Generalized tonic-clonic seizure

Seizures result from overactivity in the brain. Generalized 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).

Many people with generalized tonic-clonic seizures have vision, taste, smell, or sensory changes, hallucinations, or dizziness before the seizure. This is called an aura.

The seizures often result in rigid muscles. This is followed by violent muscle contractions and loss of alertness (consciousness). 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:

• Confusion
• Drowsiness or sleepiness that lasts for 1 hour or longer (called the post-ictal state)
• Loss of memory (amnesia) about the seizure episode
• Headache
• Weakness of 1 side of the body for a few minutes to a few hours following seizure (called Todd paralysis)

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 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.

Treatment for tonic-clonic seizures includes medicines, changes in lifestyle for adults and children, such as activity and diet, and sometimes surgery. Your doctor can tell you more about these options.

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

Abou-Khalil BW, Gallagher MJ, Macdonald RL. Epilepsies. In: Daroff RB, Jankovic J, Mazziotta JC, Pomeroy SL, eds. Bradley's Neurology in Clinical Practice. 7th ed. Philadelphia, PA: Elsevier; 2016:chap 101.

Wiebe S. The epilepsies. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 403.

Updated 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.