What Is Epilepsy?
Epilepsies are chronic neurological disorders in which clusters of nerve cells, or neurons, in the brain sometimes signal abnormally and cause seizures. Neurons normally generate electrical and chemical signals that act on other neurons, glands and muscles to produce human thoughts, feelings and actions.
During a seizure, many neurons fire (signal) at the same time—as many as 500 times per second, much faster than normal. This surge of excessive electrical activity happening at the same time causes involuntary movements, sensations, emotions and behaviors, and the temporary disturbance of normal neuronal activity may cause a loss of awareness.
Epilepsy can be considered a spectrum disorder because of its different causes, different seizure types, its ability to vary in severity and impact from person to person, and its range of coexisting conditions. There also are many different types of epilepsy, resulting from a variety of causes.
Types of Epilepsy
Just as there are many different kinds of seizures, there are many different kinds of epilepsy. Hundreds of different epilepsy syndromes—disorders characterized by a specific set of symptoms that include epilepsy as a prominent symptom—have been identified. Some of these syndromes appear to be either hereditary or caused by mutations. For other syndromes, the cause is unknown. Epilepsy syndromes are frequently described by their symptoms or by where in the brain they originate.
- Absence epilepsy is characterized by repeated seizures that cause momentary lapses of consciousness. These seizures almost always begin in childhood or adolescence and tend to run in families, suggesting that they may be at least partially due to genetic factors. Individuals may show purposeless movements during their seizures, such as a jerking arm or rapidly blinking eyes, while others may have no noticeable symptoms except for brief times when they appear to be staring off into space. Immediately after a seizure, the person can resume whatever he or she was doing. However, these seizures may occur so frequently (in some cases up to 100 or more a day) that the person cannot concentrate in school or other situations.
- Childhood absence epilepsy usually stops when the child reaches puberty. Although most children with childhood absence epilepsy have a good prognosis, there may be long-lasting negative consequences, and some children will continue to have absence seizures into adulthood and/or go on to develop other seizure types.
- Frontal lobe epilepsy is a common epilepsy syndrome that features brief focal seizures that may occur in clusters. It can affect the part of the brain that controls movement and involves seizures that can cause muscle weakness or abnormal, uncontrolled movement such as twisting, waving the arms or legs, eye deviation to one side, or grimacing, and are usually associated with some loss of awareness. Seizures usually occur when the person is asleep but also may occur while awake.
- Temporal lobe epilepsy (TLE) is the most common epilepsy syndrome with focal seizures. These seizures are often associated with auras of nausea, emotions (such as déjà vu or fear), or unusual smell or taste. The seizure itself is a brief period of impaired consciousness that may appear as a staring spell, dream-like state or repeated automatisms. TLE often begins in childhood or teenage years. Research has shown that repeated temporal lobe seizures are often associated with shrinkage and scarring (sclerosis) of the hippocampus. The hippocampus is important for memory and learning. It is not clear whether localized asymptomatic seizure activity over years causes hippocampal sclerosis.
- Neocortical epilepsy is characterized by seizures that originate from the brain’s cortex, or outer layer. The seizures can be either focal or generalized. Symptoms may include unusual sensations, visual hallucinations, emotional changes, muscle contractions, convulsions and a variety of other symptoms, depending on where in the brain the seizures originate.
There are many other types of epilepsy that begin in infancy or childhood. For example:
- Infantile spasms are clusters of seizures that usually begin before the age of six months. During these seizures the infant may drop their head, jerk an arm, bend at the waist and/or cry out.
- Children with Lennox-Gastaut syndrome have several different types of seizures, including atonic seizures, which cause sudden falls and are also called drop attacks. Seizure onset is usually before age four years. This severe form of epilepsy can be very difficult to treat effectively.
- Rasmussen’s encephalitis is a progressive form of epilepsy in which half the brain shows chronic inflammation.
- Some childhood epilepsy syndromes, such as childhood absence epilepsy, tend to go into remission or stop entirely during adolescence, whereas other syndromes, such as juvenile myoclonic epilepsy (which features jerk-like motions upon waking) and Lennox-Gastaut syndrome, are usually present for life once they develop.
- Children with Dravet syndrome have seizures that start before age one and later in early childhood develop into other seizure types.
- Hypothalamic hamartoma is a rare form of epilepsy that first occurs during childhood and is associated with malformations of the hypothalamus at the base of the brain. People with hypothalamic hamartoma have seizures that resemble laughing or crying. Such seizures frequently go unrecognized and are difficult to diagnose.
When Seizures Are 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 (a life-threatening condition that can occur in pregnant women) are examples of conditions involving seizures that may not be associated with epilepsy. Regardless of the type of seizure, it’s important to inform your doctor when one occurs.
