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Epilepsy

Epilepsy is a brain disorder which results in repeated seizures. Nerve cells (neurons) normally communicate with each other through electrical impulses. During a seizure, these impulses become overactive, causing strange sensations, emotions, and behavior, or sometimes convulsions, muscle spasms, and loss of consciousness. Having a seizure does not mean that a person has epilepsy. Only when a person has had two or more otherwise unexplained or unprovoked seizures is he or she considered to have epilepsy. Epilepsy can be very different from one person to another. Some people have seizures that are easily controlled, don’t affect their daily lives, and go away in time. Others may be overwhelmed by constant seizures that affect their thinking and/or memory. The seizures can be so serious that they cause frequent injuries. They leave people unable to work, drive a car, or have an enjoyable social or family life. Because many conditions can cause seizures, it’s important to see a neurologist for an accurate diagnosis. The goal is to find a treatment that will stop the seizures without causing serious side effects. There are many epilepsy treatments available to reduce the frequency and severity of seizures. Unfortunately, not everyone responds well to treatment or reaches the goal of being completely free of seizures. For children without severe epilepsy syndromes, the seizures may stop after several years. Others may also experience a decrease in the frequency and severity of seizures over time. Such improvements are more likely if the epilepsy has been well-controlled by antiepileptic medication or epilepsy surgery.

Affected Population

Anyone can have epilepsy. It can start at any age. In the United States, it affects about one in 100 people. 40% of those are children under age 18.

Epilepsy is not contagious and is not caused by mental illness or other mental problems. Many people with epilepsy have normal or above-average intelligence. However, seizures can cause brain damage, particularly if they are severe.

Causes

Epilepsy is a disorder with many possible causes. Anything that disturbs the normal pattern of neuron activity, from illness to brain damage to abnormal brain development, can lead to seizures. Epilepsy may develop because of an abnormality in brain wiring, an imbalance of nerve signaling chemicals called neurotransmitters, or some combination of these factors. One of the most-studied neurotransmitters that plays a role in epilepsy is GABA  (gamma-aminobutyric acid) which is an inhibitory neurotransmitter. Research on GABA has led to drugs that alter the amount of this neurotransmitter in the brain or change how the brain responds to it. About half of all seizures (50%) have no known cause. However, in other cases, the seizures are clearly linked to identifiable problems. In many cases, epilepsy develops as a result of brain damage from stroke, head injury, encephalitis, alcoholism, and Alzheimer's Disease. Seizures may stop once these disorders are treated successfully. However, the odds of becoming seizure-free after the primary disorder is treated are uncertain and vary depending on the type of disorder, the brain region that is affected, and how much brain damage occurred prior to treatment. Epilepsy is associated with a variety of developmental and metabolic disorders, as well, including cerebral palsy and autism. Epilepsy is just one of a set of symptoms commonly found in people with these disorders. Seizures are often triggered by factors such as lack of sleep, alcohol consumption, stress, or hormonal changes associated with the menstrual cycle.

These seizure triggers do not cause epilepsy but can provoke first seizures or cause breakthrough seizures in people who otherwise experience good seizure control with their medication. Sleep deprivation in particular is a universal and powerful trigger of seizures. For this reason, people with epilepsy should make sure to get enough sleep and should try to stay on a regular sleep schedule as much as possible. For some people, light flashing at a certain speed or the flicker of a computer monitor can trigger a seizure; this problem is called photosensitive epilepsy.

Different Kinds of Seizures

Doctors have described more than 30 different types of seizures. Seizures are divided into two major categories -- focal seizures and generalized seizures. However, there are many different types of seizures in each of these categories. Focal seizures, also called localization related or partial seizures, start in just one part of the brain. About 60 percent of people with epilepsy have focal seizures. These seizures are frequently described by the area of the brain in which they originate. For example, someone might be diagnosed with temporal lobe seizures if the seizures originate from the temporal lobe of the brain. Generalized seizures are a result of abnormal neuronal activity on both sides of the brain. These seizures may cause loss of consciousness, falls, or massive muscle spasms.

Not all seizures can be easily defined as either focal or generalized. Some people have seizures that begin as focal seizures but then spread to the entire brain. Other people may have both types of seizures but with no clear pattern.

Different Kinds of Epilepsy

Just as there are many different kinds of seizures, there are many different kinds of epilepsy. Doctors have identified hundreds of different epilepsy syndromes -- disorders characterized by a specific set of symptoms that include epilepsy. Some of these syndromes appear to be hereditary. For other syndromes, the cause is unknown. Epilepsy syndromes are frequently described by their symptoms or by where in the brain they originate. Types of epilepsy include: Absence seizures (Petit Mal), Frontal Lobe epilepsy, and Temporal Lobe epilepsy (TLE).  There are many other types of epilepsy, each with its own characteristic set of symptoms. Many of these, including Lennox-Gastaut syndrome and Rasmussen's Encephalitis, begin in childhood. Seizure syndromes do not, however, always appear in childhood. Epilepsy syndromes that are easily treated, do not seem to impair cognitive functions or development, and usually stop spontaneously are often described as benign. Benign epilepsy syndromes include benign infantile encephalopathy and benign neonatal convulsions. Other syndromes, such as early Myoclonic Encephalopathy, include neurological and developmental problems. However, these problems may be caused by underlying neurodegenerative processes rather than by the seizures. Epilepsy syndromes in which the seizures and/or the person's cognitive abilities get worse over time are called progressive epilepsy.

