Epilepsy Therapies Symposium | Do We Really "Outgrow" Seizures?

Initiation and maintenance of antiseizure therapy can be relatively straightforward in most patients. Depending on epilepsy type, patients may be more or less likely to enter remission or a resolution of their epilepsy and the International League Against Epilepsy developed clinically guiding definitions in this regard. The mechanisms by which resolution or remission are achieved are poorly understood which complicates clinical decision making and risk estimate for future seizure relapse.

Using high-frequency oscillations from brief intraoperative neural recordings to predict the seizure onset zone.

Background: While high-frequency oscillations (HFOs) and their stereotyped clusters (sHFOs) have emerged as potential neuro-biomarkers for the rapid localization of the seizure onset zone (SOZ) in epilepsy, their clinical application is hindered by the challenge of automated elimination of pseudo-HFOs originating from artifacts in heavily corrupted intraoperative neural recordings. This limitation has led to a reliance on semi-automated detectors, coupled with manual visual artifact rejection, impeding the translation of findings into clinical practice.

Methods: In response, we have developed a computational framework that integrates sparse signal processing and ensemble learning to automatically detect genuine HFOs of intracranial EEG data.

Benchmarking signal quality and spatiotemporal distribution of interictal spikes in prolonged human iEEG recordings using CorTec wireless brain interchange.

Neuromodulation through implantable pulse generators (IPGs) represents an important treatment approach for neurological disorders. While the field has observed the success of state-of-the-art interventions, such as deep brain stimulation (DBS) or responsive neurostimulation (RNS), implantable systems face various technical challenges, including the restriction of recording from a limited number of brain sites, power management, and limited external access to the assessed neural data in a continuous fashion. To the best of our knowledge, for the first time in this study, we investigated the feasibility of recording human intracranial EEG (iEEG) using a benchtop version of the Brain Interchange (BIC) unit of CorTec, which is a portable, wireless, and externally powered implant with sensing and stimulation capabilities.

Prophecy or empiricism? Clinical value of predicting versus determining genetic variant functions.

The recent explosion of epilepsy genetic testing has created challenges for interpretation of gene variants. Assessments of the functional consequences of genetic variants either by predictive or experimental strategies can contribute to estimating pathogenicity, but there is no consensus on which approach is best. The Special Interest Group on Epilepsy Genetics hosted a session during the Annual American Epilepsy Society Meeting in December 2022 to discuss this topic.

Epigenetic genes and epilepsy - emerging mechanisms and clinical applications.

An increasing number of epilepsies are being attributed to variants in genes with epigenetic functions. The products of these genes include factors that regulate the structure and function of chromatin and the placing, reading and removal of epigenetic marks, as well as other epigenetic processes. In this Review, we provide an overview of the various epigenetic processes, structuring our discussion around five function-based categories: DNA methylation, histone modifications, histone-DNA crosstalk, non-coding RNAs and chromatin remodelling.

X-linked serotonin 2C receptor is associated with a non-canonical pathway for sudden unexpected death in epilepsy.

Sudden Unexpected Death in Epilepsy is a leading cause of epilepsy-related mortality, and the analysis of mouse Sudden Unexpected Death in Epilepsy models is steadily revealing a spectrum of inherited risk phenotypes based on distinct genetic mechanisms. Serotonin (5-HT) signalling enhances post-ictal cardiorespiratory drive and, when elevated in the brain, reduces death following evoked audiogenic brainstem seizures in inbred mouse models. However, no gene in this pathway has yet been linked to a spontaneous epilepsy phenotype, the defining criterion of Sudden Unexpected Death in Epilepsy.

Nine-year prospective efficacy and safety of brain-responsive neurostimulation for focal epilepsy.

Objective: To prospectively evaluate safety and efficacy of brain-responsive neurostimulation in adults with medically intractable focal onset seizures (FOS) over 9 years.