Causes of Epilepsy
Epilepsies are chronic neurological disorders in which clusters of nerve cells, or neurons, in the brain sometimes signal abnormally and cause seizures. Neurons normally generate electrical and chemical signals that act on other neurons, glands and muscles to produce human thoughts, feelings and actions.
During a seizure, many neurons fire (signal) at the same time—as many as 500 times per second, much faster than normal. This surge of excessive electrical activity happening at the same time causes involuntary movements, sensations, emotions and behaviors, and the temporary disturbance of normal neuronal activity may cause a loss of awareness.
Epilepsy can be considered a spectrum disorder because of its different causes, different seizure types, its ability to vary in severity and impact from person to person, and its range of coexisting conditions. There also are many different types of epilepsy, resulting from a variety of causes. Recent adoption of the term “epilepsies” underscores the diversity of types and causes:
- Some people may have convulsions (sudden onset of repetitive general contraction of muscles) and lose consciousness.
- Others may simply stop what they are doing, have a brief lapse of awareness and stare into space for a short period.
- Some people have seizures very infrequently, while other people may experience hundreds of seizures each day.
Risk Factors for Epilepsy
Anyone can develop epilepsy and have seizures. This condition affects both males and females of all races, ethnic backgrounds and ages.
Epilepsies have many possible causes, but about half of people living with epilepsy do not know the cause. In other cases, epilepsies are clearly linked to genetic factors, developmental brain abnormalities, infection, traumatic brain injury (TBI), stroke, brain tumors or other identifiable problems. Anything that disturbs the normal pattern of neuronal activity—from illness to brain damage to abnormal brain development—can lead to seizures.
Epilepsies may develop because of an abnormality in brain wiring, an imbalance of nerve signaling in the brain (in which some cells either over-excite or over-inhibit other brain cells from sending messages) or some combination of these factors. In some pediatric conditions, abnormal brain wiring causes other problems such as intellectual impairment.
In other people, the brain’s attempt to repair itself after a head injury, stroke or other problem may inadvertently generate abnormal nerve connections that lead to epilepsy. Brain malformations and abnormalities in brain wiring that occur during brain development may also disturb neuronal activity and lead to epilepsy.
Genetic mutations may play a key role in the development of certain epilepsies. Many types of epilepsy affect multiple blood-related family members, pointing to a strong inherited genetic component. In other cases, gene mutations may occur spontaneously and contribute to development of epilepsy in people with no family history of the disorder (called de novo mutations). Overall, researchers estimate that hundreds of genes could play a role.
Several types of epilepsy have been linked to mutations in genes that provide instructions for ion channels, the "gates" that control the flow of ions in and out of cells to help regulate neuronal signaling. For example, most infants with Dravet syndrome, a type of epilepsy associated with seizures that begin before the age of one year, carry a mutation in the SCN1A gene that causes seizures by affecting sodium ion channels.
Genetic mutations have been linked to disorders known as the progressive myoclonic epilepsies, which are characterized by ultra-quick muscle contractions (myoclonus) and seizures over time. For example, Lafora disease, a severe, progressive form of myoclonic epilepsy that begins in childhood, has been linked to a gene that helps to break down carbohydrates in brain cells.
Mutations in genes that control neuronal migration—a critical step in brain development—can lead to areas of misplaced or abnormally formed neurons, called cortical dysplasia, in the brain that can cause neurons to misfire and lead to epilepsy.
Other genetic mutations may not cause epilepsy, but may influence the disorder in other ways. For example, one study showed that many people with certain forms of epilepsy have an abnormally active version of a gene that results in resistance to antiseizure drugs. Genes also may control a person’s susceptibility to seizures, or seizure threshold, by affecting brain development.
Epilepsies may also develop as a result of brain damage associated with many types of conditions that disrupt normal brain activity. Seizures may stop once these conditions are treated and resolved. However, the chances 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. Examples of conditions that can lead to epilepsy include:
- Brain tumors, including those associated with neurofibromatosis or tuberous sclerosis complex, two inherited conditions that cause benign tumors called hamartomas to grow in the brain
- Head trauma
- Alcoholism or alcohol withdrawal
- Alzheimer’s disease
- Strokes, heart attacks and other conditions that deprive the brain of oxygen (a significant portion of new-onset epilepsy in elderly people is due to stroke or other cerebrovascular disease)
- Abnormal blood vessel formation (arteriovenous malformations) or bleeding in the brain (hemorrhage)
- Inflammation of the brain
- Infections such as meningitis, HIV and viral encephalitis
Cerebral palsy or other developmental neurological abnormalities may also be associated with epilepsy. About 20 percent of seizures in children can be attributed to developmental neurological conditions. Epilepsies often co-occur in people with abnormalities of brain development or other neurodevelopmental disorders. Seizures are more common, for example, among individuals with autism spectrum disorder or intellectual impairment. In one study, one-third of children with autism spectrum disorder had treatment-resistant epilepsy.
