By: Neha Kinariwalla
Epilepsy is actually not a single disease, but multiple disorders that can be caused by many different factors depending on the case. Currently it is believed that there are over thirty different epileptic syndromes and thirty eight different types of seizures (check into the last blog post to clarify the distinction). For over half of the people who have epilepsy, the illness is idiopathic, meaning that there is no identifiable cause to the condition. In the other half, the condition can be a result of various causes.
1. Genetic Causes
The hereditary risk is about 5-20%. Defects in genes may not lead directly to epilepsy but they can change how excited the brain can get and make someone more prone to seizures. Genetics are typically related to generalized seizures. Usually the development of epilepsy requires multiple gene abnormalities in conjunction with an environmental trigger. There is a potential to treat people with epilepsy through gene therapy. Science has been advancing very quickly.
2. Head Trauma
Head injuries have increased drastically over the past decade, with about half a million people in the USA sustaining head injuries major enough to need hospitalization! (D'Ambriosio R., Perucca E., 2004). Although most people with head trauma do not get epilepsy, there are severe cases that result in post-traumatic epilepsy (PTE) . Recovery from this type of seizure can take years due to the fact that brain cells take time to rewire and to grow new connections or replace the ones that were lost from the injury. These weakened connections are prone to seizures and become hyper!
3. Infections & Diseases
Parasitic conditions associated with epilepsy is probably the most common and preventable cause of epilepsy in the world (de Boer H., et. al. 2008). Many studies from Latin America have shown that infection of the brain by a pork tapeworm larvae Taenia solium is a cause of epileptic seizures. Neurocysticercosis is a disease of poverty and underdevelopment. When people eat pork that contains cysticeri, there is a high risk for developing the disease. Seizures are common with multiple lesions, or holes, in the brain. This is a major reason that epilepsy is more common in the developing world than in first world nations. It's quite sad to consider that people who do not have access to proper treatment are the ones who are more prone to the illness.
4. Brain Tumors
Although brain tumors are rare in the general population, they can often cause seizures. Both benign and malignant tumors can cause focal seizures depending on where the tumor is located in the brain. It is the irritated part of the brain that usually starts, or induces, the seizure. These are usually difficult to treat.
Seizures can result from lead, carbon monoxide, and many other poisons. Overdoses on street drugs, antidepressants or other medications can also result in seizures.
This list is by no means exhaustive. The causes of epilepsy are many, but unfortunately the result for all of them is the same stigmatized perception by society. In understanding the different types of seizures and causes, we begin to realize that anyone could have a seizure. 10% of Americans will have a seizure at some point in their lives. All it takes is a little more electrical signaling...
D’Ambrosio R. & Perucca E. "Epilepsy after head injury." Curr Opin Nuerol. 2004 December; 17(6): 731-735.
de Boer HM, Mula M, Sander JW. The global burden and stigma of epilepsy. Epilepsy Behav. 2008 May;12(4):540-6. doi: 10.1016/j.yebeh.2007.12.019. Epub 2008 Feb 14. Review. PubMed PMID: 18280210.
Fisher Robert and Saul Maslah. 2006. “Overview of Epilepsy.” Retrieved July 14, 2013 (http://neurology.stanford.edu/divisions/e_handout.html).
Seizures & Epilepsy. Hope through Research. Retrieved August 19, 2013. (http://www.ninds.nih.gov/disorders/epilepsy/detail_epilepsy.htm).