Patients with drug-resistant temporal lobe epilepsy
Conditions
Interventions
Group 1: REM-theta-tCS: experimental nocturnal sleep with cathodal REM-specific theta-tCS in healthy older volunteers (6 Hz, between 5 and 255 µA, DC baseline at 130 µA, 1 s fade in/out, maximum curre
study part 2.
Group 5: Sham Stimulation: Sham REM-specific theta-tCS during nocturnal sleep in healthy older volunteers and epilepsy patients (cross-over assignment, applicable for each participant).
Sponsors
Universitätsmedizin Greifswald
Eligibility
Sex/Gender
All
Age
18 Years to 80 Years
Inclusion criteria
Inclusion criteria: - Healthy older adults aged between 60-80 years - screening in a structured telephone interview - Epilepsy patients: >18 years of age with drug-resistant temporal lobe epilepsy - Epilepsy patients: will undergo intracranial electroencephalography as part of their clinical pre-surgical evaluation of refractory focal epilepsy with a suspected temporal / temporomesial seizure onset zone - Only participants with health insurance will be included, to ensure that incidental findings can be further investigated
Exclusion criteria
Exclusion criteria: Healthy older adults: - Neurodegenerative neurological illnesses, epilepsy or history of seizures - medication acting primarily on the central nervous system - Mini Mental Status Examination scores below 24 - Severe and untreated medical conditions - History of severe alcoholism or use of drugs - Severe psychiatric disorders such as depression (if not in remission) or psychosis - Contraindication to tDCS application - Sleep disorders (and sleep medication) - insufficient German language skills (relevant for memory testing) - the following will not lead to exclusion in the epilepsy patient group: temporal sclerosis; medication acting primarily on the central nervous system Additional exclusion criteria for epilepsy patients: - 3 ASD currently taken - severe cognitive side effects of ASD (EPITRACK with a cutoff score = 28)
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Cathodal theta-tCS during REM sleep will immediately decrease E/I balance significantly more than sham tCS, as quantified by the spectral slope of the 1/f decay function in the power spectral density. The spectral slope reflects the aperiodic component of neural activity, where steeper (more negative) slopes indicate increased cortical inhibition and flatter slopes reflect higher excitation-to-inhibition ratios. This measure provides a well-established proxy of cortical E/I balance. | — |
Secondary
| Measure | Time frame |
|---|---|
| - EEG in addition to intracranial EEG data is recorded and SO. Spindle and ripple activity (spectral power and density) will be assessed. In addition the coupling between SOs, spindles and sharp-wave ripples will be evaluated as a function of stimulation condition in the following way: first the precise SO phase during which cortical spindle activity peaks will be determined, followed by the evaluation of intracranial activity in the ripple frequency range as a function of the SO-spindle coupling phase - Memory retention performance in a visual-spatial memory task and schema formation task as a function of stimulation condition, operationalized by pre- to post sleep change in % correct retrieved item locations (in visual-spatial task) and generalization accuracy and memory specificity (schema task), respectively | — |
Countries
Germany
Contacts
Public ContactJulia Ladenbauer
Universitätsmedizin Greifswald
Outcome results
None listed