Methods: Adults treated with brain-responsive neurostimulation in 2-year feasibility or randomized controlled trials were enrolled in a long-term prospective open label trial (LTT) to assess safety, efficacy, and quality of life (QOL) over an additional 7 years. Safety was assessed as adverse events (AEs), efficacy as median percent change in seizure frequency and responder rate, and QOL with the Quality of Life in Epilepsy (QOLIE-89) inventory.

Epigenetics explained: a topic "primer" for the epilepsy community by the ILAE Genetics/Epigenetics Task Force.

Epigenetics refers broadly to processes that influence medium to long-term gene expression by changing the readability and accessibility of the genetic code. The Neurobiology Commission of the International League Against Epilepsy (ILAE) recently convened a Task Force to explore and disseminate advances in epigenetics to better understand their role and intersection with genetics and the neurobiology of epilepsies and their co-morbidities, and to accelerate translation of these findings into the development of better therapies. Here, we provide a topic primer on epigenetics, explaining the key processes and findings to date in experimental and human epilepsy.

A somatic mutation in MEN1 gene detected in periventricular nodular heterotopia tissue obtained from depth electrodes.

Periventricular nodular heterotopia (PNH) is a common structural malformation of cortical development. Mutations in the filamin A gene are frequent in familial cases with X-linked PNH. However, many cases with sporadic PNH remain genetically unexplained.

Brainstem atrophy in focal epilepsy destabilizes brainstem-brain interactions: Preliminary findings.

Background: MR Imaging has shown atrophy in brainstem regions that were linked to autonomic dysfunction in epilepsy patients. The brainstem projects to and modulates the activation state of several wide-spread cortical/subcortical regions. The goal was to investigate 1.

De novo missense variant in the GTPase effector domain (GED) of leads to static encephalopathy and seizures.

encodes a GTPase of the dynamin superfamily, which plays a crucial role in mitochondrial and peroxisomal fission. Pathogenic variants affecting the middle domain and the GTPase domain of have been implicated in encephalopathy because of defective mitochondrial and peroxisomal fission 1 (EMPF1, MIM #614388). Patients show variable phenotypes ranging from severe hypotonia leading to death in the neonatal period to developmental delay/regression, with or without seizures.

Spectrum and time course of epilepsy and the associated cognitive decline in duplication syndrome.

Objective: We characterized the epilepsy features and contribution to cognitive regression in 47 patients with duplication syndrome (MDS) and reviewed these characteristics in over 280 MDS published cases.

Methods: The institutional review board approved this retrospective review of medical records and case histories of patients with MDS.

Results: The average age at enrollment was 10 ± 7 years.

Channelopathy as a SUDEP Biomarker in Dravet Syndrome Patient-Derived Cardiac Myocytes.

Dravet syndrome (DS) is a severe developmental and epileptic encephalopathy with a high incidence of sudden unexpected death in epilepsy (SUDEP). Most DS patients carry de novo variants in SCN1A, resulting in Na1.1 haploinsufficiency.

Brainstem network disruption: A pathway to sudden unexplained death in epilepsy?

Observations in witnessed Sudden Unexpected Death in Epilepsy (SUDEP) suggest that a fatal breakdown of the central autonomic control could play a major role in SUDEP. A previous MR study found volume losses in the mesencephalon in focal epilepsy that were more severe and extended into the lower brainstem in two patients who later died of SUDEP. The aims of this study were to demonstrate an association (1) between brainstem volume loss and impaired autonomic control (reduced heart rate variability [HRV]); (2) between brainstem damage and time to SUDEP in patients who later died of SUDEP.

Brain-responsive neurostimulation in patients with medically intractable seizures arising from eloquent and other neocortical areas.

Objective: Evaluate the seizure-reduction response and safety of brain-responsive stimulation in adults with medically intractable partial-onset seizures of neocortical origin.

Methods: Patients with partial seizures of neocortical origin were identified from prospective clinical trials of a brain-responsive neurostimulator (RNS System, NeuroPace). The seizure reduction over years 2-6 postimplantation was calculated by assessing the seizure frequency compared to a preimplantation baseline.