Alternative Names: Seizure - tonic-clonic; Seizure - grand mal; Grand mal seizure; Seizure - generalized
Causes, incidence, and risk factors:
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.
Tumors and brain lesions (such as hematomas ) -- more common after age 30
Risk factors include:
Any injury to the brain
Family history of seizures
Heavy alcohol use
Severe medical problems that affect electrolytes
Using recreational drugs and certain medications
Symptoms:
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:
Loss of consciousness or fainting , usually lasting between 30 seconds and 5 minutes
General muscle contraction and rigidity (tonic posture), usually lasting 15-20 seconds
Violent rhythmic muscle contraction and relaxation (clonic movement), usually lasting for 1-2 minutes
Weakness for 24-48 hours following seizure (Todd's paralysis)
Signs and tests:
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:
Protect the person from injury. Remove furniture or other objects from the area so they do not cause injury if the person falls during the seizure.
Do not attempt to force a hard object (such as a spoon or a tongue depressor) between the teeth. You can cause more damage than you can prevent.
Do not try to hold the person down during the seizure.
Turn the person to the side if vomiting occurs. Keep the person on his or her side while sleeping after the seizure is over.
If the person having a seizure turns blue or stops breathing, try to position the head to prevent the tongue from blocking the airway. Breathing usually starts on its own once the seizure is over.
CPR or mouth-to-mouth breathing is rarely needed after seizures and cannot be performed during the seizure.
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:
General anesthesia with medication that temporarily paralyze the muscles
Repeated, prolonged generalized seizures may be controlled with any of the following medications, which are usually given by injection.
Antiseizure drugs such as phenytoin or phenobarbital
Diazepam (Valium)
Lorazepam
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:
Date and time of the seizure
How long it lasted
What body parts were affected
Type of movements or other symptoms
Possible causes
How the person behaved after the seizure
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.
Support Groups:
Expectations (prognosis):
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.
Complications:
Seizure disorder
Prolonged or closely occurring seizures without returning to normal behavior(status epilepticus)
Injury from falls, bumps, and biting oneself
Injury to oneself or others if seizure occurs during driving or operating machinery
Side effects of medications (with or without symptoms)
Learning disorders (either from seizures or drugs)
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.
Calling your health care provider:
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:
The seizure lasts longer than unusual
The person is having an unusual number of seizures
Repeated seizures occur over a few minutes
Repeated seizures occur and the person does not wake up (regain consciousness) or act normally between each one
Call the health care provider if a person with seizures has new symptoms inluding:
Generally, there is no known prevention for seizures. However, the following can reduce the chances of a seizure:
Avoiding alcohol and illicit drugs
Eating a proper diet
Getting enough sleep
Taking medicines as directed
Reduce the chance of head injuries by wearing head protection and avoiding risky behavior.
References:
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.
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
Review Date: 6/3/2008 Reviewed 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.
