Atypical evolutions of benign localization-related epilepsies in children: are they predictable?

PURPOSE: To emphasize that, in some patients, different atypical evolutions occur in the course of so-called benign focal epilepsies of childhood (BFEC) and to promote interest in finding clinical and/or electroencephalographic (EEG) clues to which patients might be prone to these risky evolutions.
METHODS: Twenty-six patients who started with the typical clinical and EEG features of benign childhood epilepsy with centrotemporal spikes (BCECTS) but who had reversible or persistent, serious epileptic events including status epilepticus and language, cognitive, or behavioral impairments were followed for </=14 years. Repeated neurologic examinations, EEG records, and neuropsychological evaluations were done, and brain-imaging studies [computerized axial tomography (CAT) or magnetic resonance imaging (MRI)] were obtained in all patients.
RESULTS: The 26 patients were in four separate groups according to the nature of their atypical evolution. Eleven children had atypical benign focal epilepsy of childhood (ABFEC), three with Landau-Kleffner syndrome (LKS), seven with status epilepticus of BCECTS, and five with mixed features of the other three groups. All the children whose BCECTS evolved into ABFEC have finally recovered and are attending normal schools, although five have learning difficulties. Two of the three patients diagnosed with LKS recovered from aphasia, although some language difficulties persist in one. The seven who showed status epilepticus of BCECTS are now normal after 3-14 years of follow-up, and three of the five children showing mixed features fulfilled the criteria for a diagnosis of epilepsy with continuous spikes and waves during slow sleep (CSWS).
CONCLUSIONS: A small proportion of cases starting with BCECTS evolve into ABFEC, LKS, status of BCECTS, or epilepsy with CSWS. In such cases, BCECTS is not always benign. Clinical and EEG markers should be sought to predict these atypical evolutions.