Generalized tonic-clonic seizure
Seizure - tonic-clonic; Seizure - grand mal; Grand mal seizure; Seizure - generalized; Epilepsy - generalized seizure
Bilateral tonic-clonic seizure is a type of seizure that involves the entire body. It is also called grand mal seizure. The terms generalized seizure, convulsion, or epilepsy are most often associated with bilateral tonic-clonic seizures.
Seizures result from overactivity in the brain. Bilateral tonic-clonic seizures may occur in people of any age. They can occur once (single episode). Or, they can occur as part of a repeated, chronic illness (epilepsy). Some seizures are due to psychological problems (psychogenic or non-epileptic).
Having a brain seizure can be a terrifying experience. If you have a seizure more than once, you may have epilepsy, a problem with electrical activity in your brain. So, what causes epilepsy? For most people, the brain sends electrical signals throughout the body efficiently, in a coordinated way. In epilepsy, however, the normal pattern of electrical activity becomes disturbed. This causes the brain to be too excitable, or jumpy, and it sends out abnormal signals. The result is repeated seizures that can happen at any time. Epilepsy seizures usually begin between ages 5 and 20, but they can happen at any age. Common causes include Stroke, or a mini-stroke called transient ischemic attack; Dementia, or loss of brain function, such as Alzheimer's disease; Traumatic brain injury; Infections in the brain; Brain problems you are born with; or perhaps, a Brain tumor. Some people with epilepsy may have simple staring spells, while others have violent, uncontrollable shaking and loss of consciousness. Before each seizure, some people may have strange sensations, such as tingling, smelling an odor that isn't really there, or emotional changes. This is called an aura. Your doctor will perform a number of tests to find out if epilepsy is causing your seizures. One test, an electroencephalogram or EEG, checks your brain's electrical activity. Other tests can take detailed pictures of the part of your brain that is causing your seizures. Your doctor will most likely start treating your epilepsy with medication. These medicines, called anticonvulsants, may reduce the number of seizures you have in the future. Sometimes, changing the diet of a child with epilepsy can help prevent seizures. Your doctor will probably talk to you about making some changes in your life, such as reducing your stress, getting more sleep, and avoiding alcohol and recreational drugs. Surgery to remove a brain tumor or abnormal blood vessels or brain cells may make the seizures stop. Another surgery can place a Vagus nerve stimulator in your brain. This device is like a pacemaker for your brain that limits the number of seizures you have. For many people, epilepsy is a lifelong problem, and they'll always need to take anti-seizure medicines. There is a very low risk of sudden death with epilepsy. However, you, or someone else, can be seriously injured if you have a seizure while driving or operating equipment. If your seizures are uncontrolled, you should not drive.
Many people with generalized bilateral tonic-clonic seizures have one or more symptoms such as:
- Vision, taste, smell, or sensory changes.
- Dizziness before the seizure. This is called an aura.
Some people have a focal seizure (only affecting one part) that becomes a bilateral tonic clonic seizure.
The seizures often result in rigid muscles (tonic phase). This is followed by violent muscle contractions (clonic phase). Other symptoms that occur during the seizure may include:
- Biting the cheek or tongue
- Clenched teeth or jaw
- Loss of urine or stool control (incontinence)
- Stopped breathing or difficulty breathing
- Blue skin color
After the seizure, the person may have:
- Drowsiness or sleepiness that lasts for 1 hour or longer (called the post-ictal state)
- Loss of memory (amnesia) about the seizure episode
- Weakness of one side of the body for a few minutes to a few hours following seizure (called Todd paralysis)
Exams and Tests
The doctor will perform a physical exam. This will include a detailed check of the brain and nervous system.
An EEG (electroencephalogram) will be done to check the electrical activity in the brain. People with seizures often have abnormal electrical activity seen on this test. In some cases, the test shows the area in the brain where the seizures start. The brain may appear normal after a seizure or between seizures.
Blood and urine tests may also be ordered to check for other health problems that may be causing the seizures.
Head CT or MRI scan may be done to find the cause and location of the problem in the brain.
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Last reviewed on: 1/23/2022
Reviewed by: Joseph V. Campellone, MD, Department of Neurology, Cooper Medical School at Rowan University, Camden, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.