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1. What is epilepsy?
Epilepsy is a chronic (long-lasting) medical condition marked by recurrent
epileptic seizures. An epileptic seizure is an event of altered brain function
caused by abnormal or excessive electrical discharges from brain cells. Epilepsy
is one of the most common neurologic disorders, affecting up to 1% of the
population in the United States.
There are different types of seizures, different types of epilepsy syndromes,
and different causes of epilepsy. For example, both brain tumors and stroke can
cause seizures and lead to chronic epilepsy. Some of the causes can be diagnosed
and treated with medications, and some require surgery.
2. What are some of the causes of epilepsy?
Approximately 65% of newly diagnosed epilepsy cases have no obvious cause.
Of the remaining 35%, the more common reasons include stroke, congenital
abnormalities (those we are born with), brain tumors, trauma, and infection. It
is important to determine the cause to help guide treatment.
3. Who treats epilepsy?
A neurologist, a doctor who specializes in diseases of the brain and nervous
system, best determines the diagnosis of epilepsy. Some neurologists take
advanced training and become epileptologists. These physicians specialize in the
diagnosis and treatment of epilepsy. This involves determining the cause of the
epilepsy and starting anticonvulsant medication to prevent further seizures.
Many internists and family practice physicians also treat epilepsy.
4. How is epilepsy diagnosed?
The evaluation of patients with epilepsy is aimed at determining the type of
seizures (epileptic versus nonepileptic) and their cause, since various seizure
types respond best to specific treatments. The diagnosis is based on:
- The
patient's medical history, including any family history of seizures,
associated medical conditions, and current medications. The doctor will ask
you some important questions, including the following:
-- At what age did the seizures begin?
-- What circumstances surrounded your first seizure?
-- What factors seem to bring on the seizures?
-- What do you feel before, during, and after the seizures?
-- How long do the seizures last?
-- Have you been treated for epilepsy before?
-- What medications were prescribed and in what dosages?
-- Was the treatment effective?
- Others who have often seen you before, during, and after
seizures, such as family and close friends, should be present to provide
details of your seizures if they involve loss of consciousness.
- A
complete physical and neurological examination of muscle strength, reflexes,
eyesight, hearing, and ability to detect various sensations, so that your
doctors can better understand the cause of your seizures. Additional testing
often includes:
-- An electroencephalogram (EEG), which measures electrical activity in the brain
-- Imaging studies of the brain, such as magnetic resonance
imaging (MRI)
-- Blood tests to measure red and white blood cell counts,
blood
sugar, blood electrolyte levels, and to evaluate liver
and kidney function. Blood tests help rule out other illnesses.
-- Other tests as needed, including magnetic resonance
spectroscopy (MRS), positron emission tomography (PET), and
single photon emission computed tomography (SPECT)
The most important part of the evaluation is the electroencephalogram (EEG),
because it is the only test that directly detects electrical activity in the
brain (seizures are defined by abnormal electrical activity in the brain).
During an EEG, electrodes (small metal disks) are attached to specific locations
on your head. The electrodes are also attached to a monitor to record the
brain's electrical activity. The EEG is useful to confirm a diagnosis of
epilepsy and to determine the type of epilepsy.
The routine EEG procedure takes about 90 minutes, but a routine EEG records
only about 20 minutes of brain waves. Because this is such a short amount of
time, the results of routine EEG studies are often normal, even in people known
to have epilepsy. Therefore, prolonged EEG monitoring may be necessary.
Prolonged EEG-video monitoring is an even better diagnostic method. During
this type of monitoring, an EEG monitors the brain's activity and cameras
videotape body movements and behavior during a seizure. Prolonged monitoring
often requires the patient to spend time in a special hospital facility for
several days. Prolonged EEG-video monitoring is sometimes required to
definitively diagnose epilepsy.
5. How is epilepsy treated?
The majority of epileptic seizures are controlled with drug therapy,
particularly anticonvulsant drugs. The type of treatment prescribed will depend
on several factors, including the type of epilepsy (focal/partial versus
generalized), the frequency and severity of the seizures, the person's age,
overall health, and medical history. An accurate diagnosis of the type of
epilepsy (not just the type of seizure, since most seizure types occur in
different types of epilepsy) is critical to choosing the best treatment.
There are many drugs available to treat epilepsy, including:
- phenytoin (Dilantin or Phenytek)
- phenobarbital
- carbamazepine (Tegretol or Carbatrol)
- primidone (Mysoline)
- ethosuximide (Zarontin)
- valproic acid (Depakene)
- divalproex (Depakote, Depakote ER)
- diazepam (Valium) and related medications such as clonazepam
(Klonopin) and clorazepate (Tranxene)
- felbamate (Felbatol)
- gabapentin (Neurontin)
- lamotrigine (Lamictal)
- tiagabine (Gabitril)
- topiramate (Topamax)
- levetiracetam (Keppra)
- zonisamide (Zonegran)
In general, for a given type of epilepsy there are only minor differences
among appropriate drugs. The choice is most often based on other factors
specific to each patient, such as which side effects can be tolerated and which
delivery method is acceptable.
