A 38-year-old woman with a 5-year history of temporal lobe epilepsy presents to neurology clinic with recurrent breakthrough seizures over the past 3 months. She reports that during these events, she experiences lip smacking and picking at her clothes for approximately 90 seconds, followed by 5-10 minutes of postictal confusion. She denies loss of consciousness during the episodes. She has been compliant with levetiracetam 2000 mg daily, and serum drug level is 18 mcg/mL (therapeutic range 12-46 mcg/mL). Brain MRI reveals left mesial temporal sclerosis. Which of the following best explains the mechanism of her inadequate seizure control despite therapeutic drug levels?

1. A)Inadequate levetiracetam dosing; seizure threshold can only be lowered by increasing to maximum recommended dose of 3600 mg/day
2. B)Development of secondary generalized epilepsy; focal seizures have progressed to generalized tonic-clonic seizures requiring dual antiepileptic therapy
3. C)Pharmacoresistance due to increased P-glycoprotein expression at the blood-brain barrier reducing levetiracetam penetrationGABARITO
4. D)Levetiracetam inefficacy for mesial temporal lobe seizures; lacosamide is the preferred agent for this specific epilepsy syndrome
5. E)Postictal confusion indicating evolution to status epilepticus requiring immediate benzodiazepine monotherapy