A seizure is a sudden, uncontrolled burst of electrical activity in the brain. It can cause changes in behavior, movements, feelings and levels of consciousness. Having two or more seizures at least 24 hours apart that don't have a known cause is considered to be epilepsy.
There are many types of seizures, and they have a range of symptoms and severity. Seizure types vary by where they begin in the brain and how far they spread. Most seizures last from 30 seconds to two minutes. A seizure that lasts longer than five minutes is a medical emergency.
Seizures can happen after a stroke or a head injury. They also may be caused by an infection such as meningitis or another illness. Many times, though, the cause is unknown.
Most seizure disorders can be controlled with medicine. However, managing seizures can affect your daily life. You can work with your health care provider to balance seizure control and medicine side effects.
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Symptoms vary based on the type of seizure. They also can range from mild to severe. Seizure symptoms may include:
- Temporary confusion.
- A staring spell.
- Jerking movements of the arms and legs that can't be controlled.
- Loss of consciousness or awareness.
- Cognitive or emotional changes. They may include fear, anxiety or a feeling that you've already lived this moment, known as deja vu.
Health care providers typically classify seizures as focal or generalized. Seizures are classified based on how and where the brain activity causing the seizure began. If providers don't know how the seizures began, they may classify the seizures as unknown onset.
Focal seizures result from electrical activity in one area of the brain. This type of seizure can occur with or without loss of consciousness:
- Focal seizures with impaired awareness. These seizures involve a change or loss of consciousness or awareness that feels like being in a dream. People having these types of seizures may seem awake but they stare into space and don't respond to their environment. They may perform repetitive movements such as hand rubbing, mouth movements, repeating certain words or walking in circles. They may not remember the seizure or even know that it occurred.
Focal seizures without impaired awareness. These seizures may alter emotions. They also may change the way things look, smell, feel, taste or sound. But the seizures don't cause a loss of consciousness.
During these types of seizures, people may suddenly feel angry, joyful or sad. Some people have nausea or unusual feelings that are hard to describe. These seizures may result in trouble speaking and involuntary jerking of a body part such as an arm or a leg. They also may cause sudden sensory symptoms such as tingling, dizziness and seeing flashing lights.
Symptoms of focal seizures may be confused with other disorders of the brain or nervous system. They include migraine, narcolepsy or mental illness.
Seizures that appear to involve all areas of the brain from the time they start are called generalized seizures. Different types of generalized seizures include:
- Absence seizures. Absence seizures, formerly known as petit mal seizures, often occur in children. Absence seizures typically cause a person to stare into space or make subtle body movements such as eye blinking or lip smacking. They usually last for 5 to 10 seconds. These seizures may happen up to hundreds of times a day. They may occur in clusters and can cause a brief loss of awareness.
- Tonic seizures. Tonic seizures cause stiffening of the muscles. These seizures usually affect muscles in the back, arms and legs. People who experience these seizures may lose consciousness and fall to the ground.
- Atonic seizures. Atonic seizures, also known as drop seizures, cause a loss of muscle control. People having this type of seizure may suddenly fall down or drop their head.
- Clonic seizures. Clonic seizures are associated with repeated jerking muscle movements. These seizures usually affect the neck, face and arms on both sides of the body.
- Myoclonic seizures. Myoclonic seizures usually appear as sudden brief jerks or twitches of the arms and legs. There is often no loss of consciousness.
- Tonic-clonic seizures. Tonic-clonic seizures, previously known as grand mal seizures, are the most dramatic type of epileptic seizure. They can cause a sudden loss of consciousness, body stiffening and shaking. They sometimes cause people to lose control of their bladder or to bite their tongue. They may last for several minutes. Tonic-clonic seizures also may start as focal seizures that then spread to involve most or all of the brain.
When to see a doctor
Seek immediate medical help if you have a seizure or if you see someone have a seizure and any of the following occurs:
- The seizure lasts more than five minutes.
- The person isn't breathing after the seizure stops.
- A second seizure follows immediately.
- The seizure is accompanied by a high fever.
- The seizure is accompanied by heat exhaustion.
- The person who had the seizure is pregnant.
- The person who had the seizure has diabetes.
- The seizure resulted in an injury.
If you experience a seizure for the first time, seek medical advice.
Nerve cells in the brain, known as neurons, create, send and receive electrical impulses. This allows the cells to communicate. Anything that disrupts the communication pathways can lead to a seizure. Some types of seizure disorders may be caused by genetic changes.
The most common cause of seizures is epilepsy. But not every person who has a seizure has epilepsy. Sometimes seizures may be caused or triggered by:
- A high fever. When this happens, the seizure is known as a febrile seizure.
- An infection of the brain. This may include meningitis or encephalitis.
- Severe general illness, including a severe infection of COVID-19.
- Lack of sleep.
- Low blood sodium. This can happen with medicine that makes you urinate.
- Certain medicines that treat pain, depression or help people stop smoking . They can make it easier for seizures to happen.
- A new, active brain injury, such as head trauma. It can cause bleeding in an area of the brain or a new stroke.
- The use of legal or illegal drugs that may be sold on the streets, such as amphetamines or cocaine.
- Alcohol misuse, including during times of withdrawal or extreme intoxication.
Having a seizure can sometimes lead to complications that are dangerous for you or others. You might be at risk of:
- Falling. If you fall during a seizure, you can injure your head or break a bone.
- Drowning. If you have a seizure while swimming or bathing, you're at risk of accidental drowning.
- Car accidents. A seizure that causes loss of awareness or the inability to control a vehicle while conscious can be dangerous.
- Pregnancy complications. Seizures during pregnancy pose dangers to people who are pregnant and their babies. And certain anti-seizure medicines increase the risk of birth defects. If you have epilepsy and plan to become pregnant, work with your health care provider. Your provider can adjust your medicines and monitor your pregnancy as needed.
- Emotional health issues. People with seizures are more likely to have depression, anxiety or other emotional health issues. Dealing with the condition and the side effects of anti-seizure medicines can cause these issues.
Feb. 04, 2023