Analysis of brain network effective connectivity in juvenile myoclonic epilepsy

Juvenile Myoclonic Epilepsy (JME) is a prevalent idiopathic generalized epilepsy whose neurophysiological mechanisms remain elusive. This study aims to elucidate the aberrant brain network patterns in JME through a multi-modal fMRI approach combining local consistency, functional connectivity, and causal interaction analysis. Resting-state fMRI data were acquired from 37 JME patients and 35 healthy controls. Regional homogeneity (ReHo) and amplitude of low-frequency fluctuations (ALFF) analyses identified eight brain regions with significant between-group differences (FDR-corrected p < 0.05), including the right middle frontal gyrus, right insula, right medial/paracingulate gyrus, bilateral superior frontal gyri, left postcentral gyrus, and left superior occipital gyrus. These regions served as regions of interest (ROIs) for subsequent functional and effective connectivity analyses. Functional connectivity analysis revealed increased connectivity strength between the right middle frontal gyrus and right medial or paracingulate gyrus, as well as between the right insula and right medial/paracingulate gyrus (two-sample t test, p < 0.01), despite decreased local synchrony in these regions. Dynamic causal modeling (DCM) demonstrated bidirectional enhancement of effective connectivity between the right insula and right medial or paracingulate gyrus in patients (Bayesian posterior probability > 0.95). These findings suggest that the observed decoupling of local neuronal synchronization and long-range connectivity may reflect compensatory neuroadaptive processes, particularly involving the salience network (insula) and cognitive control circuitry (cingulate regions).The integration of ReHo/ALFF mapping with DCM provides a novel framework for understanding the neurodevelopmental trajectory of JME, highlighting the critical role of cortico-subcortical dysregulation in its pathogenesis.