Objective EEG Bed Side Assessment of Impaired Conscious Awareness in Epilepsy

July 2, 2025 updated by: Gesine Hermann, MD, University Hospital Schleswig-Holstein
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.

Study Overview

Status

Completed

Conditions

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

  1. 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;
  2. assess with neuropsychological testing reductions in interictal conscious awareness in patients with epilepsy;
  3. test, whether markers established under (1) are valid in individuals with epilepsy and interictally reduced conscious awareness (see (2)).

Study Type

Observational

Enrollment (Actual)

49

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Germany
      • Kiel, Germany, 24105
        • Department of Neurology

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

Patients with diagnosed absence epilepsy at least 18 years old; age-matched controls.

Description

Inclusion Criteria:

  • age minimum 18 years
  • diagnosis of (absence) epilepsy // healthy age-matched controls
  • being of good health (besides epilepsy in the case group)

Exclusion Criteria:

  • central nervous system disorders (besides epilepsy in the case group)
  • substance abuse
  • pregnancy

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
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 the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
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.
3 years
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.
3 years
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.
3 years
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.
3 years

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
EEG based measures (Outcome 4) correlate with
Time Frame: 3 years
The investigators hypothesize that the graph modularity level correlates with neuropsychological test scores in the surveyed data of epilepsy patients.
3 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University Hospital Schleswig-Holstein

Collaborators

German Research Foundation

Investigators

  • Principal Investigator: Inken Toedt, Dr. phil. Dipl.-Psych., University Hospital Schleswig-Holstein, Kiel
  • Study Director: Helmut Laufs, PD Dr. med., University Hospital Schleswig-Holstein, Kiel

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

October 1, 2021

Primary Completion (Actual)

May 24, 2025

Study Completion (Actual)

May 24, 2025

Study Registration Dates

First Submitted

March 12, 2021

First Submitted That Met QC Criteria

March 12, 2021

First Posted (Actual)

March 16, 2021

Study Record Updates

Last Update Posted (Estimated)

July 8, 2025

Last Update Submitted That Met QC Criteria

July 2, 2025

Last Verified

July 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • D 558/17

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

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.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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