What Is Focal Epilepsy?

Electrical misfires in the brain can cause either generalized epilepsy or focal epilepsy, also called partial epilepsy. Generalized seizures involve the entire brain and full body convulsions. Focal seizures start from a particular part of the brain and affect a specific part of the body or mind. Focal or local seizures may only cause a twitching arm or a strange visual image or a sudden change of mood. Focal epilepsy can, however, lead to generalized seizures and become more serious.

Severity

• Focal epilepsy may also be referred to as cortical dysplasia, which describes a malformation of the cortex, the outermost layer of brain tissue, that can lead to pediatric epilepsy. Benign focal epilepsy of childhood (BFEC) is very mild and usually goes away by puberty. It is most often diagnosed between ages five and eight. However, focal cortical dysplasia is a common cause of intractable epilepsy in children and is a frequent cause of epilepsy in adults.

Causes

• Focal epilepsy is congenital, that is, present at birth. During development of the embryo and fetus, neurons may not move to the proper, outermost gray matter in the brain, which requires a very specific structure of layers. Neurons may also become too large ("balloon cells") with a displaced nucleus and lack of dendrites or axons to send proper signals. Science Daily lists common causes of focal epilepsy as temporal sclerosis, cortical malformations, vascular disease, tumors, infections and injuries.

Symptoms

• According to the Oxford Journals, symptoms of more serious focal epilepsy include a large head, reduced deep tendon reflexes, language regression after the onset of seizures, hyperactivity, impulsivity, aggressive behavior, mental retardation or developmental disorders. If childhood epilepsy has resulted in developmental delays, then physical therapy and other corrective activities may be needed in addition to treatment for seizures.

Traditional Treatment

• Sometimes no treatment is needed for focal epilepsy, especially for BFEC. If treatment is necessary, it is aimed at symptoms, namely seizures. If anti-seizure medication does not work, the condition may be called Intractable Focal Epilepsy and doctors will consider other treatments. Surgery may be possible, depending on where the cortical dysplasia is located. The abnormality may be removed or it may be disconnected from the rest of the brain.

Other Treatment

• Surgery results in good seizure control in about 60 percent of patients. Other remedies may bring relief for the remaining 40 percent. "Intractable Focal Epilepsy," reviewed in the New England Journal of Medicine, describes newer treatments such as the gamma knife. Implantable devices, which can detect a seizure and deliver a small electrical shock to stop it, are an option in come cases. Treatment may result in a cure or only in reduction of symptoms.