Patients with epilepsy who also have periventricular nodular heterotopia (PVNH) are difficult to manage surgically because the relative influence of the nodular tissue and the overlying cortex on the generation of seizures is variable. A review of the relevant medical literature suggests that inter-ictal spiking from nodules often occurs in patients with PVNH, but it is rare for patients to experience seizures arising from the nodular tissue alone. It is more likely to find that the onset of seizures occurs simultaneously with overlying neocortex or mesial temporal structures.
Thompson SA, Kalamangalam GP, Tandon N. Intracranial evaluation and laser ablation for epilepsy with periventricular nodular heterotopia. Seizure. 2016;41:211-216.