Epilepsy
Epilepsy is currently defined as a tendency to have recurrent seizures (sometimes called fits). A seizure is caused by a sudden burst of excess electrical activity in the brain, causing a temporary disruption in the normal message passing between brain cells. This disruption results in the brain’s messages becoming halted or mixed up. Anything that disrupts the normal function of the brain can cause seizures and epilepsy.
The brain is responsible for all the functions of your body, so what you experience during a seizure will depend on where in your brain the epileptic activity begins and how widely and rapidly it spreads. For this reason, there are many different types of seizure and each person will experience epilepsy in a way that is unique to them. Although roughly half of all seizures have no known cause, there are certain factors that can trigger seizures, such as brain trauma, genetic abnormalities, infections and tumors.
Epilepsy is not a sign of brain damage – many people with epilepsy can function well between seizures. However, people with brain damage are more likely to develop epilepsy.
Sometimes the reason epilepsy develops is clear. It could be because of brain damage caused by a difficult birth; a severe blow to the head; a stroke which starves the brain of oxygen; or an infection of the brain such as meningitis. Very occasionally the cause is a brain tumour..
Epilepsy is a disorder with many possible causes. Anything that disturbs the normal pattern of neuron activity - from illness to brain damage to abnormal brain development - can lead to seizures. Epilepsy may develop because of an abnormality in brain wiring, an imbalance of nerve signaling chemicals called neurotransmitters, or some combination of these factors. Having a seizure does not necessarily mean that a person has epilepsy. Only when a person has had two or more seizures is he or she considered to have epilepsy. EEGs and brain scans are common diagnostic test for epilepsy.
Epilepsy with a known cause is called ‘symptomatic’ epilepsy. For most people - six out of ten, in fact - there is no known cause and this is called ‘idiopathic’ epilepsy.
Some people with epilepsy may experience unusual sensations or movements minutes or hours before they have a seizure. This sensation, called an aura, is actually a simple partial seizure. The exact nature of the aura is often unique to each individual, although it may include noticing a strange taste in the mouth, twitching in one limb or an inexplicable feeling of fear or apprehension. Because most people experience the same progression of events during each seizure, auras can serve as a warning that a seizure is going to occur.
