Drug-Resistant Focal Epilepsy
Conditions
Keywords
Drug-Resistant Epilepsy, Temporal Interference Stimulation, Stereo-EEG
Brief summary
This study evaluates whether a non-invasive brain stimulation technique called Temporal Interference (TI) can reduce epilepsy-related abnormal brain activity and influence sleep-related brain rhythms in adults with focal drug-resistant epilepsy undergoing stereo-EEG monitoring for clinical care. Up to 30 participants will complete stimulation sessions during wakefulness and, when possible, natural non-REM sleep. Brain activity will be recorded using scalp EEG and implanted sEEG electrodes before, during, and after TI stimulation. Some participants may also receive subthreshold direct stimulation through implanted electrodes for comparison. The study aims to determine whether TI can reduce epilepsy biomarkers, alter sleep-related brain activity, and compare favorably with conventional direct electrical stimulation while remaining within established safety limits.
Interventions
Non-invasive electrical stimulation delivered through scalp electrodes using paired sinusoidal currents with differential carrier frequencies to create a low-frequency envelope targeting deep brain structures including the epileptic focus or thalamus.
Subthreshold biphasic electrical stimulation delivered through implanted stereo-EEG contacts, remaining below thresholds for after-discharges and perceptual sensations.
Sponsors
Study design
Eligibility
Inclusion criteria
* Adult patients with focal DRE who will undergo presurgical evaluation with sEEG * Availability of at least one sEEG electrode inserted into the thalamus for clinical purposes * sEEG performed with the indication to identify one single epileptic focus * Ability to provide written informed consent and comply with the study protocol
Exclusion criteria
\- Remote resective/ablative brain surgery
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Interictal epileptiform discharge rate | 20-minute baseline, 20-minute stimulation, 20-minute post-stimulation | The interictal epileptiform discharge (IED) rate per minute is a classical biomarker of epilepsy. It is derived from sEEG macro- and microcontacts. |
| Single-unit firing rate | 20-minute baseline, 20-minute stimulation, 20-minute post-stimulation | single unit firing rate is the number of action potentials ("spikes") that an isolated neuron emits per second. It is derived from sEEG microcontacts. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| High-frequency oscillations | 20-minute baseline, 20-minute stimulation, 20-minute post-stimulation | The high-frequency oscillation rate per minute (frequency \>80 Hz) is an alternative biomarker of epilepsy. it is derived from sEEG macro- and microcontacts. |
| local field potential spectral power | 20-minute baseline, 20-minute stimulation, 20-minute post-stimulation | The power of local field potentials in defined frequency bands (theta: 4-8 Hz, beta: 13-30 Hz, gamma: 30-100 Hz) will be measured from macro- and microcontacts. |
| Sleep microstructure | 20-minute baseline, 20-minute stimulation, 20-minute post-stimulation | Sleep microstructure is comprised of sleep spindles (sleep specific transients of 10-16 Hz exceeding 0.5 seconds) and slow oscillations (delta wave transients \< 0.5 Hz) measured in scalp EEG and sEEG macrocontacts. Rates are provided per minute |
Contacts
Duke University