Diseases and Conditions
Grand mal seizure

Updated: 6/10/2014


A grand mal seizure — also known as a generalized tonic-clonic seizure — features a loss of consciousness and violent muscle contractions. It's the type of seizure most people picture when they think about seizures in general.

Grand mal seizure is caused by abnormal electrical activity throughout the brain. Most of the time grand mal seizure is caused by epilepsy. In some cases, however, this type of seizure is triggered by other health problems, such as extremely low blood sugar, high fever or a stroke.

Many people who have a grand mal seizure will never have another one. However, some people need daily anti-seizure medications to control and prevent future grand mal seizure.


Grand mal seizures have two stages:

  • Tonic phase. Loss of consciousness occurs, and the muscles suddenly contract and cause the person to fall down. This phase tends to last about 10 to 20 seconds.
  • Clonic phase. The muscles go into rhythmic contractions, alternately flexing and relaxing. Convulsions usually last for less than two minutes.

The following signs and symptoms occur in some but not all people with grand mal seizures:

  • Aura. Some people experience a warning feeling (aura) before a grand mal seizure. This warning varies from person to person, but may include feeling a sense of unexplained dread, a strange smell or a feeling of numbness.
  • A scream. Some people may cry out at the beginning of a seizure because the muscles around the vocal cords seize, forcing air out.
  • Loss of bowel and bladder control. This may happen during or following a seizure.
  • Unresponsiveness after convulsions. Unconsciousness may persist for several minutes after the convulsion has ended.
  • Confusion. A period of disorientation often follows a grand mal seizure. This is referred to as postictal confusion.
  • Fatigue. Sleepiness is common after a grand mal seizure.
  • Severe headache. Headaches are common but not universal after grand mal seizures.

When to see a doctor

If you see someone having a seizure:

  • Call for medical help.
  • Gently roll the person onto one side and put something soft under his or her head.
  • Loosen tight neckwear.
  • Don't put anything in the mouth — the tongue can't be swallowed and objects placed in the mouth can be bitten or inhaled.
  • Don't try to restrain the person.
  • Look for a medical alert bracelet, which may indicate an emergency contact person and other information.
  • Note how long the seizure lasts.

A grand mal seizure lasting more than five minutes, or immediately followed by a second seizure, should be considered a medical emergency in most people. This is also a medical emergency if the person is pregnant, injured or diabetic. Seek emergency care as quickly as possible.

Additionally, seek medical advice for you or your child:

  • When the number of seizures experienced increases significantly without explanation
  • When new signs or symptoms of seizures appear


Grand mal seizures occur when the electrical activity over the whole surface of the brain becomes abnormally synchronized. The brain's nerve cells normally communicate with each other by sending electrical and chemical signals across the synapses that connect the cells.

In people who have seizures, the brain's usual electrical activity is altered. Exactly what causes the changes to occur remains unknown in about half the cases.

However, grand mal seizures are sometimes caused by underlying health problems, such as:

Injury or infection

  • Traumatic head injuries
  • Infections, such as encephalitis or meningitis, or history of such infections
  • Injury due to a previous lack of oxygen
  • Stroke

Congenital or developmental abnormalities

  • Blood vessel malformations in the brain
  • Genetic syndromes
  • Brain tumors

Metabolic disturbances

  • Very low blood levels of glucose, sodium, calcium or magnesium

Withdrawal syndromes

  • Using or withdrawing from drugs, including alcohol

Risk factors

Risk factors for grand mal seizures include:

  • A family history of seizure disorders
  • Any injury to the brain from trauma, stroke, previous infection and other causes
  • Sleep deprivation
  • Medical problems that affect electrolyte balance
  • Illicit drug use
  • Heavy alcohol use


Certain activities could be dangerous if you have a seizure while doing them. Activities include:

  • Swimming. If you go in water, wear a life preserver and don't go alone.
  • Bathing. Bathing also can pose a risk of drowning. Shower instead.
  • Driving a car or operating other equipment. Most states have licensing restrictions for driving for people with a history of seizures.

The force of a seizure or falling as a result of a seizure can cause injury. In extreme cases, seizures can be fatal, particularly if medication is not taken consistently or properly.

Types of injuries that can occur with seizures include:

  • Joint dislocations
  • Head injuries
  • Bone fractures

Repeated seizures

Whether repeated seizures can cause brain damage has been studied extensively, but there's no simple answer.

The longer a seizure lasts, the more likely it is to lead to changes in brain function and structure. Repeated brief seizures also can lead to brain changes, sometimes causing a normal brain to become epileptic, a process known as kindling.

