What is Dravet syndrome?
Dravet syndrome, also called severe myoclonic epilepsy of infancy (SMEI), is a severe form of epilepsy. It appears during the first year of life with frequent fever-related seizures, febrile seizures that, by definition, are rare beyond age 5. Later, other types of seizures typically arise, including myoclonus (involuntary muscle spasms). Status epilepticus – a state of continuous seizure requiring emergency medical care – may also occur.
Because of the number and severity of seizures experienced, children with Dravet syndrome typically experience poor development of language and motor skills, hyperactivity and difficulty relating to others.
Who gets it?
Dravet syndrome occurs equally in both boys and girls and has no ethnic, geographic or socioeconomic boundaries. Many of the children diagnosed with Dravet syndrome do have a genetic mutation in the SCN1A gene.
What causes it?
In 30 to 80 percent of cases, Dravet syndrome is caused by defects in the SCN1A gene required for the proper function of brain cells. The SCN1A gene helps control the flow of sodium ions to neurons in the brain and to muscle and endocrine cells throughout the body. In Dravet syndrome, a mutation in the SCN1A gene causes the gene to allow too many or too few sodium ions to reach neurons and cells, triggering an “electrical storm” in the brain that manifests as seizures.
Testing and diagnosis
The specialty team at Cook Children’s will begin your child’s diagnosis by looking at his or her medical history and, when possible, your family’s medical history as well. A thorough physical examination will be performed and your doctor will ask questions about your child’s symptoms and seizures, such as when did they begin, how often do they happen and how long do they last?
Blood may be drawn so that the doctor can rule out other causes of your child’s seizures. Your doctor may also record your child’s brain waves using electroencephalography (EEG) testing. Depending on your child’s particular case, your doctor may also recommend an MRI and even 3-D modeling to get a clearer picture of your child’s brain and seizure activity. In some instances, genetic testing may be done since recent studies suggest that nearly 80 percent of Dravet syndrome patients possess a mutation in the SCN1A gene.
Once testing is complete, if your doctor determines that your child has Dravet syndrome, the Dravet syndrome team will work closely with you and your family to create a plan for both short-term treatment and long-term care.
How is it treated?
Seizures in Dravet syndrome are difficult to control, but can be reduced by anticonvulsant drugs. A ketogenic diet, high in fats and low in carbohydrates, also may be beneficial.
As children with Dravet syndrome get older, their decline in cognitive function stabilizes, and in many, it improves slightly. However, most teenagers with Dravet syndrome are dependent on caregivers.
The degree of cognitive impairment appears to correlate with the frequency of seizures. For this reason, your child’s treatment plan will focus on controlling the number of seizures your child has and their severity.
Depending on your child’s particular diagnosis, antiepileptic, or anticonvulsant medications, will be prescribed to prevent, or at least reduce, seizures. For some children with a history of prolonged seizures (seizures episodes that last for longer periods of time) or status epilepticus “rescue” medications are prescribed to stop seizures in progress.
Since Dravet syndrome can interfere with your child’s development and cognitive skills, your doctor will also recommend physical and occupational therapy. Developmental delays typically appear within the first four years of life. Treating developmental issues early helps to maintain a better quality of life for your child, and your family.
Because Dravet syndrome can be challenge for the family and caregivers, our therapists work closely with your whole family so that you can help to encourage your child at home. We will also work with educators and other caregivers involved in your child’s daily routine.
Cook Children’s understands kids and families and we offer a variety of support services do help make your journey easier to navigate. For that reason your care team may include:
- Dravet syndrome specialists
- Nurse practitioner
- Patient navigator
- Child Life specialists
- Social workers
You’ll also find a strong support network for every member of the family.