Medical Information


Information found here will help families, professionals, and other concerned parties become familiar with the medical aspects of Dravet syndrome, including diagnosis, testing, and genetic mechanisms.


Dravet syndrome, also known as severe myoclonic epilepsy of infancy (SMEI), is a rare genetic disorder which occurs in roughly 1:16,000 to 1:21,000 births [1]. It is a progressive disorder characterized by multiple seizure types, often including life-threatening status epilepticus (prolonged seizures that require emergency care.) The course of the condition is variable from patient to patient and earmarks of the syndrome include multiple seizure types that are resistant to treatment, developmental delays, lowered immunity, orthopedic concerns, and hyperactivity. A significant number of patients have a family history of febrile seizures or seizure disorders.


The first seizure occurs in an otherwise healthy infant during the first year of life, presenting with or without fever, and the seizure is often prolonged. In the second year of life, additional seizures types appear, such as myoclonic seizures. Seizures are difficult to control and may be reduced by anticonvulsant drugs, although current treatment options are extremely limited. The ketogenic diet, high in fats and low in carbohydrates, may also be beneficial.


Children with Dravet syndrome (DS) have poor language development and impaired motor skills. Early development is normal before seizures start, but in the second year of life development typically slows. Later, regression becomes evident and is often accompanied by hyperactivity and mental retardation. As children with DS get older their decline in cognitive function stabilizes and seizures have a tendency to improve. However, most teenagers with DS are dependent on caregivers and will require life-long care. Individuals with DS also face a higher incidence of SUDEP (sudden unexplained death in epilepsy) and have associated co-morbid conditions which also need to be properly managed.


[1] Incidence of Dravet Syndrome in a US Population


NEXT: Diagnosis & Testing