What Is a Grand Mal Seizure? (Tonic-Clonic Seizure)

While the term “grand mal” is still widely used in casual conversation, the medical community now refers to these events as generalized tonic-clonic seizures. They are the most dramatic type of seizure, involving a loss of consciousness and violent muscle contractions.

In this guide, we will explore what happens during a grand mal seizure, the causes, and what you should do if you witness one.

Table of Contents

1. What Happens During a Grand Mal Seizure?

A grand mal seizure affects the entire brain. It typically consists of two distinct stages:

The Tonic Phase: The person loses consciousness and their muscles suddenly stiffen. This often causes them to fall to the ground. They may let out a brief cry as air is forced out of the lungs.
The Clonic Phase: The person’s muscles begin to jerk rhythmically. This usually lasts for one to three minutes. During this time, they may lose control of their bladder or bowel, or accidentally bite their tongue or cheek.

2. The Four Stages of a Seizure

Many people experience a grand mal seizure in four specific steps:

Aura: Some people feel a “warning” sign before a seizure starts, such as a strange smell, a feeling of anxiety, or dizziness.
The Seizure (Tonic-Clonic): The physical stiffening and jerking described above.
Postictal State: After the jerking stops, the person enters a period of deep sleep or extreme confusion.
Recovery: It can take minutes or hours for the person to fully regain their memory and physical strength.

3. Common Causes and Triggers

Grand mal seizures are caused by abnormal electrical activity in the brain. Common causes include:

Epilepsy: A chronic neurological disorder.
Brain Injury: Trauma from an accident or stroke.
Medical Conditions: Extremely low blood sugar, high fever (common in children), or infections like meningitis.
Withdrawal: Sudden withdrawal from alcohol or certain medications (like benzodiazepines).

Triggers for those with epilepsy may include sleep deprivation, flashing lights, or high levels of stress.

4. First Aid: What to Do (and What NOT to Do)

If you see someone having a grand mal seizure, stay calm and follow these steps:

What TO Do:

Gently roll them onto their side. This helps keep the airway clear.
Protect their head. Place something soft (like a folded jacket) under their head.
Clear the area. Move hard or sharp objects away.
Time it. Keep track of how long the seizure lasts.

What NOT to Do:

DO NOT put anything in their mouth. It is a myth that people can swallow their tongues. Putting an object in their mouth can cause choking or broken teeth.
DO NOT restrain them. Trying to hold them down can cause bone or muscle injuries.

5. When to Call 911

Most seizures stop on their own, but emergency medical help is necessary if:

The seizure lasts longer than 5 minutes.
A second seizure starts immediately after the first.
The person does not wake up after the jerking stops.
The person is pregnant or injured.
It is the person’s first-ever seizure.

6. Diagnosis and Treatment

Doctors typically diagnose the cause of seizures using:

EEG (Electroencephalogram): To look at brain wave patterns.
MRI or CT scans: To check for physical abnormalities in the brain.
Blood tests: To check for infections or chemical imbalances.

Treatment usually involves daily anti-seizure medications. In some cases, doctors may recommend nerve stimulation therapy or a specific diet (like the ketogenic diet).

Disclaimer: This content is for informational purposes only and does not constitute medical advice. Always seek the advice of a physician or other qualified health provider with any questions you may have regarding a medical condition.