Reflex seizure

Reflex seizures are epileptic seizures that are consistently induced by a specific stimulus or trigger making them distinct from other epileptic seizures, which are usually unprovoked. Reflex seizures are otherwise similar to unprovoked seizures and may be focal (simple or complex), generalized, myoclonic, or absence seizures. Epilepsy syndromes characterized by repeated reflex seizures are known as reflex epilepsies. Photosensitive seizures are often myoclonic, absence, or focal seizures in the occipital lobe, while musicogenic seizures are associated with focal seizures in the temporal lobe. Triggers may include various stimuli with the most common (75 to 80%) being flickering lights resulting in photosensitive seizures. Reflex epilepsies are generally thought to be genetic in origin. The inheritance pattern is dependent on the type of reflex epilepsy with some types lacking a specific genetic inheritance patterns. For example, photogenic epilepsy is thought to follow an autosomal dominant pattern with incomplete penetrance, while seizures triggered by proprioceptive stimuli do not follow an observable inheritance pattern. The underlying mechanism involves the stimulation of existing network of neurons by the specific trigger. The treatment of reflex epilepsy generally involves decreasing exposure to a person's triggers as well as anti-epileptic medications. Reflex epilepsy is relatively rare, making up approximately 5% of epilepsy syndromes. Reflex seizures can be either generalized or focal seizures or both. However, for any given stimulus there may be a large variation in the kind of elicited seizure. For example, reading epilepsy may cause myoclonic jerks in the jaw or may cause focal seizures in the regions of the brain responsible for reading. In reflex epilepsy generalized seizures are more common than focal seizures. Generalized seizures are seizures that arise in large areas of the brain including both hemispheres. Generalized seizures can take the form of myoclonic jerks, absences, or generalized tonic-clonic seizures.