What is a Seizure? What is Epilepsy? Risk Factors, or 'Why Me?'
What is a Seizure?
More than 2.5 million Americans, and nearly 50 million people worldwide, have epilepsy. Despite its frequency, epilepsy remains a feared and poorly understood disease. This article is a brief overview of definitions, common risk factors, and treatments for epilepsy.
A seizure is a transient event caused by abnormal excitability of all or part of the brain. The principal cells of the brain, or neurons, use several different types of chemicals (called neurotransmitters) to communicate with each other. These chemical messages are translated into electrical signals, which allow neurons in different parts of the brain to work together and perform tasks: to move your arm, read a book, or tell a story. Normal balancing mechanisms ensure that these signals travel in an orderly fashion. When the brain is injured or when there is an abnormality of the brain's neurotransmitters, normal brain activity is interrupted and replaced by giant waves of electrical impulses that flood the brain's circuits. This abnormal electrical activity is a seizure.
Not all seizures look the same. What you experience or what others see during a seizure, depends on the type of seizure. There are two main types of seizures: generalized and partial.
Generalized seizures Generalized seizures involve the entire brain immediately, causing loss or alteration of consciousness. Generalized seizures include grand mal seizures, during which a person falls down unconscious and the body stiffens and jerks. Petit mal, or absence seizures, are generalized seizures during which there is momentary loss of consciousness without abnormal body movements.
Partial seizures Partial, or focal seizures, begin in one part of the brain. They cause varied symptoms, including auras (unusual warning sensations such as sounds, smells, or a funny feeling in the stomach), staring, chewing, lip smacking, shaking or stiffening of part of the body, wandering, or confusion. A partial seizure may remain in one part of the brain or spread to the rest of the brain. Most seizures last only seconds or a few minutes, but may be followed by sleep or confusion for several hours.
What is Epilepsy?
Not everyone who has a seizure has epilepsy. Epilepsy is a chronic neurological disorder characterized by recurrent, unprovoked seizures. Unprovoked means that there is no immediate cause for the seizure, such as a fever, an infection of the brain, or head trauma. Nearly 10 percent of people will have a seizure during their lifetime; most of these are provoked seizures during an acute illness or condition. These people may never have another seizure, and therefore do not have epilepsy.
If you have had more than one seizure, you may have epilepsy. Between seizures, most people with epilepsy are completely normal. Seizures can occur at any time, often without warning. In most people, seizures are easily controlled with treatment and may go away entirely; in others, seizures continue despite treatment and may last a lifetime.
Risk Factors, or 'Why Me?';
This is one of the most common questions I hear from my patients. There are dozens of underlying causes of epilepsy. Your doctor may not be able to find the specific cause of your epilepsy, and in fifty percent of patients, no exact cause can be found despite thorough testing. Some of the known causes include: Head trauma: Concussion (brief loss of consciousness) is considered to be mild head trauma, and increases the risk of epilepsy only slightly. On the other hand, moderate or severe head injury with prolonged loss of consciousness or brain hemorrhage greatly increases the risk of epilepsy. Infections of the brain: These include meningitis, encephalitis, and brain abscess. Stroke: A brain infarct (caused by lack of blood flow to part of the brain) or hemorrhage increases the risk of epilepsy. Alcohol: Individuals who drink heavily have a risk for seizures when they stop drinking abruptly (withdrawal seizures), and also have an increased risk of epilepsy. Brain tumors: Seizures may be the first sign of a brain tumor. For this reason, brain imaging is recommended for all patients who have new seizures in adulthood. Rarely, a slow-growing brain tumor may be found in people who have had seizures for years. Degenerative brain diseases: These include diseases such as Alzheimer's disease, multiple sclerosis, and Parkinson's disease. Mental retardation and cerebral palsy. Cortical dysplasia and migration disorders: These are abnormalities in the way the brain grows and develops. Some of the brain cells do not migrate to their proper positions, resulting in a “tangle” of neurons. These tangles have abnormal electrical connections, and therefore predispose a brain to seizures.
Genetic predisposition: Some types of epilepsy run in families. If you have generalized epilepsy, your first-degree relatives (parents, siblings, and children) have about a fourfold increased risk for epilepsy. First-degree relatives of people with partial seizures have twice the risk of developing epilepsy as the general population. Although there is some increased risk, it is important to remember that the overall risk of epilepsy in other family members is still low. Age: The risk of seizures is highest in young children and in the elderly. Gender: The incidence of epilepsy is higher in males than females, suggesting that factors associated with gender are important in the development of epilepsy. Febrile seizures during infancy: Infants who experience febrile seizures are at an increased risk for later development of epilepsy. In addition to these risk factors, certain situations can lower the seizure threshold and therefore trigger a seizure in people with epilepsy. They are: lack of sleep or erratic sleep schedules. excessive consumption of alcohol. physical or emotional stress. flashing or flickering lights (rare, only in certain types of epilepsy).
fever. hormones' many women with epilepsy have seizures predominantly during one part of their menstrual cycle.
Diagnosis
The diagnosis of epilepsy depends largely on your medical history. Because your doctor will probably never see one of your seizures, an accurate description of what happens, either from you or from someone who witnesses your seizure, is essential. Additional tests will help to confirm the diagnosis and to determine which type of epilepsy you have.
EEG An EEG (electroencephalogram) measures the electrical activity in your brain. The presence of abnormal electrical activity, or "spikes," can help to determine if you have epilepsy, and help to identify the region of the brain where your seizures begin. Longer EEG recordings over several days, known as ambulatory EEG or video-EEG monitoring may show abnormal activity even when the first EEG was normal.
