Health Library

Dravet Syndrome

Dravet syndrome is also known as “severe myoclonic epilepsy of infancy.” It is rare. It affects one in every 15,000 children. The goal of treatment is to improve quality of life by controlling seizures and improving cognitive outcomes. Cognitive outcomes are a a person’s ability to think and reason.

What Causes Dravet Syndrome?

Most cases of Dravet syndrome are caused by a change of the SCN1A gene that causes brain cells to not work correctly. Most of the time, Dravet syndrome occurs randomly. It is not inherited from the parent. This change in the SCN1A gene is found in about 80 percent of all diagnosed cases of Dravet syndrome. A blood test can show if this genetic change is present.

If the SCN1A gene change is not present, other gene changes may be responsible for the child having Dravet syndrome.

What are the Symptoms of Dravet Syndrome?

The first sign of Dravet syndrome is a seizure in the child’s first year of life. It is usually triggered by a fever. This seizure affects one side of the body. It is typically clonic (convulsions) or tonic-clonic (the body stiffens, then convulses).

Over the following months or years, seizures happen more often. They may look different, although the child usually does not have a fever.

Children with Dravet syndrome typically have more than one kind of seizure. Seizure types can include:

• Absence seizures and atypical absence seizures
• Atonic seizures
• Myoclonic seizures
• Focal seizures
• Bilateral tonic-clonic seizures
• Non-convulsive status epilepticus

Seizures for children with Dravet syndrome last from a few minutes to an hour or longer. Children with Dravet syndrome may have several seizures in a row. Some seizures can be life-threatening. These need emergency medical treatment.

Seizures triggers for Dravet syndrome can include:

• Fever
• Illness (especially when the child has a fever)
• Sudden temperature changes (such as stepping into a warm bath)
• Stress
• Some medications

Other Conditions Associated with Dravet Syndrome

Children who have Dravet syndrome usually have hard-to-control seizures. Most of them can also have developmental problems, including:

• Autism spectrum disorder
• Hyperactivity
• Mood issues such as anxiety and depression
• Behavioral issues
• Communication delays

These problems begin to appear around the age of 2. At that point, children with Dravet syndrome may stop gaining new developmental skills. They may start to lose some of the developmental progress they have made. Around the age of 6, these children often begin to stabilize developmentally.

Other conditions that are associated with Dravet syndrome include:

• A weakened immune system
• Dental health issues
• Dysautonomia (a malfunction of the autonomic nervous system, which controls breathing, digestion and other vital functions)
• Heart problems
• Growth and nutrition problems
• Orthopedic issues, such as a crouched posture or scoliosis (abnormal curvature of the spine)
• Sleep disturbances
• Unsteadiness

How is Dravet Syndrome Diagnosed?

Dravet syndrome is commonly misdiagnosed. An early diagnosis is essential. It means families can address developmental concerns earlier in a child’s life. This is when therapies are most helpful.

A diagnosis is based on:

• Seizure history
• A physical and neurologic examination
• An electroencephalogram (EEG), a test that detects electrical activity in the brain.
• Genetic testing to identify a change in the SCN1A gene. This gene causes about 80% of diagnosed Dravet syndrome cases.

How is Dravet Syndrome Treated?

Currently, there is no known cure for Dravet syndrome. Symptoms are different from child to child. Each patient must have a personalized treatment plan that meets their specific needs.

A child’s treatment plan may include:

• An effective combination of medications. Most children with Dravet syndrome are on more than one anti-seizure medication.
• A ketogenic diet. This has helped some children with Dravet syndrome achieve better seizure control.
• “Rescue medication.” This is used when a seizure lasts so long that it becomes life-threatening.
• Physical, occupational, speech and play therapy.
• Working with a team of specialists to address other concerns. This may include heart issues and sleeping problems.

Scientists are developing new genetic therapies for Dravet syndrome. These therapies aim to control seizures and treat other conditions that occur with Dravet, especially cognitive disorders.

In most cases, doctors do not recommend surgery for Dravet syndrome.

A child may undergo blood tests, EEGs and imaging studies to monitor the effectiveness of treatment.

Dravet Syndrome Prognosis

Children do not outgrow Dravet syndrome. The condition affects every area of their lives. They may need constant care to keep them safe. Constant care will help them avoid seizure triggers. Treatment plans can be complex. The medical team can work with family members to find support and resources to help the child reach their full potential.