Learn about the different types of seizures and what causes them. Also find out what to do if you see someone having a seizure.
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 seizures can be controlled with medicine. However, managing seizures can affect your daily life. You can work with your health care professional to balance seizure control and medicine side effects.
Symptoms vary based on the type of seizure. They also can range from mild to severe. Seizure symptoms may include:
A classification system distinguishes the different types of seizures. Health care professionals typically classify seizures as focal or generalized. Seizures are classified based on how and where the brain activity causing the seizure began. If health care professionals 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 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 conditions 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:
Seizures can have a beginning phase, middle phase and end phase.
Prodrome. This is the earliest warning that a seizure may occur, but it is not part of the seizure itself. During the prodrome, people may have a hard-to-describe sense that a seizure may happen. They also may have changes in behavior. This can happen in the hours or even days before a seizure.
The prodrome stage may include an aura. The aura is the first symptom of a seizure. Symptoms during the aura may include the feeling that a person or place is familiar, known as deja vu, or a feeling that a person or place is not familiar. Or people may simply feel strange, feel fear or panic, or even have pleasant feelings. Symptoms also may include smells, sounds, tastes, blurred vision or racing thoughts. The prodrome may include a headache, numbness or tingling, nausea, or dizziness.
Many people with seizures have a prodrome or aura as part of their experience, but some people do not.
Postictal. This is the period after a seizure during recovery. The postictal stage can last minutes or hours. Some people recover quickly while others take hours. The length of the postictal stage depends on the type of seizure and what part of the brain was affected.
During this phase, people may be slow to respond, have trouble with memory, and have trouble talking or writing. They may feel sleepy, confused, dizzy, sad, scared, anxious or frustrated. They also may have nausea, a headache, weakness, feel thirsty or have a loss of bladder control.
Seek immediate medical help if you have a seizure or if you see someone have a seizure and any of the following occurs:
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 seizures 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:
Having a seizure can sometimes lead to complications that are dangerous for you or others. You might be at risk of:
After a seizure, a health care professional thoroughly reviews your symptoms and medical history. You may need several tests to determine the cause of your seizure and evaluate how likely it is that you'll have another one.
Tests may include:
An electroencephalogram (EEG). In this test, electrodes attached to your scalp record the electrical activity of your brain. The electrical activity shows up as wavy lines on an EEG recording. The EEG may reveal a pattern that tells whether a seizure is likely to occur again.
EEG testing also may help exclude other conditions that mimic epilepsy. Depending on the details of your seizures, this test may be done at a clinic, overnight at home or over a few nights in the hospital.
Imaging tests may include:
Single-photon emission computed tomography (SPECT). A SPECT test uses a small amount of low-dose radioactive material that's injected into a vein. The test creates a detailed 3D map of the blood flow in your brain that happens during a seizure.
A health care professional also may conduct a type of SPECT test called subtraction ictal SPECT coregistered to MRI (SISCOM). The test may provide even more-detailed results. This test is usually done in a hospital with overnight EEG recording.
An EEG records the electrical activity of the brain via electrodes affixed to the scalp. EEG results show changes in brain activity that may be useful in diagnosing brain conditions, especially epilepsy and other conditions that cause seizures.
Not everyone who has one seizure will have another one. Because a seizure can be an isolated incident, you may not need to start treatment unless you've had more than one.
The optimal goal in seizure treatment is to find the best possible therapy to stop seizures, with the fewest side effects.
Treatment of seizures often involves the use of anti-seizure medicines. There are many different options for anti-seizure medicines. Most people with epilepsy will stop having seizures after trying just one or two medicines.
The goal of medicine is to find what works best for you and causes the fewest side effects. Sometimes a health care professional might recommend more than one medicine.
Finding the right medicine and dosage can be complex. You may need to try several different medicines. Common side effects may include weight changes, dizziness, fatigue and mood changes. Very rarely, more-serious side effects can cause damage to the liver or bone marrow.
A health care professional considers your condition, how often you have seizures, your age and other factors when choosing which medicine to prescribe. The care professional also will review any other medicines you may be taking to ensure that the anti-seizure medicines won't interact with them.
