Pseudotemporal Epilepsy with Periventricular Nodular Heterotopia

Scientific background: Periventricular nodular heterotopia (PNH) that is one of the subgroups of neuronal migration disorders is associated with intractable epilepsy. However the etiopathogenesis of seizures in PNH patients are still unclear. Heterotopias are not involved in the epileptic network, alone. A complex relation between nodules, hippocampus and neocortex has been reported as the cause. Case: A 20 year-old male patient with intractable seizures is presented with ictal and interictal EEG findings compatible with right temporal lobe seizure. Although his first MRI was reported as hyperintensity in right hippocampus, repeated MRI examination according to epilepsy protocol revealed bilateral PNH, with no signal change in hippocampus. Conclusion: The aim of this case report is to discuss the importance of PNH in the differential diagnosis of intractable seizures, and to mention that neurologists and radiologists can easily miss these lesions, if the walls of ventricles are not checked carefully.