Generalized Seizures (Grand Mal Seizures)


What Is It?

Normally, the brain’s nerve cells (neurons) communicate with one another by firing tiny electric signals that pass from cell to cell. The firing pattern of these electric signals reflects how busy the brain is at any moment, and the location of these signals indicates what the brain is doing, such as thinking, seeing, feeling, hearing, controlling the movement of muscles, etc. A seizure occurs when the firing pattern of the brain’s electric signals suddenly becomes very abnormal and unusually intense, either in an isolated area of the brain or throughout the brain.

If the whole brain is involved, the electrical disturbance is called a generalized seizure. They used to be called grand mal seizures. The most easily recognizable manifestation of a generalized seizure is the body stiffness and jerking limbs known as tonic-clonic motor activity.

Epilepsy is the condition of being prone to repetitive seizures, but this can be any kind of seizures, not just generalized seizures. A person can have a seizure without having epilepsy. Today, seizure disorder is the more commonly used term instead of epilepsy.

A seizure can be provoked by any situation that seriously disturbs the physical or chemical environment of the brain. Some common triggers include:

  • A severe chemical imbalance in the blood — Abnormal levels of blood acids, sodium, calcium or blood sugar (especially in diabetics)
  • Drug reactions — Reactions to illegal drugs (“crack” cocaine, amphetamines and others), anesthetics or prescription medications (penicillin, anti-asthma drugs, anticancer drugs and many others)
  • Drug withdrawal — Withdrawal from alcohol or sedatives
  • Medical illnesses — Extreme high blood pressure (hypertension), eclampsia (a complication of pregnancy), liver failure, kidney failure, sickle-cell disease, systemic lupus erythematosus and many others
  • A local problem involving the brain — Head trauma, developmental brain disorders, stroke, brain tumors, and infections in or near the brain (brain abscess, encephalitis, meningitis)
  • Other causes — High fever, sleep deprivation, starvation, flashing lights (even from video games), intermittent noise and, rarely, menstruation

If doctors can successfully treat the underlying physical or chemical disturbance in the brain, the seizure problem often goes away. If not, seizures may return again and again, whenever the underlying problem flares up.

Sometimes, a person will experience an unprovoked generalized seizure, one that occurs for no apparent reason. In some people, this type of seizure may be related to a genetic (inherited) vulnerability that makes the brain cells unusually sensitive to minor changes in the environment. In other cases, the brain may have an increased risk of seizures because of lingering brain damage caused by prior head trauma, or by a previous stroke, brain tumor or brain infection.

Fortunately, many people who are evaluated by a doctor for their first unprovoked seizure never experience a second one. However, if a second seizure occurs, the risk of having a third or even more is about 80 percent. For this reason, doctors often regard the second seizure as a sign of epilepsy.


A seizure begins suddenly. Without warning, the person loses consciousness and experiences the following symptoms:

  • Becomes rigid (extends the arms and legs, arches the back) and falls down
  • Utters a cry (the “epileptic cry”) as the diaphragm contracts and forces air out between the contracted vocal cords
  • Has jerking movements of the arms, legs, and trunk muscles
  • Involuntarily passes urine and sometimes feces

Within two minutes or less, the seizure subsides, leaving the person confused and sleepy. Over the following 24 hours, he or she may complain of sore muscles, headache, fatigue and difficulty concentrating.


If you have had symptoms of a seizure, your doctor will begin by looking for an underlying medical trigger, such as low blood sugar or eclampsia. If your doctor can confirm a definite medical reason for your seizure, your treatment will be geared toward correcting the underlying illness.

If your seizure appears to be unprovoked (not triggered by any underlying medical problem), your doctor will review your medical history, family history and any eyewitness reports of your seizure symptoms. Next, the doctor will perform a thorough physical and neurological examination and order routine blood tests. In most cases, the results of your examinations and blood tests will be normal.

