Causes and Risk Factors of Epilepsy

Genetics, brain damage, brain infections, and more

In This Article

Epilepsy is a disorder that's characterized by uncontrolled and disorganized communication between nerve cells in the brain. In around half of the people who are diagnosed with epilepsy, the cause is unknown.

For the other half, the cause may be attributed to one or more specific factors such as genetics, brain injury or damage, structural changes in the brain, certain conditions and illnesses, and developmental disorders.

epilepsy causes
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Common Causes

Epilepsy is a complex disorder with a variety of causes. Anything that disrupts the brain's normal electrical pattern can lead to seizures. Around half of epilepsy cases can be linked to specific factors, including:

  • Genetics
  • Brain damage
  • Brain infections
  • Developmental disorders
  • Structural changes in the brain
  • Alcohol

Genetics

Most genetic epilepsies begin in childhood and are caused by a genetic defect in the ion channels or receptors.

It's important to note that for most people with a genetic form of epilepsy, genes are not the only cause. (Genetics is covered in more detail below.)

Brain Damage

Conditions that cause damage to your brain can cause epilepsy. These include:

  • Stroke
  • Tumors
  • Traumatic head injuries
  • Brain damage that occurs before birth (such as from oxygen deprivation or maternal infection) 

Stroke is the leading cause of epilepsy in adults who are diagnosed after age 65. 

Brain Infections

Some cases of epilepsy are caused by infections that affect and inflame your brain, such as:

  • Meningitis
  • Viral encephalitis
  • Tuberculosis
  • Acquired immunodeficiency syndrome (AIDS)

Developmental Disorders

Epilepsy appears to be more common in people with certain developmental disorders, including:

Structural Changes in the Brain

Certain differences in the structure of your brain can cause seizures, including:

  • Hippocampal sclerosis (a shrunken hippocampus, a part of your brain that plays a major role in learning, memory, and emotions)
  • Focal cortical dysplasia (abnormality of brain development where neurons failed to migrate to their appropriate location)

Alcohol

Some studies have shown that chronic abuse of alcohol may be associated with the development of epilepsy in some people. This research suggests that repeated alcohol withdrawal seizures may make the brain more excitable overtime. In addition, this population also has a higher incidence of traumatic brain injury that can also cause epilepsy.

Genetics

If epilepsy runs in your family, it's most likely due to a genetic component. Some epilepsies with unknown causes may also have a genetic component that's not yet understood.

While some specific genes are linked to certain types of epilepsy, in most cases, genes don't necessarily cause epilepsy—they may just make it more likely to occur under the right circumstances.

If you get a traumatic head injury and you have a family history of epilepsy, for example, you may be more likely to develop it. Genes are only a piece of the complex puzzle for most people.

Several of the specific epilepsy syndromes and types are known to have a genetic component.

Familial Neonatal Epilepsy

Seizures usually start between four and seven days after a baby is born and most stop around six weeks after birth, though they may not stop until 4 months of age. Some babies may end up having seizures later in life as well.

Mutations in the KCNQ2 gene are most often the cause, though mutations in the KCNQ3 gene can also be a factor.

Genetic Epilepsy With Febrile Seizures Plus (GEFS+)

GEFS+ is a spectrum of seizure disorders. Seizures usually start between the ages of 6 months and 6 years when the child has a fever, called a febrile seizure.

Some kids also develop seizures without fever, usually generalized seizures such as absence, tonic-clonic, myoclonic, or atonic. The seizures typically stop during early adolescence.

SCN1A, SCN1B, GABRG2, and PCDH19 are some of the genes that have been linked to GEFS+.

Dravet Syndrome

This syndrome is considered to be on the severe side of the GEFS+ spectrum. Seizures usually begin around the age of 6 months. Many kids with this syndrome have their first seizure when they have a fever.

Myoclonic, tonic-clonic, and atypical absence seizures also develop, which are difficult to control and may get worse as the child gets older. Intellectual disability is common.

More than 80 percent of people with Dravet syndrome have mutations in the sodium channel gene SCN1A.

Ohtahara Syndrome

In this rare syndrome, tonic seizures usually start within the first month after birth, though this may happen up to three months later.

One out of three babies may also develop focal, atonic, myoclonic, or tonic-clonic seizures. While rare, this type of epilepsy can be fatal before the age of 2. Some children may later develop West syndrome or Lennox-Gastaut syndrome.

A number of genes have been associated with Ohtahara syndrome, including STXBP1, SLC25A22, CDKL5, ARX, SPTAN1, PCDH19, KCNQ2, and SCN2A.

Juvenile Myoclonic Epilepsy

One of the most common generalized epilepsies with a genetic component, juvenile myoclonic epilepsy consists of tonic-clonic, absence, and myoclonic seizures that begin any time from the ages of 5 to 16 years. Seizures tend to be well-controlled with medication and seem to improve when you reach your 40s.

The genes associated with this syndrome are CACNB4, GABRA1, GABRD, and EFHC1, though the patterns tend to be complex.

