Zijlmans M, Imbach L, Frauscher B, Sarnthein J. Protocol for multicentre comparison of interictal high-frequency oscillations as a predictor of seizure freedom. Brain Commun. 2022 Jun 9;4(3):fcac151. doi: 10.1093/braincomms/fcac151. eCollection 2022.
PubMed 35770134Dimakopoulos V, Megevand P, Boran E, Momjian S, Seeck M, Vulliemoz S, Sarnthein J. Blinded study: prospectively defined high-frequency oscillations predict seizure outcome in individual patients. Brain Commun. 2021 Sep 2;3(3):fcab209. doi: 10.1093/braincomms/fcab209. eCollection 2021.
PubMed 34541534Fedele T, Burnos S, Boran E, Krayenbuhl N, Hilfiker P, Grunwald T, Sarnthein J. Resection of high frequency oscillations predicts seizure outcome in the individual patient. Sci Rep. 2017 Oct 23;7(1):13836. doi: 10.1038/s41598-017-13064-1.
PubMed 29062105Dimakopoulos V, Gotman J, Klimes P, von Ellenrieder N, Tan SB, Smith G, Gliske SV, Maltseva M, Manalo MK, Pail M, Brazdil M, van Blooijs D, van 't Klooster MA, Johnson S, Laboy S, Ledergerber D, Imbach L, Papadelis C, Sperling MR, Zijlmans M, Cimbalnik J, Jacobs J, Stacey WC, Frauscher B, Sarnthein J. Multicentre analysis of seizure outcome predicted by removal of high-frequency oscillations. Brain. 2025 May 13;148(5):1769-1777. doi: 10.1093/brain/awae361.
PubMed 39530262
Study at a glance
From the registry record, last updated by the sponsor on 7 Dec 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Multicenter Comparison of Interictal High Frequency Oscillations as a Predictor of Seizure Freedom
- ClinicalTrials.gov ID
- NCT05332990
- Acronym / sponsor ID
- multiHFO / multiHFO
- Conditions
- Epilepsy Intractable
- Study type
- Observational
- Recruitment status
- Unknown status
- Enrolment
- 300 participants (estimated)
- Lead sponsor
- University of ZurichUniversity, hospital or other
- Collaborators
- McGill University, University of Michigan, University of Calgary, Cook Children's Health Care System, St. Anne's University Hospital Brno, Czech Republic, Mayo Clinic, Thomas Jefferson University, UMC Utrecht, Schweizerisches Epilepsie Zentrum
- Study start
- 1 May 2022 (actual)
- Primary completion
- 1 May 2024 (estimated)
- Study completion
- 1 May 2024 (estimated)
- First posted
- 18 Apr 2022 (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.
In drug-resistant focal epilepsy, interictal high frequency oscillations (HFO) recorded from intracranial EEG (iEEG) may provide clinical information for delineating epileptogenic brain tissue. The iEEG electrode contacts that contain HFO are hypothesized to delineate the epileptogenic zone; their resection should then lead to postsurgical seizure freedom.
We test whether our prospective definition of clinically relevant HFO is in agreement with postsurgical seizure outcome. The algorithm is fully automated and is equally applied to all datasets. The aim is to assess the reliability of the proposed detector and analysis approach.
Detailed description
We use an automated data-independent prospective definition of clinically relevant HFO that has been validated in data from two independent epilepsy centers. In this study, we combine retrospectively collected datasets from 9 independent epilepsy centers. The analysis is blinded to clinical outcome. We use iEEG recordings during NREM sleep with a minimum of 12 epochs of 5 minutes of NREM sleep. We automatically detect HFO in the ripple (80-250 Hz) and in the fast ripple (250-500 Hz) band. There is no manual rejection of events in this fully automated algorithm. The type of HFO that we consider clinically relevant is defined as the simultaneous occurrence of a fast-ripple and a ripple. We calculate the temporal consistency of each patient's HFO rates over several data epochs within and between nights. Patients with temporal consistency < 50% are excluded from further analysis. We determine whether all electrode contacts with high HFO rate are included in the resection volume and whether seizure freedom (ILAE 1) was achieved at ≥2 y follow-up.
