Hippocampal malrotation in supernumerary der(22) syndrome and epilepsy: a case report

Abstract

We report the clinical, electroencephalographic and neuroradiologic findings of a patient with supernumerary der(22) syndrome – partial 22 trisomy, derived from a (11;22) maternal translocation – and a wide spectrum of cerebral malformation. Magnetic resonance study evidenced a partial midline defect (hypoplasia of the corpus callosum, mild dilatation of the mid portion of the occipital horn of the lateral ventricles and a mild enlargement of the frontal horns) and a malrotation of the body and the tail of both hippocampi, which present a vertical position. This patient was severely mentally retarded and he was affected by drugresistant focal epilepsy: the seizures were of fronto-temporal origin with possible secondary generalization. The electroencephalographic studies showed a pattern similar to that observed in other cortical malformations. About 30% of the patients with der(22) have cerebral malformation but none presents an hippocampal malrotation. Moreover, this defect seems to be linked to the epilepsy. (J Pediatr Neurol 2003; 1(1): 39–42).

Keywords

epilepsy - hippocampal malrotation - supernumerary der(22)