Brain imaging Brain images are pictures of your brain that are taken in order to look for areas of abnormality that might account for the seizures. The most common type of brain scan is CT (computerized tomography). A more sensitive type of scan is MRI (magnetic resonance imaging), which produces a high-quality image of your brain. Most patients with partial seizures will have brain imaging.
Blood tests A blood sample may be taken to look for any medical conditions that may be the cause of the seizures.
Treatment
My patients often ask, "How many seizures is too many? Should I change my medications?" The answers to these questions are different for each patient. Optimal seizure control allows you to lead a normal, active life. For my patient E.L., even a single seizure would mean he could not drive to work, causing significant disruption of his daily life. For G.A., on the other hand, nighttime seizures two or three times a month do not interfere with her work and family life, and she prefers to have infrequent seizures rather than experience the side effects that would accompany more medications. Only you can determine your best seizure control. If you think that you are having too many seizures, discuss this concern with your doctor. Uncontrolled seizures can result in limits on driving, loss of employment, deterioration in school performance, and loss of self-esteem. If your seizures are not under control within a year of diagnosis, request referral to a specialist in brain disorders or epilepsy.
Antiepileptic Medications
The most common treatment for epilepsy is the daily use of anticonvulsant or antiepileptic drugs to prevent seizures. These medications act on brain signaling to limit hyperexcitability. While medications do not cure epilepsy, they allow many people to live normal, active lives free, or nearly free, of seizures.
Who needs medication? Not all patients with seizures require treatment with antiepileptic drugs, and some patients need only one or two years of drug therapy. Most patients with epilepsy, however, will require one or more drugs for many years. Overall, there is about a 60 percent chance of good seizure control with a single drug, and about 75 percent with additional drugs.
Choosing medication There are nearly two dozen different medications approved for the treatment of seizures. Certain medications work best for certain types of seizures, and your doctor will choose your first medication based on the type of epilepsy you have. Ultimately, this may not be the best drug for you, and changes in your medications may be necessary in order to find the best combination to prevent seizures with the fewest possible side effects. It is generally agreed that using a single medication is best, when possible. Using two medications may improve seizure control, but can also greatly increase the chance of side effects.
The drugs and their side effects The most commonly used antiepileptic medications are listed below, including the number of doses per day and the most troublesome or serious side effects. Because antiepileptic drugs work by decreasing brain hyperactivity, it is not surprising that many side effects are related to dulling of normal brain activity. Therefore, nearly all the antiepileptic drugs can cause sleepiness, difficulty with concentration and memory, blurred vision, and trouble with balance in some patients.
The new antiepileptic medications (Neurontin, Lamictal, Topamax, Gabitril) may be better tolerated than older medications. This chart does not provide an exhaustive list of side effects; as with any medication, you should discuss potential side effects fully with your doctor prior to beginning any antiepileptic medication. Medication Doses per day Side effects (in addition to those listed above) Phenytoin (Dilantin) one to two coarsening of the face, gum thickening, excessive hair growth, skin rash, liver abnormalities Carbamazepine (Tegretol, Tegretol XR, Carbatrol) two to three skin rash, liver abnormalities, low white blood cell count Valproate (Depakote, Depakene) three nausea, vomiting, weight gain, hair loss, tremor, liver dysfunction Phenobarbital one sedation, mental dulling Primidone (Mysoline) two sedation, mental dulling Ethosuximide (Zarontin) two nausea, vomiting Felbamate (Felbatol) two insomnia, decreased appetite, nausea, vomiting, headache, potentially fatal blood cell or liver abnormalities Gabapentin (Neurontin) three behavioral effects, movement disorders, weight gain Lamotrigine (Lamictal) two skin rash (potentially serious) Topiramate (Topamax) two word-finding difficulty, weight loss, kidney stones Tiagabine (Gabitril) two nervousness, irritability.
In general, no one drug has been proven to be more effective than the others for treatment of most seizures, and your doctor will often choose a drug depending on its potential side effects or how many times per day it needs to be taken. As mentioned above, it may take some time to find exactly the right combination of medications for you. Because antiepileptic drugs work by preventing seizures, it is important that you take them regularly. If the level of medication in your blood is too low, you may not be protected against a seizure.
Other Treatment Options
About 20 to 25 percent of patients will continue to have seizures despite treatment with antiepileptic medications. For these patients, several other therapies are available, including:
Ketogenic diet This is a high-fat, low-carbohydrate, no-sugar diet that is effective for some children with hard-to-control seizures. The diet is very strict, can be difficult to follow, and does not work for every child. It must be monitored closely by your doctor and nutritionist. The diet seems to be more effective for children than adults.
Vagus nerve stimulation This treatment involves electronic stimulation of the brain using an implanted device, like a pacemaker. Placement of the stimulator has been shown to reduce the frequency of seizures by about 50 percent in carefully selected patients.
Epilepsy surgery Some patients with frequent partial seizures may be candidates for brain surgery. This procedure removes the part of the brain that is causing the seizures or prevents the spread of seizure activity from one part of the brain to another. Epilepsy surgery has its own risks and benefits, and is not appropriate for every patient with epilepsy.
Conclusion
Epilepsy is a common neurological disease. If it isn't adequately treated, it can be disabling. Frequent seizures can lead to social isolation, poor school or job performance, restriction of driving privileges, family stress, and loss of independence and self-esteem. Exciting advances in the past 10 years, however, offer many new options for the treatment of epilepsy, including new medications, the ketogenic diet, vagal nerve stimulation, and epilepsy surgery. If you or someone you know has epilepsy, talk to a doctor about treatment options. Most patients can achieve acceptable seizure control with one or more of these treatments.
