Dravet Syndrome

Dravet syndrome is a rare and severe form of epilepsy. At some point before age 1, children with Dravet syndrome begin to have frequent, prolonged seizures that are difficult to control with standard epilepsy treatments.

At first, children with Dravet syndrome appear healthy and develop normally. As the seizures continue, cognitive and motor development may slow or stop. The severity of the developmental delay varies from child to child. In some children, cognitive delays may go through periods of improvement, although most patients have some degree of lifelong disability.

Current treatment options for Dravet syndrome include medications, special diets and an implantable device called a vagal nerve stimulator. It is often very challenging to find a treatment or combination of treatments that completely controls the seizures. Research to uncover new treatments is underway, and children who don't improve with available therapies may be eligible for clinical trials.

Recent studies suggest Dravet syndrome affects around 1 in 15,000 children. Three percent to 8 percent of children who have seizures in their first year of life are eventually diagnosed with the syndrome.

Causes

More than 80 percent of Dravet syndrome patients have a mutation in a gene called SCN1A. This mutation affects the sodium channels in the brain, which are important for regulating the firing of nerve cells. Other genetic mutations may also cause Dravet.

These mutations usually occur spontaneously during fetal development and are not inherited from a parent. However, there are rare cases of families with more than one affected child.

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The first sign of Dravet syndrome is usually a convulsive seizure that is triggered by a fever, typically around 5 to 8 months of age. First, the body stiffens, then one or both sides of the body start to jerk repeatedly.

Children with Dravet syndrome go on to have other types of seizures in the weeks or months after the first event. The seizures tend to be long (more than two minutes) and difficult to control with medication. They may be triggered by infections, changes in body temperature, flashing lights or other visual stimuli, and emotional stress or excitement.

Between the ages of 1 and 5 years, many children begin to show signs of developmental delay as well as other health issues that have been associated with Dravet syndrome. These can include:

  • Poor coordination
  • Unsteady gait
  • Slow speech development
  • Behavioral issues such as hyperactivity, irritability and traits associated with autism
  • Frequent infections
  • Slow growth and poor weight gain

Many children with Dravet syndrome are initially misdiagnosed, since the diagnosis depends on the child's history of seizures and other symptoms that emerge as seizures progress. Another complication is that the usual tests used to evaluate epilepsy — magnetic resonance imaging (MRI) and electroencephalography (EEG) — appear normal at first in babies with Dravet syndrome. Experts believe some children are never correctly diagnosed.

In particular, Dravet syndrome may be first mistaken for febrile seizures, a common type of childhood seizure triggered by a fever. Unfortunately, medications used to treat febrile seizures can worsen seizures in children with Dravet.

Experts recommend genetic testing for children who have had any of the following:

  • Two or more prolonged (more than 10 minutes) seizures by age 1
  • One prolonged seizure and a hemi-clonic seizure (seizure causing rhythmic jerking in one side of the body) by age 1
  • Two seizures that affect alternating sides of the body
  • Seizure onset before 18 months of age, followed by myoclonic seizures (isolated jerking of a muscle or muscle group), absence seizures (brief periods when the child appears to stare into space, also called petit mal seizures) or both types

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Because Dravet syndrome is so rare, it can be difficult to find a pediatric neurologist who has experience in treating it. The Dravet Syndrome Foundation maintains a searchable listing of physicians who have treated patients with Dravet syndrome and related epilepsies. To search the site, visit www.dravetfoundation.org.

When caring for children with Dravet syndrome, our main goals are to achieve the best possible control of the seizures, prevent a dangerous type of seizure called status epilepticus, and improve the child's and family's quality of life.

To reduce the frequency and severity of the seizures, patients must avoid seizure triggers and take medications. A ketogenic diet — low in carbohydrates and high in fats — may also help. Surgery is generally not recommended, but an implantable device called a vagal nerve stimulator may reduce seizures in some cases.

Working with experts such as a speech therapist, physical therapist and occupational therapist can help improve patients' motor and cognitive development. Psychological and social support for the whole family is also important.

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UCSF Research & Clinical Trials

 

Reviewed by health care specialists at UCSF Benioff Children's Hospital.

Related Information

UCSF Clinics & Centers

Pediatric Epilepsy Center of Excellence
1825 Fourth St., Fifth Floor
San Francisco, CA 94158
Phone: (415) 353-2437
Fax: (415) 353-2400
Appointment information

Neurosurgery Clinic
1825 Fourth St., Fifth Floor, 5A
San Francisco, CA 94158
Phone: (415) 353-7500
Fax: (415) 353-2889
Appointment information

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