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Generalized tonic-clonic seizure

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Central nervous system
Central nervous system

Alternative Names    Return to top

Seizure - tonic-clonic; Seizure - grand mal; Grand mal seizure; Seizure - generalized

Definition    Return to top

A generalized tonic-clonic seizure is a seizure involving the entire body. It is also called a grand mal seizure. Such seizures usually involve muscle rigidity, violent muscle contractions, and loss of consciousness.

Causes    Return to top

Generalized tonic-clonic seizures are the type of seizure that most people associate with the term "seizure," convulsion, or epilepsy. They may occur in people of any age, as a single episode, or as part of a repeated, chronic condition (epilepsy).

Generalized seizures are caused by abnormal electrical activity at the same time in many parts of the brain or over a large area of the brain. This results in loss of alertness (consciousness) and body stiffening, which is followed by shaking of the arms and legs.

Abnormal electrical activity may start in one part of the brain and cause isolated symptoms. See: Partial seizures.

Sometimes this abnormal electrical activity spreads through the brain, resulting in a generalized seizure. This is called secondary generalization.

Seizures can be caused by injuring or inflamation to a specific area of the brain, or they can be due to stress on the brain from a bodywide process such as severely low blood sugar.

Idiopathic seizures are seizures that occur without an identifiable cause. They usually begin between ages 5 and 20, but can occur at any age. The person can have a family history of epilepsy or seizures.

Problems that are present from before birth (congenital brain defects) and injuries to the brain that occur near the time of birth can cause seizures to begin in infancy or early childhood. Brain injury usually causes seizures within 2 years after the injury. Seizures that occur within 2 weeks of injury do not necessarily mean that repeated seizures (epilepsy) will develop.

Febrile seizures (in children) are usually caused by rapidly rising fevers in children. These usually run in families.

Other causes of seizures include:

Risk factors include:

Symptoms    Return to top

Many patients have an aura (sensory warning sign) preceding the seizure. This can include a visual, taste, smell, sensory, or other hallucination or dizziness.

The seizure itself involves:

Almost all people lose consciousness, and most people have both tonic and clonic muscle activity.

After the seizure, the person usually has:

Exams and Tests    Return to top

A doctor will diagnose this type of seizure based on the symptoms and after ruling out other medical conditions that can cause similar symptoms. Disorders that may cause symptoms resembling seizures include transient ischemic attacks, rage, or panic attacks.

A neuromuscular examination done when the person is not actively having seizures may or may not reveal any problems.

An EEG may show changes and possible the location of the cause of the seizure. This test can be normal in between seizures. A normal EEG does not rule out a seizure disorder.

Blood tests may be done to determine the cause of the seizures. This may include:

Tests for the cause may include procedures such as:

Treatment    Return to top

EMERGENCY FIRST AID

If a person has repeated or prolonged seizures without regaining consciousness or returning to normal behavior, the body may develop a severe lack of oxygen. This an emergency situation - seek immediate medical help.

EMERGENCY TREATMENT BY A MEDICAL TEAM

The health care team may need to take measures to protect the airway. This may include using tubes to keep the airway open. Breathing will be supported as needed.

Other treatments prescribed by a doctor may include:

Repeated, prolonged generalized seizures may be controlled with any of the following medications, which are usually given by injection.

After the seizures are controlled, the patient will be given anticonvulsants. Tests will be done to determine the cause of the condition, if it is not already known.

AFTER THE SEIZURE

Treat any injuries from bumps or falls. Record details of the seizure to report to the person's primary health care provider. You should note the following details:

If a cause is identified, treating the cause may stop seizures. Treatment may include medication, surgery to repair of tumors or brain lesions, or other therapies.

An isolated seizure due to an obvious trigger (such as fever or a drug) is treated by eliminating or avoiding that factor. An isolated seizure without an obvious trigger may not require treatment.

Antiseizure medicines may prevent or reduce the number of future seizures. Medicines may be used alone or in combination with another drug.

Patients who continue to have seizures despite several medications may benefit from a vagal nerve stimulator (implantable device similar to a heart pacemaker that stimulates a nerve in the neck) or from brain surgery to remove tissue responsible for causing the seizures.

Informational jewelry or cards (such as Medic-Alert bracelets) alerting others about the seizures may help a patient receive prompt medical treatment if one occurs.

Outlook (Prognosis)    Return to top

Generalized tonic clonic seizures may only occur one time. Seizures that continue to occur are referred to as epilepsy.

After a brain injury, patients may or may not have a seizure. Some will develop a chronic seizure disorder. It is difficult to predict who will have this problem.

Death or permanent brain damage from seizures is rare. A serious injury can occur if a seizure occurs while driving or operating dangerous equipment. Such activities are often restricted if you have poorly controlled seizure disorders.

Work, school, and recreational activities do not necessarily need to be restricted for those with well-controlled seizures.

Possible Complications    Return to top

Women who are pregnant or planning to become pregnant may need to take additional medications or vitamins, such as folic acid supplements, to reduce the risk of birth defects associated with certain antiseizures drugs. Such women may need to be followed in a high-risk pregnancy clinic.

Certain antiseizure drugs may cause or worsen osteoporosis. People taking these medicines for a long period of time should discuss their risk of osteoporosis with their doctor.

When to Contact a Medical Professional    Return to top

Call your local emergency number (such as 911) if this the first time a person has had a seizure or a seizure is occurring in someone who is not wearing a medical ID bracelet and does not carry instructions explaining what to do in the event of a seizure.

If the person has had a seizure before, call for an ambulance if:

Call the health care provider if a person with seizures has new symptoms inluding:

Prevention    Return to top

Generally, there is no known prevention for seizures. However, the following can reduce the chances of a seizure:

Reduce the chance of head injuries by wearing head protection and avoiding risky behavior.

References    Return to top

Foldvary-Schaefer N, Wyllie E. Epilepsy. In: Goetz CG. Textbook of Clinical Neurology. 3nd ed. St. Louis, Mo: WB Saunders; 2007.

Marx J. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 5th ed. St. Louis, Mo: Mosby; 2002.

Krumholz A, Wiebe S, Gronseth G, et al. Practice Parameter: evaluating an apparent unprovoked first seizure in adults (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology and the American Epilepsy Society. Neurology. 2007 Nov 20;69(21):1996-2007.

Spencer SS. Seizures and epilepsy. In: Goldman L, Ausiello D, eds. Cecil Textbook of Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007.

Tomson T, Hiilesmaa V. Epilepsy in pregnancy. BMJ. 2007 Oct 13;335(7623):769-73.

Sheth RD, Hardin CL. Screening for bone health in epilepsy. Epilepsia. 2007;48 Suppl 9:39-41

Update Date: 6/3/2008

Updated by: Daniel B. Hoch, PhD, MD, Assistant Professor of Neurology, Harvard Medical School, Department of Neurology, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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