Epileptic
encephalopathy is defined as a condition where the epileptic activity itself may contribute to the severe neurological and
cognitive impairment seen, over and above that which would be expected from the underlying pathology alone. The
epilepsy syndromes at high risk of this are a disparate group of conditions characterized by epileptic
seizures that are difficult to treat and developmental delay. In this review, we discuss the ongoing debate regarding the significance of inter-ictal discharges and the impact of the
seizures themselves on the cognitive delay or regression that is a common feature of these syndromes. The syndromes also differ in many ways and we provide a summary of the key features of the early-onset epileptic
encephalopathies including Ohtahara and West syndromes in addition to later childhood-onset syndromes such as Lennox Gastaut and Doose syndromes. An understanding of the various severe
epilepsy syndromes is vital to understanding the rationale for treatment. For example, the resolution of
hypsarrhythmia in
West syndrome is associated with an improvement in cognitive outcome and drives treatment choice, but the same cannot be applied to frequent inter-ictal discharges in
Lennox Gastaut syndrome. We discuss the evidence base for treatment where it is available and describe current practice where it is not. For example, in
West syndrome there is some evidence for preference of hormonal treatments over
vigabatrin, although the choice and duration of hormonal treatment remains unclear. We describe the use of conventional and newer anti-epileptic medications in the various syndromes and discuss which medications should be avoided. Older possibly forgotten treatments such as
sulthiame and
potassium bromide also have a role in the severe
epilepsies of childhood. We discuss hormonal treatment with particular focus on the treatment of
West syndrome, continuous spike wave in slow wave sleep (CSWS)/electrical
status epilepticus in slow wave sleep (ESES) and
Landau Kleffner syndrome. The role of the
ketogenic diet has in recent years come to the fore of the management of these severe
epilepsies and we describe successful use in
myoclonic astatic epilepsy,
Lennox Gastaut syndrome and
Dravet syndrome. It is important that resective
epilepsy surgery is not ignored in the management of these children, particularly those with hemi-pathology who may present with ESES and respond well to hemispheric disconnection. Adjunctive and symptomatic surgical treatments such as
vagal nerve stimulation and corpus callosotomy may improve seizure burden. Finally, it is vital that the identification and treatment of developmental, behavioural and psychiatric co-morbidities are not neglected and that a rational, holistic approach is taken to the management of epileptic
encephalopathies.