When people think of epilepsy, they often envision jerking limbs and a loss of consciousness. These symptoms describe tonic-clonic seizures, previously called grand mal seizures.

Here’s what you need to know about tonic-clonic seizures, including their symptoms, causes, diagnosis, and treatment options. We’ll also cover what you can do if you witness someone having a tonic-clonic seizure.

Symptoms of Tonic-Clonic Seizures

Tonic-clonic seizures have two phases. The term “tonic-clonic” describes what happens during each phase.

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Tonic Phase

“Tonic” refers to muscle stiffening or contraction. During the tonic phase, which generally lasts less than 30 seconds, a person may also:

• Cry or groan as tightening muscles force air out
• Lose consciousness
• Fall down
• Bite their tongue
• Foam at the mouth

Clonic Phase

“Clonic” refers to rhythmic jerking or convulsions, usually of the face, arms, and legs. This phase can be brief or last a few minutes.

As the clonic phase ends, muscle tension eases throughout the body. A person may lose bladder or bowel control during this time, leading to accidental urination or a bowel movement.

Awareness usually returns gradually after the seizure — a person may feel confused, irritable, tired, or depressed. Some people also develop temporary weakness in a limb or on one side of the body, called Todd’s paralysis. These symptoms are all normal for a person coming out of a tonic-clonic seizure.

“I know how horrible these seizures can be. The next day, my body was so shattered, it was hard to carry my briefcase.”

— A MyEpilepsyTeam Member

When Is a Seizure a Medical Emergency?

If a tonic-clonic seizure lasts more than five minutes, or a second seizure begins before the person recovers, it is a medical emergency called status epilepticus. Seek urgent medical help.

Diagnosing Tonic-Clonic Seizures

Some people have one tonic-clonic seizure and never have another. Other people have many tonic-clonic seizures, which can make an epilepsy diagnosis more straightforward.

Reaching a diagnosis of epilepsy can take time and feel frustrating. You may need to see several doctors and have multiple tests before your healthcare team can confirm a diagnosis.

An electroencephalogram (EEG), which measures electrical activity in the brain, is one important tool for diagnosing epilepsy. EEG testing may show abnormal brain activity between seizures that can help establish a diagnosis.

Magnetic resonance imaging (MRI) scans create detailed images of the brain. These scans may help your doctor determine whether changes in brain structure are causing seizure activity.

A neurologist will likely review your medical history, talk with people who witnessed the seizure, and look at any available videos to help make a diagnosis.

“I’ve seen my son have these types of seizures many times. I know they want you to try and record them. I never have. It’s very difficult to watch alone to try and record.”

— A MyEpilepsyTeam Member

How Are Tonic-Clonic Seizures Treated?

Generalized tonic-clonic seizures are typically treated with anti-seizure medications. When you’re first diagnosed, your doctor may prescribe:

• Lamotrigine (Lamictal)
• Levetiracetam (sold as Keppra, Roweepra, or Spritam)
• Sodium valproate

If one of these doesn’t help, your doctor will likely move to the next until all three have been tried.

If none of those medications help, your healthcare team may add another medication. They may try combinations of the drugs listed above or add another medication to one of them.

Other medications they may try include:

• Clobazam (sold as Onfi or Sympazan)
• Perampanel (Fycompa)
• Topiramate (sold as Eprontia, Topamax, or Trokendi XR)

If those medications aren’t successful at controlling tonic-clonic seizures, your doctors may add a second-line medication. These include:

• Brivaracetam (Briviact)
• Lacosamide (Vimpat)
• Phenobarbital
• Primidone (Mysoline)
• Zonisamide (sold as Zonegran or Zonisade)

Some medications, like carbamazepine (Tegretol), are used for certain seizure types but may worsen absence or myoclonic seizures in some people.

Not all medications work for everyone, and your doctor may prescribe several different medications before finding the drug or combination of drugs that works best for you.

“Today marks one year since my last tonic clonic seizure. The longest I’ve gone without one so far.”

— A MyEpilepsyTeam Member

When to Call Emergency Services

You should call emergency services immediately if:

• A seizure lasts five minutes or longer
• A person has repeated seizures without recovering in between
• You witness someone’s first seizure
• The person remains unresponsive five or more minutes after the seizure is over
• The person having a seizure gets injured because of the seizure
• A seizure causes breathing problems
• A pregnant person has a seizure
• You witness a seizure in water

You can also provide seizure first aid if you know what to do and feel confident helping. However, treat any of these situations as a medical emergency.

Join the Conversation

On MyEpilepsyTeam, people share their experiences with epilepsy, get advice, and find support from others who understand.

Do you or your loved one experience tonic-clonic seizures? Let others know in the comments below.