The seriousness of repeated seizures underscores the need for control with medication.

Preparing for your appointment

You're likely to start by seeing your family doctor or a general practitioner. However, you'll probably be referred to a doctor who specializes in nervous system disorders (neurologist).

It's good to be prepared for your appointment. Here's some information to help you get ready for your appointment, and to know what to expect from your doctor.

What you can do

  • 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 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?
  • Do I need to restrict any activities?
  • 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?

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?
  • Can you describe a typical seizure?
  • How long do the seizures last?
  • 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?

Tests and diagnosis

Medical history

Your doctor will ask for a detailed description of the seizure, which is crucial for diagnosis. Because people who have grand mal seizures lose consciousness and don't remember their seizures, the description needs to come from people who have witnessed the seizures.

Your doctor may try to determine whether a particular trigger, such as intense exercise, loud music, flashing lights (such as those caused by video games or television) or lack of sleep, preceded your seizure. However, most people have no identifiable or consistent trigger.

Neurological exam

If you've had a seizure, your doctor usually will perform a neurological exam that tests:

Muscle condition

  • Reflexes
  • Muscle tone
  • Muscle strength
  • Sensory function

Motor symptoms

  • Gait
  • Posture
  • Coordination
  • Balance

He or she may also ask questions to assess your thinking, judgment and memory.

Blood tests and scans

Blood tests may be ordered as appropriate to check for problems that could be causing or triggering the seizures.

Your doctor may also suggest scans or tests designed to detect abnormalities within the brain.

  • Electroencephalogram (EEG). An EEG displays the electrical activity of your brain via electrodes affixed to your scalp. People with epilepsy often have changes in their normal pattern of brain waves, even when they're not having a seizure.

    In some cases, your doctor may recommend video-EEG monitoring, which may require a hospital stay. This allows your doctor to compare — second by second — the behaviors observed during a seizure with your EEG pattern from exactly that same time.

    This comparison can help your doctor pinpoint the type of seizure disorder you have, which helps identify the most appropriate treatment options, and it can help make sure that the diagnosis of seizures is correct.

  • Brain imaging. Computerized tomography (CT) scan and magnetic resonance imaging (MRI) produce detailed images of your brain and may reveal tumors, cysts and structural abnormalities.

    During a CT scan or an MRI, you will lie on a padded table that slides into a machine. Your head will be immobilized in a brace, to improve precision while images of your brain are taken.

Treatments and drugs

Not everyone who has one seizure will have another one, and because a seizure can be an isolated incident, your doctor may decide to 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, such as:

  • Carbamazepine (Carbatrol,Tegretol, others)
  • Phenytoin (Dilantin, Phenytek)
  • Valproic acid (Depakene)
  • Oxcarbazepine (Trileptal)
  • Lamotrigine (Lamictal)
  • Gabapentin (Gralise, Neurontin)
  • Topiramate (Topamax)
  • Phenobarbital
  • Zonisamide (Zonegran)
  • Levetiracetam (Keppra)
  • Tiagabine (Gabitril)
  • Pregabalin (Lyrica)
  • Felbamate (Felbatol)
  • Ethosuximide (Zarontin)
  • Lorazepam (Ativan)
  • Clonazepam (Klonopin)
  • Clobazam (Onfi)
  • Rufinamide (Banzel)
  • Perampanel (Fycompa)

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 by taking only one drug, but others require 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:

  • Fatigue
  • Dizziness
  • 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.

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.

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

It's also important to know that some anti-seizure medications can alter the effectiveness of oral contraceptive (birth control) 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.

Lifestyle and home remedies

If you have a seizure disorder, wear a medical bracelet to help emergency medical personnel. The bracelet should state whom to contact in an emergency, what medications you use and what drugs you're allergic to.

Coping and support

Even after they're under control, seizures can affect your life. Grand mal seizures can be frightening to those around you.

Children may get teased or be embarrassed by their condition, and both children and adults may be frustrated by living with the constant threat of another seizure. Poor self-esteem, depression and suicide are increased in people who have repeated seizures.

Most states restrict those who've had seizures from driving until they've gone a long time without a seizure. Even recreational activities can be affected, because you can't do certain activities, such as swimming, alone.

You may find it helpful to talk with other people who are in the same situation you are. Besides offering support, they may also have advice or tips for coping that you'd never considered.

The Epilepsy Foundation has a network of support groups, as well as online forums, for teens and adults who have seizures and for parents of children who have seizures. You can reach the Epilepsy Foundation at 800-332-1000 or through its website.

You can also ask your doctor if he or she knows of any support groups in your area.

Content from Mayo Clinic