Epilepsy is a disease in which nerve cells in the brain do not work correctly. When the nerve cells do not work, a seizure may happen. Different types of seizures result when nerves in the brain misfire. Many things can cause epilepsy, such as:1,2
- Genetics
- Infection
- Brain tumor
- Stroke
- Head injury
Only half of people with epilepsy find a specific cause for their disease. Often, a person’s epilepsy is as unique as they are.2,3
Age-related conditions
Certain types of epilepsy are more common in different age groups. For example, epilepsy that follows a stroke is more common in people over 65. Older adults are also more likely to have dementia (such as Alzheimer's disease), which can cause changes in the brain. These changes can cause seizures.2
In newborns, epilepsy may be caused by:2
- Lack of oxygen during birth
- Problems with blood sugar or electrolytes
- Bleeding in the brain
- Drug use by the mother
Fevers and infections can cause seizures in older children. And 1 in 3 children with autism spectrum disorder may also have epilepsy.2
People of all ages can have a head injury, which may also be called traumatic brain injury (TBI). Young adults are most likely to have severe head injuries that lead to epilepsy.2
Brain damage
Anything that damages tissues of the brain can lead to epilepsy. This includes:1,4,5
- Stroke
- Traumatic brain injury from falls, combat, or car accidents
- Infections such as meningitis or encephalitis
- Brain tumors
- Brain diseases like Alzheimer’s
These types of epilepsy may be called structural epilepsy. Structural epilepsy occurs when something has changed the structure of the brain. This change in structure causes seizures.6
Structural epilepsy may also happen because a genetic mutation (change) has caused someone’s brain to have a different structure than it would otherwise.6
Autoimmune epilepsy
Our immune system works to protect the body from invaders like viruses, fungi, and bacteria. Antibodies are proteins made in our bodies to protect us from invaders. Sometimes, these antibodies lose their ability to tell harmful invaders from healthy cells. When antibodies attack brain cells, it can cause autoimmune epilepsy. Sometimes, tumors or infections can trigger these antibodies.7
New onset seizures are seizures that happen for the first time. Doctors believe 5 to 35 percent of people with sudden, severe seizures have autoimmune epilepsy. This may be caused by:1,7
- An autoimmune disease like rheumatoid arthritis, thyroiditis, Crohn’s disease, ulcerative colitis, multiple sclerosis, and lupus
- Cancer
People with autoimmune epilepsy are also more likely to have a close relative with an autoimmune disease.7
Gene changes (mutations)
Many people wonder: Is epilepsy genetic, or does it run in families? The answer: Sometimes.
Genes tell specific cells in the body what to do. Sometimes these genes change, and those changes lead to a disease like epilepsy. These genetic changes may be inherited or may happen for the first time in a person with a new mutation.8
Epilepsy may be caused by many different genetic changes. Genetic testing has helped doctors find specific changes in genes tied to epilepsy. As of mid-2020, this included the genes:9
- ALDH7A1
- ARX
- CACNA1A
- CDKL5
- CHD2
- CHRNA4
- CLN2 and other CLN genes
- DNM1
- Dup 15q
- FOLR1
- FOXG1
- GABRA1
- GRIN2A
- GRIN2B
- HCN1
- KCNQ2 and Q3
- KCNT1
- LGI1
- MEF2C
- PCDH19
- Phelan McDermid
- POLG1
- PRRT2
- PTEN
- Rett-MECP2
- Ring 14
- Ring chromosome 20
- SCN1A
- SCN2A
- SCN8A-related genes
- SLC13A5
- SLC25A22
- SLC6A1
- SPTAN1
- STRADA
- STXBP1
- SYNGAP
- TBCK-related ID
- WWOX
Some diseases with genetic causes that are tied to epilepsy are:8,9
- Autism spectrum disorder
- Down syndrome
- Angelman syndrome
- Tuberous sclerosis
- Neurofibromatosis
- Glut1 deficiency syndrome
Doctors are still learning how genetics play a role in epilepsy. Some types of epilepsy seem more likely to be passed from parent to child. Other types of epilepsy are less likely to be inherited.