Epilepsy - medical information
What is epilepsy?
- Epilepsy is a condition in which there is a tendency to have seizures.
- A one off seizure does not necessarily mean that you have epilepsy.
- An epileptic seizure happens when there is a sudden electrical discharge in the brain.
- This causes changes in sensation, behaviour or consciousness.
There are over forty different types of seizure – because the brain is responsible for such a wide range of functions and seizure activity in different parts of the brain can cause different seizures.
Most last from a few seconds to a few minutes and usually stop without the need for any treatment.
The two main groups of seizures:
- Generalised seizures – the whole brain is affected by the abnormal electrical activity disturbance and the person becomes unconscious. This can be very brief or may last a few minutes. Some generalised seizures may involve sudden changes in muscle tone (stiffening or complete loss of tone) that will mean the person falls to the floor. This may then be followed by jerking movements. In other generalised seizures, such as absence seizure, the person will stop all activity and remain still in a day dream like state (but unconscious).
- Focal seizures – the abnormal electrical activity is focussed in just one part of the brain. The type of seizure will depend on exactly where in the brain the focus of activity is. There are usually changes in the level of awareness but the person will not be unconscious.
What causes epilepsy?
The causes of epilepsy fall into three groups:
In around 60% of cases, the cause is unknown. But with advances in brain imaging techniques and our understanding of genetics causes may be found in more cases.
What triggers a seizure?
We often do not know why a seizure occurs at one time and not another, but there are certain factors that may increase the likelihood of a seizure and these are known as triggers.
Common seizure triggers include:
- Illness (raised temperature)
- Changes in medication
- Flashing lights (although photosensitive epilepsy is quite rare, affecting only around 5% of those with epilepsy)
Treatment of epilepsy
The first line of treatment for children with epilepsy is medication using antiepileptic drugs or AEDs. Most medication is taken twice daily and it is important that the medication is taken in the way that the doctor has prescribed. AEDs are not a cure for epilepsy, but they can reduce the amount of seizures a person is having.
Some people experience side effects from taking medication, but these often subside after a while. It is important to keep a record of any side effects so that these can be reported to the doctor.
There are other treatments for epilepsy and these include the use of implanted devices (like a cardiac pacemaker) such as a Vagus Nerve Stimulator (VNS) and dietary treatments such as the ketogenic diet. In some cases neurosurgery may be a treatment option.