What is “atonic”? Atonic means without tone. Normal tension in a muscle is tone. In atonic seizures, a person’s head may nod, they may drop what they are holding, their muscles suddenly lose strength, their eyelids droop, and the person usually drops to the ground. Atonic seizures can also be called “drop seizures”. The seizure usually lasts less than 15 seconds and the person stays unconscious. Childhood is usually when they start and last into adulthood. Helmets are used for protection to keep from injury due to falling.
Another name for this type of seizure is “akinetic” (a-kin-ET-ik), which means “without movement.
WHO IS AT RISK FOR ATONIC SEIZURES? Atonic seizures usually begin in childhood and are often seen in syndromes like Lennox Gastaut syndrome.
WHAT IS IT LIKE TO HAVE AN ATONIC SEIZURE? The person’s body will go limp. If they are sitting, their upper body and head slump over. Usually if standing, the person will fall to the ground limp. This is different from tonic seizures. People fall down to the ground stiff. Their muscles are suddenly contracting.
WHAT HAPPENS AFTER AN ATONIC SEIZURE? First Aid is usually needed after the seizure due to the fall. The person may or may not be confused. People who have atonic seizures are recommended to wear helmets for protection.
HOW OFTEN WILL THEY OCCUR WHEN SOMEONE HAS ATONIC SEIZURES? People who have atonic seizures may have one or up to several in a row. If with a person having an atonic seizure, make sure the area is safe to prevent injuries.
HOW CAN I TELL IF SOMEONE IS HAVING AN ATONIC SEIZURE? If the person is sitting, their head may droop down all of a sudden. If the person is standing, they will suddenly fall to the ground.
HOW ARE ATONIC SEIZURES USUALLY DIAGNOSED? The description of the seizure by the witness usually gives an idea of the diagnosis. Monitoring with EEG will confirm it. Other tests may have to be performed if the seizures continue. Tests will check the heart rhythm and/or blood pressure. Tests will see if this the reason for the person was falling.
HOW ARE ATONIC SEIZURES TREATED? They can be treated with surgery (callosotomy), diet (ketogenic or modified Atkins), device (Vagal nerve stimulator), and medicine.
IF I THINK MY LOVED ONE OR CHILD MAY HAVE ATONIC SEIZURES, WHAT SHOULD I DO? If you think you or a loved one may be having atonic seizures, talk to your doctor immediately. Atonic seizures may cause injuries due to falls. Correct diagnosis is important for treatment.