Although the different types of epilepsy vary greatly, in general,
medications can control seizures in about 70% of epilepsy patients.
It may take several months before the best drug and dosage is determined for
you. During this adjustment period, you may be monitored with frequent blood
tests. It is very important to keep your follow-up appointments with your doctor
and the laboratory to minimize your risk for serious side effects and to prevent
complications.
When seizures continue despite treatment for epilepsy, it may be because the
episodes thought to be seizures are nonepileptic. In such cases, you should get
a second opinion from a specialist and undergo EEG-video monitoring so the
diagnosis can be reevaluated. In specialized centers, about 15% to 20% of
patients referred for persistent, refractory or intractable seizures ultimately
prove to have nonepileptic conditions instead.
6. What are the side effects of epilepsy medications?
As is true of all drugs, the drugs used to treat epilepsy have side effects.
The occurrence of side effects depends on the dose, type of medication, and
length of treatment. The side effects worsen with higher doses but tend to be
less severe with time as the body adjusts to the medication. Anti-epileptic
drugs are usually started at lower doses and increased gradually to make this
adjustment easier.
Side effects of epilepsy drugs can include blurry or double vision, fatigue,
sleepiness, unsteadiness, stomach upset, skin rashes, low blood cell counts,
liver problems, swelling of the gums, hair loss, weight gain, and tremor.
7. What precautions should pregnant women take?
Women who have seizures can have healthy children, provided they receive good
prenatal care. It is very important that women who have epilepsy discuss
pregnancy with their doctors BEFORE getting pregnant. All women of child-bearing
age who have epilepsy should take a multivitamin containing folic acid daily,
because some epilepsy medications deplete the body of important vitamins.
Many seizure medications can prevent birth control pills from working
effectively, which may lead to unplanned pregnancy. If pregnancy occurs
unexpectedly, women should NOT discontinue their seizure medication without
first consulting with their physicians. Abruptly discontinuing seizure
medication commonly leads to more frequent seizures, which can also harm the
baby.
The frequency of seizures usually does not change significantly during
pregnancy. Medication blood levels should be checked often. This precaution is
taken because levels gradually decrease during pregnancy and reach their lowest
level around the time of delivery, which may result in breakthrough seizures.
All seizures occurring during pregnancy should be reported to your physician.
Women should NEVER discontinue seizure medications without consulting
their physicians.
Most pregnant women with epilepsy have normal vaginal deliveries, although
cesarean sections (removal of the baby through an incision made in the abdomen)
are required in some cases.
Women taking seizure medications can breast-feed their infants. Some
medications can cause babies to become very sleepy and irritable after feedings.
If these effects occur, discontinue breast-feeding until you consult with your
physician.
8. What is epilepsy surgery?
Epilepsy surgery involves the surgical removal of the region of the brain
responsible for the abnormal electrical signals that cause seizures. This region
of brain is called the epileptogenic zone. It is determined by neuroimaging
studies, electrical recordings from the scalp (EEG), and clinical signs during a
seizure. Epilepsy surgery can provide a "cure" for epilepsy, in that
it can eliminate the source of seizures and epilepsy.
9. Who is a candidate for epilepsy surgery?
Generally, patients with seizures that start in a focal area of the brain,
and whose seizures have not been controlled with medication, are considered for
surgery. This region may be small or may involve several lobes of the brain. A
comprehensive pre-surgical evaluation, starting with EEG-video monitoring and
high-resolution brain MRI at an experienced epilepsy surgery center, is
typically performed before a patient is recommended for epilepsy surgery.
10. What types of surgery are performed?
Surgery typically involves resection, or removing the abnormal portion of
brain that is causing the seizures. Brain tumors, vascular (blood vessel)
abnormalities, old strokes, and congenital malformations may also be removed if
they are believed to be causing the seizures.
The most common type of resective epilepsy surgery performed is the temporal
lobectomy, which involves removing a portion of the temporal lobe, usually for a
syndrome called mesial temporal sclerosis. Resection
can be performed in other brain regions, such as the frontal lobe (frontal
lobectomy), depending on where the epileptogenic zone is located. Prior to
resection, surgery may be necessary to implant EEG electrodes directly on or in
the brain to help localize the seizures. After seizures are recorded from these
implanted electrodes, another surgery is performed to remove the electrodes and
perform the resection. Other types of surgery may involve resection of more than
one lobe or brain region. In severe cases, when an entire cerebral hemisphere is
involved in the epilepsy, surgery may involve disconnecting that hemisphere from
the rest of the brain.
11. What are other surgical treatments for epilepsy?
Vagal nerve stimulation (VNS) is another surgical option for the treatment
of epilepsy. It involves implantation of an electrode that stimulates the vagus
nerve, a nerve that travels through the neck and is connected to various areas
of the brain. With this new treatment, approximately 40-60% of patients are
helped, in that seizures may become less frequent or less severe. VNS is
typically reserved for those epilepsy patients who are not candidates for
resective surgery.
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