Psychiatric and Behavioural Disorders in Children with Epilepsy (ILAE Task Force Report): Behavioural effects of epilepsy surgery.

There are relatively few studies of the behavioural outcome of epilepsy surgery in children that have used standardised behavioural measures before and after the procedure. Those investigations that have used such measures are often on mixed groups with mixed pathology, implying that the numbers, when stratified, are very small. They are also often retrospective. Furthermore, because placebo surgery is generally not an option, the studies have been open and they are usually uncontrolled. The few available data suggest that, although individual children may benefit or deteriorate, there is little overall group effect of temporal or extratemporal surgery on behavioural/psychiatric outcome. Hemispherectomy has traditionally been associated with the expectation of marked behavioural improvement but firm data are lacking. Multiple subpial transection performed for electrical status epilepticus of slow-wave sleep in the Landau-Kleffner syndrome can result in marked improvements in cognition and behaviour. Vagus nerve stimulation appears to improve quality of life and mood/behaviour but again the quality of the data has been questioned. There is a need for large, prospective, multicentre, collaborative studies using standardised cognitive and behavioural measures before and after surgery to provide an adequate database on the outcome of various categories of procedures, pathologies and patients.