The natural history and prognosis of epilepsy

Epilepsy is a brain condition characterized by the recurrence of unprovoked seizures. Generally, prognosis refers to the probability of attaining seizure freedom on treatment and little is known about the natural history of the untreated condition. Here, we summarize aspects of the prognosis and prognostic predictors of treated and untreated epilepsy and of its different syndromes. Usually, epilepsy is a fairly benign condition. Most epilepsies have a good prognosis for full seizure control and eventual discontinuation of AEDs, but epilepsy syndromes have differing outcomes and responses to treatment. Prognostic factors include aetiology, EEG abnormalities, type of seizures and the number of seizures experienced before treatment onset, and poor early effects of drugs. Early response to treatment is an important positive predictor of long-term prognosis, while the history of a high number of seizures at the time of diagnosis, intellectual disability, and symptomatic aetiology are negative predictors. Different prognostic patterns can be identified, suggesting that the epileptogenic process is not static. Epilepsy carries a greater than expected risk of premature death. Aetiology is the single most important risk factor for premature death.