Following a ketogenic diet can improve seizure control. A ketogenic diet is high in fat and very low in carbohydrates. But it can be challenging to follow because there's a limited range of foods allowed.
Variations on a high-fat, low-carbohydrate diet also may be helpful but less effective. They include low glycemic index and Atkins diets. These modified diets are still being studied.
If treatment with at least two anti-seizure medicines isn't effective, surgery may be an option. The goal of surgery is to stop seizures from happening. Surgery works best for people who have seizures that always begin in the same place in the brain. There are several types of surgery, including:
If the area of the brain where seizures start is unable to be removed or disconnected, devices that provide electrical stimulation may help. They can reduce seizures along with continued anti-seizure medicine use. Stimulation devices that may offer seizure relief include:
Women who've had seizures typically are able to have healthy pregnancies. But birth defects related to certain medicines can sometimes occur.
In particular, valproic acid — a medicine for generalized seizures — has been associated with cognitive deficits and neural tube defects, such as spina bifida, in babies. The American Academy of Neurology recommends that women don't use valproic acid during pregnancy because of risks to their babies.
Discuss these risks with your health care team. Creating a plan with your health care team before you become pregnant is particularly important. In addition to the risk of birth defects, pregnancy can alter your medicine levels.
In some cases, it may be appropriate to change the dose of seizure medicine before or during pregnancy. The goal is to be on the lowest dose of the safest seizure medicine that is effective for seizure control.
Taking folic acid before pregnancy may help prevent some complications related to taking anti-seizure medicines while pregnant. Folic acid is found in standard prenatal vitamins. It's recommended that all people of childbearing age take folic acid while on anti-seizure medicines.
Some anti-seizure medicines can alter the effectiveness of birth control. Ask your health care professional if your medicine may interact with your birth control. Other forms of birth control may need to be considered.
Researchers are studying other potential therapies to treat seizures. They include therapies to stimulate the vagus nerve, other cranial nerves or the brain without surgery.
One area of research showing promise is MRI-guided focused ultrasound. The therapy involves pointing ultrasound beams, which are sound waves, to an area of the brain that's causing the seizures. The beam creates acoustic energy to destroy brain tissue in a targeted way without surgery. This type of therapy can reach deeper brain structures. It also can focus on a target without damaging the nearby tissue.
In vagus nerve stimulation, an implanted pulse generator and lead wire stimulate the vagus nerve, which leads to stabilization of irregular electrical activity in the brain.
Here are some steps you can take to help with seizure control:
Seizures don't usually result in serious injury, but if you have recurrent seizures, injury is a possibility. These steps can help you avoid injury during a seizure:
It's helpful to know what to do if you witness someone having a seizure. If you're at risk of having seizures in the future, pass this information along to family, friends and co-workers so that they know what to do if you have a seizure.
To help someone during a seizure, take these steps:
Stress due to living with a seizure disorder can affect your mental health. It's important to talk with your health care provider about your feelings and seek ways you can find help.
Your family members can provide much-needed support. Tell them what you know about your seizures. Let them know they can ask you questions, and be open to conversations about their worries. Help them understand your condition by sharing educational materials or other resources that your health care professional has given you.
Meet with your supervisor and talk about your seizures and how they affect you. Discuss what you need from your supervisor or co-workers if a seizure happens while at work. Consider talking with your co-workers about seizures. This will help widen your support system and bring about acceptance and understanding.
Remember, you don't have to go it alone. Reach out to family and friends. Ask your health care professional about local support groups or join an online support community. Don't be afraid to ask for help. Having a strong support system is important to living with any medical condition.
Sometimes seizures need immediate medical attention, and there's not always time to prepare for an appointment.
Other times, your first appointment to evaluate a seizure may be with your health care professional. Or you may be referred to a specialist. You might see a specialist trained in brain and nervous system conditions, known as a neurologist. Or you might be referred to a neurologist trained in epilepsy, known as an epileptologist.
To prepare for your appointment, consider what you can do to get ready. Also understand what to expect.
For seizures, some basic questions to ask your health care professional include:
In addition to the questions that you've prepared, don't hesitate to ask any other questions you may have during your appointment and anytime that you don't understand something.
A health care professional is likely to ask you a number of questions: