Focal (partial) epilepsies
In focal (partial) epilepsies, the patient may be aware (simple partial seizures) during the seizures, or have impaired awareness (complex partial seizures). Focal (partial) seizures can evolve to bilateral (secondarily generalised) tonic-clonic seizures. The most common form of structural focal (partial) epilepsy is mesial temporal lobe epilepsy due to hippocampal sclerosis—other causes include tumours and head injuries, and in children, congenital brain anomalies and perinatal brain injury.
Carbamazepine is generally considered the drug of choice for focal (partial) epilepsies.
For children, use:
carbamazepine (preferably modified-release) 2.5 mg/kg orally, twice daily for 5 days, then increase to initial target dose of 5 mg/kg twice daily. If needed, increase up to 10 mg/kg twice daily1. epilepsy, focal (partial) carbamazepine
For adults, use:
carbamazepine modified-release 100 mg orally, at night for 1 to 2 weeks, then every week increase the daily dose by 100 to 200 mg to initial target dose of 200 mg twice daily. If needed, increase up to 600 mg twice daily1. carbamazepine
The earliest sign of dose-related toxicity is usually diplopia, starting 30 to 60 minutes after the morning dose. Serum carbamazepine concentration is of limited use for determining the dose.
If carbamazepine does not fully control focal (partial) seizures or is not tolerated, refer for expert advice. A range of drugs can be used second-line (see Second-line drugs used for focal (partial) epilepsy) and none is preferred—choice is based on the factors listed in Factors affecting choice of antiepileptic drug.
Adults: clobazam, gabapentin, lacosamide, lamotrigine, levetiracetam, oxcarbazepine, perampanel, phenytoin, pregabalin, sodium valproate [NB1] [NB2], tiagabine, topiramate, zonisamide
Children: clobazam, gabapentin, lamotrigine, levetiracetam, oxcarbazepine, phenobarbital (phenobarbitone), phenytoin, sodium valproate [NB1] [NB2], tiagabine, topiramate, zonisamide
NB1: Avoid sodium valproate in females of childbearing potential (see teratogenic and neurodevelopmental effects of antiepileptic drugs).
NB2: If considering starting sodium valproate in a male of reproductive potential, see Sodium valproate use in males of reproductive potential; a discussion about the potential risk of neurodevelopmental disorders in children born to males taking sodium valproate may be appropriate.
If the patient's seizures are not controlled after trying two or three second-line drugs, the patient should be referred to a specialist epilepsy centre.
Patients with focal (partial) epilepsy who do not respond to antiepileptic drugs may be suitable for surgery—the most common procedure is anterior temporal lobectomy for temporal lobe epilepsy associated with hippocampal sclerosis or another temporal lobe lesion. Sometimes surgery is effective even when no structural lesion is found. After surgery, up to 80% of patients achieve long-term seizure control.