Paediatricians and neurologists recognize that certain clusters of symptoms and signs and patients’ characteristics go together, and this is what we mean by a syndrome. The idea of epilepsy syndromes goes back many years, but a revised scheme or classification of epilepsy was proposed by the International League Against Epilepsy (ILAE) in 1989. In this classification, an epileptic syndrome is characterized by both clinical and EEG findings. On the clinical side, the age at onset of seizures, the family history, the seizure type(s), and neurological findings are all relevant to the classification, as is the appearance of the EEG between and during seizures. Identifying epileptic syndromes allows greater precision of diagnosis and of prognosis than simply classifying seizure types.

The same type of seizure can occur in different syndromes. For example, tonic-clonic (grand mal) seizures can occur in association with typical absences (primary generalized epilepsy) or in association with partial seizures (location-related epilepsy). Conversely a person with one syndrome may have seizures of more than one type. For example, a child with primary generalized epilepsy may have both absence and tonic-clonic seizures (both petit and grand mal). Identifying an epileptic syndrome helps to select the most appropriate investigations, decide on the most appropriate anti-epileptic treatment, and to predict most accurately the outcome. However, it must be understood that even if an epilepsy syndrome is identified, this does not necessarily give any information about the underlying cause of the epilepsy. Indeed, one syndrome such as West’s syndrome may have several more or less well identified causes.

Many of the different epilepsy syndromes begin in childhood, and are best characterized by onset by age. However, it is important to think in terms of the two great divisions of primary generalized epilepsy, in which the seizure discharge is generalized from the beginning, and location-related epilepsy, in which the seizure begins in one particular part (location) of the cortex, even if the seizure then becomes a secondary generalized one. A location-related epilepsy usually implies some local structural damage to, or disorder of, nerve cells. One example would be seizures following a head injury.

Some syndromes have common features and a predictable outcome. For example, some children develop nocturnal partial seizures often occurring at night, and characterized by large EEG spikes over the central and temporal regions of the brain on one side. Others are rather loose collections of a few common characteristics irregularly linked together.

In the opinion of most experts, only about 40-50 per cent of children with epilepsy can be ‘put into’ an epilepsy syndrome. When these children cannot be ‘put into’ or classified into an epilepsy syndrome, then the children’s epilepsy must be classified according to the seizure type or types that the child is experiencing, and this used as the best basis for prognostic judgement.

The question of inheritance of epilepsy, but with the advances in genetic research, the classification of epilepsy syndromes may eventually become replaced by specific epilepsy disorders or diseases classified genetically. However, for the time being, the concept of epilepsy syndromes is of some use.

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