Clonic Seizures

Dravet syndrome is a severe form of epilepsy characterized by prolonged seizures that appear in the first year of life.

Dravet syndrome patients may experience different types of seizures. These are often characterized by motor symptoms that may include jerking movements (clonic seizures), limp muscles (atonic seizures), rigid muscles (tonic seizures), and muscle twitching (myoclonic seizures).

What are clonic seizures?

Clonic seizures are characterized by rhymical jerking movements caused by muscles repeatedly stiffening and relaxing. These motor symptoms can affect the whole body or individual parts of the body such as the arms or legs. These movements cannot be stopped by restraining the person.

Clonic seizures may last just a few seconds or up to one minute. During these seizures, the person may lose control of their bodily functions.

Clonic seizures may start on just one side of the brain (focal onset) or on both sides of the brain simultaneously (generalized onset).

Focal onset clonic seizures cause motor symptoms only on one side of the body while generalized onset clonic seizures affect the whole body. During a focal onset clonic seizure, the person is usually aware of what is happening while they may lose consciousness during a generalized onset clonic seizure.

Clonic seizures are rare. They may occur in various ages, including in newborns. Brief and infrequent clonic seizures can occur in infants, and may disappear on their own within a short time. More commonly, clonic movements are seen in tonic-clonic seizures, where they are followed by muscle stiffening.

Clonic seizure management

It is important to protect a person having clonic seizures from falls to avoid injuries.

Patients should also have an emergency seizure management plan that contains detailed information about what to do in case of a seizure.

Anticonvulsants may be used to help prevent clonic seizures. These medicines work by reducing the excitability of nerve cells. First-line anticonvulsant agents for clonic seizures include Depacon (sodium valproate), Lamictal (lamotrigine), and Topamax (topiramate).

If seizures do not respond to treatment, doctors may perform an electroencephalography (EEG) to look at the electrical activity of the brain. This can help them determine where in the brain the seizures start, what may be triggering them, and what type of seizure the patient is having. This information may allow them to pick a more effective treatment for the patient.


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.