EEG brain activity
An EEG records the electrical activity of your brain via electrodes affixed to your scalp. EEG results show changes in brain activity that may be useful in diagnosing brain conditions, especially epilepsy and other seizure disorders.
During a high-density electroencephalogram (EEG) test, electrodes are placed on your scalp closely spaced together. Like conventional EEG, high-density EEG records brain activity. A high-density EEG test can help your doctor locate the area in your brain where seizures occur.
CT scans allow doctors to see cross-sectional CT scan images (slices) of your body.
Pinpointing seizure location
This example shows SPECT scans taken during and between seizures. The differences represent areas where blood flow increased during the seizure. Once identified, that location is fitted onto an MRI scan of the brain.
After a seizure, your doctor will thoroughly review your symptoms and medical history. Your doctor may order several tests to determine the cause of your seizure and evaluate how likely it is that you'll have another one.
Tests may include:
- A neurological exam. Your doctor may evaluate your behavior, motor abilities and mental function to determine if you have a problem with your brain and nervous system.
- Blood tests. Your doctor may take a blood sample to check your blood sugar levels and look for signs of infections, genetic conditions or electrolyte imbalances.
- Lumbar puncture. If your doctor suspects an infection as the cause of a seizure, you may need to have a sample of cerebrospinal fluid removed for testing.
- An electroencephalogram (EEG). In this test, doctors attach electrodes to your scalp with a paste-like substance. The electrodes record the electrical activity of your brain, which shows up as wavy lines on an EEG recording. The EEG may reveal a pattern that tells doctors whether a seizure is likely to occur again. EEG testing may also help your doctor exclude other conditions that mimic epilepsy as a reason for your seizure. Depending on the details of your seizures, this test may be done at an outpatient visit in the clinic, overnight at home with an ambulatory device or over a few nights in the hospital.
Imaging tests may include:
- Magnetic resonance imaging (MRI). An MRI scan uses powerful magnets and radio waves to create a detailed view of your brain. Your doctor may be able to detect lesions or abnormalities in your brain that could lead to seizures.
- Computerized tomography (CT). A CT scan uses X-rays to obtain cross-sectional images of your brain. CT scans can reveal abnormalities in your brain that might cause a seizure, such as tumors, bleeding and cysts.
- Positron emission tomography (PET). A PET scan uses a small amount of low-dose radioactive material that's injected into a vein to help visualize active areas of the brain and detect abnormalities.
- Single-photon emission computerized tomography (SPECT). A SPECT test uses a small amount of low-dose radioactive material that's injected into a vein to create a detailed, 3D map of the blood flow activity in your brain that happens during a seizure. Doctors may also conduct a type of SPECT test called subtraction ictal SPECT coregistered with MRI (SISCOM), which may provide even more-detailed results. This test is usually done in a hospital with overnight EEG recording.
Magnetic resonance imaging (MRI) uses a magnetic field and radio waves to create clear and detailed cross-sectional images of your head and body.
You don't need to prepare for an MRI. Unless otherwise instructed, eat normally (before the procedure) and if you take medications, continue to do so. Once checked in, you'll likely change into a gown and robe.
Remove all accessories, such as your watch, jewelry and hairpins. Also remove things like wigs, dentures and hearing aids. Tell your MRI technologist if you have metal or electronic devices in your body, because their presence may be a safety hazard. The magnet may disable your electronic device or affect the MR image quality.
Before your exam, the MRI technologist may confirm your health issues and answer any last-minute questions.
Most MRI machines look like a big doughnut. A large magnet is housed within a circular structure. You'll lie down on a table that slides into the opening of the magnet. Depending on where you need magnetic resonance imaging, a small device called a coil may be placed around the body part being examined. The coil receives the magnetic resonance signal.
Your technologist will monitor you from another room, but you can talk with him or her by microphone. In some cases, a friend or family member may stay with you. If you are especially anxious or have claustrophobia, you may be offered a mild sedative.
Magnetic resonance imaging is safe for children, and an adult may stay in the scanning room for reassurance. Young children, toddlers and infants may need sedation since they must remain still throughout the imaging process.
The exam itself is painless, but noisy. You don't feel the magnetic field or radio waves, and there are no moving parts to see. However, the magnet produces repetitive tapping and thumping sounds, so you'll likely be offered earplugs or special metal-free headphones to help block the noise. MRIs that require your head to be in the machine often include a mirror for you to see out.
Here's how an MRI is created. Most machines use tube-shaped magnets. The strong magnetic field is produced by passing an electric current through wire loops inside of the magnet's protective housing. Other coils in the magnet send and receive radio waves.
Once you're positioned inside the magnet, some protons within your body will align with the magnetic field. This is harmless and you won't feel it happening.
Once aligned, these protons respond to low-power radio waves that stimulate signals from your body. The radio waves are generated by specialized radio frequency coils (RF coils), which are antennas designed for medical imaging.
