Brain Cells (Neurons)
Copyright © Nucleus Medical Media, Inc.
A seizure happens when there are certain types of abnormal electrical activity in the brain. During a seizure, you may:
- Lose consciousness
- Stare into space
- Have convulsions (abnormal jerking of the muscles)
- Experience abnormalities of sensation or emotion
If you have two or more seizures that are not due to an illness or other trigger, then it is considered a seizure disorder. This condition is also known as epilepsy. Seizure disorders may be classified by the part of the brain they affect and the kinds of symptoms they cause. One way to categorize into two important groups is:
- Generalized seizure disorder—onset is throughout the brain, not from a single focal location
- Partial seizure disorder (focal seizure)—begins within certain areas of the brain
Seizures are caused by abnormal brain function. For many people, it is not known what causes the malfunction. Some known causes include:
- In newborns:
- Congenital brain abnormalities (present at birth)
- Birth injuries that deprive the brain of oxygen
- Metabolic disorders
- Maternal drug use
- In infants and children:
- Febrile seizure —caused by spike in fever in a baby or very young child
- Brain tumor
- Infections ( encephalitis, cerebritis, brain abscess)
- In children and adults:
- In elderly:
Factors that may increase your chance of developing seizures or a seizure disorder include:
- Previous brain injury—seizure disorder usually develops within one year of injury
- Previous brain infection
- Abnormal blood vessel that has formed in the brain
- Brain tumor
- History of stroke
- History of complex febrile seizures
- Use of certain medicines or recreational drugs
- Stopping the use of medicines, recreational drugs, or alcohol
- Drug overdose
- Exposure to toxins (eg, arsenic, lead, or carbon monoxide)
- Family history of seizure disorders
- Toxemia during pregnancy
- Chemical abnormalities (decreased or excess blood sodium or glucose, low blood calcium)
- Liver or kidney failure
- Severe, untreated high blood pressure
- Chronic diseases (eg, lupus , polyarteritis nodosa, porphyria, sickle cell disease, Whipple’s disease)
- Cysticercosis (an infection caused by a pork tapeworm)
If you already have a seizure disorder, the following factors can increase your chance of having a seizure:
- Sleep deprivation
- Hormonal changes (such as those that occur at points during the menstrual cycle)
- Flashing lights, especially strobe lights
- Use of certain medicines
- Missing doses of anti-epileptic medicines
There are many kinds of seizure disorders with a variety of symptoms, such as:
- Aura—a sensation at the start of a seizure, may involve the perception of an odd smell or sound, visual symptoms, or unusual stomach sensations
- Loss of consciousness
- Repeated jerking of a single limb
- Generalized convulsion with uncontrollable jerking of muscles throughout the body
- Hand rubbing
- Lip smacking
- Picking at clothing
- Perception of an odor, sound, or taste
- Loss of bladder or bowel control
- Postictal state—a state of drowsiness, alteration in responsiveness, and/or confusion that commonly occurs after a generalized tonic-clonic seizure; may last minutes, hours, or days
Symptoms of generalized seizure disorders include:
- Generalized tonic-clonic seizures—loss of consciousness, stiffening, uncontrollable jerking of muscles throughout the body
- Absence seizures—staring, eye blinking, or eye rolling
Symptoms of partial seizure disorder include:
- Complex partial or temporal lobe seizures:
- May lose contact with reality, stop purposeful activity, and begin a series of automatic gestures (eg, lip smacking, hand-wringing, or picking at clothing)
- May appear as a brief moment of confusion or loss of attentiveness
- May have a perception of unusual sights, sounds, or smells
- Simple partial seizures:
- Does not involve a loss of contact with reality or a loss of consciousness
- Single area of the body may move uncontrollably (eg, leg or arm shaking)
- May include the perception of an odor, sound, or taste, or an unrelated emotion
Your doctor will ask about your symptoms and medical history. A physical exam will be done. You may need to see a neurologist. These doctors specialize in the nervous system and brain.
