Electrical Status Epilepticus in Sleep: Response of Neuropsychological Deficits and Epileptiform Activity to Clobazam Treatment

Electrical status epilepticus in sleep (ESES) is a pattern of abnormal discharges in the electroencephalogram (EEG). Children who have this pattern present seizures and neuropsychological regression. There are no studies that systematically evaluate the response of abnormal discharges in the EEG, seizures and neuropsychological regression to different antiepileptic treatments. Therefore, treatment strategies in ESES are not based on scientific evidence. High-dose benzodiazepines such as diazepam (valium) have been reported to improve the severe EEG abnormalities of patients with ESES in the short-term. But the long-term response of seizures and neuropsychological regression has not been systematically studied. Clobazam is a benzodiazepine derivative with antiepileptic properties. The pharmacologic properties of clobazam make of this drug a particularly useful option in ESES: in patients with ESES the alpha-2 subunit of the GABA receptor is preferentially up-regulated and clobazam may have a higher affinity for this particular subunit, so investigators expect a higher effect of this drug on ESES patients than with other benzodiazepines (Loddenkemper et al, in preparation). The aim of our study is to objectively evaluate the response to clobazam treatment of neuropsychological deficits, seizures and abnormal discharges in the EEG in patients with ESES. Clobazam treatment is used in routine clinical practice and investigators will objectively quantify its effect. Our working hypothesis is that high-dose clobazam treatment may control the abnormal epileptiform discharges in the EEG in patients with ESES. The reduction in abnormal epileptiform discharges may lead to an improvement in neuropsychological deficits and seizures. The predicted improvement in seizures and neuropsychological function would lead to a better quality of life in these patients.