Grand Mal Seizures

Medically Reviewed By William C. Lloyd III, MD, FACS
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What are grand mal seizures?

Grand mal seizures, or generalized tonic-clonic seizures, are seizures that involve muscle contractions, muscle rigidity, and loss of consciousness. These seizures result from abnormal electrical activity in the brain. Grand mal seizures affect the entire body, and may happen just once or multiple times (as in the case of epilepsy). The cause of grand mal seizures may not be immediately recognized, if ever. Treatable medical conditions that may be responsible for grand mal seizures include electrolyte imbalance, illicit drug use, brain tumor, meningitis, head trauma, and many others.

Grand mal seizures tend to follow a pattern of symptoms that can become recognizable. The seizure often starts with an aura, or a change in sensation characterized by hallucinations, dizziness, and abnormal sights, smells, tastes or feelings. The aura is followed by loss of consciousness, a contraction of all the muscles (tonic phase), and then rhythmic muscle spasms (clonic phase). Grand mal seizures often last for several minutes.

Usually, people recover from a grand mal seizure feeling mild confusion, weakness, and tiredness. Grand mal seizures are marked by amnesia (memory loss), so that the person who has the seizure does not remember what happened. While the seizure itself generally does not cause permanent damage, it is possible for injury to result during the seizure.

Grand mal seizures are generally controlled with medications, surgery, or electrical stimulation. A single grand mal seizure often does not require treatment, although prompt medical evaluation is imperative. For patients with recurrent seizures, or epilepsy, many different types of treatments are available.

Seek immediate medical care (call 911) for any seizure, as prompt medical treatment may reduce the risk and severity of future seizures

What are the symptoms of grand mal seizures?

Symptoms of grand mal seizures are related to abnormal electrical activity in the brain, and include auras, muscle rigidity, and muscle spasms.

Aura symptoms of grand mal seizures

The aura is the initial phase of a grand mal seizure and may be marked by:

  • Abnormal sensations
  • Changes in hearing, taste or smell
  • Dizziness or vertigo
  • Hallucinations
  • Loss of vision or changes in vision

Tonic-clonic symptoms of grand mal seizures

Following the aura, the seizure will progress into tonic and clonic phases, which are marked by:

  • Biting your cheek or tongue

  • Incontinence (loss of control of urine or stools)

  • Loss of consciousness

  • Muscle contraction of the entire body (tonic phase, which usually lasts several seconds)

  • Muscle twitching, spasms, or seizures of the entire body (clonic phase, which may last for a few minutes)

Serious symptoms that might indicate a life-threatening condition

Grand mal seizures can be life threatening. Seek immediate medical care (call 911) for any seizure, as prompt medical treatment may reduce the risk and severity of future seizures.

What causes grand mal seizures?

Grand mal seizures may occur just once or, if they recur, may be an indication of epilepsy. All seizures are caused by abnormal electrical activity in the brain, which may be a result of injury, illness, a genetic condition, or may have no known cause. In patients with epilepsy, a grand mal seizure may arise from a trigger, such as mental or physical stress.

Causes of grand mal seizures

Abnormal electrical activity in the brain may arise from a variety of causes, many of which can be serious or potentially life threatening including:

  • Alcohol and drug withdrawal

  • Brain infection

  • Brain injury

  • Brain tumor

  • Certain genetic conditions such as phenylketonuria (inability to break down the amino acid phenylalanine)

  • Dementia

  • Encephalitis (inflammation and swelling of the brain due to a viral infection or other causes)

  • Recent brain surgery

Triggers of grand mal seizures

A single grand mal seizure, especially in people with epilepsy, may result from a trigger including:

  • Consumption of alcohol or other drugs
  • Emotional stress
  • Fever
  • Lack of sleep
  • Medication side effects
  • Trauma to the head

What are the risk factors for grand mal seizures?

A number of factors increase the risk of developing grand mal seizures. Not all people with risk factors will get grand mal seizures. Risk factors for grand mal seizures include:

  • Family history of certain genetic conditions
  • Family history of epilepsy
  • Recent brain surgery
  • Recent head injury
  • Recent infection of the brain

Reducing your risk of grand mal seizures

If you are prone to seizures or have epilepsy, trigger avoidance may be the best way to avoid a grand mal seizure. Eating a balanced diet and leading a healthy lifestyle may also minimize your risk of seizure.

You may be able to lower your risk of grand mal seizures by:

  • Avoiding alcohol and drugs

  • Avoiding emotional stress

  • Eating a healthy, balanced diet

  • Following the treatment plan prescribed by your medical professional

  • Getting enough sleep

How are grand mal seizures treated?

A single grand mal seizure generally does not require treatment, but prompt medical attention should be obtained to ensure that epilepsy does not develop. For recurrent grand mal seizures, there are generally three treatments used: medication, surgery, and electrical stimulation. Other treatments may help you cope with the complications of grand mal seizures.

Common treatments for grand mal seizures

Treatments for grand mal seizures that do not spontaneously resolve include:

  • Antiepileptic drugs to reduce abnormal electrical activity in the brain

  • Brain surgery to remove the epileptic focus (location in the brain where seizures start)

  • Electrical stimulation to interfere with abnormal electrical activity

Other treatments for grand mal seizures

In addition to treatments designed to interfere with abnormal electrical activity, treatment for grand mal seizures may include:

  • Changes in diet, especially in children with such conditions as phenylketonuria (inability to break down the amino acid phenylalanine)

  • Social or behavioral therapy to help deal with the complications of seizures and the changes in lifestyle that they produce

Complementary treatments

Some complementary treatments may help some people in their efforts to deal with grand mal seizures and their treatments. These treatments, sometimes referred to as alternative therapies, are used in conjunction with traditional medical treatments. Complementary treatments are not meant to substitute for traditional medical care. Be sure to notify your doctor if you are consuming nutritional supplements or homeopathic (nonprescription) remedies as they may interact with the prescribed medical therapy.

Complementary treatments may include:

  • Acupuncture

  • Massage therapy

  • Nutritional dietary supplements, herbal remedies, tea beverages, and similar products

  • Yoga

What are the potential complications of grand mal seizures?

Grand mal seizures may occur just once, in which case complications are limited. Recurrent seizures, however, may have a profound impact on your life. Complications of untreated or poorly controlled grand mal seizures can be serious, even life threatening in some cases. You can help minimize your risk of serious complications by following the treatment plan you and your health care professional design specifically for you. Complications of grand mal seizures include:

  • Absenteeism from work or school

  • Brain damage

  • Damage to your tongue or mouth due to biting during seizure

  • Injury during seizure

  • Pulmonary aspiration (inhaling blood, vomited material, or other substances into lungs)

  • Status epilepticus (recurrent seizures without recovery)

  • Withdrawal or depression

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Jan 19
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
  1. NINDS epilepsy information page. National Institute of Neurological Disorders and Stroke.
  2. Generalized tonic-clonic seizure. PubMed Health, a service of the NLM from the NIH.
  3. Hesdorffer DC, Benn EK, Cascino GD, Hauser WA. Is a first acute symptomatic seizure epilepsy? Mortality and risk for recurrent seizure. Epilepsia 2009; 50:1102.