Atonic seizures are seizures characterized by a loss of muscle tone that causes the patient to fall to the ground. They usually onset in childhood, although a relatively small percentage of children develop atonic seizures. Persisting through adulthood, the seizures may not respond to medications and patients will be obliged to take precautions to protect themselves from injury if their seizures cannot be controlled with medication.
In an atonic seizure, the patient's head usually drops and the eyelids droop before muscle tone is lost elsewhere in the body and the patient falls down. It is the result of what is essentially a temporary glitch in the brain's wiring that sends mixed signals to the nerves, leading to a relaxation in muscle tension. Without the tension that is normally present in the muscles, the body cannot support itself.
The patient usually remains conscious and the seizure lasts less than a minute. Some patients experience temporary paralysis for a few minutes after an atonic seizure, while others may be able to resume regular activities immediately afterward. First aid is not required during or after the seizure, unless the patient has been injured by a fall. The biggest risk with atonic seizures is that the patient will fall on a hard surface or sharp object, potentially incurring a head injury, breaking a limb, or being otherwise injured.
Atonic seizures are also known as drop attacks, a reference to the head drooping and the falls that tend to accompany them. People who experience them usually alert friends and family so that they can be aware of what is happening during a seizure and so they know how to respond. Alert friends and family may, for example, catch someone who is falling to reduce the risk of injury. Medical cards or bracelets may be carried as well so that in the event that a seizure occurs in a strange environment, bystanders will know how to respond.
Electroencephalograms can be used to examine brain activity and diagnose a patient with a seizure disorder. A neurologist may recommend medications that can be tried to control the seizures. If the patient does not respond to medications, there are other options. Some people with seizure disorders have seizure dogs, service animals who are trained to signal when they detect the warning signs of a seizure, giving the patient time to get into a safe position. People prone to atonic seizures can also make adjustments to their home environments to make them safer in the event of a fall.