A seizure is a sudden alteration of behavior due to a temporary change in the electrical functioning of the brain, especially the cortex. It may be an alteration in behavior, consciousness, movement, perception and/or sensation.
Epilepsy is the tendency to have recurrent seizures. Seizures can include:
- Uncontrolled movements, such as shaking of arms or legs
- Loss of consciousness, which may consist of a complete collapse or simply staring into space. Afterward the person will not remember this event.
- Fainting spells with incontinence or followed by excessive fatigue
- Odd sounds, distorted perceptions, sudden feelings of fear for no apparent reason
Types of Seizures
Seizure disorders may be classified by the part of the brain they affect and the kinds of symptoms they cause. There are two broad types of seizures.
Generalized Seizure Disorder
In generalized seizures, abnormal, excessive electricity occurs throughout the whole brain at once, with no apparent focal point of onset or warning beforehand.
Generalized seizures alter consciousness and can be convulsive or non-convulsive. This is the type of seizure that most people recognize through stiffening and jerking movements.
Partial Seizure Disorder (Focal Seizure)
Partial seizures begin in one place in the brain and only affect that part of the brain. Depending on where they start and which parts of the brain they involve, partial seizures may or may not alter consciousness or awareness.
SIMPLE PARTIAL SEIZURES
Simple partial seizures or focal seizures do not alter consciousness. These occur in the focus of the brain and only last a short time. This type of seizure is also known as an aura because it often serves as a warning that a bigger seizure will follow.
These seizures consist of an unusual emotion, sensation or movement. Some people experience an overwhelming emotion like fear or dread or smell an unpleasant odor sent from another part of their brain.
COMPLEX PARTIAL SEIZURES
Complex partial seizures involve deep, central structures of the brain that affect consciousness. These seizures may begin as a simple partial seizure (like a funny feeling or emotion) before it spreads to the areas of the brain that controls awareness.
During a complex partial seizure, a person typically stares blankly and performs automatic, unconsciously repeated movements, such as lip smacking, picking at one's clothes and wandering around aimlessly and confused. These movements are called automatisms. During the seizure, the person's ability to speak, understand and respond is usually affected.
Causes
For many people, the cause of their seizures is unknown. Some known causes include:
- In newborns:
- Congenital brain abnormalities
- Birth injuries that deprive the brain of oxygen
- Metabolic disorders
- Maternal drug use
- Infection
- In infants and children:
- A spike in fever
- Brain tumor
- Infections
- In children and adults:
- Congenital conditions
- Genetic
- Head trauma
- Infections
- Stroke
- Brain tumor
- In elderly:
- Stroke
- Trauma
- Brain tumor
- Degenerative diseases, like Alzheimer’s disease
Seizure Disorder Risk Factors
Factors that may increase your chance of developing seizures or a seizure disorder include:
- Previous brain injury or infection
- Abnormal blood vessel formed in the brain
- Brain tumor
- History of stroke
- Use of certain medicines or recreational drugs
- Exposure to toxins, such as arsenic, lead or carbon monoxide
- Family history of seizure disorders
- Alzheimer’s disease
- Toxemia during pregnancy
- Chemical abnormalities that decrease or increase blood sodium or glucose
- Liver or kidney failure
- Severe, untreated high blood pressure
- Chronic diseases, such as lupus, polyarteritis nodosa, porphyria or sickle cell disease
- Syphilis
- Cysticercosis
Diagnosis & Treatment at UVA
Your doctor will ask about your symptoms, medical history and perform a physical exam. Your doctor may order tests that include:
- Blood tests
- Electroencephalogram (EEG)
- Magnetic resonance imaging (MRI) scan
- Computed tomography (CT) scan
- Lumbar puncture
- Magnetoencephalography (MEG)
- Positron emission tomography (PET) scan
- Single photon emission computed tomography (SPECT)
Treatment aims to understand the underlying cause of your seizures, prevent future seizures and help you avoid factors that may stimulate seizure activity. There's a wide variety of anti-seizure medication. Your doctor may prescribe them alone or in combination with other treatment methods.
Surgery
You may need surgery if medicine does not work or the side effects are too severe. Surgery involves the removal of the area of the brain that's responsible for starting the seizure. This is only an option for people who have very localized areas of the brain involved.
Vagus Nerve Stimulation (VNS)
During VNS, your doctor implants a device in your chest that provides intermittent electrical stimulation to the vagus nerve. This prevents or decreases the frequency of your seizures.
Deep Brain Stimulation
Deep brain stimulation involves a device that sends electrical impulses to specific parts of the brain to treat epilepsy.
Gamma Knife
Gamma Knife radiosurgery can be an effective treatment for epilepsy that arises from gliomas and other causes.
Ketogenic Diet
Ketogenic diets are high in fat and low in carbohydrates and proteins. This diet keeps the body’s chemical balance in ketosis, which can decrease the frequency of your seizures. Ketogenic diets are most successful in children. Learn more from our Ketogenic Diet Clinic.
Content was created using EBSCO’s Health Library. Edits to original content made by Rector and Visitors of the University of Virginia. This information is not a substitute for professional medical advice.