Seizures

A seizure occurs when there's abnormal electical activity in the brain.

What is epilepsy?

Epilepsy is a medical condition that produces seizures that affect a variety of mental and physical functions. When a person has two or more seizures, they are considered to have epilepsy. These seizures are a result of sudden abnormal electrical activity in the brain. The exact type of seizure will depend on where it starts and then spreads within the brain.

What are seizures?

A seizure is a disturbance in the normal regulation pattern of the electrical activity of the brain.  Although there are many causes and types of seizures, the common feature is a spreading wave of uncontrolled electrical activity.  This abnormal activity within the brain will usually create outward changes in the person experiencing a seizure.  Signs and symptoms may include muscle spasms, mental confusion, loss of consciousness and/or uncontrolled or aimless body movements.  In general, seizures last a finite period of seconds to minutes, and then stop on their own.

There are two main types of seizures:

Generalized seizures begin with sudden abnormal electrical activity throughout the entire brain at once. These seizure types include: tonic-clonic convulsions ("grand mal" seizures) and absence seizures ("petit mal" or staring seizures).

Partial seizures begin with abnormal electrical activity in just one part of the brain.  Although the activity starts in a specific area of the brain, this activity can spread to other parts as well.  These seizures types include:  simple partial seizures, complex partial seizures, and secondarily generalized seizures.

Epilepsy vs seizures?

Seizures are characterized by a sudden change in movement, behavior, sensation or consciousness produced by an abnormal electrical discharge in the brain. Epilepsy is a condition of spontaneously recurring seizures. Having a single seizure does not necessarily mean a person has epilepsy. High fever, severe head injury, lack of oxygen, or a number of other factors can cause a single seizure.

Epilepsy, on the other hand, tends to be a lifelong condition that affects how electrical energy and connections behave in the brain.

First Aid

Convulsive seizures

• When providing seizure first aid for generalized tonic-clonic (grand mal) seizures or partial seizures with secondary generalization, these are the key things to remember:
• Keep calm and reassure other people who may be nearby.
• Don't hold the person down or try to stop their movements.
• Time the seizure.
• Clear the area around the person of anything hard or sharp.
• Loosen ties or anything around the person's neck that may make breathing difficult.
• Put something flat and soft, like a folded jacket, under the person's head.
• Turn them gently onto one side. This will help keep their airway clear.
• Do not try to force their mouth open with any hard implement or with fingers. A person having a seizure CANNOT swallow their tongue. Efforts to hold the tongue down can injure teeth or the jaw.
• Don't attempt artificial respiration except in the unlikely event that a person does not start breathing again after the seizure has stopped.
• Stay with the person until the seizure ends naturally.
• Be friendly and reassuring as consciousness returns.
• Offer to call a taxi, friend or relative to help the person get home if they seems confused or unable to get home by themself.

Most generalized tonic-clonic (grand mal) seizures end by themselves. In a person with a history of seizures, they are not a medical emergency even though they can appear frightening. If the seizure stops naturally after a few minutes without injury, the person does not necessarily need to go to a hospital. In other circumstances, an ambulance might need to be called.

An ambulance should be called if:

• The person does not have a history of seizures.
• The seizure happened in water.
• The person is not wearing any medical ID, and there is no way of knowing whether or not the seizure is caused by epilepsy.
• The person is pregnant, injured, or diabetic.
• The seizure continues for more than five minutes.
• A second seizure starts shortly after the first has ended.
• Consciousness does not start to return after the shaking/convulsing has stopped.

If the ambulance arrives after the person has returned to consciousness, the person should be asked whether the seizure was associated with epilepsy and whether emergency care is needed.

What are some of the causes of epilepsy?

There are many causes of epilepsy.  Some causes are hereditary, and can results in seizures starting in either childhood or as an adult.  Other causes include head trauma, meningitis, brain tumors, stroke, or multiple sclerosis.  However, if you have experienced a seizure, please note that many times, none of these diagnoses are made.  In most cases, no clear cause of the seizure can be determined.  Please consult with you physician about your personal situation.

How is epilepsy diagnosed?

Epilepsy is diagnosed by meeting with your neurologist and undergoing a series of basic tests.  The first step is to review your medical history (including a detailed recounting of the seizures) with your physician.  This physician will also conduct a thorough neurological examination.  In most cases, an EEG (electroencephalogram) and MRI (magnetic resonance imaging) test will be performed as well.  You will meet with the physician after these tests to discuss your overall personal health situation.

How is epilepsy treated?

The mainstay of epilepsy therapy remains anti-seizure medications.  Various medications have been used for decades, and they remain very effective for the majority of patients with epilepsy.  In more recent years, medications with better side effect profiles and safer long-term records have been introduced. 

For patients who do not respond to medications, the vagus nerve stimulator and resective epilepsy surgery are also options.  Finally, there are a number of investigational interventions currently in development.  Please discuss these options and your personal situation with your neurologist.

What is an electroencephalography (EEG)?

An electroencephalogram (EEG) is a test to detect abnormalities in the electrical activity of the brain.  Brain cells (or neurons) communicate by producing electrical signals. To perform an EEG test, electrodes are placed on the scalp to detect and record patterns of this electrical activity and check for abnormalities.

The test is performed by an EEG technician. At the beginning of the test, you will lie on your back on a table or in a reclining chair.  The technician will apply between 16 and 25 flat metal discs (the electrodes) in different positions on your scalp. The electrodes are affixed to your scalp with a paste and are connected by wires to an amplifier and a recording machine.  There is no invasive part of this test, and you should feel no discomfort.

As the test begins, the recording machine converts the electrical signals into a series of wavy lines that are recorded on a computer. You will need to lie still with your eyes closed because any movement can alter these results.  You may be asked to do certain things during the recording, such as breathe deeply for several minutes or look at a flickering light.

Your health care provider may want you to discontinue some medications before the test. Do not change or stop medications without first consulting your physician.

You should avoid all foods containing caffeine for 24 hours before the test and have clean, dry hair, free of all styling products.

Sometimes it is necessary to sleep during the test, so you may be asked to reduce your sleep time the night before.  Please discuss this possibility with your physician.

The EEG test is used to help diagnose the presence and type of seizure disorders, to look for causes of confusion, and to evaluate head injuries, tumors, infections, degenerative diseases, and metabolic disturbances that affect the brain.  It is also used to partly evaluate sleep disorders and to investigate periods of unconsciousness.

Information taken from (Department of Veterans Affairs)