Epilepsy is the name for a group of disorders of the brain
characterized by a tendency to recurrent seizures or convulsions or 'fits'. It is responsible for an enormous amount of suffering,
affecting some 50 million people of all ages, especially in childhood,
adolescence and the elderly.
At least one hundred million people will experience epilepsy
at some time in their lives. About 2 million new cases occur each year.
Epilepsy is universal and the most common serious neurological
disorder.
Seizures are caused by sudden, usually brief, excessive electrical
discharges in a group of brain cells. During a seizure, the neurons in
the brain (nerve cells hat produce electrical discharges) may fire as
many as 500 times a second, which disturbs the normal activity of
neurons, glands and muscles.
Different parts of the brain can be so affected and the
precise way in which epilepsy presents can vary, depending on the
particular brain cells involved.
Some seizures affect the whole body and result from widespread
electrical discharges over most of the brain. These are called
tonic-clonic seizures. Other seizures may be more localised with the
discharges just affecting a small part of the brain. These are known as
partial seizures and may consist of merely subjective experiences, some
involuntary motor activity or combinations of both, with or without
loss of consciousness. Sometimes a seizure starts as a partial one but
then spreads to the whole brain, becoming tonic-clonic.
A seizure or attack may not involve actual convulsions or jerky
movements. The patient may experience temporary loss of consciousness,
a change in perception or even a funny feeling in the abdomen. The
symptoms depend on the type of epilepsy. Some patients may go into a
dream-like state, others may experience inexplicable feelings of joy or
sadness and others yet may display strange repetitive motions like
blinking or twitching. Seizures can occur several times a day to once
every few months.
