Antiepileptic Drugs Reduce Risk of Recurrent Unprovoked Seizures
Clinical question: What are the updated recommendations for treating first unprovoked seizure in adults?
Background: Approximately 150,000 adults present with an unprovoked first seizure in the U.S. annually, and these events are associated with physical and psychological trauma. Prior guidelines discussed evaluation of unprovoked first seizures in adults but did not address management. This publication aims to analyze existing evidence regarding prognosis and therapy with antiepileptic drugs (AEDs).
Study design: Evidence-based appraisal of a systematic review.
Setting: Literature published from 1966 to 2013 on MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials.
Synopsis: Ten prognostic studies describing risk of recurrence were found. Generalized tonic-clonic seizures were the major seizure type. Cumulative incidence of recurrent seizure increased over time, with the majority occurring within the first two years, regardless of treatment with AED; however, there were treatment differences among these studies and wide variation in recurrence rates.
Recurrence risk was lower with AED therapy, though patients were not randomized. Increased risk of recurrence was associated with prior brain lesion causing the seizure, EEG with epileptiform abnormalities, imaging abnormality, and nocturnal seizure.
Five studies were reviewed for prognosis following immediate AED therapy. Immediate AED treatment reduced risk of recurrence by 35% over the first two years. Among studies, “immediate” ranged from within one week to up to three months. Two studies described long-term prognosis, concluding that immediate AED treatment was unlikely to improve the chance of sustained seizure remission.
Five studies were used to describe adverse events in patients treated with AED. Adverse event incidence varied from 7% to 31%, and the incidents that occurred were largely mild and were reversible.
Bottom line: In adults presenting with unprovoked first seizure, the risk of recurrence is highest in the first two years and can be reduced with immediate AED therapy, though AED therapy was not shown to improve long-term prognosis.
Citation: Krumholz A, Wiebe S, Gronseth GS, et al. Evidence-based guideline: management of an unprovoked first seizure in adults. Report of the Guideline Development Subcommittee of the American Academy of Neurology and the American Epilepsy Society. Neurology. 2015;84(16):1705-1713.
