A rare non-syndromic cerebral malformation due to abnormal neuronal migration characterized by clusters of disorganized neurons in abnormal locations such as periventricular and subcortical. The extent of the lesions ranges from isolated single to bilateral confluent nodules. Pediatric patients typically show variable degrees of developmental delay, intellectual disability, and intractable epilepsy, and concomitant cerebral and/or systemic malformations are frequent. Milder forms may present with onset of seizures in adulthood. [from
ORDO]