Epilepsy

Epilepsy is caused by surges of electrical activity

Epilepsy is a common neurological disorder which causes seizures.

One in 133 people in the UK has epilepsy, and at any one time 300,000 have an active form of the condition.

---

What causes epilepsy?

An epileptic seizure is caused by over-activity of the brain cells, which produces a surge of electricity.

This may be due to a variety of factors, such as brain damage from birth injuries, head injury, stroke, brain tumours and alcoholism.

There is some evidence to suggest the condition sometimes has a genetic basis - although it is rare for it to run in families.

In many instances, the cause of the condition is a mystery.

Are there different types of seizure?

Yes. Essentially, there are two types.

A partial seizure begins in one specific part of the brain, and may spread to other areas.

A generalised seizure can start in both sides of the brain at once.

Partial seizures:

• Simple partial seizure - Confined to one particular area of the brain. The person retains consciousness, but may be fearful, and experience a strong sense of deja vu. Symptoms include jerking of an arm and an unpleasant taste in the mouth.

• Complex partial seizure - The electrical disturbance spreads, disrupting consciousness. The person may interact with the surroundings, but be unaware of what they are doing and have no recollection of the event.

  Symptoms may include repeatedly chewing, swallowing or scratching. Afterwards the person is likely to be confused for some minutes.

Generalised seizures:

• Tonic clonic seizure - This leads to 'grand mal' convulsions in which the person loses consciousness, falls to the ground, becomes stiff and shakes.

  In some instances a tonic clonic seizure may occur after an initial partial seizure - in which case the person may have some warning of what is about to occur.

• Absence attack - A blank spell lasting a matter of seconds from which recovery is almost immediate.

• Myoclonic seizures - Jerks caused by a sudden contraction of the muscles. Can affect the whole body usually restricted to one or both arms and sometimes the head.

• Tonic seizures - All the muscles contract. The body stiffens and the person will fall over if unsupported.

• Atonic seizures - All muscle tone is lost and the person simply drops to the ground.

How is epilepsy treated?

There are a wide range of anti-epileptic drugs to prevent seizures.

Which drug is prescribed will depend on the individual patient, and their particular form of epilepsy.

The drugs are effective, but can have side effects, including drowsiness and dizziness.

Some drugs may produce longer term side effects, such as acne and weight gain.

Anti-epileptic drugs should not be taken in tandem with some other medications. They may also slightly increase the risk of malformations if taken during pregnancy.

Is surgery an option?

Yes, for people who do not respond to drug treatment.

The most common form of surgical treatment is to remove the hippocampus - a part of the brain involved in memory which is particularly vulnerable to damage.

Other forms of surgery which may be considered include:

• Temporal lobectomy - a larger part of the temporal lobe is removed.
• Sub-pial resection - fine cuts are made in the motor areas of the brain.
• Hemispherectomy - the removal of the whole of one side of the brain
• Corpus callosotomy - cutting the fibres that connect the two halves of the brain.

An alternative to neurosurgery is a treatment called vagal nerve stimulation in which a pacemaker device is placed under the skin to stimulate the vagus nerve in the neck.

This form of treatment does not usually cure the epilepsy, but can reduce seizure frequency and severity.