Screening for & Preventing Epilepsy
Medical professionals will conduct an electroencephalogram (EEG) to monitor electrical activity in the brain. By attaching electrodes to your scalp, this screening may determine a pattern in activity that leads to seizures and when another may occur.
Many people with a first seizure will never have a second seizure, and physicians often counsel against starting antiseizure drugs at this point. In some cases where additional epilepsy risk factors are present, drug treatment after the first seizure may help prevent future seizures. Evidence suggests that it may be beneficial to begin antiseizure medication once a person has had a second unprovoked seizure, as the chance of future seizures increases significantly after this occurs. A person with a preexisting brain problem—for example, a prior stroke or traumatic brain injury—will have a higher risk of experiencing a second seizure. In general, the decision to start antiseizure medication is based on the doctor’s assessment of many factors that influence how likely it is that another seizure will occur in that person.
Researchers also have identified several different genes that influence the risks associated with febrile seizures in certain families. Studying these genes may lead to new understandings of how febrile seizures occur and perhaps point to ways of preventing them.
Signs & Symptoms of Epilepsy
Hundreds of different epilepsy syndromes—disorders characterized by a specific set of symptoms that include epilepsy as a prominent symptom—have been identified. Some of these syndromes appear to be either hereditary or caused by de novo mutations. For other syndromes, the cause is unknown. Epilepsy syndromes are frequently described by their symptoms or by where in the brain they originate.
- Absence epilepsy is characterized by repeated seizures that cause momentary lapses of consciousness. These seizures almost always begin in childhood or adolescence and tend to run in families, suggesting that they may be at least partially due to genetic factors. Individuals may show purposeless movements during their seizures, such as a jerking arm or rapidly blinking eyes, while others may have no noticeable symptoms except for brief times when they appear to be staring off into space. Immediately after a seizure, the person can resume whatever he or she was doing. However, these seizures may occur so frequently (in some cases up to 100 or more a day) that the person cannot concentrate in school or other situations.
- Childhood absence epilepsy usually stops when the child reaches puberty. Although most children with childhood absence epilepsy have a good prognosis, there may be long-lasting negative consequences, and some children will continue to have absence seizures into adulthood and/or go on to develop other seizure types.
- Frontal lobe epilepsy is a common epilepsy syndrome that features brief focal seizures that may occur in clusters. It can affect the part of the brain that controls movement and involves seizures that can cause muscle weakness or abnormal, uncontrolled movement such as twisting, waving the arms or legs, eye deviation to one side, or grimacing, and are usually associated with some loss of awareness. Seizures usually occur when the person is asleep but also may occur while awake.
- Temporal lobe epilepsy (TLE) is the most common epilepsy syndrome with focal seizures. These seizures are often associated with auras of nausea, emotions (such as déjà vu or fear), or unusual smell or taste. The seizure itself is a brief period of impaired consciousness that may appear as a staring spell, dream-like state or repeated automatisms. TLE often begins in childhood or teenage years. Research has shown that repeated temporal lobe seizures are often associated with shrinkage and scarring (sclerosis) of the hippocampus. The hippocampus is important for memory and learning. It is not clear whether localized asymptomatic seizure activity over years causes hippocampal sclerosis.
- Neocortical epilepsy is characterized by seizures that originate from the brain's cortex, or outer layer. The seizures can be either focal or generalized. Symptoms may include unusual sensations, visual hallucinations, emotional changes, muscle contractions, convulsions and a variety of other symptoms, depending on where in the brain the seizures originate.
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. In fact, doctors have described more than 30 types.
Focal Seizures
In some focal seizures, the person remains conscious but may experience motor, sensory or psychic feelings (for example, intense déjà vu or memories) or sensations that can take many forms. The person may experience sudden and unexplainable feelings of joy, anger, sadness or nausea. He or she also may hear, smell, taste, see or feel things that are not real and may have movements of just one part of the body—for example, just one hand.
In other focal seizures, the person has a change in consciousness, which can produce a dreamlike experience. The person may display strange, repetitious behaviors such as blinks, twitches and mouth movements (often like chewing or swallowing, or even walking in a circle). These repetitive movements are called automatisms. More complicated actions, which may seem purposeful, can also occur involuntarily. Individuals may also continue activities they started before the seizure began, such as washing dishes in a repetitive, unproductive fashion. These seizures usually last just a minute or two.
Some people with focal seizures may experience auras—unusual sensations that warn of an impending seizure. Auras are usually focal seizures without interruption of awareness (e.g., déjà vu or an unusual abdominal sensation), but some people experience a true warning before an actual seizure. An individual’s symptoms, and the progression of those symptoms, tend to be similar every time. Other people with epilepsy report experiencing a prodrome, a feeling that a seizure is imminent lasting hours or days.
