What Causes Epilepsy?
In more than half of all cases, no cause can be found.
The person with epilepsy is apparently healthy in every respect and there is no underlying illness, disease or damage causing them to have seizures. This kind of epilepsy is sometimes called idiopathic epilepsy. It would seem that some of us just have a greater propensity than others to have seizures.
Sometimes a cause for the epilepsy can be found. Anything that damages or injures the brain can result in epilepsy. Some of the common causes are head injuries, strokes brain infections e.g. meningitis or encephalitis and birth defects. Other more rare causes are brain tumours and some genetic conditions like tuber sclerosis.
Any person's brain has the capacity to produce a seizure, if the circumstances are appropriate. Most brains are not likely to do this spontaneously, and can, therefore, be said to have a high "seizure threshold" or high resistance to seizures. Individuals vary as to their threshold and it is probably one part of the genetic characteristics. Someone with a low threshold might develop epilepsy spontaneously, without other factors being involved. Sometimes, a predisposition to seizures can be seen in some families, where several members are affected.
The genetics of epilepsy, however, are not straightforward. In some individuals, the existing seizure threshold may be lowered if the brain is subject to unusual stimulation, such as, certain frequencies of flickering light and some drugs, or is injured. If the injury is severe e.g. due to a road traffic accident, infection, birth trauma, stroke or tumour, then epilepsy may develop as a consequence.
Many individuals attribute the onset of their seizures to some relatively minor event, such as a blow on the head or an emotional upset. Although, these cannot be completely discounted, in such cases, it is likely that family predisposition to seizures plays a more important role.
Is epilepsy an inherited condition?
In many cases, there is no family history of the condition at all. However, it would seem that some types of epilepsy do tend to occur more frequently in some families. Recent research has discovered that some forms of epilepsy have been linked to the inheritance of specific genes.
For example, Juvenile Myoclonic Epilepsy is linked to a gene, which has been located on chromosome six. It is possible to inherit this gene and not have a seizure, which would suggest that even where a person may have a genetic disposition to epilepsy; it does not necessarily mean that epilepsy will develop.
Is epilepsy ever contagious?
No. There is no way you can catch epilepsy from another person.