As a final step in the diagnostic process, your doctor may order an electroencephalogram (EEG), a painless test that detects the electrical activity in your brain and translates it into a series of printed patterns. In 40 percent to 50 percent of people with epilepsy, the first EEG will show a specific combination of patterns that confirms the diagnosis. If the first EEG is normal, repeat EEG tracings usually will detect the abnormal brain-wave pattern.

Sometimes, even when a series of EEG tests fails to show evidence of seizure activity, the diagnosis can be based on evidence from the eyewitness reports of people who have seen your seizure episodes.

In some cases, the doctor may also order a magnetic resonance imaging (MRI) or computed tomography (CT) scan of your brain to look for evidence of a local problem, such as a brain tumor or scarring from a previous brain injury. These scans are especially important if:

  • You are an adult with your first generalized seizure
  • You have an unusual pattern of symptoms
  • Your neurological exam is abnormal
  • You have a history of brain damage (birth trauma, Head injury, train tumor, encephalitis, meningitis)

Expected Duration

About half of all people who have one unprovoked seizure never experience another.

Most people who have epilepsy will be able to avoid seizures if they get sufficient sleep and take prescribed medications as directed. Most people with epilepsy need to take medication indefinitely. Never stop medication without specific instructions from your physician.

If you have had only a couple of seizures and have a normal EEG, your doctor might consider reevaluating the need for medication if you have no seizures after two to five years.


Most of the time epilepsy cannot be prevented. But whether or not you have epilepsy, you can help prevent ever experiencing a generalized seizure by:

  • Avoid using illegal drugs.
  • Drink alcohol in moderation or not at all.
  • Faithfully follow your doctor’s treatment plan if you have diabetes or high blood pressure.
  • Protect yourself from head trauma by wearing seat belts and bicycle helmets. If you play sports, wear appropriate protective headgear.
  • If you are pregnant, see your doctor regularly for prenatal care.


If you have had only one unprovoked seizure, you may not experience another. For this reason, your doctor may decide to monitor your condition without prescribing medication. In most cases, you will be considered to have a low risk of a second seizure if you have no history of brain injury (tumor, trauma, infections), no family history of epilepsy and normal results on diagnostic tests, including an EEG.

If you have had at least two seizure episodes, and you have been diagnosed with epilepsy, your doctor will treat you with an anti-epileptic medication (an anticonvulsant). Common anti-epileptic medications used to treat generalized seizures include valproate (Depakote), carbamazepine (Tegretol, Carbatrol and others), phenytoin (Dilantin), and phenobarbital. If your seizures cannot be controlled with one drug alone, you doctor will try a two-drug combination.

When To Call A Professional

Call your doctor immediately if you or anyone in your family experiences a series of symptoms that appear to be a generalized seizure. If you already have been diagnosed with epilepsy, call your doctor if you continue to have seizures even though you are taking anti-epileptic medication.

If you witness someone having a generalized seizure that lasts for more than five minutes, call for emergency medical help immediately. Also call for emergency medical help immediately if you witness someone having a generalized seizure who:

  • Does not awaken soon after the seizure is over
  • Is a pregnant woman
  • Is wearing medical identification jewelry stating that he or she has diabetes
  • Has suffered a seizure after head trauma
  • Has suffered a seizure while swimming


Many factors play a role in determining whether a person with generalized epilepsy eventually becomes seizure-free. Overall, the outlook is best in those who have had very few seizures before beginning treatment, have good seizure control with only one anti-epileptic drug, have a normal EEG between seizures, have no history of brain damage and have a normal neurological exam at the end of treatment.

In many cases, the prognosis is very good. With proper treatment, up to 70 percent of people with epilepsy ultimately become seizure-free for five or more years. Eventually, about 30 percent are able to discontinue medication permanently.

Most children with generalized seizures can lead normal lives, including participating in organized sports, with minimal restrictions.

Johns Hopkins patient information

Last revised:

Diseases and Conditions Center

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.