Epilepsy is a disease associated with lasting derangement of brain function and predisposition to recurring seizures . It may arise from a variety of genetic, structural or metabolic causes . Seizures and epilepsy are generally divided into focal and generalized according to the mode of seizure onset as well as into genetic, structural/metabolic, or unknown according to the underlying cause or etiology . Focal or localization-related epilepsies have previously been referred to as partial epilepsies .
Most of the focal epilepsies are either structural or unknown, which means there is a presumed focal structural cause that cannot be identified historically or be seen with current imaging techniques. If the patient undergoes epilepsy surgery, the cause is sometimes subsequently defined pathologically. Focal epilepsies of childhood, including benign epilepsy of childhood with centrotemporal spikes and Panayiotopoulos syndrome, are of unknown cause but may have a genetic component.
The causes, clinical manifestations, and electroencephalographic features of the localization-related epilepsies are reviewed here. The focal epilepsies of childhood are discussed in detail separately. (See "Benign partial epilepsies of childhood".)
The management of focal epilepsy and other epilepsy syndromes are discussed separately. (See "Overview of the management of epilepsy in adults" and "Initial treatment of epilepsy in adults" and "Evaluation and management of drug-resistant epilepsy" and "Surgical treatment of epilepsy in adults" and "Overview of the treatment of seizures and epileptic syndromes in children".)
Most of the localization-related epilepsies are the result of a structural brain abnormality, even though this cannot always be identified. These cases represent most cases of adult-onset epilepsy, although these are common in childhood as well. If imaging studies are normal, the cause remains unknown.