[Advances in our knowledge of the causation and pathophysiology of reflex epilepsies]

In recent years our knowledge of the pathophysiology and aetiology of reflex seizures and epilepsies has advanced significantly due to the contributions made by modern functional neuroimaging and neurophysiology techniques, as well as the findings of research being conducted in molecular biology. The aim of our review is to summarise and integrate these contributions in order to describe the current state of our knowledge on the subject.

The fundamental pathophysiological pattern is common to all types of reflex epilepsy and is based on the existence of a hyperexcitable cortical or subcortical neuronal area that can respond to a physiological stimulus in an exaggerated manner. This focal hyperexcitability may derive from a predisposing genetic substrate (idiopathic reflex epilepsy) or from a focal cortical lesion (lesional reflex epilepsy). Some genetic substrates have been reported in isolated families and there are many candidate genes, but we still do not know enough about the genetic base. The lesion-based aetiology is very heterogeneous, but disorders affecting cortical development are the lesions with the greatest capacity to cause reflex epilepsy. Clinical expression is conditioned by the topography of the lesion and not by the type of underlying lesion.

Future characterisation of reflex epileptic seizures and syndromes must include a diagnosis centred around three axes, that is, topographic, lesional and genetic.