SCN1A and encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy: The hippocampal formation acts as an epicenter of more intense structural changes even in epilepsy syndromes in which no clear indication of seizure genesis in the hippocampus exists, such as SCN1A-related Dravet syndrome [52] and idiopathic generalized epilepsy syndromes [20, 53].