Ring chromosome 20 syndrome: A link between epilepsy onset and neuropsychological impairment in three children

Abstract

Ring chromosome 20 [r(20)] syndrome is a well-defined chromosomal disorder characterized by epilepsy, mild-to-moderate mental retardation, and lack of recognizable dysmorphic features. Epilepsy is often the most important clinical manifestation of the syndrome, even if its appearance is not constantly precocious. Seizures are frequently drug resistant. We describe three children with [r(20)] syndrome in whom the onset of epilepsy (age at onset range: 4 years and 6 months to 9 years and 4 months) determined a kind of epileptic status (age at onset range: 6 years and 10 months to 9 years and 8 months) with dramatic neuropsychological deterioration. This epileptic status lasted for several months because of refractoriness to most antiepileptic drugs (AEDs), but it was treated successfully with a combination of valproate and lamotrigine in two children. As soon as seizures stopped, the children showed prompt recovery with partial restoration of the neuropsychological impairment. This clinical picture can be described as abrupt epileptic encephalopathy.