Modern Analytical Techniques in Epilepsy Research

Epilepsy remains one of the most prevalent neurological disorders, characterised by complex aetiology encompassing genetic, structural, metabolic, and inflammatory factors. Despite advances in neuroimaging and neurophysiological diagnostics, there is a persistent lack of sensitive and specific biomarkers to enable early diagnosis, risk stratification, and monitoring of therapeutic efficacy. Key epilepsy biomarkers include neurotransmitters, energy–related compounds, tryptophan pathway metabolites, and choline derivatives. Their determination employs liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS), high–performance liquid chromatography (HPLC) with electrochemical or fluorescence detection, gas chromatography with tandem mass spectrometry (GC–MS/MS), high–resolution mass spectrometry (HRMS), and proton nuclear magnetic resonance (1H–NMR) spectroscopy, revealing metabolic disturbances in neurotransmission, energy metabolism, and oxidative stress associated with epileptogenesis. Among these techniques, LC–MS/MS currently provides the highest analytical sensitivity and specificity for quantifying low–abundance epilepsy–related metabolites, while HPLC with conventional detection remains a simpler and more cost–effective alternative for routine clinical laboratories. This review presents the current state of knowledge regarding chromatographic techniques applied to the analysis of mentioned metabolites, as well as therapeutic drug monitoring of antiepileptic drugs. Key sample preparation stages are also discussed. Various biological matrices–plasma, serum, urine, cerebrospinal fluid (CSF), dried blood spots (DBSs), and brain tissue—are evaluated. Novel approaches are also presented, including hair samples, microsampling techniques, and headspace analysis of volatile metabolites. Chromatographic techniques constitute the foundation of contemporary metabolomic research in epileptology, enabling biomarker identification and supporting personalised medicine. Further standardisation and translational validation remain necessary, as current evidence is insufficient for routine clinical implementation.