An epileptic seizure is a “transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain.” Epilepsy is a disorder of the brain characterized by an enduring predisposition to generate epileptic seizures and by the neurobiological, cognitive, psychological, and social consequences of this condition. The widely accepted operational definition of epilepsy requires that an individual have at least two unprovoked seizures on separate days, generally 24 hours apart. An unprovoked seizure refers to a seizure that occurs in the absence of an acute brain insult or systemic disorder. This nosology is based on the observation that while a single unprovoked seizure is often an isolated event that does not recur during an individual’s lifetime, two unprovoked seizures rarely occur in isolation and are associated with high risk of the individual experiencing more seizures. In some cases, such as when the seizure occurs in the setting of a potentially epileptogenic brain insult such as an episode of encephalitis or a traumatic brain injury (TBI), it is possible to recognize the specific form of epilepsy at its earliest presentation. In such cases, the diagnosis of epilepsy can be made after the very first unprovoked seizure. Based on its definition, epilepsy is not a single disorder but rather a syndrome or syndromes. Different forms of epilepsy syndrome(s) have different causes, different manifestations, different implications for short- and longterm management and treatment, and different outcomes.
© 2016 by Taylor & Francis Group, LLC.