In Epilepsia
OBJECTIVE : Anti-seizure medication (ASM) is the primary treatment for epilepsy. In clinical practice, methods to assess ASM efficacy (predict seizure freedom or seizure reduction), during any phase of the drug treatment lifecycle, are limited. This scoping review identifies and appraises prognostic electroencephalography (EEG) biomarkers and prognostic models that use EEG features, which are associated with seizure outcomes following ASM initiation, dose adjustment or withdrawal. We also aim to summarise the population and context in which these biomarkers and models were identified and described, in order to understand how they could be used in clinical practice.
METHODS : Between January 2021 - October 2022, four databases, references and citations were systematically searched for ASM studies investigating changes to interictal EEG or prognostic models using EEG features and seizure outcomes. Study bias was appraised using a modified Quality in Prognosis Studies criteria. Results were synthesised into a qualitative review.
RESULTS : 875 studies were identified, 93 were included. Biomarkers identified were classed as qualitative (visually identified by wave morphology) or quantitative. Qualitative biomarkers include identifying hypsarrhythmia, centrotemporal spikes, interictal epileptiform discharges (IED), classifying the EEG as normal/abnormal/epileptiform, and photoparoxysmal response. Quantitative biomarkers were statistics applied to IED, high-frequency activity, frequency band power, current source density estimates, pairwise statistical interdependence between EEG channels, and measures of complexity. Prognostic models using EEG features were Cox proportional-hazards models and machine learning models. There is promise that some quantitative EEG biomarkers could be used to assess ASM efficacy, but further research is required. There is insufficient evidence to conclude any specific biomarker can be used for a particular population or context, to prognosticate ASM efficacy.
SIGNIFICANCE : We identified a potential battery of prognostic EEG biomarkers, which could be combined with prognostic models to assess ASM efficacy. However, many confounders need to be addressed for translation into clinical practice.
Reynolds Ashley, Vranic-Peters Michaela, Lai Alan, Grayden David B, Cook Mark J, Peterson Andre
2023-Feb-15
AED, EEG, anti-epileptic drugs, anticonvulsant, biological marker
