Periventricular Nodular Heterotopias Induced-Seizures in an Adolescent

A female adolescent with no relevant past history was admitted to the Pediatric Emergency Department with two episodes of seizures without trauma, fever, or other symptoms. Head-MRI revealed bilateral subependymal nodular irregularities lining the lateral ventricles, with similar signal evolution to grey matter, confirming the diagnosis of periventricular nodular heterotopias (PVNH). Genetic testing revealed a Filamin A (<i>FLNA)</i> variant; family studies were negative. Further investigation excluded associated comorbidities. PVNH is a rare condition caused by an abnormality in neuronal migration and is part of a phenotypically and genetically heterogeneous group of disorders. <i>FLNA</i> variants are PVNH's most common cause and are responsible for classical neuroradiologic imaging, characterized by bilateral symmetrical nodules with predominantly anterior and mid-body distribution along the linings of lateral ventricles. Classical PVNH typically affects females presenting with seizures in mid-adolescence, with normal/mildly impaired cognition; males are more severely affected. <i>FLNA</i>-induced PVNH may be associated with comorbidities, which may be severe. Other rarer genetic causes combine PVNH with complex brain or systemic abnormalities, resulting in developmental delay and a worse prognosis. Genetic diagnosis is essential for adequate counseling, follow-up, seizure control, vigilance, and treatment of comorbidities, as they may have a great impact on the patient's quality of life.