When Are Seizures Not Epilepsy?

While any seizure is cause for concern, having a seizure does not by itself mean a person has epilepsy. First seizures, febrile seizures, nonepileptic events, and eclampsia are examples of seizures that may not be associated with epilepsy.

Diagnosis

Doctors have developed a number of different tests to determine whether a person has epilepsy and, if so, what kind of seizures the person has. In some cases, people may have symptoms that look very much like a seizure but in fact are nonepileptic events caused by other disorders. Even doctors may not be able to tell the difference between these disorders and epilepsy without close observation and intensive testing.

Such testing may include electroencephalogram (EEG) monitoring, a brain scan, or developmental, neurological, and behavioral tests.

Treatment

Accurate diagnosis of the type of epilepsy a person has is crucial in choosing an effective treatment. There are many different ways to treat epilepsy. Currently available treatments can control seizures at least some of the time in about 80% of people with epilepsy. However, another 20% have intractable seizures. Once epilepsy is diagnosed, it is important to begin treatment as soon as possible. Research suggests that medication and other treatments may be less successful in treating epilepsy once seizures and their consequences become established. Treatment options include medications, surgery, devices (such as a vagus nerve stimulator), dietary modifications, and biofeedback.

Medications for epilepsy are referred to as anticonvulsants or antiepileptic drugs (AEDs). Most people with epilepsy will benefit from treatment with one or more AEDs. These medications reduce the frequency or severity of seizures in more than 80 percent of people that take them. There are several medications available. Some of them work better for some types of epilepsy than others. Your physician will recommend an AED based on the following:

  • Type of epilepsy
  • Severity and frequency of seizures
  • Response to previous medications (if any)
  • Your age
  • Risk of side effects from the medication

Antiepileptic drugs can cause a variety of side effects. They may cause drowsiness, nausea, weight loss/weight gain, or allergic reactions. The risk of side effects increases if more than one antiepileptic drug is used at the same time. Antiepileptic drugs can also interfere with other medications. For instance, some antiepileptic drugs can cause birth control pills to be less effective at preventing pregnancy. It is important to talk to your doctor about the choice of medication, how often it is taken, and any side effects. The amount of medication recommended each day may be increased or decreased over time. For instance, many patients may start a new medication at a low dose and increase the dose over the following weeks or months. This process is called titration. The goal of titration is to reach a drug concentration in the blood (drug level) that controls the seizures but minimizes the risk of side effects. Drug levels may be measured through blood tests to confirm that drug levels are in an effective and safe range.  Modern AED’s often require no blood monitoring.

Additional blood tests may be performed to ensure that the antiepileptic medications are not damaging other organs, such as the liver or bone marrow. It is important to take your medication as prescribed. Many people with epilepsy must take an antiepileptic medication for the rest of their lives to prevent further seizures. If a person, especially a child, has been seizure-free for several years, your physician may recommend a trial period without the medication.

Effects on Daily Life

Most people with epilepsy lead outwardly normal lives. Approximately 80 percent can be significantly helped by modern therapies, and some may go months or years between seizures. However, the condition can and does affect daily life for people with epilepsy, their family, and their friends. People with severe seizures that resist treatment have, on average, a shorter life expectancy and an increased risk of cognitive impairment, particularly if the seizures developed in early childhood. These impairments may be related to the underlying conditions tha cause epilepsy or to epilepsy treatment rather than the epilepsy itself.

It is not uncommon for people with epilepsy, especially children, to develop behavioral and emotional problems. Sometimes these problems are caused by embarrassment or frustration associated with epilepsy.

In children, these problems can be minimized if parents encourage a positive outlook and independence, do not reward negative behavior with unusual amounts of attention, and try to stay attuned to their child's needs and feelings. Families must learn to accept and live with the seizures without blaming or resenting the affected person.

Many people with epilepsy also live with an ever-present fear that they will have another seizure.

For many people with epilepsy, the risk of seizures restricts their independence, in particular the ability to drive with epilepsy. Most states and the District of Columbia will not issue a driver's license to someone with epilepsy unless the person can document that they have gone a specific amount of time without a seizure (the waiting period varies from a few months to several years). Some states make exceptions for this policy when seizures don't impair consciousness, occur only during sleep, or have long auras or other warning signs that allow the person to avoid driving when a seizure is likely to occur. Studies show that the risk of having a seizure-related accident decreases as the length of time since the last seizure increases. One study found that the risk of having a seizure-related motor vehicle accident is 93 percent less in people who wait at least 1 year after their last seizure before driving, compared to people who wait for shorter intervals. The risk of seizures also restricts people's recreational choices. For instance, people with epilepsy should not participate in sports such as skydiving or motor racing where a moment's inattention could lead to injury. Other activities, such as swimming and sailing, should be done only with precautions and/or supervision. It is important to take steps to avoid potential sports-related problems such as dehydration, overexertion, and hypoglycemia, as these problems can increase the risk of seizures.

Special risks

Although most people with epilepsy lead full, active lives, they are at special risk for two life-threatening conditions: status epilepticus and sudden unexplained death in epilepsy (SUDEP).