High-frequency oscillations detected by electroencephalography as biomarkers to evaluate treatment outcome,mirror pathological severity and predict susceptibility to epilepsy

High-frequency oscillations(HFOs)in the electroencephalography(EEG)have been extensively investigated as a potential biomarker of epileptogenic zones.The understanding of the role of HFOs in epilepsy has been advanced considerably over the past decade,and the use of scalp EEG facilitates recordings of HFOs.HFOs were initially applied in large scale in epilepsy surgery and are now being utilized in other applications.In this review,we summarize applications of HFOs in 3 subtopics:(1)HFOs as biomarkers to evaluate epilepsy treatment outcome;(2)HFOs as biomarkers to measure seizure propensity;(3)HFOs as biomarkers to reflect the pathological severity of epilepsy.Nevertheless,knowledge regarding the above clinical applications of HFOs remains limited at present.Further validation through prospective studies is required for its reliable application in the clinical management of individual epileptic patients.

Altered brain activity in juvenile myoclonic epilepsy with a monotherapy:a resting-state fMRI study

Background:Juvenile myoclonic epilepsy(JME)is the most common syndrome of idiopathic generalized epilepsy.Although resting-state functional magnetic resonance imaging(rs-fMRI)studies have found thalamocortical circuit dysfunction in patients with JME,the pathophysiological mechanism of JME remains unclear.In this study,we used three complementary parameters of rs-fMRI to investigate aberrant brain activity in JME patients in comparison to that of healthy controls.Methods:Rs-fMRI and clinical data were acquired from 49 patients with JME undergoing monotherapy and 44 ageand sex-matched healthy controls.After fMRI data preprocessing,the fractional amplitude of low-frequency fluctuation(fALFF),regional homogeneity(ReHo),and degree centrality(DC)were calculated and compared between the two groups.Correlation analysis was conducted to explore the relationship between local brain abnormalities and clinical features in JME patients.Results:Compared with the controls,the JME patients exhibited significantly decreased fALFF,ReHo and DC in the cerebellum,inferior parietal lobe,and visual cortex(including the fusiform and the lingual and middle occipital gyri),and increased DC in the right orbitofrontal cortex.In the JME patients,there were no regions with reduced ReHo compared to the controls.No significant correlation was observed between regional abnormalities of fALFF,ReHo or DC,and clinical features.Conclusions:We demonstrated a wide range of abnormal functional activity in the brains of patients with JME,including the prefrontal cortex,visual cortex,default mode network,and cerebellum.The results suggest dysfunctions of the cerebello-cerebral circuits,which provide a clue on the potential pathogenesis of JME.