Doctors will ask about the individual's history of seizures, along with other diseases, surgeries, and medications. A thorough history of recreational drug and alcohol use or abuse is equally important. It is helpful for the doctor to distinguish seizure subtypes, partial or generalized; time of day of the event, including whether the seizure occurred during wakefulness or sleep; and any known triggers, such as a flickering light, severe sleep deprivation, or dehydration.
Doctors will perform a complete physical examination. A complete physical examination will include a neurological examination and brain function tests.
Laboratory data utilized in the diagnostic evaluation of patients with seizure disorders may include CT scan imaging, magnetic resonance imaging (MRI), and electroencephalograph (EEG). A complete blood panel, including drug-toxic screening and urinalysis are usually performed. Urine tests can determine if the individual is having a seizure due to illicit drug use, such as cocaine or methamphetamine. Blood tests will determine the basic functioning of the body, such as electrolyte (including sodium and potassium) levels and kidney and liver function.
A blood test that measures the hormone prolactin may be used to determine if a seizure was caused by epilepsy. The test, which must be used within 10-20 minutes after a seizure, measures levels of the hormone prolactin in the blood. Prolactin is produced by the pituitary gland, but an area of the brain called the hypothalamus controls its release. Researchers think that epileptic seizures affect the hypothalamus and may alter the release of prolactin, causing levels of the hormone to rise.
Electroencephalogram (EEG): An EEG records the electrical activity of the brain via electrodes. The electrodes are attached to the scalp. Individuals with epilepsy often have changes in the normal pattern of brain waves, even when they are not having a seizure.
To prepare for an EEG, healthcare professionals recommended that individuals avoid elaborate hair styling, metallic hair spray, or greasy hair products. The individual should refrain from caffeine for six hours before the test. The procedure itself is painless and usually lasts about 30 minutes. However, it can take as long as an hour to place the electrodes on the scalp properly.
Video-EEG monitoring may also be used in some individuals as a diagnostic tool while they are having a seizure. Video monitoring can be helpful because it allows the doctor to compare the behaviors that occur during a seizure with an EEG pattern from the same time. Knowing where the seizure originates in the brain helps the doctor in treating the condition. Individuals undergoing video-EEG may be required to stay in a hospital or clinic for several days. The individual is monitored on video constantly during this time. The EEG electrodes stay attached for the entire time, which may cause discomfort in some individuals.
Computerized tomography (CT): Computerized tomography, or CT, uses special x-ray equipment to produce images of body structure. CT machines obtain images from many different angles and join them together to show cross-sectional images of the brain and skull. CT scans can reveal abnormalities in brain structure including tumors, cysts, strokes, or tangled blood vessels. This helps the doctor rule out other potential causes of the individual's seizures.
To prepare for a CT scan of the head, individuals should remove such things as earrings, eyeglasses, dentures, and hairpins. An intravenous (IV) line may be inserted into a vein if the test requires the injection of a contrast material, which makes abnormalities easier to see. During the test, the individual will lie on a table that slides into the CT machine. Depending on the number of images needed, the scan can take between two and 20 minutes. The procedure is painless, but some individuals may experience discomfort or claustrophobia while having to sit still.
Magnetic resonance imaging (MRI):
A magnetic resonance imaging (MRI) device uses radio waves and a strong magnetic field to produce detailed images of the brain. Like CT scans, MRIs can reveal brain abnormalities that could be causing seizures. Dental fillings and braces may distort the images.
During the test, the individual will lie on a padded table that slides into the MRI machine. The head will be immobilized in a brace to improve precision. The test is painless, but some individuals experience an uncomfortable feeling similar to claustrophobia inside the MRI device's close quarters. Sedative medications, such as alprazolam (Xanax®), can be given to sensitive individuals.
Positron emission tomography (PET): Positron emission tomography (PET) scans use injected radioactive material to help visualize active areas of the brain. After the radioactive material is injected into a vein, it will take 3-90 minutes for the substance to accumulate in the brain tissue. During this waiting period, the individual will be asked to rest quietly and not talk or move around much. The actual scan takes 30-45 minutes. The amount of radioactive material used in the test is very small.
Single-photon emission computerized tomography (SPECT): Single-photon emission computerized tomography (SPECT) is used primarily in individuals being evaluated for epilepsy surgery when the area of seizure onset is unclear on MRIs or EEGs. SPECT imaging requires two scans, one during a seizure and one 24 hours later. Radioactive material is injected for both scans and then the two results are compared.
