Epilepsy, AbsenceNCT04799795
Objective EEG Bed Side Assessment of Impaired Conscious Awareness in Epilepsy
An observational study of Epilepsy, Absence, run by University Hospital Schleswig-Holstein at 1 site in Germany.
Trial summary
In this project EEG recordings between healthy participants and those with a diagnosed Absence-epilepsy will be compared. The investigators suggest differences in EEG microstate analysis and neuropsychological parameters related to interictal cognitive impairment in these patients. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Epilepsy, Absence
- How many people
- 49 participants
- Where
- 1 siteGermany
- Study dates
- 1 Oct 2021to 24 May 2025
- 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
- Healthy volunteers accepted
- Adult, Older adult
Study population: Patients with diagnosed absence epilepsy at least 18 years old; age-matched controls.
Who may be able to join
- age minimum 18 years
- diagnosis of (absence) epilepsy // healthy age-matched controls
- being of good health (besides epilepsy in the case group)
Who cannot join
- central nervous system disorders (besides epilepsy in the case group)
- substance abuse
- pregnancy
Trial locations and contacts
1 site in 1 country.
About this study
In this project EEG recordings between healthy participants and those with a diagnosed Absence-epilepsy will be compared. The investigators suggest differences in EEG microstate analysis and neuropsychological parameters related to interictal cognitive impairment in these patients. This projects goal is to derive an EEG-based measure of conscious awareness.
Read the detailed description
This projects goal is to derive an EEG-based measure of conscious awareness to be applied in the care for epilepsy patients. The established terminology of "ictal" versus "interictal" is deceptive because it suggests that during the "interictal" phase epileptic activity is absent and detrimental mechanisms of the disease are only active during seizures. But evidence exists that cognitive impairment extends to states traditionally considered interictal. The development of an objective, ideally ambulatory test assessing cognitive impairment would not only provide a deeper understanding of the pathology but induce a change in clinical practice: if cognitive impairment could be demonstrated "interictally", this fact would help to weigh treatment effects against potential side-effects.
In this project the investigators will set out to
- identify EEG markers in healthy volunteers, which reflect the changes in spatial and temporal dynamics of neuronal activity during states of reduced conscious awareness using sleep as an example of a state of reduced conscious awareness;
- assess with neuropsychological testing reductions in interictal conscious awareness in patients with epilepsy;
- test, whether markers established under (1) are valid in individuals with epilepsy and interictally reduced conscious awareness (see (2)).
- Conditions
- Epilepsy, Absence
- Keywords
- interictal activity, impaired consciousness, absence epilepsy
- Medical subject headings
- Epilepsy, Absence
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| healthy subjects | Age-matched healthy participants will be recruited via flyers at public education facilities and online advertisement. Participants need to be healthy and without central nervous system disorders and substance abuse. The investigators will also exclude pregnant women from the experiment. | |
| patients with absence epilepsy | Apart from the diagnosis of epilepsy, patients need to be of good health and without central nervous system disorders and substance abuse. The investigators will also exclude pregnant women from the experiment. |
What is being measured
The primary outcome is the main question the study is designed to answer.
temporal integration changes according to different sleep states
The investigators develop an EEG-based measure of impaired conscious awareness based on wakefulness and deepening sleep stages which will serve as a model for increasingly impaired conscious awareness. By performing a microstate analysis on EEG data, the investigators hypothesize a decrease of the temporal integration, a prerequisite for conscious awareness, of the EEG gradually from wakefulness to deep sleep.
Measured: 3 years
temporal integration changes in interictal EEG
The investigators apply the aforementioned analysis (leading to Outcome 1) on interictal EEG recordings obtained from patients with diagnosed absence epilepsy. The investigators hypothesize a reduced temporal integration in epilepsies with reduced consciousness.
Measured: 3 years
graph modularity changes according to different sleep states
The investigators will calculate the EEG-based functional connectivity and graph modularity for each sleep state. The investigators hypothesize that during wakefulness, graph modularity will be lower than during the descent to sleep.
Measured: 3 years
graph modularity changes in interictal EEG
The investigators will calculate the EEG-based functional connectivity and graph modularity for the absence epilepsy condition. The investigators hypothesize that impaired consciousness will be reflected in lower graph modularity compared to healthy subjects.
Measured: 3 years
Secondary outcomes (1)
EEG based measures (Outcome 4) correlate with
The investigators hypothesize that the graph modularity level correlates with neuropsychological test scores in the surveyed data of epilepsy patients.
Measured: 3 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Mar 2021
- Study start1 Oct 2021
- Primary completion24 May 2025
- Study completion24 May 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (10)Papers the sponsor has linked to this study.
