What is epilepsy?

Epilepsy is a condition of having recurrent (2 or more) seizures that are unprovoked by fever, sudden head injury, sudden change in blood chemistry, breath-holding, or toxin exposure. 

What is a seizure?

A seizure is a sudden usually brief  (several seconds to a few minutes long) change in brain function produced by abnormal electrical activity of large numbers of brain nerve cells firing simultaneously. This activity can produce loss of conscious awareness, uncontrolled sensations, abnormal involuntary motor movements, falls, stiffening, convulsive jerking of the body and limbs or any combination of the above.

What are different types of seizures?

Seizures are usually distinguished by whether or not they involve the whole brain (generalized type) or just part of the brain (partial seizure). Often a good description of how a seizure started, how it evolved and ended can help your doctor to understand whether a seizure is generalized or partial. EEG findings can also help doctors to understand better the type of seizure a patient is having.

• Generalized Absence seizures are very short, usually 3-10 seconds. There may be a sudden pause in speech and activity, staring, eyelid drooping or fluttering, slight head nod, but sudden resumption of activity immediately after the seizure is over.
   
• Generalized Myoclonic seizures consist of sudden lightning-like jerks of the limbs and/or body. They may or may not cause the person to fall. They last a fraction of a second and the person recovers immediately after. Sometimes they can be mixed with a different seizure such as an absence or tonic seizure.
   
• Generalized Atonic (Akinetic) seizures consist of sudden loss of body tone and postural control. If standing the person will suddenly fall to the ground. These are commonly brief and in pure form the person will not seem to lose consciousness and get right up afterwords.
   
• Generalized tonic seizures consist of sudden stiffening of the entire body.
   
• Generalized clonic seizures are those characterized by repetitive rhythmical jerking of both sides of the body and limbs. A mixture of these two is the more common
   
• Generalized Tonic-Clonic seizure in which the seizure starts with total body stiffening then this is followed by rhythmical repetitive jerking of both arms and legs. After one of these the patient usually is limp and unresponsive and in what is called a postictal state. 
   
• A simple partial seizure can consist of a localized stiffening or jerking of one limb, one side of the face, or turning of the eyes or head or both to the left or right as if there is an irresistible force involved. There can also be sensory type (visual, auditory, tactile, or psychosensory) partial seizures. In a simple partial seizure the person remains fully aware and can respond to their environment in a meaningful way.
   
• A complex partial seizure produces loss of awareness and can consist of a motionless stare, sometimes a fearful look, and often automatic movements of the hands or mouth such as fumbling with items, clothes, or chewing though there may be nothing in the person’s mouth. Partial seizures can spread to involve the whole brain after they begin and produce bilateral tonic or clonic activity. This is called a partial seizure with secondary generalization. 

What causes epilepsy?

Although there are many identifiable causes of epilepsy, such as congenital brain malformations, or injuries to the brain (brain infections, severe head trauma, lack of oxygen to the brain, stroke, etc.) most children who have epilepsy have no identifiable cause of their epilepsy. It is rare to have epilepsy caused by a brain tumor in a child. Some children with degenerative brain diseases or chromosome abnormalities also have epilepsy. 

Some children have a family history of epilepsy. There are some types of epilepsy that have recently been found to be due to specific abnormalities in genes which make proteins that regulate the flow of chemical ions  across nerve cell membranes. This makes it difficult for nerve cells to regulate themselves and prevent abnormal electrical activity of these cells. A seizure occurs as the result of many brain cells having abnormal electrical firing patterns simultaneously.

How do doctors evaluate a child with epilepsy?

The process of treating epilepsy begins with the doctor taking a thorough medical history, including the details of what the child does during a seizure, and exploring the child’s previous health history and developmental profile. A general physical and neurological exam are also performed.

Most children will receive an EEG (electroencephalogram) the purpose of which is to add further information to the child’s profile to help understand if a child is experiencing generalized seizures or partial seizures or both or even neither. The EEG can also help identify if a child has a particular epilepsy syndrome. This can influence the child’s treatment in substantial ways.

If a child is thought to have partial seizures it is common to obtain a brain MRI scan to look for an identifiable structural abnormality of the brain. Such testing is not always necessary in every child with epilepsy. There are some epilepsy syndromes that can be defined simply by history, exam, and EEG findings and are not associated with structural brain abnormalities. Such children do not need to have an MRI scan.

How is epilepsy treated?

The treatment of epilepsy begins first by determining that seizures are likely to occur with such frequency that they should be treated with antiseizure medication often called “anticonvulsant or anti-epileptic” drugs. There are at least 12 different types of medication available in the United States for treating epilepsy. The task of the doctor is to match the medication to the patient. Some medications are effective for certain types of seizures, but may be completely ineffective for other seizure types.

Like all prescription medications, every anti-seizure medication has some sort of side effect associated with its use. Some are minor, tolerable and can be eliminated or minimized with time or with reducing the dose, while other rare side effects are more serious and even sometimes life-threatening. Some medications are better to use than others if a child has liver problems or kidney problems. Some anti-seizure medications can interact with other medications taken by a child to treat other conditions while others have no such interactions. Unfortunately there is no single anti-seizure that is the best one for all children with epilepsy. Treatment must be individualized.

What if anti-seizure medicines don’t work? 

If medication is taken regularly without missed doses, approximately 70% of children can have their seizures completely controlled with the first medicine chosen for treatment. If medicines do not work and a child has tried 2 or 3 different medicines, the child should be considered for another form of treatment. Some children, especially those with temporal lobe epilepsy, or with discrete brain lesions can have brain surgery with excellent results and become seizure free with little or no side effects from the surgery.

Other children can benefit from the use of the ketogenic diet. This is a rigid mathematically calculated diet high in fats and low in carbohydrate and protein which must be implemented by the family. It can sometimes produce complete or near-complete freedom from seizures. Unfortunately, this works to this extent only in a small proportion of patients (less than 25%). For others there can be a 50% or greater reduction in seizures which for some patients can lead to an improved quality of life.

Another form of treatment, vagal nerve stimulation, can reduce seizures in some patients by 50-75% but only rarely eliminates seizures. This requires surgical placement (under the skin of the upper left chest) of a device that generates regular electrical impulses transmitted by a wire under the skin to the vagus nerve in the left side of the neck. The patient and family can also use a magnet to activate the device when it feels like there is a seizure coming on (an aura). Sometimes activating the device will prevent the seizure from evolving to a more intense seizure.

How can I learn more about epilepsy?

A very good place to learn more information about epilepsy and seizures is on the web site maintained by the Epilepsy Foundation of America – www.efa.org. From this you can link onto the local San Diego affiliate web site if you are interested in supporting or learning about activities of the local chapter of the EFA.

CSSD Division of Neurology