Papadelis, Christos

The 2023 American Epilepsy Society Annual Course “It’s About Time” addressed timing in epilepsy evaluation and treatment with respect to health disparity and vulnerable populations and diagnostic, clinical, and epilepsy surgery evaluation. This comprehensive course included topics on gaps in epilepsy care and optimization of behavioral health for patients with epilepsy. The summary details current knowledge in areas of seizure forecasting and epileptogenesis. Intricacies and controversies over timing were discussed for treatment of nonconvulsive seizures and ictal-interictal patterns, acute symptomatic seizures, neuromodulation versus surgery, and epilepsy surgery in status epilepticus. Timing regarding clinical care in autoimmune-associated epilepsy, developmental and epileptic encephalopathy, and dietary therapy were examined. Additionally, salient topics on using novel biomarkers and collaboration with neuropsychological outcomes were also tackled in this all-encompassing lecture series.

Abstract In drug-resistant focal epilepsy, interictal high-frequency oscillations (HFOs) recorded from intracranial EEG (iEEG) may provide clinical information for delineating epileptogenic brain tissue. The iEEG electrode contacts that contain HFO are hypothesized to delineate the epileptogenic zone; their resection should then lead to postsurgical seizure freedom. We test whether our prospective definition of clinically relevant HFO is in agreement with postsurgical seizure outcome. The algorithm is fully automated and is equally applied to all data sets. The aim is to assess the reliability of the proposed detector and analysis approach. We use an automated data-independent prospective definition of clinically relevant HFO that has been validated in data from two independent epilepsy centres. In this study, we combine retrospectively collected data sets from nine independent epilepsy centres. The analysis is blinded to clinical outcome. We use iEEG recordings during NREM sleep with a minimum of 12 epochs of 5 min of NREM sleep. We automatically detect HFO in the ripple (80–250 Hz) and in the fast ripple (250–500 Hz) band. There is no manual rejection of events in this fully automated algorithm. The type of HFO that we consider clinically relevant is defined as the simultaneous occurrence of a fast ripple and a ripple. We calculate the temporal consistency of each patient’s HFO rates over several data epochs within and between nights. Patients with temporal consistency <50% are excluded from further analysis. We determine whether all electrode contacts with high HFO rate are included in the resection volume and whether seizure freedom (ILAE 1) was achieved at ≥2 years follow-up. Applying a previously validated algorithm to a large cohort from several independent epilepsy centres may advance the clinical relevance and the generalizability of HFO analysis as essential next step for use of HFO in clinical practice.