The symptoms of focal seizures can easily be confused with other disorders. The strange behavior and sensations caused by focal seizures also can be mistaken for symptoms of narcolepsy, fainting or even mental illness. Several tests and careful monitoring may be needed to make the distinction between epilepsy and these other disorders.
Generalized Seizures
Generalized seizures are a result of abnormal neuronal activity that rapidly emerges on both sides of the brain. These seizures may cause loss of consciousness, falls or massive muscle contractions. The types of generalized seizures and their effects include:
- Absence seizures may cause the person to appear to be staring into space with or without slight twitching of the muscles.
- Tonic seizures cause stiffening of muscles of the body, generally those in the back, legs and arms.
- Clonic seizures cause repeated jerking movements of muscles on both sides of the body.
- Myoclonic seizures cause jerks or twitches of the upper body, arms or legs.
- Atonic seizures cause a loss of normal muscle tone, which often leads the affected person to fall down or drop the head involuntarily.
- Tonic-clonic seizures cause a combination of symptoms, including stiffening of the body and repeated jerks of the arms and/or legs as well as loss of consciousness.
- Secondary generalized seizures.
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.
Some people recover immediately after a seizure, while others may take minutes to hours to feel as they did before the seizure. During this time, they may feel tired, sleepy, weak or confused.
Following focal seizures or seizures that started from a focus, there may be local symptoms related to the function of that focus. Certain characteristics of the post-seizure state may help locate the region of the brain where the seizure occurred. A classic example is called Todd’s paralysis, a temporary weakness in the part of the body that was affected depending on where in the brain the focal seizure occurred. If the focus is in the temporal lobe, post-ictal symptoms may include language or behavioral disturbances, even psychosis. After a seizure, some people may experience headache or pain in muscles that contracted.
Diagnosing Epilepsy
A number of tests are used to determine whether a person has a form of epilepsy and, if so, what kind of seizures the person has.
An electroencephalogram (EEG) can assess whether there are any detectable abnormalities in the person’s brain waves and may help to determine if antiseizure drugs would be of benefit. Video monitoring may be used in conjunction with EEG to determine the nature of a person’s seizures and to rule out other disorders such as psychogenic non-epileptic seizures, cardiac arrhythmia or narcolepsy that may look like epilepsy.
A magnetoencephalogram (MEG) detects the magnetic signals generated by neurons to help detect surface abnormalities in brain activity. MEG can be used in planning a surgical strategy to remove focal areas involved in seizures while minimizing interference with brain function.
The most commonly used brain scans include:
- CT (computed tomography)
- MRI (magnetic resonance imaging)
- PET (positron emission tomography)
CT and MRI scans reveal structural abnormalities of the brain such as tumors and cysts, which may cause seizures. A type of MRI called functional MRI (fMRI) can be used to localize normal brain activity and detect abnormalities in functioning. Single-photon emission computed tomography (SPECT) is sometimes used to locate seizure foci in the brain.
A modification of SPECT, called ictal SPECT, can be very helpful in localizing the brain area generating seizures. In a person admitted to the hospital for epilepsy monitoring, the SPECT blood flow tracer is injected within 30 seconds of a seizure, then the images of brain blood flow at the time of the seizure are compared with blood flow images taken in between seizures. The seizure onset area shows a high blood flow region on the scan.
PET scans can be used to identify brain regions with lower-than-normal metabolism, a feature of the epileptic focus after the seizure has stopped.
Taking a detailed medical history, including symptoms and duration of the seizures, is still one of the best methods available to determine what kind of seizures a person has had and to determine any form of epilepsy. The medical history should include details about any past illnesses or other symptoms a person may have had, as well as any family history of seizures.
Since people who have suffered a seizure often do not remember what happened, caregiver or other accounts of seizures are vital to this evaluation. The person who experienced the seizure is asked about any warning experiences. The observers will be asked to provide a detailed description of events in the timeline they occurred.
Blood samples may be taken to screen for metabolic or genetic disorders that may be associated with the seizures. They also may be used to check for underlying health conditions such as infections, lead poisoning, anemia and diabetes that may be causing or triggering the seizures. In the emergency department, it is standard procedure to screen for exposure to recreational drugs in anyone with a first seizure.
Tests devised to measure motor abilities, behavior and intellectual ability are often used as a way to determine how epilepsy is affecting an individual. These tests also can provide clues about what kind of epilepsy the person has.
Treating Epilepsy
Accurate diagnosis of the type of epilepsy a person has is crucial for finding an effective treatment. There are many different ways to successfully control seizures. Doctors who treat epilepsies come from many different fields of medicine and include neurologists, pediatricians, pediatric neurologists, internists, family physicians and neurosurgeons. An epileptologist is someone who has completed advanced training and specializes in treating epilepsies.
