Advances in epilepsy treatment

Jun 1 2007

Epilepsy and seizures affect 2.5 million Americans, 181,000 new cases of epilepsy are diagnosed every year, and the disorder incurs an estimated $12.5 billion in annual direct and indirect costs.

About 450,000 children ages 15 and younger develop epilepsy each year, and of these, 315,000 are school-aged children. Children and adolescents are more likely to have epilepsy of unknown or genetic origin. The rate of new cases in children is highest before age 2, gradually declines until about age 10, and then stabilizes.

“Brain injury or infection can cause epilepsy at any age; however, the cause of epilepsy is unknown for about half of all individuals with the disorder,” said Howard Weiner, MD, a pediatric epilepsy neurosurgeon at NYU Comprehensive Epilepsy Center, and an American Association of Neurological Surgeons (AANS) spokesperson. Children may be born with a defect in the structure of their brain, or they may suffer a head injury or infection that causes their epilepsy. Severe head injury is the most common known cause in young adults. In middle age, strokes, tumors, and injuries are more frequent cause. In people age 65 and older, stroke is the most common known cause, followed by degenerative conditions such as Alzheimer's disease. Seizures may not begin immediately after a person incurs a brain injury – seizures may occur many months later.

The emotional and physical toll can have a very negative impact on patients with refractory epilepsy. Uncontrolled seizures may cause significant physical injury or accidents, as well as cause cognitive disturbances, poor school or work performance, inability to work, and progressive memory deterioration. People with epilepsy may feel socially isolated and limited, thus diminishing their quality of life. The families of patients may also be significantly impacted emotionally by the disorder.

According to the AANS, tremendous advances have been made in epilepsy treatment over the past decade. Epilepsy may be treated with drug therapy, surgery, biofeedback, vagus nerve stimulation (VNS) or a ketogenic diet. The wide range of antiepileptic drugs (AEDs) remains the cornerstone of treatment.

AEDs treat the symptoms of epilepsy (the seizures), rather than curing the underlying condition. The drugs act on the brain to prevent the seizures from starting by reducing the tendency of the brain cells to send excessive and confused electrical signals. Before any drug is prescribed, it is important to discuss potential benefits, side effects and risks with your doctor.

Brain surgery may be a viable alternative for some people whose seizures cannot be controlled by medication. A person who has been given adequate dosages of several seizure medications, for an appropriate period of time without good results, is unlikely to achieve complete seizure control with any other medication.

Epilepsy surgery can benefit patients who have seizures associated with structural brain abnormalities, such as benign brain tumors and cortical dysplasia, malformations of blood vessels (such as arteriovenous malformations and cavernous angiomas), the genetic disorder tuberous sclerosis, and strokes. The goal of epilepsy surgery is to identify an abnormal area of brain cortex from which the seizures originate and remove it without causing any major functional impairment.

Surgery is most commonly performed to treat partial epilepsy, since only one area of the brain is involved. After surgery, many patients will be seizure-free, while others will have better controlled seizures. A few patients may not improve and will need to explore further treatment options.

In some cases, a palliative approach is used to stop the spread of seizures, when the actual seizure focus cannot be determined accurately. One such approach involves cutting the nerve fibers connecting the two sides of the brain through a corpus callosotomy. The corpus callosum is a band of nerve fibers located deep in the brain that connects the two sides (hemispheres) of the brain. It helps the hemispheres share information, but it also contributes to the spread of seizure impulses from one side of the brain to the other.

Some conditions are associated with seizures arising from one entire half of the brain – one hemisphere which is not functioning normally. A functional hemispherectomy is a surgical procedure performed in these cases, in which the epileptic, non-functioning hemisphere is disconnected from the remaining, normal hemisphere in order to stop the seizures.

“Depending on how well the seizure focus can be defined, between 50 and 90 percent of children who have epilepsy surgery stop having seizures entirely or experience a major reduction in the number of seizures. Many people in the field believe that the earlier in a child's development that surgery is performed, the better the outcome,” stated Dr. Weiner.