[Heterotopia as the cause of seizures. A case report of familial periependymal heterotopia].

INTRODUCTION

Cortical development disorders constitute a group of entities resulting from an interruption in the development of the central nervous system. Most of them derive from the stoppage of migration, but proliferation and organisation can also be affected. Heterotopia is the most frequent of all migration disorders.

CASE REPORTS

We describe three cases of familial periependymal heterotopia consisting in three sisters who, after having seizures in infancy, were submitted to a magnetic resonance (MR) scan that revealed isointense nodules in the cortical grey matter in all the MR sequences. They were diagnosed as having periependymal heterotopia. The existence of a history of early onset seizures in the family of the mother supported the diagnosis of familial heterotopia.

CONCLUSIONS

Heterotopia is the most frequently occurring anomaly affecting cortical development and, of these, the periependymal form is the most common. Periependymal heterotopia may be determined by sex-linked inheritance (X chromosome). It is considered to be one of the most common congenital disorders in familial and early onset epilepsy. MR is the preferred diagnostic technique, since its high resolution allows it to identify and characterise heterotopias.