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 once seizures and their consequences become established. There are several treatment approaches that can be used depending on the individual and the type of epilepsy. If seizures are not controlled quickly, referral to an epileptologist at a specialized epilepsy center should be considered, so that careful consideration of treatment options, including dietary approaches, medication, devices and surgery, can be performed in order to gain optimal seizure treatment.
Medications
The most common approach to treating epilepsies is to prescribe antiseizure drugs. More than 20 different antiseizure medications are available today, all with different benefits and side effects. Most seizures can be controlled with one drug (monotherapy). Deciding on which drug to prescribe, and at what dosage, depends on many different factors, including seizure type, lifestyle and age, seizure frequency, drug side effects, medicines for other conditions and, for a woman, whether she is pregnant or will become pregnant. It may take several months to determine the best drug and dosage. If one treatment is unsuccessful, another may work better.
Seizure medications include:
Generic | U.S. Brand Name |
Carbamazepine | Carbatrol; Tegretol |
Clobazam | Frisium; Onfi |
Clonazepam | Klonopin |
Diazepam | Diastat; Valium |
Divalproex sodium | Depakote; Depakote ER |
Eslicarbazepine acetate | Aptiom |
Ezogabine | Potiga |
Felbamate | Felbatol |
Gabapentin | Neurontin |
Lacosimide | Vimpat |
Lamotrigine | Lamictal |
Levetiracetam | Keppra; Keppra XR |
Lorazepam | Ativan |
Oxcarbazepine | Oxtellar; Oxtellar XR; Trileptal |
Perampanel | Fycompa |
Phenobarbital | |
Phenytoin | Dilantin; Phenytek |
Pregabalin | Lyrica |
Primidone | Mysoline |
Rufinamide | Banzel |
Tiagabine hydrochloride | Gabitril |
Iramate | Amax; Amax XR |
Valproic acid | Depakene |
Vigabatrin | Sabril |
The U.S. Food and Drug Administration (FDA) approved cannabidiol (Epidiolex, derived from marijuana) for the treatment of seizures associated with Lennox-Gastaut syndrome and Dravet syndrome for children aged two and older. The drug contains only a small amount of the psychoactive element in marijuana and does not induce euphoria associated with the drug. The FDA approved cenobamate tablets to treat adults with partial-onset seizures. FDA also has approved the drug fenfluramine to reduce the frequency of convulsive seizures associated with Dravet syndrome in children aged two years and older.
For many people with epilepsy, seizures can be controlled with monotherapy at the optimal dosage. Combining medications may amplify side effects such as fatigue and dizziness, so doctors usually prescribe just one drug whenever possible. Combinations of drugs, however, are still sometimes necessary for some forms of epilepsy that do not respond to monotherapy.
When starting any new anti seizure medication, a low dosage will usually be prescribed initially followed by incrementally higher dosages, sometimes with blood-level monitoring, to determine when the optimal dosage has been reached. It may take time for the dosage to achieve optimal seizure control while minimizing side effects. The latter are usually worse when first starting a new medicine.
Most side effects of antiseizure drugs are relatively minor, such as fatigue, dizziness or weight gain. Antiseizure medications have differing effects on mood: some may worsen depression, while others may improve depression or stabilize mood. However, severe and life-threatening reactions such as allergic reactions or damage to the liver or bone marrow can occur. Antiseizure medications can interact with many other drugs in potentially harmful ways. Some antiseizure drugs can cause the liver to speed the metabolism of other drugs and make the other drugs less effective, as may be the case with oral contraceptives. Since people can become more sensitive to medications as they age, blood levels of medication may need to be checked occasionally to see if dosage adjustments are necessary. The effectiveness of a medication can diminish over time, which can increase the risk of seizures. Some citrus fruits and products, particularly grapefruit juice, may interfere with the breakdown of many drugs, including antiseizure medications, causing them to build up in the body, which can worsen side effects.
Some people with epilepsy may be advised to discontinue their antiseizure drugs after two to three years have passed without a seizure. Others may be advised to wait for four to five years. Discontinuing medication should always be done with supervision of a healthcare professional. It is very important to continue taking antiseizure medication for as long as it is prescribed. Discontinuing medication too early is one of the major reasons people who have been seizure-free start having new seizures and can lead to status epilepticus. Some evidence also suggests that uncontrolled seizures may trigger changes in the brain that will make it more difficult to treat the seizures in the future.
The chance that a person will eventually be able to discontinue medication varies depending on the person’s age and his or her type of epilepsy. More than half of children who go into remission with medication can eventually stop their medication without having new seizures. One study showed that 68 percent of adults who had been seizure-free for two years before stopping medication were able to do so without having more seizures, and 75 percent could successfully discontinue medication if they had been seizure-free for three years. However, the odds of successfully stopping medication are not as good for people with a family history of epilepsy, those who need multiple medications, those with focal seizures, and those who continue to have abnormal EEG results while on medication.
