Genetic reflex epilepsies

Key words Photosensitive epilepsy Non-verbal and verbal induced epilepsies References Abstract Reflex epilepsies (RE) are rare epileptic syndromes with seizures induced by specific triggering factors (either by visual, auditory, somato-sensitive or somato-motor stimulation, or by higher cortical function activities). Their frequency depends on the type of epilepsies, and can reach 25% for photosensitive epilepsy. Spontaneous seizures may also occur. " Reflex seizures " can be classified into a simple " pure " reflex epilepsy and a complex group. The former comprises seizure triggered by simple sensory stimuli or by movements (photosensitive epilepsies). The latter are triggered by complex mental and emotional processes (verbal and non-verbal epilepsies). RE may also be classified into epilepsies that are primary or idiopathic (a genetic basis is likely) and epilepsies that are secondary or symptomatic (with an acquired basis). Reflex epilepsies are generally considered as idiopathic. Primary RE frequently have a family history, an age of onset in early life, a benign prognosis and good response to medication (sodium valproate (Dépakine®), lamictal (Lamotrigine®)), and an electroencephalogram (EEG) with a variable presentation but an almost invariable normality of background activity. Electroencephalographic seizures expression may be partial or generalized. Secondary RE occur later, frequently in patients with an associated neurologic and non epileptic impairment. There is sometimes less stereotypy in clinical expression, a poorer response to drugs for focal seizures triggered by specific stimuli (carbamazepine (Tégrétol®), phenytoin (Dihydan®)), and frequently an abnormal interictal EEG background.