Critical issues in the treatment of epilepsy.

Classification of seizure types and evaluation and treatment of seizure disorders are discussed. Once the diagnosis of a seizure is made, the seizure type must be identified; this will help in determining the treatment. In partial seizures, the electrical discharge occurs focally, while generalized seizures involve both cerebral hemispheres simultaneously. Magnetic resonance imaging is the preferred test in the evaluation of patients with seizures, although computed tomography and electroencephalography can also be helpful. Selection of an antiepileptic drug (AED) is based on efficacy, toxicity, and, to a lesser degree, cost. Adverse reactions occur in up to 50% of patients. First-line AEDs include carbamazepine, ethosuximide, phenobarbital, primidone, phenytoin, and valproic acid. Serum AED concentrations can be helpful in managing patients with epilepsy. The serum concentrations required to control seizures or resulting in toxicity may vary among patients. Most seizures are manageable with oral AEDs. Medications of choice in status epilepticus include diazepam, lorazepam, phenytoin, and phenobarbital. The key to treating epilepsy is correct diagnosis of the seizure type and, when possible, the type of epilepsy. Most patients with epilepsy respond to one of the first-line AEDs; second-line agents may be useful in patients who do not respond to one or a combination of the first-line agents.