There are specific syndromes in which certain antiseizure medications should not be used because they may make the seizures worse. For example, carbamazepine can worsen epilepsy in children diagnosed with Dravet syndrome.
Diet
Dietary approaches and other treatments may be more appropriate depending on the age of the individual and the type of epilepsy. A high-fat, very low-carbohydrate ketogenic diet is often used to treat medication-resistant epilepsies. The diet induces a state known as ketosis, which means that the body shifts to breaking down fats instead of carbohydrates to survive. A ketogenic diet effectively reduces seizures for some people, especially children with certain forms of epilepsy. Studies have shown that more than 50 percent of people who try the ketogenic diet have a greater than 50 percent improvement in seizure control and 10 percent experience seizure freedom. Some children are able to discontinue the ketogenic diet after several years and remain seizure-free, but this is done with strict supervision and monitoring by a physician.
The ketogenic diet is not easy to maintain, as it requires strict adherence to a limited range of foods. Possible side effects include impaired growth due to nutritional deficiency and a buildup of uric acid in the blood, which can lead to kidney stones.
Researchers are looking at modified versions of and alternatives to the ketogenic diet. For example, studies show promising results for a modified Atkins diet and for a low-glycemic-index treatment, both of which are less restrictive and easier to follow than the ketogenic diet, but well-controlled randomized controlled trials have yet to assess these approaches.
Surgery
Evaluation for surgery is generally recommended only after focal seizures persist despite the person having tried at least two appropriately chosen and well-tolerated medications, or if there is an identifiable brain lesion believed to cause the seizures. When someone is considered to be a good candidate for surgery, experts generally agree that it should be performed as early as possible.
Surgical evaluation takes into account the:
- Seizure type
- Brain region involved
- Importance of the area of the brain where seizures originate (the focus) for everyday behavior
Prior to surgery, individuals with epilepsy are monitored intensively in order to pinpoint the exact location in the brain where seizures begin. Implanted electrodes may be used to record activity from the surface of the brain, which yields more detailed information than an external scalp EEG. Surgeons usually avoid operating in areas of the brain that are necessary for speech, movement, sensation, memory and thinking, or other important abilities. fMRI can be used to locate such “eloquent” brain areas involved in an individual.
While surgery can significantly reduce or even halt seizures for many people, any kind of surgery involves some level of risk. Surgery for epilepsy does not always successfully reduce seizures, and it can result in cognitive or personality changes as well as physical disability, even in people who are excellent candidates for it. Nonetheless, when medications fail, several studies have shown that surgery is much more likely to make someone seizure-free compared to attempts to use other medications. Anyone thinking about surgery for epilepsy should be assessed at an epilepsy center experienced in surgical techniques and should discuss with the epilepsy specialists the balance between the risks of surgery and desire to become seizure-free.
Even when surgery completely ends a person’s seizures, it is important to continue taking antiseizure medication for some time. Doctors generally recommend continuing medication for at least two years after a successful operation to avoid recurrence of seizures.
Surgical procedures for treating epilepsy disorders include:
- Surgery to remove a specific, targeted brain region causing the seizures (the seizure focus) is the most common type of surgery for epilepsy, which doctors may refer to as a lobectomy or lesionectomy, and is appropriate only for focal seizures that originate in just one area of the brain. The most common type of lobectomy is a temporal lobe resection, which is performed for people with medial temporal lobe epilepsy. In such individuals, one hippocampus (there are two, one on each side of the brain) is seen to be shrunken and scarred on an MRI scan.
- Multiple subpial transection may be performed when seizures originate in part of the brain that cannot be removed. It involves making a series of cuts that are designed to prevent seizures from spreading into other parts of the brain while leaving the person’s normal abilities intact.
- Corpus callosotomy, or severing the network of neural connections between the right and left halves (hemispheres) of the brain, is done primarily in children with severe seizures that start in one half of the brain and spread to the other side. Corpus callosotomy can end drop attacks and other generalized seizures. However, the procedure does not stop seizures in the side of the brain where they originate, and these focal seizures may get worse after surgery.
- Hemispherectomy and hemispherotomy involve removing half of the brain’s cortex, or outer layer. These procedures are used predominantly in children who have seizures that do not respond to medication because of damage that involves only half the brain, as in Rasmussen’s encephalitis. While this type of surgery is excessive and performed only when other therapies have failed, with intense rehabilitation, children can recover many abilities.
- Thermal ablation for epilepsy, also known as laser interstitial thermal therapy, directs a set amount of energy to a specific, targeted brain region causing the seizures (the seizure focus). The energy, which is changed to thermal energy, destroys the brain cells causing the seizures. Laser ablation is less invasive than open brain surgery for treating epilepsy.