Conditions resembling seizure disorders: Seizure disorders must be differentiated from a variety of problems whose symptoms approximate or closely resemble those of epilepsy. These include cerebrovascular (stroke-related) disorders, migraine, narcolepsy (a neurological condition with uncontrollable sleep attacks and persistent daytime sleepiness), syncope (fainting), and anxiety.
A pseudoseizure, or more properly a non-epileptogenic seizure, may also occur. These "spells" are not triggered by nerve cell discharges that cause true epilepsy, although the individual may experience muscle twitching and even apparent loss of consciousness. These spells have a psychiatric component and often coexist in persons who have epilepsy with true seizures. EEG monitoring can help distinguish disorders that mimic epilepsy from true seizures.
signs and symptoms
Seizures can affect any process the brain coordinates due to abnormal activity in brain cells. A seizure can produce temporary confusion, complete loss of consciousness, a staring spell, or uncontrollable jerking movements of the arms and legs.
Symptoms vary depending on the type of seizure. In most cases, an individual with epilepsy will tend to have the same type of seizure each time, so the symptoms will be very similar from episode to episode, but some individuals have many different types of seizures, with different symptoms each time.
Doctors will classify seizures as either partial or generalized, based on how the abnormal brain activity begins. When seizures appear to result from abnormal activity in just one part of the brain, they are called partial or focal seizures. Seizures that seem to involve all of the brain are called generalized seizures. In some cases, seizures can begin in one part of the brain and then spread throughout the rest of the brain. Seizures may progress from partial to generalized.
Most individuals with epilepsy can lead outwardly normal lives. Currently, epilepsy cannot be cured. However, for some individuals epilepsy does eventually go away with age. Most seizures do not cause brain damage. It is not uncommon for individuals with epilepsy, especially children, to develop behavioral and emotional problems, sometimes the consequence of embarrassment and frustration or bullying, teasing, or avoidance in school and other social settings. For many individuals with epilepsy, the risk of seizures restricts their independence (some states refuse drivers licenses to people with epilepsy) and recreational activities. Individuals with epilepsy are at special risk for two life-threatening conditions: status epilepticus and sudden unexplained death. Most women with epilepsy can become pregnant, but they should discuss their epilepsy and the medications they are taking with their doctors. Infertility in women with epilepsy is rare. Women with epilepsy have a 90% or better chance of having a normal, healthy baby.
Simple partial seizures: Simple partial seizures do not result in loss of consciousness. These seizures may alter emotions or change the way things look, smell, feel, taste, or sound.
Complex partial seizures: Complex partial seizures alter consciousness, causing the individual to lose awareness for a period of time. Complex partial seizures often result in staring and non-purposeful movements, such as hand rubbing, lip smacking, arm positioning, vocalization, or swallowing.
Generalized seizures involve epileptic activity in all or most of the brain.
Absence seizures (petit mal). Absence seizures are characterized by staring, subtle body movements, and brief lapses of awareness.
Myoclonic seizures: Myoclonic seizures usually appear as sudden jerks of the arms and legs.
Atonic seizures: Atonic seizures are also known as drop attacks and may cause the individual to suddenly collapse or fall down.
Tonic-clonic seizures (grand mal): Tonic-clonic seizures are the most common form of generalized seizures. They are also the most widely recognized epileptic seizure. In a tonic-clonic seizure, the person loses consciousness, the body stiffens, and then they fall to the ground. This is followed by jerking movements. After a minute or two, the jerking movements usually stop and consciousness slowly returns.
risk factors and causes
Epilepsy is not associated with any particular disease. Many abnormalities of the nervous system can result in seizure activity. Seizures can also occur in the healthy nervous system when its metabolic balance is disturbed. The cause of epilepsy may be idiopathic (not clearly known) or related to a particular disease state, such as a brain trauma or a brain tumor. About 35% of all cases of epilepsy have no clearly definable cause.
Although epilepsy is more common in children than young adults, in seniors age 70 the incidence of epilepsy is nearly twice that of children, and in those over 80, it is more than three times that of children.
The risk of epilepsy from birth through age 20 is approximately 1%. Within this group, the risk is highest during the first year of life and increases somewhat at the onset of puberty. From age 20-55 it decreases again, but increases after age 55. The prevalence of epilepsy in the United States has been estimated to be about five to eight in every 1,000 individuals.
