Reflex seizures in Rett syndrome.

Reflex seizures are a rare phenomenon among epileptic patients, in which an epileptic discharge is triggered by various kinds of stimuli (visual, auditory, tactile or gustatory). Epilepsy is common in Rett syndrome patients (up to 70%), but to the authors' knowledge, no pressure or eating-triggered seizures have yet been reported in Rett children. We describe three epileptic Rett patients with reflex seizures, triggered by food intake or proprioception. One patient with congenital Rett Sd. developed infantile epileptic spasms at around seven months and two patients with classic Rett Sd. presented with generalised tonic-clonic seizures at around five years. Reflex seizures appeared when the patients were teenagers. The congenital-Rett patient presented eating-triggered seizures at the beginning of almost every meal, demonstrated by EEG recording. Both classic Rett patients showed self-provoked pressure -triggered attacks, influenced by stress or excitement. Non-triggered seizures were controlled with carbamazepine or valproate, but reflex seizures did not respond to antiepileptic drugs. Risperidone partially improved self-provoked seizures. When reflex seizures are suspected, reproducing the trigger during EEG recording is fundamental; however, self-provoked seizures depend largely on the patient's will. Optimal therapy (though not always possible) consists of avoiding the trigger. Stress modifiers such as risperidone may help control self-provoked seizures.

Genetic causes of epilepsy.

BACKGROUND: The contribution of genetic factors to the origin of different epilepsies is a fact established by epidemiological, clinical, and molecular studies. These studies have made it possible to identify numerous mutations in different genes that cause or predispose to the development of certain types of epilepsy. REVIEW SUMMARY: The study of single-gene epilepsies has contributed relevant data regarding the pathophysiology of epilepsy. Most of these genes encode voltage- or ligand-gated ion channels. Other single-gene epilepsies are related to mutations that provoke alterations in neuronal maturation and migration during embryonic development. Nevertheless, the most common forms of epilepsy are not caused by single mutations but by a combination of polymorphisms, most of which are unknown, that generate an alteration in neuronal excitability. In some syndromes, genetic alterations and their consequences have made it possible to explain the therapeutic response to different drugs. Therefore, the progress being made in genetics is changing the classification and diagnosis of epilepsy; moreover, it can sometimes influence the choice of treatment. CONCLUSION: The advances made in genetic knowledge of epilepsy have led to the description of new epilepsy syndromes and to a better characterization of known ones. However, the genes responsible for the most common forms of idiopathic epilepsy remain mostly unknown. This means that for the time being, in clinical practice, genetic diagnosis is limited to uncommon syndromes and to cases in which treatment decisions or genetic counseling can be derived from the diagnosis.