Devices
Electrical stimulation of the brain remains a therapeutic strategy of interest for people with medication-resistant forms of epilepsy who are not candidates for surgery. The FDA-approved vagus nerve stimulator is surgically implanted under the skin of the chest and is attached to the vagus nerve in the lower neck. The device delivers short bursts of electrical energy to the brain via the vagus nerve. On average, this stimulation reduces seizures by about 20 to 40 percent. Individuals usually cannot stop taking epilepsy medication because of the stimulator, but they often experience fewer seizures and may be able to reduce the dosage of their medication.
Responsive stimulation involves the use of an implanted device that analyzes brain activity patterns to detect a forthcoming seizure. Once detected, the device administers an intervention, such as electrical stimulation or a fast-acting drug, to prevent the seizure from occurring. These devices are also known as closed-loop systems. NeuroPace, one of the first responsive stimulation, closed-loop devices, is available for adults with refractory epilepsy (hard-to-treat epilepsy that does not respond well to trials of at least two medicines).
Experimental devices that are not approved by the FDA for use in the U.S. (as of March 2015) include the following:
- Deep brain stimulation using mild electrical impulses has been tried as a treatment for epilepsy in several different brain regions. It involves surgically implanting an electrode connected to an implanted pulse generator (similar to a heart pacemaker) to deliver electrical stimulation to specific areas in the brain to regulate electrical signals in neural circuits. Stimulation of an area called the anterior thalamic nucleus has been particularly helpful in providing at least partial relief from seizures in people who had medication-resistant forms of the disorder.
- A report on trigeminal nerve stimulation (using electrical signals to stimulate parts of the trigeminal nerve and affected brain regions) showed efficacy rates similar to those for vagal nerve stimulation, with responder rates hovering around 50 percent. (A responder is defined as someone having greater than a 50 percent reduction in seizure frequency.) Freedom from seizures, although reported, remains rare for both methods. A trigeminal nerve stimulation device is available for use in Europe, but it is not yet approved in the U.S.
- Transcutaneous magnetic stimulation involves a device being placed outside the head to produce a magnetic field to induce an electrical current in nearby areas of the brain. It has been shown to reduce cortical activity associated with specific epilepsy syndromes.
Living with Epilepsy
The majority of people with epilepsy can do the same things as people without the disorder and have successful and productive lives. In most cases, it does not affect job choice or performance. One-third or more of people with epilepsy, however, may have cognitive or neuropsychiatric co-concurring symptoms that can negatively affect their quality of life.
Many people with epilepsy are significantly helped by available therapies, and some may go months or years without having a seizure. However, people with treatment-resistant epilepsy can have as many as hundreds of seizures a day, or they can have one seizure a year with sometimes disabling consequences. On average, having treatment-resistant epilepsy is associated with an increased risk of cognitive impairment, particularly if the seizures developed in early childhood. These impairments may be related to the underlying conditions associated with the epilepsy rather than to the epilepsy itself.
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 been seizure-free for a specific amount of time (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. Commercial drivers’ licenses have additional restrictions. In addition, people with epilepsy should take extra care if a job involves operation of machinery or vehicles.
The risk of seizures also limits people’s recreational choices. Individuals may need to take precautions with activities such as climbing, sailing, swimming or working on ladders. Studies have not shown any increase in seizures due to sports, although these studies have not focused on any activity in particular. There is some evidence that regular exercise may improve seizure control in some people, but this should be done under a doctor’s supervision. The benefits of sports participation may outweigh the risks, and coaches or other leaders can take appropriate safety precautions. Steps should be taken to avoid dehydration, overexertion and hypoglycemia, as these problems can increase the risk of seizures.
Education & Employment
By law, people with epilepsy (or disabilities) in the U.S. cannot be denied employment or access to any educational, recreational or other activity because of their epilepsy. However, significant barriers still exist for people with epilepsy in school and work. Antiseizure drugs may cause side effects that interfere with concentration and memory. Children with epilepsy may need extra time to complete schoolwork, and they sometimes may need to have instructions or other information repeated for them. Teachers should be told what to do if a child in their classroom has a seizure, and parents should work with the school system to find reasonable ways to accommodate any special needs their child may have.
Pregnancy & Parenthood
Females with epilepsy are often concerned about whether they can become pregnant and have a healthy child. Epilepsy itself does not interfere with the ability to become pregnant. With the right planning, supplemental vitamin use and medication adjustments prior to pregnancy, the odds of a female with epilepsy having a healthy pregnancy and a healthy child are similar to those without a chronic medical condition.
Children of parents with epilepsy have about a 5 percent risk of developing the condition at some point during life, in comparison to about a 1 percent risk in a child in the general population. However, the risk of developing epilepsy increases if a parent has a clearly hereditary form of the disorder. Parents who are concerned that their epilepsy may be hereditary may wish to consult a genetic counselor to determine their risk of passing on the disorder.
