The brain contains billions of nerve cells — called neurons — that communicate with one another by sending and receiving electrical signals. A seizure occurs when large groups of neurons fire at the same time and produce abnormal electrical activity — an “electrical storm” — that interrupts normal brain function. This sudden, temporary interruption in brain activity causes changes in behavior, sensation, movements, or awareness.

Brain damage is an injury to brain tissue that affects a person’s physical, emotional, or behavioral health and is caused by a head injury, an illness, or a condition. Typically, an isolated seizure does not lead to lasting brain damage but sometimes has a negative effect on brain function. However, a person with uncontrolled epilepsy or rare types of epilepsy may be at greater risk of brain damage.

What Causes Brain Damage?

Brain damage occurs when neurons and their connections are destroyed. It is thought that isolated seizures have a negative impact on the brain.

However, researchers in neurology believe that whether an epileptic seizure can cause long-term brain damage depends on several factors, including:

• The type of seizures a person has
• The number of seizures they experience
• The cause of the seizures
• The response of a person’s epilepsy to available treatments

Isolated vs. Repeated Seizures

A seizure is defined as a single event that a person experiences just once or very rarely. Often called “isolated seizures,” these events can result from triggers including low blood sugar, alcohol misuse, high fever, infection, brain tumors, and medications. Isolated seizures typically do not require specific treatment other than managing the underlying medical problem.

Repeated or recurring seizures are defined as two or more seizures occurring within a short period without a provoking factor. When a person has recurring seizures, an isolated seizure with a high risk of recurrence, or a seizure associated with a specific syndrome, they are considered to have epilepsy. Epilepsy often requires medical treatment to manage and control symptoms

How Long Can a Seizure Last Before Causing Brain Damage?

The longer a seizure lasts, the greater the potential for harm. While there isn’t a specific duration that guarantees brain damage, seizures lasting more than five minutes, or recurrent seizures without recovery within that time frame, require urgent medical attention. The type of seizure also plays a role in the risk.

For example, generalized convulsive seizures lasting more than five minutes are considered a medical emergency. Other types of seizures are less likely to cause serious brain injury unless they last for more than 30 minutes.

4 Seizure Types That May Cause Brain Damage

Some seizures listed below are known to cause negative long-term effects on brain function. Here, we discuss four kinds of seizures that put people at an increased risk for brain damage.

1. Refractory (Uncontrolled) Epilepsy

People with refractory seizures are at a higher risk of brain damage compared to those with controlled epilepsy.

Epilepsy can be challenging to treat, and not everyone responds well to antiepileptic drugs. Some individuals develop drug resistance, continuing to experience seizures despite taking medication — this condition is known as “refractory (uncontrolled) epilepsy.”

In the United States, about 33 percent of adults and 20 percent to 25 percent of children with epilepsy have drug-resistant epilepsy.

People with uncontrolled seizures are up to 10 times more likely to have sudden unexplained death in epilepsy.

Uncontrolled epilepsy can also result from misdiagnosis, improperly prescribed or used medications, or lifestyle factors such as a poor diet, high stress, and lack of sleep. If uncontrolled epilepsy doesn’t improve, it can cause brain damage and negatively affect a person’s quality of life.

2. Status Epilepticus

Another group at greater risk of brain damage from seizures includes those who experience episodes of status epilepticus.

A typical seizure lasts from 30 seconds to two minutes. However, in some cases, seizures occur back-to-back without giving the person time to fully recover, leaving them unconscious. When a seizure lasts longer than five minutes, or when recurrent seizures happen without recovery in between, it is called “status epilepticus.” During status epilepticus, neurons can be destroyed, leading to permanent brain injury.

Although status epilepticus is rare, it can occur with any type of epilepsy or seizure. The condition is a medical emergency that may lead to permanent brain damage or death. One study found that people who survive status epilepticus have significant changes in their behavior, learning, and memory. The researchers reported that this result seemed to especially affect children whose brains were still developing.