- Other trials for Epilepsy, AbsenceStudies 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
- Observational
- Observational model
- Case-control
- Time perspective
- Prospective
- Enrolment
- 49 participants (actual)
Sponsor and investigators
- Lead sponsor
- University Hospital Schleswig-Holstein
- Sponsor type
- University, hospital or other
- Collaborators
- German Research Foundation
- Responsible party
- Principal investigator, Gesine Hermann, MD, University Hospital Schleswig-Holstein
- Investigators
- Inken Toedt, Dr. phil. Dipl.-Psych., Principal investigator, University Hospital Schleswig-Holstein, KielHelmut Laufs, PD Dr. med., Study director, University Hospital Schleswig-Holstein, Kiel
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04799795
- Sponsor's protocol ID
- D 558/17
- Status last verified
- Jul 2025
- First submitted
- 12 Mar 2021
- Last updated
- 8 Jul 2025
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Analysis protocols and analysis scripts will be shared between this studies collaborators through a public platform, probably GitHub. The corresponding repositories will be openly accessible. Calculated data will be accessible in the context of planned publications afterwards. The collected raw data, therefore IPD won't be shared before the final investigation by the study group.
Publications
Brodbeck V, Kuhn A, von Wegner F, Morzelewski A, Tagliazucchi E, Borisov S, Michel CM, Laufs H. EEG microstates of wakefulness and NREM sleep. Neuroimage. 2012 Sep;62(3):2129-39. doi: 10.1016/j.neuroimage.2012.05.060. Epub 2012 May 30.
PubMed 22658975Haimovici A, Tagliazucchi E, Balenzuela P, Laufs H. On wakefulness fluctuations as a source of BOLD functional connectivity dynamics. Sci Rep. 2017 Jul 19;7(1):5908. doi: 10.1038/s41598-017-06389-4.
PubMed 28724928Kuhn A, Brodbeck V, Tagliazucchi E, Morzelewski A, von Wegner F, Laufs H. Narcoleptic Patients Show Fragmented EEG-Microstructure During Early NREM Sleep. Brain Topogr. 2015 Jul;28(4):619-35. doi: 10.1007/s10548-014-0387-1. Epub 2014 Aug 29.
PubMed 25168255Laufs H, Rodionov R, Thornton R, Duncan JS, Lemieux L, Tagliazucchi E. Altered FMRI connectivity dynamics in temporal lobe epilepsy might explain seizure semiology. Front Neurol. 2014 Sep 11;5:175. doi: 10.3389/fneur.2014.00175. eCollection 2014.
PubMed 25309503Tagliazucchi E, Crossley N, Bullmore ET, Laufs H. Deep sleep divides the cortex into opposite modes of anatomical-functional coupling. Brain Struct Funct. 2016 Nov;221(8):4221-4234. doi: 10.1007/s00429-015-1162-0. Epub 2015 Dec 9.
PubMed 26650048Tagliazucchi E, Laufs H. Decoding wakefulness levels from typical fMRI resting-state data reveals reliable drifts between wakefulness and sleep. Neuron. 2014 May 7;82(3):695-708. doi: 10.1016/j.neuron.2014.03.020.
PubMed 24811386Tagliazucchi E, Roseman L, Kaelen M, Orban C, Muthukumaraswamy SD, Murphy K, Laufs H, Leech R, McGonigle J, Crossley N, Bullmore E, Williams T, Bolstridge M, Feilding A, Nutt DJ, Carhart-Harris R. Increased Global Functional Connectivity Correlates with LSD-Induced Ego Dissolution. Curr Biol. 2016 Apr 25;26(8):1043-50. doi: 10.1016/j.cub.2016.02.010. Epub 2016 Apr 13.
PubMed 27085214Tagliazucchi E, von Wegner F, Morzelewski A, Brodbeck V, Borisov S, Jahnke K, Laufs H. Large-scale brain functional modularity is reflected in slow electroencephalographic rhythms across the human non-rapid eye movement sleep cycle. Neuroimage. 2013 Apr 15;70:327-39. doi: 10.1016/j.neuroimage.2012.12.073. Epub 2013 Jan 9.
PubMed 23313420Tagliazucchi E, von Wegner F, Morzelewski A, Brodbeck V, Jahnke K, Laufs H. Breakdown of long-range temporal dependence in default mode and attention networks during deep sleep. Proc Natl Acad Sci U S A. 2013 Sep 17;110(38):15419-24. doi: 10.1073/pnas.1312848110. Epub 2013 Sep 3.
