Development of novel stimulation tools for seizure intervention
Prof. Carola Haas
Prof. Ulrich Egert
Prof. Ilka Diester
Mesial temporal lobe epilepsy (MTLE) is the most common form of focal epilepsies in adults. MTLE is often associated with hippocampal sclerosis (HS) comprising neuronal cell death and structural reorganization. Considering that MTLE patients are often resistant to medication, current therapy relies mainly on resection of the epileptogenic focus. Since surgical intervention carries a high risk for the affected patient, other treatment options are desperately needed. Recently, deep brain stimulation (DBS) evolved as a promising approach for seizure interference. Typically, high-frequency stimulation (HFS, 100-200 Hz) is performed in the hippocampus or the anterior thalamic nucleus to interfere with limbic seizures, assuming that electrical pulses reduce the seizure threshold by disrupting network synchronization (Li and Cook, Epilepsia, 2018). However, in MTLE with severe HS, current stimulation protocols are often not effective. It is assumed, that extensive neuronal cell loss and glial scarring (Velasco et al., Epilepsia, 2007) alter the electrical resistance in sclerotic neural tissue. This hampers the efficacy of HFS, since stimulation can only be successful when targeting a sufficiently preserved network. Therefore, patients with severe HS may require specific stimulation parameters to achieve seizure control. In fact, a small cohort study (Lim et al., Neuromodulation, 2016) pointed to the use of low-frequency stimulation (LFS). However, to systematically assess anti-ictogenic effects of LFS in relation to disease parameters, studies in translational animal models are crucial.