Tonic-Clonic (Grand Mal) Seizure: Symptoms, Outlook, and More

Medically Reviewed By Nancy Hammond, M.D.

Grand mal seizures are now known as tonic-clonic seizures. Per their name, they occur when someone experiences both tonic and clonic symptoms. ‘Tonic’ refers to muscle stiffness, and ‘clonic’ refers to uncontrolled jerking or contractions. This article explains the symptoms, causes, and treatment of tonic-clonic seizures. It also discusses the risk factors and outlook.

What is a tonic-clonic (grand mal) seizure?

A child wears electrodes on their head while sitting in a clinic.
Bisual Studio/Stocksy United

Tonic seizures and clonic seizures can occur individually from each other. However, as the name suggests, a tonic-clonic seizure is a type of epileptic seizure that starts with a tonic phase, followed by a clonic phase.

Tonic seizure episodes can cause:

  • muscle stiffness or tension
  • indeliberate noises, like a cry or a groan
  • impaired awareness
  • accidental biting of the tongue or cheek, which may cause blood in the saliva
  • falling

Clonic seizures can cause involuntary, uncontrolled muscle contractions. Because of the involuntary movements, clinicians may refer to tonic-clonic seizures as a type of motor seizure.

Tonic-clonic seizure symptoms may affect the whole body.

What are the symptoms of tonic-clonic (grand mal) seizure?

Additional symptoms of a tonic-clonic seizure include:

  • abrupt loss or reduction in consciousness
  • general stiffening of the body
  • jerking that is regular, rhythmic, or sustained
  • bending and relaxing at the joints
  • difficulty breathing
  • blueness or discoloration of the skin, particularly around the mouth and nails
  • loss of control of the bladder or bowel

A tonic-clonic seizure usually lasts 1–3 minutes. The tonic stage possibly may last only seconds.

Tonic-clonic seizures can be recurrent, meaning another seizure may happen again immediately after an initial tonic-clonic seizure or later on.

Aura symptoms

Some people may experience a seizure aura with a tonic-clonic seizure. Aura refers to unusual symptoms that occur before the tonic phase begins, such as:

  • changes in mood
  • changes in understanding or thinking
  • headaches
  • changes in senses, such as hearing, taste, or smell
  • vision changes

However, not everyone Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source will experience an aura. Auras are more likely with seizures that start focally, in one area of the brain.

Symptoms during recovery

After a tonic-clonic seizure, a person may experience:

Call 911 for severe seizure symptoms

Not all seizures are medical emergencies, but some are. Call 911 or seek emergency medical treatment for any of the following traits with seizures:

  • The seizure lasts 5 minutes or more Trusted Source Centers for Disease Control and Prevention (CDC) Governmental authority Go to source .
  • It could be the person’s first seizure.
  • The person has multiple seizures in a row without recovery.
  • The person has difficulty recovering afterward, such as difficulty breathing or regaining consciousness.
  • The person was injured before, during, or after the seizure.
  • The seizure happened in water, such as while showering or swimming.
  • The person has another health condition, such as diabetes or heart disease, or is pregnant.

It is advisable to place anyone having a seizure in the recovery position to reduce the impact Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source of breathing difficulties.

Learn more about first aid during a seizure.

What causes a tonic-clonic (grand mal) seizure?

Tonic-clonic seizures can occur on their own or develop as a secondary effect Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source of a focal or generalized seizure. “Focal” means that seizure activity occurs in just one area of the brain. “Generalized” means that seizure activity affects multiple areas of the brain.

Tonic-clonic seizures can happen as provoked seizures. These are not the result of epilepsy but are a symptom of acute illness. Conditions such as infections, stroke, and concussion can provoke tonic-clonic seizures.

Learn more about what can cause provoked seizures.

Epilepsy can cause tonic-clonic seizures. During an epileptic seizure, the brain’s nerve cells send hundreds of uncontrolled electrical signals, which cause the symptoms of epilepsy.