Degenerative disorders: There are several genetic, neurodegenerative (nerve damaging) disorders that are associated with seizures, including tuberous sclerosis, neurofibromatosis Tay-Sachs disease, phenylketonuria (PKU), and Sturge-Weber syndrome.
Febrile seizures: Febrile seizures are age-associated seizures brought on by a fever in infants or small children. During a febrile seizure, a child often loses consciousness and shakes, moving limbs on both sides of the body. Less commonly, the child becomes rigid or has twitches in only a portion of the body, such as an arm or a leg, or on the right or the left side only. Most febrile seizures last a minute or two, although some can be as brief as a few seconds while others last for more than 15 minutes. Febrile seizures occur in 3-4% of children.
Head injury: Seizures may develop at or around the time of injury or years after, usually within two years.
Heredity: There is also an increased incidence of epilepsy in relatives of those with a seizure disorder. However, some individuals may have a genetic predisposition to the development of seizures that is not familial based.
Infections: Infections of the nervous system may damage neurons and result in a lowered seizure threshold. Infections include meningitis (infections of the coverings of the brain and spinal fluid), encephalitis (infection of the brain itself), and human immunodeficiency virus (HIV).
Medications: The presence of certain drugs can cause seizure activity. In addition, abrupt withdrawal of some substances can lead to seizure activity. The medications that may induce seizures include the tricyclic antidepressants (such as amitriptylline or Elavil®), lithium (Eskalith®), antipsychotic medications (such as chlorpromazine or Thorazine®), aminophylline (Theodur®), and high doses of penicillin (Pen VK®). Illicit drug use, particularly cocaine, heroin, amphetamines, and PCP, can cause seizures. Alcohol withdrawal can lead to seizure activity. Alcohol-induced seizures usually occur 12-24 hours after the last drink but can occur up to 48 hours or more after binge drinking. Withdrawal from prescription narcotics (such as morphine) can result in seizure activity.
Metabolic disturbances: Metabolic disorders are a group of changes in various processes in the body, such as blood sugar metabolism, cardiovascular functioning (including blood flow and cellular oxygenation), and hormonal regulation. Conditions that sometimes result in seizures include: electrolyte disturbances, such as altered levels of sodium, calcium, or magnesium; hypoglycemia (low blood sugar) or hyperglycemia (elevated blood sugar); renal failure (kidney disease) with uremia (increased urea in the blood) or changes that occur around the time of kidney dialysis; liver failure leading to elevation of associated toxins; and hypoxia (lowered oxygen delivery to the brain).
Movement disorders: Cerebral palsy (a movement disorder), secondary to lack of oxygen, infection, or trauma, is associated with epilepsy.
Stroke: A stroke is neurological damage to the brain as a result of a lack of oxygen. Seizures can occur at the time of a stroke or many years later.
Nutrition: The nutrient levels in young children with poorly controlled seizure disorders are often below the recommended levels. The Journal of the American Dietetic Association has reported that children with epilepsy ate statistically significant lower levels of total calories, protein, carbohydrates, fat, dietary fiber, and multiple vitamins and minerals, compared with healthy children.
Tumors: Brain tumors, both malignant (cancerous) and benign, may be associated with seizures. The location of the tumor influences the likelihood of having seizures. Tumors can place pressure on neurons and cause irregular patterns of electrical activity, which cause a seizure.
Injury: If an individual falls during a seizure, they may sustain a head injury. Drowning is a risk if the individual has a seizure while swimming or bathing.
Loss of consciousness and awareness: A seizure that causes either loss of awareness or control can be dangerous if the individual is driving a car or operating other equipment. Medications used to control seizures also can cause drowsiness, which may affect the individual's driving ability. Many states have licensing restrictions related to the individual's ability to control seizures.
Pregnancy: Seizures during pregnancy pose dangers to both mother and baby and certain anti-epileptic medications increase the risk of birth defects. A doctor will advise an individual with epilepsy who is considering becoming pregnant. Most women with epilepsy can become pregnant and have a healthy baby, but many need to adjust their medications and be carefully monitored throughout pregnancy.
Life-threatening complications: Life-threatening complications from epilepsy are uncommon, but do occur. Individuals who have severe, prolonged, or continuous seizures (status epilepticus) are at increased risk of permanent brain damage and death. Individuals with epilepsy, particularly those with poorly controlled epilepsy, also have a small risk of a condition called sudden unexplained death in epilepsy (SUDEP). The risk of SUDEP increases if the individual is having seizures at an early age, has frequent seizures that involve more than one area of the brain, or continues to have seizures despite treatment with medications.