What Causes Epilepsy?

Epilepsy is the result of abnormal brain function. Often, the cause of this abnormal activity is unknown. According to the National Institutes of Health, about half of all epileptic seizures have no known cause. In such cases, seizures are referred to as cryptogenic, idiopathic or primary seizures. ("Symptomatic seizures" are those in which the cause of epilepsy is known).

In some cases, there may be one specific cause of epilepsy. In other cases there may be more than one contributing factor.

Genetic Factors

Genetics appear to play a role in most cases of epilepsy. For example, only some people who suffer a head injury will develop epilepsy as a result, potentially indicating that they are genetically predisposed to the condition. According to the World Health Organization, if one parent has epilepsy, there is a 4 to 6 percent chance the child will develop the disorder as well. If both parents have epilepsy, the risk to the child increases (12 to 20 percent).

Prenatal Factors

Fetuses are vulnerable to the kind of brain damage that results in epilepsy and causes seizures at a very early age. Some of the common causes of fetal brain damage include:

• Congenital disorders (disorders that result in damage to the developing fetus)
• Lack of oxygen
• Maternal infection
• Poor nutrition.

Other possible triggers and causes of epilepsy in newborns include trauma during birth and low birth weight.

Postnatal Factors in Children and Young Adults

In children and young adults, factors that affect epilepsy risk include:

• Development disorders: About 20 percent of childhood seizures are the result of cerebral palsy and other neurological disorders, such as autism and Down's syndrome.
• Head trauma: Severe, penetrating head injuries resulting in brain damage are the most common causes of epilepsy in young adults. Approximately 50 percent of injury-related seizures will begin within a year of the initial injury.

Medical Disorders and Epilepsy

At any age, certain illnesses and medical problems can interfere with normal brain function and cause the development of epilepsy. Some of these medical problems include:

• Brain lesions (i.e. hemorrhages, tumors, etc.)
• Circulatory problems (i.e. strokes, blood disorders, etc.)
• Degenerative diseases (i.e. Alzheimer's disease, dementia, etc.)
• Heart attacks
• Infections (i.e. AIDS, meningitis, tuberculosis, etc.)
• Metabolic disorders (i.e. electrolyte imbalance, hypoglycemia, etc.)
• Toxic poisoning (i.e. alcohol or lead poisoning, etc.).

Alzheimer's disease, stroke and dementia are the leading causes of epilepsy in seniors.

Seizures: Causes and Triggers

Some of the most common triggers and causes of epilepsy seizures are:

• Alcohol abuse
• Anxiety
• Changes in blood sugar level
• Fatigue
• Fever
• Flickering lights
• Hormones
• Hyperventilation
• Illness
• Inadequate diet
• Overheating
• Reading
• Skipping medication
• Sleep
• Stress
• Use of street drugs.

Specific triggers or combinations of triggers are different for each individual. In addition, seizure threshold levels vary. Some individuals have been able to exercise greater control over their seizures by uncovering their own specific triggers and avoiding them whenever possible.

Resources

Dekker, P.A. (2002). Epilepsy: A manual for medical and clinical officers in Africa. Retrieved March 10, 2010, from http://www.who.int/mental_health/media/en/639.pdf

Epilepsy Action Staff. (n.d.) Frequently asked questions. Retrieved March 10, 2010, from http://www.epilepsy.org.au/faqs2.asp

Mayo Foundation for Medical Education and Research Staff. (2009). Epilepsy causes. Retrieved March 11, 2010, from http://www.mayoclinic.com/health/epilepsy/DS00342/DSECTION=causes

Office of Communications and Public Liaison Staff. (n.d.) NINDS epilepsy information page. Retrieved March 10, 2010, from http://www.ninds.nih.gov/disorders/epilepsy/detail_epilepsy.htm#146763109

Schachter, S. C. (2006). What causes epilepsy? Retrieved March 11, 2010 from http://www.epilepsy.com/101/EP101_cause

The Epilepsy Foundation of America^®Staff. (n.d.) Causes of epilepsy. Retrieved March 11, 2010 from http://www.epilepsyfoundation.org/about/types/causes/index.cfm