Epilepsy Triggers Causes Biology

The nervous system is an organ system of the body connected by a network of nerve cells, called “neurons.” Neurons send signals through the body’s network of nerves. This enables the control center of the nervous system, the brain, to pass on information to the rest of the body.

The Brain

The brain is an incredibly complex organ. It controls our thoughts, emotions, movements and memory. The brain is made up mostly of nerve cells — estimated at 100 billion, with even more supporting cells. The brain is constantly receiving, processing and sending information.

Neurons communicate information by firing off electrical impulses. A chemical messenger, called a “neurotransmitter,” passes this information on from cell to cell. Millions of these electrical impulses are taking place in the brain at any given moment, and the brain manages to process all of them.

The Biology of Epilepsy in the Brain

Seizures occur when there is a disruption in the electrical communication system in the brain. This causes neurons to fire off electrical impulses simultaneously and at a much faster rate than normal. The brain is unable to properly compute these jumbled messages and a seizure takes place.

If this phenomenon originates in a specific area of the brain, the symptoms of the seizure will reflect the function of that particular area. These are known as partial (or focal) seizures. For example, if there is a disturbance in the area of the brain that controls sight, the seizure will result in some sort of impaired vision. If the disturbance takes place in the right half of the brain, the seizure is likely to affect the left half of the body because the right side of the brain controls the left side of the body, and vice versa. A “generalized seizure,” which results in a loss of consciousness, occurs when a disturbance affects the whole brain.

Auras and Seizures

Some people get a feeling or warning sign that tells them they’re going to have a seizure. This is called an “aura.” Some people may experience strange sights, sounds, smells, feelings or some combination of these. Some people may feel depressed, nauseous or get a headache. Some people experience auras a few minutes before a seizure, and others get them hours before.

The type of aura an individual experiences appears to be related to the region of the brain where his or her seizures begin. Individuals with complex partial seizures (a partial seizure in which there is a loss of consciousness) are the most likely to experience auras.

Do Seizures Cause Brain Damage?

Surprisingly, permanent brain damage from seizures is extremely rare. Permanent harm could result, however, if a patient experiences prolonged seizures or seizures that occur very close together. This condition, called “status epilepticus,” is life threatening. An individual with status epilepticus experiences unrelenting or repeated seizures without regaining consciousness in between these seizures.

Causes of brain damage, although uncommon, are more likely to be the result of lack of oxygen because the patient stopped breathing for a prolonged period.

Resources

Epilepsy Action Staff. (n.d.). Epilepsy explained. Retrieved March 12, 2010, from http://www.epilepsy.org.au/epilepsy_explained2.asp#1

Epilepsy.com Staff. (n.d.). Epilepsy and the brain. Retrieved March 12, 2010, from http://www.epilepsy.com/EPILEPSY/epilepsy_brain

The Epilepsy Foundation of America® Staff. (n.d.) Epilepsy