Other potential risks to the developing child of a female with epilepsy or who takes antiseizure medication include increased risk for major congenital malformations (also known as birth defects) and adverse effects on the developing brain. The types of birth defects that have been most commonly reported with antiseizure medications include:
- Cleft lip or cleft palate
- Heart problems
- Stunted spinal cord development (spina bifida)
- Urogenital defects
- Limb-skeletal defects
Some anti seizure medications, particularly valproate, are known to increase the risk of having a child with birth defects and/or neurodevelopmental problems, including learning disabilities, general intellectual disabilities and autism spectrum disorder. It is important that parents work with a team of providers that includes a neurologist and an obstetrician to learn about any special risks associated with epilepsy and the medications the female parent may be taking.
Although planned pregnancies are essential to ensuring a healthy pregnancy, effective birth control is also essential. Some antiseizure medications can interfere with the effectiveness of hormonal contraceptives. Females who are on these enzyme-inducing antiseizure medications and using hormonal contraceptives may need to switch to a different kind of birth control that is more effective.
Prior to a planned pregnancy, a female with epilepsy should meet with their healthcare team to reassess the current need for antiseizure medications, and to determine:
- The optimal medication to balance seizure control and avoid birth defects
- The lowest dose for going into a planned pregnancy
Any transitions to either a new medication or dosage should be phased in prior to the pregnancy, if possible. Discussion about the medications should occur early with the healthcare professional.
Using supplemental folic acid prior to conception and continuing the supplement during pregnancy is an important way to lower the risk for birth defects and developmental delays. Prenatal multivitamins should also be used prior to the beginning of pregnancy. Pregnant people with epilepsy should get plenty of sleep and avoid other triggers or missed medications to avoid worsening of seizures.
During labor and delivery, it is important for the female to take her same formulations and doses of antiseizure drugs at the usual times; it is often helpful to bring medications from home. If a seizure does occur during labor and delivery, intravenous short-acting medications can be given if necessary. It is unusual for the newborns of females with epilepsy to experience symptoms of withdrawal from the antiseizure medication (unless it is phenobarbital or a standing dose of benzodiazepines), but the symptoms resolve quickly, and there are usually no serious or long-term effects.
The use of antiseizure medications is considered safe for breastfeeding. On very rare occasions, the baby may become excessively drowsy or feed poorly, and these problems should be closely monitored. However, experts believe the benefits of breastfeeding outweigh the risks except in rare circumstances. One large study showed that children who were breastfed by female parents with epilepsy on antiseizure medications performed better on learning and developmental scales than children who were not breastfed. It is common for the antiseizure medication dosing to be adjusted again in the postpartum setting, especially if the dose was altered during pregnancy.
With the appropriate selection of safe anti seizure medicines during pregnancy, use of supplemental folic acid and, ideally, with pre-pregnancy planning, most people with epilepsy can have a healthy pregnancy with good outcomes for themselves and their developing child.
Consider participating in a clinical trial so clinicians and scientists can learn more about epilepsies, seizures and related disorders. Clinical research uses human volunteers to help researchers learn more about a disorder and perhaps find better ways to safely detect, treat or prevent disease.
All types of volunteers are needed—those who are healthy or may have an illness or disease—of all different ages, sexes, races and ethnicities to ensure that study results apply to as many people as possible, and that treatments will be safe and effective for everyone who will use them.
For information about participating in clinical research, visit NIH Clinical Research Trials and You. Learn about clinical trials currently looking for people with epilepsies and seizures at Clinicaltrials.gov.
There are additional ways for people with epilepsies and their families to help advance research. Pregnant females who are taking antiseizure drugs can help researchers learn how these drugs affect unborn children by participating in The North American Antiepileptic Drug (AED) Pregnancy Registry, which is a philanthropic arm of Harvard Medical School and housed at Massachusetts General Hospital. Registry participants are given educational materials on preconception planning and perinatal care and are asked to provide information about the health of their children. (This information is kept confidential.)
People with epilepsy can help research efforts by making arrangements to donate tissue either at the time of surgery for epilepsy, or at the time of death. Researchers can then use the tissue to study epilepsy and other disorders to better understand what causes seizures. For example, the NIH NeuroBioBank is an effort to coordinate a network of brain banks it supports in the U.S. where brain tissue and data are collected, evaluated, stored and made available to researchers in a standardized way for the study of neurological, psychiatric and developmental disorders, including epilepsy. A list of participating NIH NeuroBioBank repositories and additional brain banks is maintained on the NIH NeuroBioBank website. Each brain bank may have different protocols for registering a potential donor. Individuals are strongly encouraged to contact the brain bank directly to learn more.