None — Epilepsy
Epilepsy is a condition characterized by recurrent seizures (periods of abnormal electrical activity in the brain). The seizures are usually brief (lasting from a few seconds to a few minutes). However, confusion may last for much longer.
According to the Epilepsy Foundation, about 3 million people in the U.S. have epilepsy. Roughly 200,000 new cases are diagnosed annually. Peak onset occurs before age two and after 65. In 70 percent of cases, the cause can't be found. Some known causes include: brain tumors, infection or injury to the brain, genetic conditions, and lead poisoning.
There are two main classes of epilepsy: generalized seizures and partial seizures. In generalized seizures, the abnormal electrical activity affects both hemispheres (sides) of the brain at the onset and the patient loses consciousness for at least a brief period of time. There are several subcategories of generalized seizures:
Generalized tonic clonic seizures (also called grand mal seizures) are the most common type of generalized seizure. They occur in two phases. During the tonic phase, the limbs stiffen and breathing sometimes decreases or stops. That's followed by the clonic phase, characterized by jerking of the limbs and face.
Absence seizures (also known as petit mal seizures) cause a lapse of awareness, like staring into space. They last only a few seconds, beginning and ending abruptly. These types of seizures usually occur in children and are often undetected.
Atonic seizures cause a sudden loss of muscle tone, leading to a drop of the head, inability to stand or sit upright or collapse of the body. Since these seizures occur without warning, patients are at high risk of injury from a fall.
Myoclonic seizures are brief, rapid jerks of the muscles, usually affecting both sides of the body at the same time.
In partial seizures, the abnormal electrical activity occurs in a specific area in one side of the brain. These are the most common types of seizures in epilepsy. There are two kinds of partial seizures:
Simple partial seizures can cause unusual movements, emotions and sensations. The patient remains conscious and remembers the events that happen during the seizure. Some people are able to talk while the seizure is ongoing, while others are unable to talk or move.
Complex partial seizures affect a larger portion of the brain than simple partial seizures. The patient has an altered state of consciousness, in which he/she is unaware of what's happening, unable to interact with others and has no control over movements or speech. Patients usually don't remember what happened during the seizure.
Diagnosing and Controlling Seizures
Dawn Eliashiv, M.D., Neurologist with Cedars-Sinai Medical Center in Los Angeles, says seizures are much more common than many believe. However, some people only equate seizures with jerking and loss of consciousness. Thus, less common symptoms (like staring, nonsense talking or repetitive movements) may be missed until the patient has had several episodes of seizures.
Sometimes the only way to make a definite diagnosis is to perform an EEG (electroencephalograph), or recording of the electrical activity of the brain. According to the National Institute of Neurological Disorders and Stroke, people with epilepsy often have abnormal brain activity even when they aren't having a seizure.
There are several medications used to control epilepsy. A medication that works for one person may be ineffective for someone else. So doctors often have to try several drugs to find the one that provides the best control over seizures. According to the Epilepsy Foundation of America, 70 percent of people with epilepsy are successfully treated with medication and free of seizures. For others, medications can reduce the severity/frequency of seizures. In about 10 percent of patients, medications are unable to provide adequate control over seizures.
Surgery for Seizure Control
One option for some patients who aren't able to gain adequate control over seizures is surgery. The goal is to remove the portion of the brain where seizures start. Eliashiv says if the seizures originate on both sides of the brain, patients are not usually good candidates. Surgery may also not be an option when the seizures originate in an area near speech, language, hearing or other important functional areas of the brain.
Each patient must be individually evaluated for consideration. The patient is usually hospitalized and monitored with EEG and a video camera. This helps doctors obtain more information about the symptoms associated with a seizure and the location of the abnormal electrical activity. A more precise type of brain mapping uses a grid of electrodes implanted directly onto the surface of the brain.
Experts estimate about 64 percent of patients who have epilepsy surgery are seizure free after the treatment. For others, surgery can significantly reduce seizure activity. Patients who have surgery will still need to take their medication for about two more years to give the brain time to adapt.