Abstract
SUMMARY Malformations of cortical development, cortical dysplasia, neuronal migration disorders, cortical dysgenesis - believe it or not, but these all terminologies refer to just one type of disorder. In the past decade, many authors have used all of the above mentioned terminologies. However, malformations of cortical development and cortical dysplasia are found to be widely used among various authors. Myriads of studies have been reported which show these cortical disorders as the cause of epilepsy. In surgical series from various epilepsy centers, it is estimated that more than half of the children referred for intractable epilepsy have developmental malformations of different types. Moreover, in the adult population, the frequency of these malformations is in the range of 20%. We performed a retrospective study (mainly from the archives of Dept. of Radiology) on 90 patients with neuronal migration disorders. The patients were in various age groups (more than half of them belonged to pediatric age group). The patients were imaged with MRI and classified according to the recent classification criteria put forward by Barkovich and Kuzniecky. Each of the abnormalities were thoroughly studied for their subgroups (if present), site of the lesion, presence of history of epilepsy and accompanying malformations. Moreover, they were further grouped as single, double and multiple on the basis of the number of malformations. 66 patients had single, 19 had more than one and 5 had more than two malformations. Polymicrogyria was found in 26 patients and accounted for the largest group in our study. It was closely followed by heterotopias and schizencephaly. Twenty four of our patients had a history of epilepsy. Heterotopias and polymicrogyria were mostly seen in these patients. 53
