Idiopathic West Syndrome followed by childhood absence epilepsy.

West Syndrome (WS) is a severe epileptic encephalopathy occurring in the first year of life. According the ILAE classification of epileptic seizures and epilepsy the etiology could be symptomatic or cryptogenic. Some authors identified a small group of patients (5%) with a particular good outcome, a complete recovery from seizures and a normal cognitive development within the cryptogenic group that they suggested to be idiopathic. Between 1996 and 2007, at the Neurology Division of the Bambino Gesù Children's Hospital in Rome, we collected 241 patients with WS. Sixteen (6.6%) were considered with idiopathic aetiology. All clinical notes of these patients were reviewed in order to evaluate the prevalence of other epileptic syndrome after WS. Two of them had at the age of 8 and 3 months idiopathic WS, and at the age of 6 and 4 years respectively, they presented with childhood absence epilepsy (CAE) successfully treated with valproate. The favorable evolution of the WS and the later occurrence of an idiopathic form of epilepsy, such as CAE, confirm the possibility of an idiopathic aetiology for WS that, although rare, can represent one of the etiologies of otherwise severe syndrome. Even if a common physiophatogenetic role, probably related to a genetic predisposition, could be hypothesized and appears to be intriguing, no data are available and more studies are needed to confirm this hypothesis.