Atonic seizures are a type of seizure that involves a sudden loss of muscle tone. They typically cause a person to become limp and fall to the floor.
During an atonic seizure, the regular electrical activity in the brain becomes disrupted, meaning that the person has a temporary inability to move or speak and loses muscle strength. The seizure may start in one part of the brain or the entire brain. These types of seizures generally first occur in childhood, and they may extend into adulthood.
Although there is no cure for atonic seizures, some treatments help manage the symptoms. People may also be able to prevent some seizures by identifying and avoiding triggers.
In this article, we look at atonic seizures in more detail, including the potential causes and treatments. We also explain when a person should see a doctor.
An atonic seizure is a type of seizure. A seizure occurs as a result of a period of uncontrolled electrical activity in the brain. It can cause muscle problems, strange behaviors, unusual sensations, and an altered state of awareness.
Different types of seizures cause various symptoms. An atonic seizure causes the muscles to lose all their normal tension. As a result, the person suddenly becomes limp and may remain in this state for about 15 seconds.
Doctors may also call these episodes drop seizures or drop attacks, as the person can sometimes fall to the floor without notice.
The atonic seizure may affect the entire body or only certain parts, such as the eyelids or head.
The symptoms of an atonic seizure in adults include:
- falling to the ground
- part or all of the body becoming limp
- dropping things
The symptoms of an atonic seizure in children include:
- going limp and falling
- sudden loss of muscle tone
- briefly losing consciousness
- drooping eyelids
- nodding head
Following a seizure, the individual may return to their normal alert state and recover quickly, or they may feel confused about what happened and appear disoriented.
In some cases, a person may sustain an injury as a result of falling. They will likely be able to treat any bruises, cuts, or other mild injuries at home, but if they have a serious injury, they should visit a doctor immediately. Adults and children who fall frequently may need to consider wearing headgear and other forms of protection.
There are two types of atonic seizures: focal and generalized. Focal seizures affect a small area of the brain and may only lead to muscle weakness in one area of the body.
Conversely, generalized seizures can begin throughout both halves of the brain, affecting a more significant proportion of the body. When an atonic seizure involves the entire brain, doctors call it a generalized onset atonic seizure. These seizures begin with a sudden drop of the head, trunk, or whole body.
Atonic seizures are most common in children. Although they may sometimes last into a person’s adult years, many children do outgrow them.
Sometimes, atonic seizures are linked to Lennox-Gastout syndrome, which is a severe form of childhood epilepsy that causes frequent and multiple types of seizures. Children living with Lennox-Gastout syndrome often also have developmental and behavioral issues.
Multiple factors, including rapid breathing and flickering lights, can trigger seizures in people with this form of epilepsy.
Doctors need to use a variety of tests to diagnose atonic seizures. One of the most important tools in diagnosing these seizures is having an observer who can describe or record what they saw.
The standard test that doctors use to diagnose epilepsy is an electroencephalogram (EEG), in which they attach electrodes to the person’s scalp to record electrical activity in the brain. An EEG can reveal whether there is any unusual activity. The patterns that doctors observe can point to the type or types of seizure someone experiences.
If doctors cannot successfully diagnose atonic seizures from an observer’s information and the EEG results, they may need to perform further tests that check for changes in blood pressure or heart rhythm.
Medicine is the most common first-line treatment for seizures, as it successfully controls seizures for about 70% of individuals living with epilepsy.
Various medicines can treat atonic seizures, although they may not be helpful for everyone. The options to prevent or stop seizures include anti-seizure medications, which some may refer to as anti-epileptic drugs. It may take some trial and error to find the best drug and dosage amount.
If medication is ineffective in reducing seizure frequency or duration, a person will need to try other treatment options. Among these is vagus nerve stimulation, which uses a small implanted device in the chest to send regular electrical pulses through the vagus nerve to the brain. The person cannot feel this stimulation. Combining this treatment with anti-seizure medication is often very effective.
People may also find dietary therapies beneficial. A ketogenic diet is a treatment option that doctors use
Brain surgery may be another treatment option for some individuals. Doctors
Some people may need to wear a helmet alongside their treatment to protect their head if they often fall during their seizures. The protection that the helmet provides will help prevent brain injury.
Family and friends may find it challenging to intervene if they witness someone having an atonic seizure because they typically happen with no warning. Observers often do not need to provide any
However, an observer can help the person who is having a seizure by:
- putting the person on their side to help clear the airway, if they have fallen to the floor
- placing a folded item of clothing or another soft item under the person’s head
- asking any other people nearby to stay at a safe distance
- noting the time at the start of the seizure
- checking for a medical bracelet or emergency information
- moving any hard or sharp objects away from the individual
- refraining from holding the person down
- making sure that there are no objects in the person’s mouth
People who have atonic seizures can have just one seizure or several consecutive ones. If a person tends to have more than one seizure, anyone supporting them should help them remain safe until they are no longer having seizures.
If the person has sustained an injury because of a fall, they may need medical attention afterward.
When someone experiences a seizure for the first time, they should make an appointment to speak with a doctor. The doctor can determine the type of seizure and what treatment option is best.
If the individual experiences two or more seizures that seem to have no cause, a doctor may diagnose them with epilepsy. Once someone has a confirmed epilepsy diagnosis, they should seek medical advice if they experience:
- a seizure that lasted more than 5 minutes
- repeated seizures over 30 minutes or longer
- remaining unconscious after the seizure has ended
- breathing that remains abnormal after the seizure
Anyone whose seizure symptoms appear to worsen should inform their doctor. They may need to increase their medication dosage, change medication, add a new medication, or try a new treatment method. Their doctor will be able to recommend the best course of action, depending on the situation.
Atonic seizures, also called drop seizures, result in an individual losing muscle tone. When a person experiences one of these seizures, their head may drop, they may drop other items, or they may fall to the floor. Atonic seizures are common in children, who may outgrow them in time.
Doctors can diagnose atonic seizures on the basis of witness accounts, EEG readings, or CT and MRI scans. Medication is the most common treatment, but ketogenic diets, vagus nerve stimulation, and surgery are other possibilities.
Anyone who is around someone who has an atonic seizure should check for any injuries once they have regained consciousness and take them to a doctor if necessary.