First unprovoked seizure in adults — when to start AED and which drug to choose?

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### Management of a First Unprovoked Seizure in Adults **1. Definitions and Risk of Recurrence** A "first unprovoked seizure" is a single seizure event not triggered by a transient systemic or neurological insult (e.g., hypoglycemia, drug withdrawal). The primary clinical question is the risk of a second seizure (recurrence). * **Baseline Risk:** Approximately 21%–45% over the first two years. * **Increased Risk Factors:** Brain imaging abnormality (e.g., old stroke, tumor), epileptiform abnormalities on EEG, or nocturnal seizures. If any of these are present, the recurrence risk exceeds 60%, meeting the ILAE definition of epilepsy. **2. To Treat or Not to Treat?** * **Normal MRI/EEG:** In this patient (35M), with normal imaging and EEG, the recurrence risk is on the lower end (~25%). * **Guidelines (AAN/ILAE):** Immediate treatment with an Antiepileptic Drug (AED) reduces the risk of a second seizure by about 35% in the first two years but does not change long-term seizure remission rates. * **Decision Making:** Should be individualized. Factors favoring treatment include high-risk occupations (e.g., driver, software engineer working at heights), personal preference to avoid any recurrence, or presence of focal features. **3. Choosing an Antiepileptic Drug (AED)** * **Broad-Spectrum (First Choice):** Levetiracetam (Keppra) or Lamotrigine. * **Levetiracetam:** Rapid titration, few drug-drug interactions, but risk of behavioral side effects (irritability). * **Lamotrigine:** Better tolerated but requires slow titration (risk of Stevens-Johnson Syndrome) and is not suitable for emergency initiation. * **Specific Situations:** Carbamazepine or Oxcarbazepine for focal seizures (though they can worsen some generalized epilepsies). Sodium Valproate is highly effective for generalized syndromes but avoided in females of childbearing age. **4. Clinical Pearl: Driving Restrictions** Regardless of whether an AED is started, patients must be informed of local driving restrictions (typically 3–12 months seizure-free). **References:** 1. Krumholz A, et al. Evidence-based guideline: Management of an unprovoked first seizure in adults. *Neurology*. 2015 (reaffirmed 2021). 2. Fisher RS, et al. ILAE official report: a practical clinical definition of epilepsy. *Epilepsia*. 2014. 3. Marson A, et al. Immediate versus deferred antiepileptic drug treatment for early epilepsy and single seizures: a randomised controlled trial (MESS trial). *Lancet*. 2005.