Brain MRI and clinical characteristics of 11 patients with bilateral periventricular nodular heterotopia

Objective To analyze the clinical characteristics,brain MRI,EEG and the anti- epileptic therapeutic efficacy of bilateral periventricular nodular heterotopia induced epilepsy.Methods According to whether there were other neural abnormalities except BPNH,the patients were divided into two groups.Seven patients had periventricular nodules only(simple BPNH)and 4 patients also presented with other cortical or cerebral malformations(BPNH plus).The clinical data were collected,and the patients were followed up for 1 year to 10 years.Results Two patterns emerged:(1)The first pattern,associated with simple BPNH,was characterized by normal intelligence and seizures occurred in the second decade of life.Partial seizures were the commonest seizure types in this study.Interictal spiking or slow wave activity was found in ectopic grey matter in four patients,and in the temporal structures in 5 patients.All of them were efiective with carbamazepine.After a long term follow up,their prognosis Was favorable. (2)The second pattern,associated with BPNH plus,was characterized by mental retardation and seizures that began during the first decade.Seizures of the BPNH plus were intractable.Four of the BPNH also had malformations of the cardiovascular system. Conclusions Simple BPNH patients have normal intelligence and partial seizures which begin during the second decade of life. The seizures are effective with carbamazepine and never become frequent and tend to become very rare or disappear.Interictal spiking activity accords with ectopic grey matter,and spiking in the temporal structures are two EEG characteristics of the simple BPNH patients.The results also suggest that we should pay attention to malformations of others systems besides neural system. Key words: Choristoma; Periaqueductal gray;  Epilepsy;  Magnetic resonance imaging