Epilepsy can develop from factors and causes such as:

  • genetic factors
  • structural differences in the brain
  • acquired brain injury or illness, such as infection, stroke, or concussion

Sometimes, the cause of epilepsy is unknown.

If you have epilepsy, certain factors can trigger the onset of a seizure. These triggers can be individual to each person, although examples include:

  • illness or fever
  • lack of sleep
  • hormonal changes
  • certain foods
  • stress

Read more about the causes and triggers of seizures.

What are the risk factors for a tonic-clonic (grand mal) seizure?

A 2019 study suggests that tonic-clonic seizures are more common in people assigned male at birth.

Other risk factors for tonic-clonic seizures can be similar to risk factors for other seizure types, such as:

  • family history of epilepsy
  • brain injury or illness
  • prolonged febrile, fever-induced, seizures
  • low birth weight
  • smoking
  • use of illegal drugs, or misuse of substances such as alcohol and prescription drugs
  • conditions such as:
    • high blood pressure
    • sleep disorders
    • structural differences in the brain
    • conditions which affect intellectual or developmental ability

Learn more about reducing your risk of seizures.

What is the treatment for a tonic-clonic (grand mal) seizure?

According to a 2022 research overview Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source , most generalized tonic-clonic seizures resolve independently and without emergency antiseizure medications. However, emergency treatment can be necessary for prolonged or recurrent seizures.

Additional treatments for epilepsy can include:

  • antiepileptic drugs
  • Epidiolex, an FDA-approved form of cannabidiol
  • nerve stimulation, such as:
  • brain surgery
  • ketogenic diets
  • complementary treatments, such as occupational therapy or seizure trigger management

Read more about treatments for epilepsy.

What is the outlook for tonic-clonic (grand mal) seizures?

Not everyone who has had a tonic-clonic seizure will have another one in their lifetime. A 2017 study suggests that the likelihood of having another tonic-clonic seizure may be 30–50%.

The outlook with tonic-clonic seizures can vary according to:

  • cause of the seizure
  • severity and frequency of seizures
  • age
  • underlying health
  • EEG results
  • imaging test results, such as from CT or MRI scans
  • treatment

Tonic-clonic seizures and epilepsy can sometimes have significant complications, such as:

However, not everyone will experience complications. Additionally, the World Health Organization (WHO) estimates that as much as 70% Trusted Source World Health Organization Highly respected international organization Go to source of people with epilepsy could be seizure-free with effective treatment. This can reduce the risk of complications and improve quality of life.

For advice about optimizing your treatment and outlook, contact your doctor.

Other frequently asked questions

Nancy Hammond, M.D., has reviewed the following questions people also ask about tonic-clonic seizures.

What are the 4 stages of a tonic-clonic seizure?

A tonic-clonic seizure may begin with an aura. However, not all do.

With or without aura, the pre-seizure stage is followed by the two main stages of a tonic-clonic seizure: a tonic phase and then a clonic phase.

Once the seizure ends, this is known as the post-ictal stage.

What is the difference between tonic and clonic seizures?

Tonic seizures and clonic seizures are two different seizure types. Tonic seizures cause muscle stiffness and tension, whereas clonic seizures cause muscle contractions or jerking.

When they occur together, this is known as a tonic-clonic seizure.

Do seizures cause brain damage?

Seizures can sometimes cause brain damage. However, damage is most likely with prolonged seizures or seizures that cause further complications.

Learn more about seizures and brain damage.

Summary

Tonic-clonic seizures, previously called grand mal seizures, are a type of epileptic seizure that occurs in two phases. These include a tonic phase, which can cause muscle stiffness, and a clonic phase, which can cause muscle contractions and jerking.

Conditions that cause injury, illness, or structural differences in the brain can lead to tonic-clonic seizures.

Treatment for tonic-clonic seizures can include medication and nerve stimulation. While some possible complications can be serious, treatment can be very effective at reducing seizures and improving quality of life.

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Medical Reviewer: Nancy Hammond, M.D.
Last Review Date: 2023 Feb 24
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