Reflex seizure triggering: Learning about seizure producing systems.

AIM: We aim to study the mechanism of reflex seizure triggering in close link with the system-epilepsy concept.

METHOD: We use data and theories presented in the literature and scrutinize a few illustrative cases.

CONCLUSIONS: The prerequisite of seizure triggering is an epilepsy-prone brain network. When it is activated, it may produce seizures manifesting the function(s) of the same system. Beyond classical reflex seizures triggered by sensory-motor stimuli, we extend the reflex-epilepsy concept to seizures induced by the normal activation of epilepsy-prone systems e.g. praxis-induced seizures and those of sleep/wake system epilepsies elicited by falling asleep (absences) or arousals from NREM sleep (seizures of genetic frontal lobe epilepsy). We suggest that normal functioning of epilepsy-prone systems may trigger seizures in epilepsies in general.