Neural functional connectivity in patients with periventricular nodular heterotopia-mediated epilepsy

Periventricular nodular heterotopia (PNH) is characterized by disabled neural migration and is usually associated with epilepsy. Despite awareness of PNH-related epilepsy, little is known about the brain-level underlying functional neural bases. Thus, we used functional magnetic resonance imaging (MRI) to examine the neurobiology of 42 subjects with PNH-related epilepsy and 42 sex- and age-matched healthy controls. Measurements of functional connectivity (FC) and whole-brain graph theory analysis of data in the resting state were performed to assess neurological organization and topology. PNH patients exhibited significantly higher FC in the parietal lobe, cingulum and thalamus, as well as significantly lower FC in frontoparietal, hippocampal, and precentral regions. Graph theory analysis identified no significant differences between patients and controls, while patients showed lower network global efficiency in the limbic and cerebellum network and occipital cortex. Seed-based FC analysis confirmed disruption of activities and interregional connectivity in remote epileptic networks of patients, which may point to underlying pathological mechanisms. The cerebellum and limbic system of patients showed altered topology, suggesting that these regions or hubs may contribute to whole-brain circuits in PNH and epilepsy.