Recently, we wrote a blog article on the genetic factors of epilepsy. We also mentioned that in many cases there are no genetic factors to epilepsy, which is known as acquired epilepsy.
Acquired epilepsy can be used to describe a number of causes that are not genetic in nature, this means they were not passed down through the family or as a result of genetic mutation.
There are a number of ways that a person without a genetic disposition to epilepsy can acquire it. These include:
Around 30% of people with brain tumours also have epilepsy and up to 60% will experience at least one seizure, which may not be enough for a diagnosis of epilepsy in itself. Tumours in the lobes of the cerebrum (cerebral cortex) or the meninges present an increased risk of developing epilepsy as well as slow growing (low grade) tumours. High grade tumours and those that are deep within the brain or the brainstem are less likely to result in seizures.
Between 2-4% of people who have a stroke will also develop epilepsy. Acute onset seizures may happen within 24 hours of a stroke, however, a single seizure may not result in an epilepsy diagnosis. Strokes are one of the most common causes of epilepsy for the elderly and account for up to 30% of cases. The risk of having a seizure or developing epilepsy is higher for those who have had a severe stroke, a stroke that is caused by bleeding on the brain (haemarrhagic stroke) or a stroke that starts in the cerebral cortex.
Between 6-20% of epilepsy cases are believed to be as a result of head trauma. A minor brain injury can increase the risk of developing epilepsy whilst a severe brain injury can increase the risk much further. For example, someone who survives a gunshot wound to the head is believed to have a 50% chance of developing epilepsy. The underlying cause of the seizure activity is from the scarring on the brain rather than the trauma itself.
Many infections are known to also carry a risk of developing epilepsy. For example, developing epilepsy having meningitis is a risk less than 10%, whereas herpes simplex encephalitis carries a risk closer to 50%. Brain infections such as cerebral malaria, toxoplasmosis and toxocariasis are also associated with the development of epilepsy.
Alzheimer’s disease, multiple sclerosis, tuberous sclerosis and autoimmune encephalitis are also known to carry risk of developing epilepsy.
It’s also worth noting that there is a common myth that vaccinations increase the risk of developing epilepsy. It has been proved to be untrue and we can’t stress enough how important it is to ensure children (and adults) receive the appropriate vaccinations to prevent the spread of disease.