Networks of cortical activity in infants with epilepsy

Epilepsy in infancy links to a significant risk of neurodevelopmental delay, calling for a better understanding of its underlying mechanisms. Here, we studied cortical activity networks in infants with early-onset epilepsy to identify network properties that could pre-empt infants’ neurodevelopmental course. We studied high-density (64 channel) electroencephalogram during non-rapid eye movement (N2) sleep in n = 49 infants at 1 year of age after being diagnosed with epilepsy during their first year of life. We computed frequency-specific networks in the cortical source space for two intrinsic brain modes: amplitude–amplitude and phase–phase correlations. Cortical activity networks of all frequency bands and connectivity modes were compared between the syndrome groups as well as between the three categories of neurocognitive development. The group differences were studied at three spatial levels: global, regional, and individual connections. Cortical mechanisms related to infant epilepsy were further compared with physiological networks using an automatic spindle detection algorithm. Our results show that global connectivity does not significantly differ between epilepsy syndromes; however, it co-varies with neurocognitive development. The largest network differences were observed at the lowest (