Deciding whether to treat or not to treat a first-ever seizure can be difficult, particularly when additional history provides no clear provoking mechanism and the critical ancillary tests such as MRI and EEG are uninformative. The practical clinical definition of epilepsy presented in the widely acknowledged International League Against Epilepsy (ILAE) official report is met under the following conditions: 2 unprovoked seizures >24 hours apart, 1 unprovoked seizure and seizure recurrence probability of >60% over the next 10 years, or diagnosis of an epilepsy syndrome.1 The report explicitly states that treatment decisions are distinct from diagnosis (i.e., the presence of disease does not necessitate treatment and the absence of disease does not preclude treatment) and that treatment decisions should be tailored to the clinical scenario and individual patient. Despite this caveat, in practice, treatment decisions are frequently based on the ILAE's 60% threshold, resulting, for example, in deferred treatment in patients with first-ever unprovoked seizure and apparent probability of recurrence <60%, particularly in light of potential antiepileptic drug (AED) adverse side effects and no known disease-modifying properties of AEDs.2 Because the reported seizure recurrence rates in patients with a first unprovoked seizure have ranged between 21% and 45% in the first 2 years,3 the practical result is that patients presenting with unprovoked first seizure and unrevealing workup are, almost by default, not treated with an AED.4,5
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