Tests may include the following:
- Blood tests—to look for abnormal levels of different substances in the blood
- Electroencephalogram (EEG) —a test that uses sensors to evaluate electrical brain activity
- Magnetic resonance imaging (MRI) scan —a test that uses magnetic waves to make pictures of structures inside the brain
- Computed tomography (CT) scan —a type of x-ray that uses a computer to make pictures of structures inside the head (used in some cases)
- Lumbar puncture —a test of the cerebrospinal fluid (CSF) from the lower back; may be done to look for infection or bleeding
- Magnetoencephalography (MEG)—an imaging device that measures the brain's magnetic fields
- Positron emission tomography (PET) —an imaging test that shows activity in the brain
- Single photon emission computed tomography (SPECT)—an imaging test that shows blood flow in the brain
The goals of treatment are to:
- Treat the underlying cause (if known)
- Prevent seizures—may be done through medicine, surgery, or special therapies
- Avoid factors that stimulate seizure activity
There are a wide variety of medicines that may be used. Some of these include:
- Certain patients of Asian ancestry may be at risk for dangerous or even fatal skin reactions with this drug. If you are of Asian descent, the FDA recommends that you get tested before taking this drug. If you have been taking it for a few months with no skin reactions, then you are at low risk. Talk to your doctor before stopping this medicine.
- Valproic acid
- Adrenocorticotropic hormone (ACTH)
- Vigabatrin (approved for use in infants)
These drugs may be given alone or in combination.
If medicine does not work or the side effects are too severe, you may need surgery. Surgery involves the removal of the seizure focus. This is the area of the brain that has been identified as starting the seizure. Surgery is only an option for people who have very localized areas of the brain involved.
Vagus Nerve Stimulation (VNS)
A device is implanted in the chest. It will provide intermittent electrical stimulation to the vagus nerve. It is not clear how this works. Somehow it prevents or decreases the frequency of seizures. You may still require medicine. The dosage may be less.
Similar to a pacemaker, a device sends electrical impulses to specific parts of the brain to treat epilepsy.
Gamma Knife radiosurgery can be effective for cases of epilepsy arising from gliomas and other causes. Find out more about Gamma Knife at UVA.
This is a very strict diet. It is high in fat and low in carbohydrates and proteins. This diet keeps the body’s chemical balance in ketosis. Ketosis decreases the frequency of seizures. The reason is unknown. Following a ketogenic diet is most successful in children. It is less successful in adults.
Modification of Activity
If you have a seizure disorder, you can take the following steps to try to decrease the chance of a seizure:
- Get enough sleep.
- Avoid excessive alcohol intake. Alcohol can make seizures more likely.
- Avoid hyperventilating.
- Avoid places where flashing or strobe lights are in use.
- Wear a medical alert bracelet. That way, if you have a seizure, people around you will understand what is happening. They will be able to take appropriate steps to be helpful.
- Consider keeping a seizure log. Record things that were happening around the time of a seizure. This will help to identify a seizure trigger.
- Take your seizure medicines according to the prescription.
There are no known ways to prevent every type of seizure disorder. You can take steps to prevent brain injuries that could lead to seizures:
- Always wear a helmet when using bikes, rollerblades, skateboards, or scooters.
- Wear protective headgear when playing contact sports.
- Dive in safe depths of water.
- Always wear a seatbelt.
- Avoid using street drugs.
- If your baby or child has a high fever, get treatment right away.
- Get prenatal care. If you have high blood pressure during pregnancy, get proper treatment.
- If you have a chronic condition, get proper care.
If you have a very severe seizure disorder, some changes may be needed to prevent serious injuries, such as:
- Depending on your condition, avoid driving.
- Do not swim or bathe alone.
- Do not work on ladders or ledges.
- Avoid or modify athletic activities.
Talk to your doctor about these kinds of issues.