Dravet syndrome overview
Fact-checked by Dravet syndrome is a severe form of infantile-onset epilepsy characterized by seizures beginning in the first year of life and a range of developmental, cognitive, behavioral, and motor problems.
It is a rare condition, with an estimated 1.2 to 6.5 people per 100,000 worldwide living with Dravet. The disease arises from genetic mutations that aren’t usually inherited, so it’s not possible to predict who will develop it, and its symptoms can vary, making diagnosis difficult.
However, an early and accurate diagnosis is key to ensuring the best possible long-term outcomes. While people with Dravet syndrome rarely become completely seizure-free, there are available treatments that can help reduce seizure frequency, prevent life-threatening complications, and improve quality of life.
Causes
In the majority of cases, Dravet syndrome is caused by mutations in the SCN1A gene. These mutations affect the production of certain sodium channels in the brain, which is thought to enable the excessive nerve cell firing that characterizes seizures.
For about 90% of people, these mutations are de novo, meaning they arise spontaneously before birth. In the remaining minority of patients, Dravet syndrome is inherited when a parent passes down the mutation to their child.
While there is a well-established link between the SCN1A gene and Dravet syndrome, this gene is also associated with other forms of epilepsy or non-epileptic conditions.
Mutations in other brain-related genes are also potential causes of Dravet syndrome in people without SCN1A mutations, but less is known about them.
Common symptoms
Dravet syndrome symptoms include seizures — typically the clearest early signs of Dravet syndrome — followed by a range of developmental problems.
Seizures usually start in the first year of life and recur repeatedly thereafter. Common types of seizures in Dravet syndrome include:
- tonic-clonic seizures: convulsive seizures affecting both sides of the body
- hemiclonic seizures: abnormal movements limited to one side of the body
- myoclonic seizures: brief muscle jerks
- absence seizures: gradual loss of awareness, marked by staring off into space, without major body movements or convulsions
The specific characteristics of Dravet syndrome seizures may change over time. In infancy, seizures are usually tonic-clonic or hemiclonic, while other seizure types tend to emerge later. In early life, seizures are commonly triggered by fevers and are prolonged, lasting over five minutes, but this becomes less common with age.
While babies with Dravet are usually developmentally normal initially, a range of cognitive, behavioral, and motor problems may emerge with Dravet syndrome in children over age 1. Developmental delays in Dravet syndrome may manifest as:
- language and speech delays
- learning disabilities
- irritability, impulsivity, or other autism-like symptoms
- inattention and hyperactivity
- low muscle tone, poor coordination, and walking abnormalities
During adulthood, other movement problems, such as slowed movement and rigidity, may become more prominent.
Individuals with Dravet syndrome are also often prone to digestive problems, sleep disturbances, and infections.
Diagnosis
Reaching a Dravet syndrome diagnosis is a complex process that often takes time and involves multiple specialists.
The process relies heavily on a detailed review of a person’s symptoms to determine if they’re consistent with Dravet syndrome. Other diagnostic tests may include:
- genetic testing to identify SCN1A mutations that often explain Dravet syndrome
- MRI scans to visualize the brain and rule out other possible seizure causes
- electroencephalogram to look at the brain’s electrical signaling and identify changes consistent with Dravet
Dravet syndrome can have clinical overlap with other rare epilepsy syndromes and developmental disorders. Genetic testing can help differentiate Dravet from these conditions, but because of the complexities of Dravet syndrome genetics, genetic testing alone is not enough to establish or rule out a diagnosis.
Treatment
Treating Dravet syndrome is an individualized process. Patients, caregivers, and healthcare providers will work together to create a tailored treatment and monitoring plan.
The main goals of Dravet syndrome treatment are to:
- reduce the frequency of seizures
- avoid prolonged seizures
- help manage non-seizure symptoms
Most patients don’t entirely eliminate seizures even with treatment, but these steps can help control the disease and improve quality of life.
One or more daily anti-seizure medications are used by most people with Dravet. The most common ones include:
- valproate (including Depakote and generics)
- clobazam (sold as Onfi and generics)
- Diacomit (stiripentol)
- fenfluramine (sold as Fintepla and generics)
- Epidiolex (pharmaceutical-grade cannabidiol)
Most people with Dravet syndrome should avoid a common class of anti-seizure medications called sodium channel blockers, which may make symptoms worse.
If seizures are severe or prolonged, patients will need emergency treatment with rescue medications. This usually involves a class of medications called benzodiazepines and others, as needed.
Non-medication approaches may also help control seizures and support participation in daily activities. These include:
- ketogenic diet: a high-fat, low-carbohydrate, limited protein diet that may reduce seizure frequency
- vagus nerve stimulation: a technique that uses a device implanted in the chest to help regulate brain signals
- physical and speech therapy: strategies that can help manage non-seizure symptoms and make daily life easier
Living with Dravet syndrome
Living with Dravet syndrome can pose challenges for patients and those close to them, as seizure and non-seizure symptoms are often disruptive and affect participation in daily activities.
Doctors typically recommend identifying events or situations that can trigger seizures and avoiding these whenever possible. Common seizure triggers include:
- fevers
- infections
- cold or warm temperatures
- physical activity
- strong emotions
- bright lights
Other ways to make life with Dravet easier include:
- keeping a seizure diary and learning how to recognize seizure warning signs
- developing an emergency seizure management plan
- making safety adaptations at home and school to ensure that children have access to emergency seizure care when needed
- seeking accommodations to make a child’s participation at school and in other community activities easier
Mental healthcare, including counseling and support groups, is also important for helping patients and their caregivers manage life with Dravet.
Long-term outlook
Many Dravet syndrome symptoms change over time. While seizures may become less frequent and prolonged with age, motor function often continues to decline. Other developmental issues may stabilize or get worse.
People with Dravet may never be entirely seizure-free or able to live independently. Regular follow-up care and monitoring can help improve quality of life and maintain seizure control.
Dravet syndrome life expectancy varies, but it is improving with advances in treatment and care. About 85% of patients survive into adulthood. Effective control of seizures may reduce the risk of life-threatening complications such as sudden unexpected death in epilepsy, the leading cause of early mortality in Dravet.
Support and resources
Connecting with a multidisciplinary healthcare team with appropriate experience, including pediatric neurologists and epilepsy specialists, is important for helping families navigate a Dravet diagnosis and long-term treatment.
Several advocacy groups and research organizations offer support resources for Dravet syndrome, including educational materials, family programs, and networking opportunities. These organizations include the Dravet Syndrome Foundation, Dravet Syndrome U.K., and the Dravet Syndrome European Federation.
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.
