LONG-TERM PROGNOSIS IN EPILEPSY

Abstract

The five studies presented in this thesis consider different aspects of the long-term prognosis of epilepsy and febrile seizures. The studies were: 1). A systemic review to examine a) how the risk of premature mortality in an individual with epilepsy changes over time and b) whether population mortality rates due to epilepsy have changed over time. (Study 1) 2). An extension of the National General Practice Study of Epilepsy (NGPSE), a prospective community-based incident cohort study to examine a) long-term seizure prognosis and mortality in people with epilepsy and b) seizure prognosis in children with febrile seizures (Study 2) 3). Two retrospective hospital-based cohort studies examining prognosis of chronic epilepsy with regard to a) frequency of different seizure patterns (Study 3) and mediumterm seizure outcome following anti-epileptic drug changes (Study 4). 4). A systematic review examining the impact of aetiology and others factors on outcome in status epilepticus (Study 5). Amongst the findings were: 1): There is no conclusive evidence that either the overall standardised mortality ratio (SMR) or the mortality rate of people with epilepsy has changed significantly over time. The SMR is highest soon after diagnosis and subsequently decreases with a possible late increase after 10 years. In the NGPSE cohort the SMR remains significantly elevated after 20 years despite over 80% currently being in terminal remission. 2): 6.7% (95% CI 4, 11%) of children with febrile seizures developed epilepsy after 20 years. 3): Approximately one-third of people with chronic epilepsy have a history of at least one significant period of seizure freedom (two or more years) while a comparable number with apparent drug-resistant epilepsy attain at least one year of seizure freedom after medication change, although approximately half subsequently relapse. 4). Aetiology and, to a lesser extent, age are the primary determinants of prognosis in status epilepticus.