What Causes Epilepsy?
Epilepsy is a condition when someone develops spontaneous recurrent seizures without any obvious trigger. They are caused due to malformations in the neuronal circuits in the brain that cause increased excitation, leading to convulsions. Think about the brain as an electrical grid, full of wires and connections. Any issues with the system by the wires either being exposed or short circuited causing increased firing of the wires. They could occur in specific ways causing specific changes in motions of limbs, face or affect the entire body causing generalized convulsions. Depending on these differences, epilepsy falls mainly in one of two categories
- Focal epilepsy – electrical discharge in a small part of the brain, of one half of the brain.
- Generalized epilepsy – electrical discharge in both hemispheres, that involves loss of consciousness.
- Focal seizures that lead to secondary generalized seizures start in one area one hemisphere and then spreads throughout.
Can Epilepsy Happen Alone?
Epilepsy is a condition that can develop alone or can occur in conjunction with another illness or a syndrome when a combination of symptoms happen together and epilepsy is one of them. 1 in 26 people will have seizures in their lifetime and 1 in 100 people suffer from epilepsy. It can affect people at any age, but mostly affects people at the extremes of age, meaning it can affect incredibly young or elderly people.
The Classified Causes of Epilepsy
The causes of epilepsy can be classified according to genetic, structural, metabolic, immune, infectious and unknown causes.
Genetic Causes
Genetic means there is one gene that is controlling the electricity in the brain which is affected, that can be newly mutated in an individual or inherited from parent to child. Therefore, you may sometimes see a family where several family members have epilepsy. The genetic causes usually cause generalized epilepsy such as Juvenile myoclonic epilepsy and it can in some cases cause focal epilepsy. We now can test for genes much easier thanks to genome sequencing and we have multiple epilepsy panels and markers of epilepsy being discovered every day. Genetic causes are a common cause of epilepsy in children and younger patients.
Structural Causes
Structural deformities can take place within the brain that can cause epilepsy. They are congenital, which means they form before the individual is born. The structural deformities that can occur are cortical dysplasia, where the cells arrange abnormally, heterotopia, where the brain cells that are on the outside are abnormally below the surface of the brain. Sometimes these structural changes can occur due to things that happen after birth, such as stroke and trauma to the brain or can be caused due to the growth of a tumor, an infection, due to the formation of a brain abscess and a condition known as hippocampal sclerosis that replaces brain tissue with scar tissue.
Metabolic Causes
Metabolic causes are related to the biochemical processes that happen within the neurons. They can be related to important brain functions such as glucose transporter, creatinine deficiency or mitochondrial issues and accumulation of toxins or lack of some compounds can lead to seizures.
Immune Causes
Issues related to the immune system can cause inflammation in the brain that leads to seizures. These are considered autoimmune disorders when the immune system gets confused and attacks the brain. This can be without obvious cause such as Rasmussen’s encephalitis and sometimes it can be triggered by a cancer that activates the immune system to fight the cancer and attacks the brain and this is called paraneoplastic encephalitis.
Infectious Causes
When microorganisms invade the brain and cause infections, it can cause seizures. It can happen while the infection is at its early stages, and also after the infection when the damage caused by the infection heals and causes scar tissue formation. COVID-19 infection can lead to seizures as shown in our own studies. Globally, infections are the leading cause of epilepsy such as HIV, Neurocysticercosis, Malaria, and Tuberculosis.
Can there be No Cause?
Not being able to find the cause of epilepsy is a common occurrence. You can have epilepsy after everything is normal, including brain scans, or even if there is no history of trauma to the brain or any family history and no obvious genetic causes. This is possible as epilepsy is a clinical diagnosis.
Conclusion
Epilepsy is a treatable condition, and finding a specific cause for it, leads to better and more effective treatment options, leading to better control of seizures.