Applying a previously validated algorithm to a large cohort from several independent epilepsy centers may advance the clinical relevance and the generalizability of HFO analysis as essential next step for use of HFO in clinical practice.
Study design
- Observational model
- Case-control
- Time perspective
- Retrospective
Who may qualify
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- Study population
- We include patients with drug-resistant focal epilepsy of all ages who 1) underwent invasive EEG recordings with subdural and/or depth electrodes as part of their pre-surgical evaluation 4, 2) underwent epilepsy surgery aiming at seizure freedom after resection of a single focus, and 3) and the postsurgical seizure outcome was determined by follow-up visits at ≥ 2 y 32. According to the International League Against Epilepsy (ILAE) Classification 3 we classify outcome into seizure freedom (ILAE 1) or recurrent seizures (ILAE 2-6). Outcome data that are assessed with the Engel scale are mapped to ILAE 1 or ILAE 2-6 respectively.
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 |
|---|---|---|
| HFO analysisWe use an automated data-independent prospective definition of clinically relevant HFO that has been validated in data from two independent epilepsy centers. | Diagnostic test | – |
Primary outcome
seizure freedom
Time frame: 2 years after surgery
ILAE grade 1
seizure recurrence
Time frame: within 2 years after surgery
ILAE grade 2-6
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Dec 2023.
- Results publication: PubMed 35770134Dimakopoulos V, Gotman J, Stacey W, von Ellenrieder N, Jacobs J, Papadelis C, Cimbalnik J, Worrell G, Sperling MR, Zijlmans M, Imbach L, Frauscher B, Sarnthein J. Protocol for multicentre comparison of interictal high-frequency oscillations as a predictor of seizure freedom. Brain Commun. 2022 Jun 9;4(3):fcac151. doi: 10.1093/braincomms/fcac151. eCollection 2022.
- Results publication: PubMed 34541534Dimakopoulos V, Megevand P, Boran E, Momjian S, Seeck M, Vulliemoz S, Sarnthein J. Blinded study: prospectively defined high-frequency oscillations predict seizure outcome in individual patients. Brain Commun. 2021 Sep 2;3(3):fcab209. doi: 10.1093/braincomms/fcab209. eCollection 2021.
- Results publication: PubMed 29062105Fedele T, Burnos S, Boran E, Krayenbuhl N, Hilfiker P, Grunwald T, Sarnthein J. Resection of high frequency oscillations predicts seizure outcome in the individual patient. Sci Rep. 2017 Oct 23;7(1):13836. doi: 10.1038/s41598-017-13064-1.
- Derived from this study: PubMed 39530262Dimakopoulos V, Gotman J, Klimes P, von Ellenrieder N, Tan SB, Smith G, Gliske SV, Maltseva M, Manalo MK, Pail M, Brazdil M, van Blooijs D, van 't Klooster MA, Johnson S, Laboy S, Ledergerber D, Imbach L, Papadelis C, Sperling MR, Zijlmans M, Cimbalnik J, Jacobs J, Stacey WC, Frauscher B, Sarnthein J. Multicentre analysis of seizure outcome predicted by removal of high-frequency oscillations. Brain. 2025 May 13;148(5):1769-1777. doi: 10.1093/brain/awae361.
- HFO analysis: publications, algorithms and dataLink provided by the sponsor.
- Individual participant dataSharing planned: No
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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. 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?
An observational study of Epilepsy Intractable, run by University of Zurich at 1 site in Switzerland.
The full registered description is in the About this study section and the official record.
Is this clinical trial currently recruiting?
The record says: status not confirmed, as of the sponsor's last update on 7 Dec 2023. 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 Switzerland. 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?
Results are not available in the source record.
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?
seizure freedom (time frame: 2 years after surgery). The study lists 2 primary outcomes in all. 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 NCT05332990, which also lists 4 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 7 Dec 2023.