The signal that your body returns is detected by the coils surrounding the specific body part targeted for imaging. A computer processes all the signals and reconstructs a highly detailed image.
The final picture is a composite, three-dimensional representation of your body. Any two-dimensional plane — or slice — can be electronically created and displayed on a computer for interpretation. These images can also be converted from the screen into photographic film for further study.
An MRI exam lasts between 30 and 90 minutes. Because movement can blur the resulting images, remain still and breathe quietly without moving your head or body.
Although not shown in this video, contrast agents are sometimes injected into your veins to enhance the appearance of certain tissues or blood vessels.
Once your MRI is complete, you may be asked to wait until the images are reviewed to make sure that no additional imaging is necessary. If no further studies are required, you'll be released and can resume your regular activities.
Vagus nerve stimulation
In vagus nerve stimulation, an implanted pulse generator and lead wire stimulate the vagus nerve, which leads to stabilization of abnormal electrical activity in the brain.
Deep brain stimulation
Deep brain stimulation involves implanting an electrode deep within your brain. The amount of stimulation delivered by the electrode is controlled by a pacemaker-like device placed under the skin in your chest. A wire that travels under your skin connects the device to the electrode.
Not everyone who has one seizure will have another one, and because a seizure can be an isolated incident, your doctor may not decide to start treatment until 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 for seizures often involves the use of anti-seizure medications. There are many different options for anti-seizure medication. One of the more recent medications approved by the Food and Drug Administration, cannabidiol (Epidiolex), is derived from marijuana. It's approved to treat certain seizures in children age 2 and older.
The goal of medication is to find the medicine that works best for you and that causes the fewest side effects. In some cases, your doctor might recommend more than one medication.
Finding the right medication and dosage can be complex. You may need to try several different medications to find out which best controls your seizures with the fewest side effects. Side effects may include weight gain, dizziness, fatigue and mood changes. More-serious side effects can cause damage to the liver or bone marrow.
Your doctor will consider your condition, your frequency of seizures, your age and other factors when choosing which medication to prescribe. Your doctor will also review any other medications you may be taking, to ensure that the anti-epileptic medications won't interact with them.
Following a diet that's high in fat and very low in carbohydrates, known as a ketogenic diet, can improve seizure control. The ketogenic diet is very strict and can be challenging to follow, as there is a limited range of foods allowed. Variations on a high-fat, low-carbohydrate diet, such as the low glycemic index and modified Atkins diets, though less effective, aren't as restrictive as the ketogenic diet and may provide benefit. These modified diets are still being studied.
If other treatments aren'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 originate in the same place in the brain. There are several types of surgery, including:
- Lobectomy (lesionectomy). Surgeons locate and remove the area of your brain where seizures begin.
- Multiple subpial transection. This type of surgery involves making several cuts in areas of the brain to prevent seizures. It's usually done when the area of the brain where seizures start can't be safely removed.
- Corpus callosotomy. This surgery cuts the network of connections between the neurons of the right and left halves of the brain. This is used to treat seizures that start in one half of the brain and travel to the other half. However, even after surgery, seizures may still occur on the side of the brain where they started.
- Hemispherectomy (hemispherotomy). This surgery removes half of the outer layer of the brain. This is an extreme type of surgery that is only used when medications aren't effective in managing seizures and seizures affect only half of the brain. Many daily functional abilities may be lost after this surgery, but children can often recover those abilities with significant rehabilitation.
- Thermal ablation (laser interstitial thermal therapy). This less invasive surgical procedure focuses highly concentrated energy at a specific target in the brain where seizures begin and destroys the brain cells that cause seizures.
Other procedures that may offer seizure relief include:
- Vagus nerve stimulation. A device implanted underneath the skin of your chest stimulates the vagus nerve in your neck, sending signals to your brain that inhibit seizures. With vagus nerve stimulation, you may still need to take medication, but you may be able to lower the dose.
- Responsive neurostimulation. During responsive neurostimulation, a device implanted on the surface of your brain or within brain tissue can detect seizure activity and deliver an electrical stimulation to the detected area to stop the seizure.
- Deep brain stimulation. Doctors implant electrodes within certain areas of your brain to produce electrical impulses that regulate abnormal brain activity. The electrodes attach to a pacemaker-like device placed under the skin of your chest, which controls the amount of stimulation produced.
Pregnancy and seizures
Women who've had previous seizures typically are able to have healthy pregnancies. Birth defects related to certain medications can sometimes occur.
In particular, valproic acid — one possible medication for generalized seizures — has been associated with cognitive deficits and neural tube defects, such as spina bifida. The American Academy of Neurology recommends that women avoid using valproic acid during pregnancy because of risks to their babies. Discuss these risks with your doctor. Because of the risk of birth defects and because pregnancy can alter medication levels, preconception planning is particularly important for women who've had seizures.
