Atonic Seizures

Dravet syndrome is a severe genetic disease marked frequent, treatment-resistant seizures that begin in infancy.  Children with Dravet syndrome can experience various types of seizures, including atonic seizures.

What are atonic seizures?

Atonic seizures, also known as drop seizures, are a type of seizure that causes a sudden loss of muscle strength. As its name implies, atonic seizures are quite different from tonic seizures, where patients experience muscle stiffening.

Episodes of atonic seizures are usually very brief, often lasting less than two seconds.

Disturbances in electrical activity in the brain leading to an atonic seizure can originate from both sides of the brain (generalized onset), or from one side of the brain (focal onset).

Patients who have focal onset atonic seizures may experience sudden weakness in one part of the body, dropping whatever they may have been holding. These patients are usually fully conscious.

Patients with generalized onset atonic seizures — the more common of the two — typically experience a sudden muscle limpness that affects the head (head dropping, and eyelid drooping), torso, and sometimes the whole body (and falling to the ground). Patients may not be fully aware of their surroundings during these types of seizures.

Management of atonic seizures

As with other types of seizures, atonic seizures can be managed using anticonvulsant medications. Other methods of possibly preventing seizures include the ketogenic diet, vagus nerve stimulation, and surgery.

Frequent falls are a concern in patients known to experience atonic seizures. Children who frequently have these types of seizures may need to wear protective gear, such as helmets or kneepads, to prevent injury during an attack.


Dravet Syndrome News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.