Principles of treatment of epilepsy

Epilepsy is a common chronic neurological condition with a prevalence of 4-8 per 1000. The present classification of epilepsy is based on: 1) the etiology, which distinguishes symptomatic epilepsies from those that are idiopathic and cryptogenic, and 2) the localization of the disorder in the brain, separating the generalized seizures from epilepsies with partial or focal onset. The majority of patients with epilepsy will go into remission and two-thirds will remain so 2 years after drug withdrawal. The impact of epilepsy on individual patients varies. Employment, driving and learning may constitute major problems. There is a small but definite increase in mortality in patients suffering from epilepsy. Treatment of epilepsy usually involves long-term medical treatment, with the ultimate aim being no seizures and no drugs. Before starting treatment, the diagnosis of epilepsy should be assured. Initiation of antiepileptic drug therapy needs a full and adequate discussion with the patient and the choice of the minimum effective dose of an appropriate monotherapy. Nonpharmacological treatments may be necessary at a relatively early stage if pharmacologic treatment is ineffective. In choosing between different anti-epileptic drugs, consideration should be given to the efficacy of the drug for an individual patient and the tolerability of the drug. There is good evidence from many studies that the chief factor determining relative effectiveness is likely to be the spectrum and incidence of adverse effects of antiepileptic drugs. Some 20% of patients developing epilepsy have a chronic disorder uncontrolled by drugs. In patients receiving and complying with optimal doses of a single antiepileptic drug, the addition of further agents is likely to result in a significant improvement in seizure control in only about 10% of patients, but inevitably it increases the risks of dose-related, idiosyncratic and chronic toxicity due to both pharmacokinetic and pharmacodynamic drug interactions. For this group of patients an appropriate aim may not be complete remission of seizures but a compromise of reduced seizure frequency with less severe seizures, to be achieved with one or, at most, two drugs. The management of these patients with unremitting seizures constitutes a treatment challenge for epileptologists.