In some cases, it may be appropriate to change the dose of seizure medication before or during pregnancy. Women should work closely with their doctors before becoming pregnant with the goal of being on the lowest necessary dose of the safest seizure medication that is effective for seizure control.
Contraception and anti-seizure medications
Some anti-seizure medications can alter the effectiveness of birth control (oral contraceptive) medication. If contraception is a high priority, check with your doctor to evaluate whether your medication interacts with your oral contraceptive, and if other forms of contraception need to be considered.
Explore Mayo Clinic studies testing new treatments, interventions and tests as a means to prevent, detect, treat or manage this condition.
Lifestyle and home remedies
Here are some steps you can take to help with seizure control:
- Take medication correctly. Don't adjust the dosage before talking to your doctor. If you feel that your medication should be changed, discuss it with your doctor.
- Get enough sleep. Lack of sleep can trigger seizures. Be sure to get adequate rest every night.
- Wear a medical alert bracelet. This will help emergency personnel know how to treat you correctly if you have another seizure.
- Be active. Exercising and being active may help keep you physically healthy and reduce depression. Make sure to drink enough water and rest if you get tired during exercise.
- Make healthy life choices. Managing stress, limiting alcoholic beverages and avoiding cigarettes all factor into a healthy lifestyle.
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:
- Take care near water. Don't swim alone or relax in a boat without someone nearby.
- Wear a helmet for protection during activities such as bike riding or sports participation.
- Take showers instead of baths, unless someone is near you.
- Modify your furnishings. Pad sharp corners, buy furniture with rounded edges and choose chairs that have arms to keep you from falling off of them. Consider carpet with thick padding to protect you if you do fall.
- Display seizure first-aid tips in a place where people can easily see them. Include any important phone numbers there, too.
Seizure first aid
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:
- Carefully roll the person onto one side
- Place something soft under his or her head
- Loosen tight neckwear
- Avoid putting your fingers or other objects in the person's mouth
- Don't try to restrain someone having a seizure
- Clear away dangerous objects if the person is moving
- Stay with the person until medical personnel arrive
- Observe the person closely so that you can provide details on what happened
- Time the seizure
- Stay calm
Coping and support
If you're living with a seizure disorder, you may feel anxious or stressed about what your future holds. Stress can affect your mental health, so it's important to talk with your health care professional 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 seizure disorder. Let them know they can ask you questions, and be open to conversations about their worries. Help them understand your condition by sharing any educational materials or other resources that your health care professional has given you.
Meet with your supervisor and talk about your seizure disorder and how it affects 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 seizure disorders — you can widen your support system and bring about acceptance and understanding.
You're not alone
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.
Preparing for your appointment
In some cases, seizures need immediate medical attention, and there's not always time to prepare for an appointment.
In other cases, your first appointment to evaluate a seizure may be with your family doctor. Or you may be referred to a specialist, such as a doctor trained in brain and nervous system conditions (neurologist) or a neurologist trained in epilepsy (epileptologist).
To prepare for your appointment, consider what you can do to get ready, and understand what to expect from your doctor.
What you can do
- Record information about the seizure. Include the time, location, symptoms you experienced and how long it lasted, if you know these details. Seek input from anyone who may have seen the seizure, such as a family member, friend or co-worker, so that you can record information you may not know.
- Be aware of any pre-appointment restrictions. At the time you make the appointment, ask if there's anything you need to do in advance to be ready for any medical tests or exams.
- Write down key personal information, including any major stresses or recent life changes.
- Make a list of all medications, vitamins or supplements that you're taking, including dosages.
- Take a family member or friend along, to help you remember all the information provided during an appointment. Also, because you may not be aware of everything that happens when you're having a seizure, your doctor may want to ask questions of someone who was a witness.
- Write down questions to ask your doctor. Preparing a list of questions will help you make the most of your time with your doctor.
For seizures, some basic questions to ask your doctor include:
- What do you think caused my seizure?
- Do I need to have any tests done?
- What treatment approach do you recommend?
- What are the alternatives to the primary approach that you're suggesting?
- How likely is it that I might have another seizure?
- How can I make sure that I don't hurt myself if I have another seizure?
- I have these other health conditions. How can I best manage them together?
- Are there any restrictions that I need to follow?
- Should I see a specialist? What will that cost, and will my insurance cover it?
- Is there a generic alternative to the medicine you're prescribing?
- Are there any brochures or other printed material that I can take home with me? What websites do you recommend?
In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment at any time that you don't understand something.
What to expect from your doctor
Your doctor is likely to ask you a number of questions:
- Can you describe your seizure episode?
- Where were you and what happened right before it started?
- Was anyone there to witness what happened?
- What do you remember feeling just before the seizure? What about right after the seizure?
- What symptoms did you experience?
- How long did the seizure last?
- Have you ever had a seizure or other neurological problem in the past?
- Do you have any family members who have been diagnosed with a seizure disorder or epilepsy?
- Have you recently traveled outside the country?
Feb. 24, 2021