PubMed 24003146von Wegner F, Tagliazucchi E, Laufs H. Information-theoretical analysis of resting state EEG microstate sequences - non-Markovianity, non-stationarity and periodicities. Neuroimage. 2017 Sep;158:99-111. doi: 10.1016/j.neuroimage.2017.06.062. Epub 2017 Jun 30.
PubMed 28673879
Study at a glance
From the registry record, last updated by the sponsor on 8 Jul 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Objective EEG Bed Side Assessment of Impaired Conscious Awareness in Epilepsy
- ClinicalTrials.gov ID
- NCT04799795
- Acronym / sponsor ID
- D 558/17
- Conditions
- Epilepsy, Absence
- Keywords
- interictal activity, impaired consciousness, absence epilepsy
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 49 participants (actual)
- Lead sponsor
- University Hospital Schleswig-HolsteinUniversity, hospital or other
- Collaborators
- German Research Foundation
- Study start
- 1 Oct 2021 (actual)
- Primary completion
- 24 May 2025 (actual)
- Study completion
- 24 May 2025 (actual)
- First posted
- 16 Mar 2021 (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 this project EEG recordings between healthy participants and those with a diagnosed Absence-epilepsy will be compared. The investigators suggest differences in EEG microstate analysis and neuropsychological parameters related to interictal cognitive impairment in these patients. This projects goal is to derive an EEG-based measure of conscious awareness.
Detailed description
This projects goal is to derive an EEG-based measure of conscious awareness to be applied in the care for epilepsy patients. The established terminology of "ictal" versus "interictal" is deceptive because it suggests that during the "interictal" phase epileptic activity is absent and detrimental mechanisms of the disease are only active during seizures. But evidence exists that cognitive impairment extends to states traditionally considered interictal. The development of an objective, ideally ambulatory test assessing cognitive impairment would not only provide a deeper understanding of the pathology but induce a change in clinical practice: if cognitive impairment could be demonstrated "interictally", this fact would help to weigh treatment effects against potential side-effects.
In this project the investigators will set out to
- identify EEG markers in healthy volunteers, which reflect the changes in spatial and temporal dynamics of neuronal activity during states of reduced conscious awareness using sleep as an example of a state of reduced conscious awareness;
- assess with neuropsychological testing reductions in interictal conscious awareness in patients with epilepsy;
- test, whether markers established under (1) are valid in individuals with epilepsy and interictally reduced conscious awareness (see (2)).
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| healthy subjects | – | –Age-matched healthy participants will be recruited via flyers at public education facilities and online advertisement. Participants need to be healthy and without central nervous system disorders and substance abuse. The investigators will also exclude pregnant women from the experiment. |
| patients with absence epilepsy | – | –Apart from the diagnosis of epilepsy, patients need to be of good health and without central nervous system disorders and substance abuse. The investigators will also exclude pregnant women from the experiment. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Patients with diagnosed absence epilepsy at least 18 years old; age-matched controls.
Key inclusion criteria (3 listed)
- age minimum 18 years
- diagnosis of (absence) epilepsy // healthy age-matched controls
- being of good health (besides epilepsy in the case group)
Key exclusion criteria (3 listed)
- central nervous system disorders (besides epilepsy in the case group)
- substance abuse
- pregnancy
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
temporal integration changes according to different sleep states
Time frame: 3 years
The investigators develop an EEG-based measure of impaired conscious awareness based on wakefulness and deepening sleep stages which will serve as a model for increasingly impaired conscious awareness. By performing a microstate analysis on EEG data, the investigators hypothesize a decrease of the temporal integration, a prerequisite for conscious awareness, of the EEG gradually from wakefulness to deep sleep.
temporal integration changes in interictal EEG
Time frame: 3 years
The investigators apply the aforementioned analysis (leading to Outcome 1) on interictal EEG recordings obtained from patients with diagnosed absence epilepsy. The investigators hypothesize a reduced temporal integration in epilepsies with reduced consciousness.
graph modularity changes according to different sleep states
Time frame: 3 years
The investigators will calculate the EEG-based functional connectivity and graph modularity for each sleep state. The investigators hypothesize that during wakefulness, graph modularity will be lower than during the descent to sleep.
graph modularity changes in interictal EEG
Time frame: 3 years
The investigators will calculate the EEG-based functional connectivity and graph modularity for the absence epilepsy condition. The investigators hypothesize that impaired consciousness will be reflected in lower graph modularity compared to healthy subjects.
1 secondary outcome
EEG based measures (Outcome 4) correlate with
Time frame: 3 years
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 8 Jul 2025.
