Is Dravet Syndrome a Type of Epilepsy?
Dravet Syndrome is a rare seizure disorder caused by a genetic abnormality that starts in infancy. It’s a lifelong epileptic condition that causes developmental and cognitive problems in people who suffer from it, according to the U.S. National Institute of Neurological Disorders and Stroke.
What are the symptoms of Dravet syndrome?
Symptoms of Dravet syndrome may range from mild to severe and include:
- Convulsive seizures that begin before 15 months of age
- Seizures are prolonged and involve half of the body
- Subsequent seizures may involve the opposite half of the body
- Temperature changes, like exiting a warm bath, can bring on a seizure
- Status epilepticus, a medical emergency condition of continuous seizure, may happen often in children with Dravet, especially before age five.
- Developmental cognitive and physical delays resulting from seizures
- Changes in eating and appetite
- Crouched gait and compromised balance as the child grows older
Most cases of Dravet (about 80%, according to the NIH) are caused by a harmful mutation of the SCN1A gene. This gene encodes for sodium channels in neuron membranes, the proper functioning of which is crucial for movement and sensory tasks and baseline homeostasis (balance) within the nervous system.
What is the treatment for Dravet syndrome?
Treatment for Dravet syndrome, until 2018, mostly relied on general seizure medications targeting the faulty neuronal sodium channels, the NIH states. This was when the U.S. Food and Drug Administration approved cannabis-based Epidiolex (cannabidiol) as the first medication for Dravet, specifically, and the first cannabidiol-based medication approved in the U.S.
Fenfluramine, first released as an appetite suppressant, is also an FDA-approved medication approved for Dravet syndrome in patients age 2 and older as of June, 2020, according to the NIH.
Other seizure medications (oxcarbazepine, carbamazepine, phenytoin, and lamotrigine) shouldn’t be used on a daily basis – especially in small children – as they can increase the number of seizures and make them worse in the long term, the NIH states.
What is the prognosis for Dravet syndrome?
Cognitive disability can range from mild to profound. Most people with Dravet, also known as severe myoclonic epilepsy of infancy (SMEI), are reliant on caretakers throughout their lives, though the severity of symptoms may vary, the NIH states.
People with Dravet have fewer seizures as they grow older, and more than a 300% increased chance of early death, according to one study. About 16 people per 1000 with Dravet will die in a given year as opposed to 5 in 1000 with no serious underlying health conditions, according to the 2016 study published in Epilepsy Research. The numbers were based on the outcomes from 100 people with Dravet followed for about 17 years.
An estimated 10% to 20% of individuals with Dravet syndrome die before they reach adulthood.