Brain cells send messages to the body through electrical signals. A seizure happens when there are abnormal electrical signals 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
When two or more seizures occur 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. The main categories are:
- Generalized seizure disorder—thought to arise throughout the brain, not from a single focal location
- Partial seizure disorder (focal seizure)—caused by more localized abnormalities; happens within certain areas of the brain
Brain Cells (Neurons)
Seizures are caused by abnormal brain function. Seizure disorders can start at any age.
For most people it is not known what causes the malfunction. Some known causes include:
- Congenital brain abnormalities—present at birth
- Birth injuries which deprive the brain of oxygen
- Metabolic disorders
- Maternal drug use
In infants and children:
- Complex 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:
- Congenital conditions—present at birth
- Head Trauma—common cause (eg, ]]>concussion]]> , skull fracture, oxygen deprivation due to ]]>near-drowning]]> )
- Infections (eg, ]]>encephalitis]]> , cerebritis, brain abscess)
The following factors increase your chance of developing some seizure disorders:
- Previous brain injury—seizure disorder usually develops within 1 year of injury
- Previous brain infection
- Brain tumor
- History of stroke
- History of complex febrile seizures
- Use of certain medications or recreational drugs
- Stopping the use of medications, recreational drugs]]> , or alcohol
- Drug overdose
- Exposure to toxins such as ]]>arsenic]]> , ]]>lead]]> , or ]]>carbon monoxide]]>
- Family history of seizure disorders
- ]]>Alzheimer’s disease]]>
- ]]>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 such as ]]>lupus]]> , ]]>polyarteritis nodosa]]> , ]]>porphyria]]> , ]]>sickle cell disease]]> , ]]>Whipple’s disease]]>
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 medications
- Missing doses of anti-epileptic medications
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, spots appearing in front of the eyes, or unusual stomach sensations; an aura is a seizure
- 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—classic convulsions; there is a loss of consciousness and the muscles throughout the body jerk uncontrollably
- Absence seizures—characterized by staring, eye blinking, or eye rolling
Symptoms of Partial Seizure Disorder Include:
Complex partial or temporal lobe seizures—may cause loss of contact with reality, stop purposeful activity, and begin a series of automatic gestures (eg, lip smacking, hand-wringing, or picking at clothing)
- May simply appears as a brief moment of confusion or loss of attentiveness
- May also have a perception of unusual sights, sounds, or smells
- Complex describes a seizure has alteration of consciousness
Simple partial seizures—will retain contact with reality and consciousness; a single area of your 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 of the electrical activity of the brain; may be done for a brief amount of time, or may be given an ambulatory monitor to use for several days, or you may be admitted to the hospital for several days
- ]]>MRI scan]]> (or sometimes ]]>CT scan]]> )—to look for abnormalities in the brain, such as tumor, blood, infection, malformed blood vessels, scarring or swelling
- ]]>Spinal tap]]> (lumbar puncture)—may be performed to look for infection and/or bleeding
- Magnetoencephalogram (MEG)—evaluates for seizure activity and combines it with imaging to localize where the seizures arise
The goals of treatment are to:
- Treat the underlying cause (if know)
- Prevent seizures—may be done through medication, surgery, or special therapies
- Avoid factors that stimulate seizure activity
There are a wide variety of medications 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 medication. ]]>*]]>
- ]]>Valproic acid]]>
These drugs may be given alone or in combination.
If medicine does not work or the side effects are too severe, surgery may be advised. 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 individuals 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 medications. The dosage may be less.
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 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 medications according to the prescription.
There are no known ways to prevent every type of seizure disorder. You can take steps to prevent brain injuries which could lead to seizures:
- Always wear a helmet when using bikes, rollerblades, skateboards, or scooters.
- Wear protective headgear when contact sports. This includes football or hockey.
- Dive in safe depths of water.
- Always wear a seatbelt.
- Avoid using street drugs.
- Control high fevers in babies and young children.
- Get prenatal care. Make sure to follow all recommendations for the treatment of high blood pressure during pregnancy.
- Carefully treat all chronic illnesses.
If you have a very severe seizure disorder, some changes may be needed to prevent serious injuries. For example:
- Depending on the frequency of seizures, you may not be able to obtain a driver’s license
- Do not swim or bathe alone, or
- Do not work on ladders or ledges
- Certain athletic activities may need to be modified or avoided
National Institute of Neurological Disorders and Stroke
The Center for Epilepsy and Seizure Education
Epilepsy. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/what.php . Accessed January 15, 2008.
Ferri FF, ed. Ferri’s Clinical Advisor: Instant Diagnosis and Treatment. Philadelphia, PA: Mosby Elsevier; 2004.
Goetz CG, ed. Textbook of clinical Neurology . 2nd ed. Philadelphia, PA: WB Saunders Company; 2006.
Goldman L, Ausiello D, eds. Cecil Textbook of Medicine. 22nd ed. Philadelphia, PA: WB Saunders Company; 2004.
Kasper D, Braunwald E, Fauci A, Hauser S, Longo D, Jameson JL. Harrison's principles of internal medicine . New York, NY: McGraw-Hill; 2005.
*12/20/2007 DynaMed's Systematic Literature Surveillance DynaMed's Systematic Literature Surveillance : 2007 safety alerts for drugs, biologics, medical devices, and dietary supplements: Carbamazepine (marketed as Carbatrol, Equetro, Tegretol and generics). Medwatch. US Food and Drug Administration website. Available at: http://www.fda.gov/medwatch/safety/2007/safety07.htm#carbamazepine .
*5/14/2008 DynaMed's Systematic Literature Surveillance DynaMed's Systematic Literature Surveillance : Neal EG, Chaffe H, Schwartz RH, et al. The ketogenic diet for the treatment of childhood epilepsy: a randomised controlled trial. Lancet Neurol. 2008 May 2. [Epub ahead of print]
Last reviewed February 2009 by ]]>Rimas Lukas, MD]]>
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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