Epileptic encephalopaties and developmental disorders

Electrical status epilepticus in sleep (ESES) is a finding on electroencephalography (EEG) defined by nearly continuous spike-wave discharges during non-REM sleep. Continuous spike-wave in slow-wave sleep (CSWS) and Landau-Kleffner syndrome (LKS) are epileptic encephalopathies of childhood and adolescence characterized by developmental regression and ESES. Only one-third of patients have an identifiable cause. In CSWS, there is global regression, whereas in LKS receptive language is primarily affected. Seizures are often the presenting symptom but do not always occur. Treatment with high-dose diazepam, immunomodulation, conventional antiseizure medications, surgery, ketogenic diet, vagus nerve stimulation, amantadine, and carbonic anhydrase inhibitors have been employed with varying success. The goal of treatment is clinical improvement, often accompanied by improvement in the EEG, and serial EEGs are employed to help gauge response to treatment. Many children have neurocognitive improvements with therapy, and in most cases, the EEG pattern resolves spontaneously; however, many are left with residual neurobehavioral sequelae.