Objective EEG Bed Side Assessment of Impaired Conscious Awareness in Epilepsy

Status

Completed

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT04799795

Enrollment

Registered

2021-03-16

Start date

2021-10-01

Completion date

2025-05-24

Last updated

2025-07-08

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Epilepsy, Absence

Keywords

interictal activity, impaired consciousness, absence epilepsy

Brief 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. 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 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)).

Interventions

None listed

Study design

Observational model

CASE_CONTROL

Time perspective

PROSPECTIVE

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Yes

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

Design outcomes

Primary

Measure	Time frame	Description
temporal integration changes according to different sleep states	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	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	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	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.

Secondary

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

Countries

Germany

Outcome results