Understanding Grand Mal Seizures

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If you or someone you care about has had a grand mal seizure, you probably have many questions about what that means and what to expect.

Grand Mal Seizures

A grand mal seizure is a type of seizure that involves uncontrolled spasms and jerking of the arms and/or legs. It generally lasts for longer than a few seconds and involves loss of consciousness or unawareness of the whole event.

Usually, a grand mal seizure refers to a major convulsion or a serious seizure. In general, grand mal seizure is not a term that medical professionals commonly use to describe seizures anymore. There are  other descriptions that your medical team is more likely to use in your chart when describing and documenting your seizure:

Partial Seizure vs. Generalized Seizure

A partial seizure is a seizure that is caused by localized electrical discharges in the brain and may or may not be associated with complete loss of consciousness or unawareness.

A generalized seizure is a seizure during which the electrical discharges involve the entire brain, always causing a loss of consciousness, which means a lack of alertness and awareness. During a generalized seizure, a person is typically unable to respond or maintain control. Sometimes a generalized seizure can cause someone to fall to the ground. And often, a person who has had a generalized seizure cannot recall all or some details of the event.

Some people might use the term "grand mal seizure" to describe a generalized seizure as a way of indicating loss of consciousness or awareness.

Tonic or Tonic-Clonic

The type of physical movements of a seizure might also be noted in your medical chart. You might have had stiffening of your muscles during your seizure, which would be described as tonic.

And if you had jerking moments of your body, this would be described as clonic. A seizure that is characterized by stiffening and jerking is described as tonic-clonic. Sometimes, people use the description "grand mal" to describe a seizure characterized by noticeable physical movements.

Grand Mal Vs. Petit Mal

In contrast to a grand mal seizure, there is a type of seizure described as a petit mal seizure, which is a seizure characterized by a few seconds or a few minutes of loss of consciousness that is not associated with falling to the ground, spasms or jerking. A petit mal seizure, sometimes called an absence seizure, is not the same as spacing out, daydreaming, or sleepwalking because it is caused by abnormal electrical activity in the brain.

A petit mal seizure is not easy to diagnose and may require confirmation of seizure activity occurring in the brain with a test called an EEG. The terms grand mal and petit mal were used more often in the past to distinguish between these two different types of seizures, but now more descriptive medical terms are used.

The Relation to Epilepsy

Not everyone who has a seizure has epilepsy. Epilepsy is a seizure disorder characterized by a tendency to have repeated seizures.

Most medical studies show that only about 50 percent of individuals who experience a seizure will have another seizure. Sometimes a first seizure is indeed a symptom of epilepsy, and sometimes it is not. It is almost impossible to predict with perfect accuracy whether or not you will have another seizure. But sometimes, depending on your medical condition and the cause of the seizure, your doctor can determine whether you are at high or low risk of experiencing further seizures.

Generally, when there are major signs of seizure activity on an EEG, this indicates a high risk of having another seizure, and anti-seizure medication may be recommended to help prevent seizures.

However, sometimes people with epilepsy have normal or almost normal EEG studies.


There are a number of reasons you might have a seizure besides epilepsy. Certain medications, severe illness, high fevers, drug or alcohol overdose, or withdrawal can all cause seizures.

Other things that can cause a seizure include head trauma, brain injury, strokes, aneurysms and brain infections.

When the brain is injured, the electrical activity that normally controls brain function may become disturbed or erratic, and may 'fire' when it shouldn't, resulting in unwanted physical actions or changes in consciousness, which manifest as a seizure. If the abnormal brain activity involves a small region of the brain, this can manifest as a partial seizure, while abnormal electrical activity involving the whole brain manifests as a generalized seizure.

Preventing Further Grand Mal Seizures

There are a variety of ways to effectively prevent seizures. If you have a certain trigger, such as alcohol, drugs, or medications, then controlling the use of that substance is by far the safest way to prevent a seizure.

However, most people who are prone to recurrent grand mal seizures could experience a seizure due to a fever, infection, sleepiness or even without any known trigger. In these instances, anti-seizure medications are often recommended to prevent or reduce recurrent seizures.

Concern Over Activities

This may be one of your greatest concerns if you have had a grand mal seizure. Depending on how long it has been since you had a seizure and whether you have been diagnosed with epilepsy, the main concerns include driving, working, and safety with sharp or heavy tools.

If you have not yet had your medical evaluation completed, you should avoid driving and using hazardous utensils for the time being. If your work does not involve driving or dangerous equipment, then you should be able to continue work if you feel up to it. If you are a pilot or a driver, however, then you should avoid operating such equipment until your doctor clears you, and you might need to find alternative work, even for the long term.

A Word From Verywell

The term grand mal comes from the French language and was used to describe very bad seizures. Yet, there is a great deal of knowledge about epilepsy and there are effective medical resources that can control seizures and epilepsy, making the term ‘grand mal’ somewhat misleading. If you or a loved one has experienced a grand mal seizure, then you should work closely with your doctors so that you can achieve optimal outcome and quality of life.

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