The Progression of Epilepsy

Abstract

Prognosis for seizure control and cognitive development varies considerably among syndromes. Several factors may interact to influence outcome of an epilepsy including a causative etiology, ictal and interictal discharges, seizure-related trauma or systemic perturbations, and antiepileptic drug (AED) effects. Clinical evidence convincingly supporting Gowers' hypothesis that seizures beget seizures is lacking. Short-term seizure suppression by early treatment does not appear to influence long-term prognosis. Malignant epilepsy syndromes usually begin in infancy or childhood, have a high seizure frequency, resist the initial AED, and are often associated with progressive cognitive dysfunction. Prompt management of some severe epilepsy syndromes may lessen cognitive decline. However, aggressive AEDs therapy must be balanced against the potential for cognitive side effects, particularly if multiple AEDs are used. Several experimental paradigms closely parallel human TLE as both have an initial precipitating injury (IPI), a latent period, then recurrent spontaneous seizures. In humans, an IPI is any medical event with neurological implications. Although transition from a latent period to a seizure disorder certainly constitutes "progression" of the disorder, convincing clinical evidence of subsequent worsening has not emerged. Substantial clinical and experimental evidence indicates some cognitive regression and focal atrophy with time for TLE and other intractable syndromes. However, seizure frequency and severity, established early in the disorder, appear stable in most patients, and even regress in benign syndromes. Factors mitigating or extinguishing epilepsies need to be further sought.