Autosomal Dominant Nocturnal Frontal Lobe Epilepsy

Seizures typically start around the age of 9 years and the majority start by age 20. They occur briefly, multiple times during sleep, and range from simply waking you up to causing screaming, wandering, twisting, crying, or other focal responses.

Though this syndrome is lifelong, seizures won't get any worse and may actually become less frequent and milder with age. They're also usually well-controlled with medication. This epilepsy isn't very common and it's almost always inherited.

Mutations in the nicotinic receptor subunit genes CHRNA4, CHRNB2, CHRNA2, and DEPDC5 have been linked to this syndrome.

Childhood Absence Epilepsy

Absence seizures usually begin between the ages of 2 and 12 years and are often genetic. In around 2 out of 3 children, the seizures stop in adolescence. Some go on to develop other types of seizures.

Genes that are associated with childhood absence epilepsy include GABRG2 and CACNA1A.

Juvenile Absence Epilepsy

This syndrome begins later in life and the seizures tend to last longer than in childhood absence epilepsy. It's also usually a lifelong condition, whereas kids with childhood absence epilepsy tend to outgrow their seizures.

Absence seizures usually start between the ages of 9 and 13 years, though they can begin anywhere from age 8 to 20. Tonic-clonic seizures, typically when waking up, are also seen in around 80 percent of people with this syndrome.

The cause is often genetic, and the genes linked to juvenile absence epilepsy are GABRG2 and CACNA1A, as well as others.

Epilepsy With Generalized Tonic-Clonic Seizures Alone

Tonic-clonic seizures can start anywhere from the age of 5 to 40 years, though most start between 11 and 23. Seizures usually happen within two hours of waking up.

Sleep deprivation, fatigue, alcohol, menstruation, flashing lights, and fever are often triggers, and most people will need medication for their whole lives.

The main gene associated with this syndrome is CLCN2.

Familial Temporal Lobe Epilepsy

If you have focal seizures that begin in the temporal lobe and a family history of similar seizures, you're considered to have this syndrome. The seizures tend to be fairly rare and mild; so mild, in fact, that they may not be recognized.

Seizures usually start after age 10 and are easily controlled with medication.

The associated gene in this hereditary epilepsy is DEPDC5.

Familial Focal Epilepsy With Variable Foci

This inherited epilepsy typically consists of one specific type of focal seizure. Those in a family who have epilepsy all have one single type of focal seizure, but the seizures may start in different parts of their brains.

The seizures are typically easy to control with medication and are usually infrequent.

The DEPDC5 gene is also linked to this syndrome.

West Syndrome

Infantile spasms begin in the first year of life and usually stop between the ages of 2 and 4 years.

Abnormalities in the genes ARX, CDKL5, SPTAN1, and STXBP1 have been found in this syndrome, though other causes include brain structural abnormalities, sometimes genetic in nature, and chromosomal abnormalities.

Benign Rolandic Epilepsy

Also known as childhood epilepsy with centrotemporal spikes, this syndrome affects around 15 percent of children with epilepsy and is more common in kids with close relatives who have epilepsy. Most outgrow it by the age of 15 years.

The gene associated with this syndrome is GRIN2A, though this is another case where the genetic pattern is extremely complex.

Risk Factors

The most common risk factors for epilepsy include:

  • Age: Though it can start at any age, epilepsy tends to show up more often in children and older adults.
  • Family history: If anyone in your family has epilepsy, your risk of developing it may be higher.
  • History of head injuries: Seizures can develop hours, days, months, or even years after head trauma, and the risk may be higher if you also have a family history of epilepsy.
  • Seizures in childhood: If you had a prolonged seizure or another neurological condition in childhood, your risk for epilepsy is higher. This doesn't include febrile seizures, which occur when you have a high fever, unless your febrile seizures were abnormally long.
  • Birth factors: If you were small at birth; you were deprived of oxygen at any point before, during, or after your birth; you had seizures within the first month after you were born; or you were born with abnormalities in your brain, your risk of epilepsy is higher.

Seizure Triggers

Certain circumstances or situations may increase the likelihood that you'll have a seizure. These are known as triggers and if you're able to figure out what yours are, that information can help you manage and potentially prevent more seizures.

Factors that may contribute to seizures include:

  • Sleep deprivation, whether it's disrupted or missed
  • Missing or skipping your medication
  • Being sick, with or without a fever
  • Feeling stressed
  • Any medications, whether over-the-counter, prescription, or nutritional supplements, that may interfere with the effectiveness of your seizure medication
  • Not getting enough vitamins and minerals
  • Low blood sugar
  • Menstrual cycles and/or hormonal changes such as puberty and menopause
  • Flashing lights or specific visual patterns, such as in video games (photo convulsive epilepsy)
  • Certain foods, activities, or noises
  • Heavy alcohol use or withdrawing from alcohol
  • Using recreational drugs

A Word From Verywell

Most risk factors for epilepsy are out of your control or difficult to control. If you believe you're at high risk, you may want to limit how much alcohol you drink and be especially cautious when it comes to head injuries.

No matter the cause of epilepsy, you have a lot of options for controlling your seizures, which can help you live a full life.

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