Stereo-EEG based personalized multichannel transcranial direct current stimulation in drug-resistant epilepsy. (May 2022)

• Record Type: Journal Article
• Authors: Daoud, Maëva; Salvador, Ricardo; El Youssef, Nada; Fierain, Alexane; Garnier, Elodie; Biagi, Maria Chiara; Medina Villalon, Samuel; Wendling, Fabrice; Benar, Christian; Ruffini, Giulio; Bartolomei, Fabrice
• Is Part Of: Clinical neurophysiology. Volume 137(2022)
• Page Start: 142
• Page End: 151
• Publication Date: 2022-05
• Subjects: Drug-resistant epilepsy -- Multichannel transcranial direct current stimulation (tDCS) -- Patient-specific approach -- Functional connectivity -- Electroencephalography; tDCS Transcranial Direct Current Stimulation -- SEEG Stereoelectrocencephalography -- EEG Electroencephalography -- DRE Drug-resistant Epilepsy -- SF Seizure Frequency -- Fc Functional connectivity -- R Responder -- NR Non-responder -- MRI Magnetic Resonance Imaging -- IQ Intelligence Quotient -- AEs Adverse events -- ICA Independent Component Analysis -- EMG Electromyography -- LMM Linear Mixed Models -- REML Restricted Maximum Likelihood -- LSM Least Squares Means -- SOZ Seizure Onset Zone -- VNS Vagus Nerve Stimulation -- SMA Supplementary motor area -- SZs Seizures -- FCD Focal cortical dysplasia -- SGTC Seizure generalized tonico-clonic -- ASM antiseizure medication -- M−2 M−1, 1 and 2 months before the first stimulation cycle -- M1C1 one month after the first cycle -- M2C1 two months after the first cycle -- M1C2 one month after the second cycle -- M2C2 two months after the second cycle -- M1C3 one month after the third cycle -- M2C3 two months after the third cycle -- M1 first month -- M2 second month -- C1 Cycle 1 -- C2 Cycle 2 -- C3 Cycle 3 -- Strength D5-D1 Strength Day 5 – Strength Day 1 (after – before tDCS cycle); Neurophysiology -- Periodicals; Electroencephalography -- Periodicals; Electromyography -- Periodicals; Neurology -- Periodicals; 612.8
• DOI: 10.1016/j.clinph.2022.02.023
• Languages: English
• ISSNs: 1388-2457

Abstract

Highlights: We used personalized multichannel tDCS to target the epileptogenic zone identified by stereoelectroencephalography (SEEG). After 6 months with 3 cycles of 5 consecutive days of tDCS treatment (2 × 20 min per day), half of the patients were responders. The efficacy of tDCS in responders was associated to a significant decrease in functional connectivity measured from scalp EEG. Abstract: Objective: In epilepsy, multichannel transcranial direct electrical stimulation (tDCS) is applied to decrease cortical activity through the delivery of weak currents using several scalp electrodes. We investigated the long-term effects of personalized, multisession, stereotactic-EEG (SEEG)-targeted multichannel tDCS on seizure frequency (SF) and functional connectivity (Fc) as measured by EEG in patients with drug-resistant epilepsy (DRE). Methods: Ten patients suffering from DRE were recruited. Multichannel tDCS (Starstim, Neuroelectrics) was applied during three cycles (one cycle every 2 months) of stimulation. Each cycle consisted of five consecutive days where patients received tDCS daily in two 20 min sessions separated by 20 min. The montages were personalized to target epileptogenic area of each patient as defined by SEEG recordings. SF during and after treatment was compared with baseline. Fc changes were analysed using scalp EEG recordings. Results: After the last tDCS session, five patients experienced a SF decrease of 50% or more compared with baseline (R: responders, average SF decrease of 74%). We estimated Fc changes between cycles and across R and non-responder (NR) patients. R presented a significant decrease in Fc (p < 0.05) at the third session in alpha and beta frequency bands compared to the first one. Conclusions: Multichannel tDCS guided by SEEG is a promising therapeutic approach. Significant response was associated with a decrease of Fc after three stimulation cycles. Significance: Such results suggest that tDCS-induced functional plasticity changes that may underlie the clinical response.