- Background: PubMed 22658975Brodbeck V, Kuhn A, von Wegner F, Morzelewski A, Tagliazucchi E, Borisov S, Michel CM, Laufs H. EEG microstates of wakefulness and NREM sleep. Neuroimage. 2012 Sep;62(3):2129-39. doi: 10.1016/j.neuroimage.2012.05.060. Epub 2012 May 30.
- Background: PubMed 28724928Haimovici A, Tagliazucchi E, Balenzuela P, Laufs H. On wakefulness fluctuations as a source of BOLD functional connectivity dynamics. Sci Rep. 2017 Jul 19;7(1):5908. doi: 10.1038/s41598-017-06389-4.
- Background: PubMed 25168255Kuhn A, Brodbeck V, Tagliazucchi E, Morzelewski A, von Wegner F, Laufs H. Narcoleptic Patients Show Fragmented EEG-Microstructure During Early NREM Sleep. Brain Topogr. 2015 Jul;28(4):619-35. doi: 10.1007/s10548-014-0387-1. Epub 2014 Aug 29.
- Background: PubMed 25309503Laufs H, Rodionov R, Thornton R, Duncan JS, Lemieux L, Tagliazucchi E. Altered FMRI connectivity dynamics in temporal lobe epilepsy might explain seizure semiology. Front Neurol. 2014 Sep 11;5:175. doi: 10.3389/fneur.2014.00175. eCollection 2014.
- Background: PubMed 26650048Tagliazucchi E, Crossley N, Bullmore ET, Laufs H. Deep sleep divides the cortex into opposite modes of anatomical-functional coupling. Brain Struct Funct. 2016 Nov;221(8):4221-4234. doi: 10.1007/s00429-015-1162-0. Epub 2015 Dec 9.
- Background: PubMed 24811386Tagliazucchi E, Laufs H. Decoding wakefulness levels from typical fMRI resting-state data reveals reliable drifts between wakefulness and sleep. Neuron. 2014 May 7;82(3):695-708. doi: 10.1016/j.neuron.2014.03.020.
- Background: PubMed 27085214Tagliazucchi E, Roseman L, Kaelen M, Orban C, Muthukumaraswamy SD, Murphy K, Laufs H, Leech R, McGonigle J, Crossley N, Bullmore E, Williams T, Bolstridge M, Feilding A, Nutt DJ, Carhart-Harris R. Increased Global Functional Connectivity Correlates with LSD-Induced Ego Dissolution. Curr Biol. 2016 Apr 25;26(8):1043-50. doi: 10.1016/j.cub.2016.02.010. Epub 2016 Apr 13.
- Background: PubMed 23313420Tagliazucchi E, von Wegner F, Morzelewski A, Brodbeck V, Borisov S, Jahnke K, Laufs H. Large-scale brain functional modularity is reflected in slow electroencephalographic rhythms across the human non-rapid eye movement sleep cycle. Neuroimage. 2013 Apr 15;70:327-39. doi: 10.1016/j.neuroimage.2012.12.073. Epub 2013 Jan 9.
- Background: PubMed 24003146Tagliazucchi E, von Wegner F, Morzelewski A, Brodbeck V, Jahnke K, Laufs H. Breakdown of long-range temporal dependence in default mode and attention networks during deep sleep. Proc Natl Acad Sci U S A. 2013 Sep 17;110(38):15419-24. doi: 10.1073/pnas.1312848110. Epub 2013 Sep 3.
- Background: PubMed 28673879von Wegner F, Tagliazucchi E, Laufs H. Information-theoretical analysis of resting state EEG microstate sequences - non-Markovianity, non-stationarity and periodicities. Neuroimage. 2017 Sep;158:99-111. doi: 10.1016/j.neuroimage.2017.06.062. Epub 2017 Jun 30.
- Individual participant dataSharing planned: No. Analysis protocols and analysis scripts will be shared between this studies collaborators through a public platform, probably GitHub. The corresponding repositories will be openly accessible. Calculated data will be accessible in the context of planned publications afterwards. The collected raw data, therefore IPD won't be shared before the final investigation by the study group.
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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.
Inken Toedt, Dr. phil. Dipl.-Psych. principal investigator
University Hospital Schleswig-Holstein, Kiel
Helmut Laufs, PD Dr. med. study director
University Hospital Schleswig-Holstein, Kiel
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, Absence, run by University Hospital Schleswig-Holstein at 1 site in Germany.
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 3 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 8 Jul 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 Germany. 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?
temporal integration changes according to different sleep states (time frame: 3 years). The study lists 4 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 NCT04799795, which also lists 10 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 8 Jul 2025.