Epilepsy is a disorder of the brain caused by temporary disturbances in the electrical activity of the brain's nerve cells. This change in brain activity leads to a seizure. Seizures can take a number of different forms and can cause brief changes in a person's:
Body movements
Awareness
Emotions
Senses, such as taste, smell, vision, or hearing.
The abnormal activity in a group of nerve cells can spread to affect neighboring parts of the brain, or in some cases to the entire brain. And because certain parts of our brains are associated with specific functions, the symptoms produced by a seizure will depend on the area of the brain that is affected and how the abnormal electrical signals spread within the brain. Just as a headache is a symptom that can have many causes, a seizure can be a symptom of many different types of brain irregularities.
Some people may only have a single seizure during their lives, and one seizure does not mean that a person has epilepsy. In fact, the term epilepsy refers to a number of different kinds of recurring seizures that happen for a number of different reasons.
If you have been diagnosed with epilepsy, you probably already know that it is NOT a mental illness, nor is it contagious; however, you may want to educate other people about epilepsy.
Although a person can develop epilepsy at any age, it is more likely to begin either in childhood or in older age (after age 65) than at any other time of life.
More than 2.7 million Americans of all ages are living with epilepsy. Every year, 181,000 Americans will develop seizures and epilepsy for the first time.
These may be underestimates because some people are reluctant to admit they have epilepsy and people with mild epilepsy may not seek help from a Neurologist.
Normal brain activity
There are billions of nerve cells (neurons) in the brain linked together to form chains. All of the functions performed in our brains are controlled by these neuron chains. Therefore, our movement, speech, thoughts, sensations, and feelings all depend on the signals being passed in a regulated and orderly way. The activity of the neuron chains is coordinated by electrical and chemical signals.
During normal brain activity, an electrical impulse travels through a neuron. When the electrical signal reaches the end of the neuron, it stimulates the production of a chemical, known as a neurotransmitter, which crosses the gap between two nerve cells.
There are different kinds of neurotransmitters. Some stimulate the next neuron to pass the signal on (excitatory neurotransmitters); others try to halt further impulse transmission around the network (inhibitory neurotransmitters).
Seizures: Disturbances in electrical activity
Seizures occur when electrical activity in parts of the brain act abnormally. During this sort of activity, groups of neurons suddenly discharge their electrical impulses at the same time. This disruption may occur in a small group of neurons, in a large one, or in the entire brain.
Because our brains have special parts that are associated with specific functions, the symptoms produced by a seizure will depend on the area of the brain that is affected.
It is believed that the actual mechanism of seizure development may be an imbalance in excitatory and inhibitory neurotransmitters, which starts in an area of the brain that is damaged or has some abnormality such as a brain lesion. A brain lesion can be caused by one or more of the following:
Congenital malformations of the brain
Head injury (birth trauma, accident, brain surgery)
Brain cell damage (due to shortage of oxygen, strokes)
Damage caused by alcohol or drug abuse
Degenerative brain diseases (Alzheimer's disease)
Brain tumors
Brain infections (bacterial meningitis, viral encephalitis, malaria, cerebral abscess)
The effect of seizures: Disturbances in brain function
A seizure can temporarily disrupt many functions of the brain such as consciousness, personality, memory, mood, behavior, sensations, and movement.
For some people, a seizure comes on without warning; other people may feel something unusual (a prodrome or precursor) during the hours or minutes before a seizure. They may perceive changes in vision, hearing, or face color, or a warning - an "aura" - as the seizure starts. Often, people who have had a seizure can remember nothing about it afterwards.
Once a seizure begins, a person may lose control of one or more of the brain's many functions such as muscle activity or awareness of surroundings. Sometimes there is a complete loss of consciousness. A person may fall, stare into space, or make jerking movements with an arm or leg. They may lose control of their bladder or bowels and/or bite their tongue or lips. Breathing may become quite shallow which can make the skin appear blue.
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