Grand mal seizures have two stages:
- Tonic phase. Loss of consciousness occurs, and the muscles suddenly contract and cause the person to fall down. This phase tends to last about 10 to 20 seconds.
- Clonic phase. The muscles go into rhythmic contractions, alternately flexing and relaxing. Convulsions usually last for less than two minutes.
The following signs and symptoms occur in some but not all people with grand mal seizures:
- Aura. Some people experience a warning feeling (aura) before a grand mal seizure. This warning varies from person to person, but may include feeling a sense of unexplained dread, a strange smell or a feeling of numbness.
- A scream. Some people may cry out at the beginning of a seizure because the muscles around the vocal cords seize, forcing air out.
- Loss of bowel and bladder control. This may happen during or following a seizure.
- Unresponsiveness after convulsions. Unconsciousness may persist for several minutes after the convulsion has ended.
- Confusion. A period of disorientation often follows a grand mal seizure. This is referred to as postictal confusion.
- Fatigue. Sleepiness is common after a grand mal seizure.
- Severe headache. Headaches are common but not universal after grand mal seizures.
When to see a doctor
If you see someone having a seizure:
- Call for medical help.
- Gently roll the person onto one side and put something soft under his or her head.
- Loosen tight neckwear.
- Don't put anything in the mouth — the tongue can't be swallowed and objects placed in the mouth can be bitten or inhaled.
- Don't try to restrain the person.
- Look for a medical alert bracelet, which may indicate an emergency contact person and other information.
- Note how long the seizure lasts.
A grand mal seizure lasting more than five minutes, or immediately followed by a second seizure, should be considered a medical emergency in most people. This is also a medical emergency if the person is pregnant, injured or diabetic. Seek emergency care as quickly as possible.
Additionally, seek medical advice for you or your child:
- When the number of seizures experienced increases significantly without explanation
- When new signs or symptoms of seizures appear
Grand mal seizures occur when the electrical activity over the whole surface of the brain becomes abnormally synchronized. The brain's nerve cells normally communicate with each other by sending electrical and chemical signals across the synapses that connect the cells.
In people who have seizures, the brain's usual electrical activity is altered. Exactly what causes the changes to occur remains unknown in about half the cases.
However, grand mal seizures are sometimes caused by underlying health problems, such as:
Injury or infection
- Traumatic head injuries
- Infections, such as encephalitis or meningitis, or history of such infections
- Injury due to a previous lack of oxygen
Congenital or developmental abnormalities
- Blood vessel malformations in the brain
- Genetic syndromes
- Brain tumors
- Very low blood levels of glucose, sodium, calcium or magnesium
- Using or withdrawing from drugs, including alcohol
Risk factors for grand mal seizures include:
- A family history of seizure disorders
- Any injury to the brain from trauma, stroke, previous infection and other causes
- Sleep deprivation
- Medical problems that affect electrolyte balance
- Illicit drug use
- Heavy alcohol use
Certain activities could be dangerous if you have a seizure while doing them. Activities include:
- Swimming. If you go in water, wear a life preserver and don't go alone.
- Bathing. Bathing also can pose a risk of drowning. Shower instead.
- Driving a car or operating other equipment. Most states have licensing restrictions for driving for people with a history of seizures.
The force of a seizure or falling as a result of a seizure can cause injury. In extreme cases, seizures can be fatal, particularly if medication is not taken consistently or properly.
Types of injuries that can occur with seizures include:
- Joint dislocations
- Head injuries
- Bone fractures
Whether repeated seizures can cause brain damage has been studied extensively, but there's no simple answer.
The longer a seizure lasts, the more likely it is to lead to changes in brain function and structure. Repeated brief seizures also can lead to brain changes, sometimes causing a normal brain to become epileptic, a process known as kindling.
The seriousness of repeated seizures underscores the need for control with medication.