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 an EEG, flat metal discs (electrodes) are attached to your scalp. In a high-density EEG, shown here, the electrodes are closely spaced together. The electrodes are connected to the EEG machine with wires. Some people wear an elastic cap fitted with electrodes, instead of having the adhesive applied to their scalps.
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:
- Neurological exam. Your doctor may test 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 for signs of infections, genetic conditions, blood sugar levels 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.
- 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.
- Computerized tomography (CT) scan. 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.
- Magnetic resonance imaging (MRI). An MRI 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.
- Positron emission tomography (PET). PET scans use 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, 3-D map of the blood flow activity in your brain that happens during a seizure. Doctors may also conduct a form of a SPECT test called subtraction ictal SPECT coregistered to magnetic resonance imaging (SISCOM), which may provide even more-detailed results.
Not everyone who has one seizure has another one. Because a seizure can be an isolated incident, your doctor may not start treatment until you've had more than one. Treatment usually involves the use of anti-seizure medications.
Many medications are used in the treatment of epilepsy and seizures, including:
- Carbamazepine (Carbatrol, Tegretol, others)
- Phenytoin (Dilantin, Phenytek)
- Valproic acid (Depakene)
- Oxcarbazepine (Oxtellar, Trileptal)
- Lamotrigine (Lamictal)
- Gabapentin (Gralise, Neurontin)
- Topiramate (Topamax)
- Zonisamide (Zonegran)
Finding the right medication and dosage can be challenging. Your doctor likely will first prescribe a single drug at a relatively low dosage, and then increase the dosage gradually until your seizures are well-controlled.
Many people with epilepsy are able to prevent seizures with just one drug, but others need more than one. If you've tried two or more single-drug regimens without success, your doctor may recommend trying a combination of two drugs.
To achieve the best seizure control possible, take medications exactly as prescribed. Always call your doctor before adding other prescription medications, over-the-counter drugs or herbal remedies. And never stop taking your medication without talking to your doctor.
Mild side effects of anti-seizure medications can include:
- Weight gain
More-troubling side effects that need to be brought to your doctor's attention immediately include:
- Mood disruption
- Skin rashes
- Loss of coordination
- Speech problems
- Extreme fatigue
In addition, the drug Lamictal has been linked to an increased risk of aseptic meningitis, an inflammation of the protective membranes that cover the brain and spinal cord that's similar to bacterial meningitis.
Surgery and other therapies
When anti-seizure medications aren't effective, other treatments may be an option:
- Surgery. The goal of surgery is to stop seizures from happening. Surgeons locate and remove the area of your brain where seizures begin. Surgery works best for people who have seizures that always originate in the same place in their brains.
- 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.
- Dietary therapy. Following a diet that's high in fat and low in carbohydrates, known as a ketogenic diet, can improve seizure control. 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.
Pregnancy and seizures
Women who've had previous seizures usually are able to have healthy pregnancies. Birth defects related to certain medications can sometimes occur.
In particular, valproic acid 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 the baby. It's especially important to avoid valproic acid during the first trimester of pregnancy, if possible.
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. Medications may be switched in rare cases.
Contraception and anti-seizure medications
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.
It's also important to know that some anti-seizure medications can alter the effectiveness of oral contraceptives — a form of birth control — and some oral contraceptives can speed up the absorption of seizure medications. 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 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.
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 the chair. 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:
- Carefully roll the person onto one side
- Place something soft under his or her head
- Loosen tight neckwear
- Remove eyeglasses
- 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
- Check for a medical alert bracelet or ID
- 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 provider about your feelings and seek ways you can find help.
Your family 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 provider 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 provider 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 a general practitioner. 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.
- Write down any symptoms you or your child has experienced, including any that may seem unrelated to the reason for which you scheduled the appointment.
- Make a list of all medications, vitamins and supplements you're taking and the dosages used. Also, write down the reasons you stopped taking any medications, whether this was because of side effects or lack of effectiveness.
- Ask a family member to come with you to the doctor, because it's not always easy to remember everything you've been told during your appointment. Also, since memory loss can happen during seizures, many times an observer is able to better describe the seizure than is the person who's had the seizure.
- 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 a grand mal seizure, some basic questions to ask your doctor include:
- Do I have epilepsy?
- Will I have more seizures?
- What kinds of tests do I need? Do these tests require any special preparation?
- What treatments are available and which do you recommend?
- What types of side effects can I expect from treatment?
- Are there any alternatives to the primary approach you're suggesting?
- Is there a generic alternative to the medicine you're prescribing?
- Do I need to restrict any activities?
- Are there any brochures or other printed material that I can take home with me? What websites do you recommend?
Don't hesitate to ask any other questions that occur to you.
What to expect from your doctor
Your doctor is likely to ask you a number of questions, such as:
- When did you or your child begin experiencing symptoms?
- How many seizures have you or your child had?
- How often do the seizures occur? How long do they last?
- Can you describe a typical seizure?
- Do the seizures occur in clusters?
- Do they all look the same, or are there different seizure behaviors you or others have noticed?
- What medications have you or your child tried? What doses were used?
- Have you tried combinations of medications?
- Have you noticed any seizure triggers, such as sleep deprivation or illness?
Feb. 24, 2021