Epilepsy - Causes

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Sleep Disorders. Some sleep disorders, such as obstructive sleep apnea or narcolepsy, have been associated with seizures, although a causal relationship is unclear. Sleep apnea and hereditary nocturnal frontal lobe epilepsy have very similar symptoms (feeling of choking, abnormal motor activity during sleep, and excessive sleepiness during the day). A 2000 study reported that a third of patients with epilepsy who did not respond to medications were later diagnosed with obstructive sleep apnea. Other studies have found that when sleep apnea is treated in patients with both epilepsy and the sleep disorder, seizure activity decreases. More research is needed.

Stroke. Seizure is a symptom of a major stroke. In some cases, injury to the brain from small strokes may cause seizures. Studies report that between 15 - 23% of stroke patients consequently have seizures. A 2005 study found that 3% of patients who have had a stroke go on to develop epilepsy. Patients who had a severe stroke were 5 times more likely to develop epilepsy than patients who had a mild stroke.

Other Causes in Adults. Other known or possible causes of epilepsy in teenage or adult years include:

• Drug abuse or withdrawal from drugs.
• Sudden withdrawal from certain antianxiety or antidepressant drugs.
• Occupational exposure to environmental triggers. High exposure to certain chemicals has been linked with seizures. A 2000 study of utility company employees revealed an association between high exposure to electromagnetic fields (EMF) and an increased risk of epilepsy and neurologic diseases that affected motor control.
• Alzheimer's or other degenerative brain diseases in the elderly.
• Nervous system infection by tapeworm larvae is an important cause of epilepsy in developing nations.

Causes of Seizures That Can Occur at Any Age

Infections of the Brain and Central Nervous System (CNS). Acute infections of the brain and the CNS can cause seizures. Some cases are complicated by brain damage that can lead to recurrent seizures afterward. The most common central nervous system infections are encephalitis and meningitis. Researchers have also found an association between epileptic seizures and CNS-occurring herpes simplex virus infections. More research is needed before any causative role can be proved.