Management of focal-onset seizures: an update on drug treatment

Focal-onset seizures are manifestations of abnormal epileptic firing of brain cells in a localised area or areas of the brain. The diagnosis of focal-onset seizures initially entails an EEG, a detailed history from the patient and eyewitnesses, as well as computer tomographic or, preferably, magnetic resonance imaging scans. Video EEG to record ictal events may be necessary to establish the correct diagnosis. Focal seizures are classified according to the International Classification of Epileptic Seizures and International Classification of Epilepsies and Epilepsy Syndromes. It is important to try to decide how the seizure event fits into this system in order to successfully evaluate and optimise treatment, as well as to give detailed information to the patient about their seizures and prognosis. Once the decision to treat the seizures has been made, the physician must choose which medication is the most appropriate to begin with. Carbamazepine, phenytoin or valproic acid (sodium valproate) are often rated as first-line drugs, but factors such as adverse-effect profiles, age, possibility of pregnancy, and concomitant diseases and medication also need to be considered. Most of the newer antiepileptic drugs (AEDs) appear to have good efficacy and better tolerability than the older agents, but evidence to support their superiority is scarce and has led to conflicting advice in several guidelines. Among the newer AEDs, lamotrigine, gabapentin, topiramate and oxcarbazepine have obtained monotherapy indication in many countries. The higher costs of the newer AEDs may inhibit their wider use, especially in poorer countries.