3. Temporal Lobe Epilepsy

People who experience temporal lobe seizures are at a higher risk for brain damage. Temporal lobe epilepsy often involves seizures that last longer and are more challenging to treat compared to other types.

Studies have shown that prolonged focal impaired awareness seizures in temporal lobe epilepsy — especially when they progress to tonic-clonic seizures — can lead to declines in cognitive functions such as thinking, reasoning, and memory, as well as brain damage. (“Tonic-clonic” refers to the seizures’ two phases.)

In severe cases where medication is ineffective, temporal lobe epilepsy may be treated with epilepsy surgery, which can further complicate the risk of long-term brain damage.

4. Seizures in Children

Seizures in children are more likely to cause brain damage than those in adults, which may be related to the presence of specific epilepsy syndromes.

The brain undergoes significant growth and development from birth through adulthood, with the most critical period occurring during the first eight years. Infants and children with epilepsy are at much higher risk of developmental challenges in cognitive, motor (muscular movement), and psychiatric (mental, emotional, and behavioral) functions. They are also at greater risk of status epilepticus and sudden unexplained death in epilepsy (SUDEP). That’s why, if your infant or child is experiencing seizures, it’s critical to seek medical care right away.

Severe seizures in a developing brain can cause changes in various brain structures and lead to neuron loss, resulting in brain abnormalities. Based on animal studies, researchers believe these changes can sometimes be irreversible, causing permanent brain damage, though some children may recover. Additionally, infants who experience seizures during their first few weeks of life (known as infantile spasms) are at a higher risk of lifelong seizure activity, developmental problems, and even related death.

Consequences of Brain Damage

The effects of uncontrolled epilepsy, prolonged seizures, and recurrent seizures go beyond the injuries or accidents that may occur during the seizure. One risk factor involves damage to neurons, which can lead to brain damage.

Examples of brain damage include:

• Impairment of cognitive processes such as memory and language
• Difficulties with school and learning
• Difficulties with social interactions
• Psychiatric symptoms such as depression or anxiety
• Changes in personality
• Difficulty with balance and coordination
• Repeated severe seizures
• Problems with vision
• Sudden unexpected death in people with poorly controlled seizures

Additionally, a person’s disease progression may begin with focal seizures — affecting just one part of the brain — and later develop to generalized (grand mal) seizures that affect multiple parts or the entire brain. This progression can complicate diagnosis and influence the long-term effects on brain function.

While these potential brain symptoms may seem alarming, it’s important to understand that each person’s experience with epilepsy is unique, and outcomes vary widely. Some people may have multiple seizures with few long-term effects, while others may face serious brain damage.

Treatment Options for Brain Damage

There is currently no treatment or cure for brain injury or brain cell death, but researchers in health care are studying ways to regenerate brain cells using stem cell therapy. This approach involves replacing damaged or lost neurons. It holds promise as an alternative therapy for people with epilepsy, though it remains experimental.

If you’re living with epilepsy, the most important step in avoiding brain damage is to address the underlying cause of the seizure (if known) and achieve seizure control. This involves:

• Following a proper treatment plan
• Adopting a healthy lifestyle to minimize the risk of worsening symptoms and triggering seizures
• Avoiding injuries that could lead to disability or brain damage

If anti-seizure medications, including rescue treatment, don’t help to control your seizures, be sure to read about other treatment options for epilepsy. Prevention of uncontrolled seizures should be the No. 1 priority to reduce the risk of permanent brain damage.

Talk With Others Who Understand

MyEpilepsyTeam is the social network for people with epilepsy and their loved ones. On MyEpilepsyTeam, more than 122,000 members come together to ask questions, give advice, and share their stories with others who understand life with epilepsy.

Do you have or suspect you have brain damage caused by your seizure disorder? Are you taking steps to avoid triggering seizures that could lead to brain injury? Share your experience in the comments below, or start a conversation by posting on your Activities page.