Epilepsy and epilepsy-related behaviour disorders among people with intellectual disability 

Epilepsy is defined as at least one epileptic seizure; this in practice means two or more epileptic seizures unprovoked by any immediate identifiable cause during a relatively short period of time. Epileptic seizure is a clinical manifestation presumed to result from an abnormal and excessive discharge of a set of neurones in the brain. An epileptic syndrome is a cluster of symptoms and signs including type of seizure, mode of seizure recurrence, neurological findings, and neuroradiological or other findings of special investigations, customarily occurring together. An epileptic syndrome can have more than one cause or the cause may remain unknown; consequently outcomes may be different. Pseudoseizure is used to denote epilepsy-like seizures without concomitant EEG changes. Epilepsy and intellectual disability are symptoms of brain origin. The former is an unstable condition, where during the seizure or ictally the behaviour of a person with epilepsy is abnormal, but between the seizures or interictally there is no affect of epilepsy on his or her behaviour. Intellectual disability is a more or less stable condition. However, the categories of the degrees of intellectual disability are neither absolute nor static, as some children may move up or down between them. This chapter deals with the diagnosis, manifestations, behavioural disorders, frequency, aetiology, treatment, effects of antiepileptic drugs on behaviour, and prognosis of epilepsy in people with intellectual disability.