Arnold Gammaitoni, PharmD, Vice President of Medical and Scientific Affairs, Zogenix, gives an overview of rare epileptic encephalopathies such as Dravet syndrome and Lennox-Gastaut syndrome.

Dravet syndrome is a rare neurological condition that usually appears during the first year of life as frequent febrile seizures. As the condition progresses, other types of seizures typically occur, including myoclonus and status epilepticus. Moderate to severe cognitive impairment is also common. Most cases of Dravet syndrome occur due to a mutation of the SCN1A gene. It can be inherited in an autosomal dominant pattern, but most people with Dravet syndrome do not have a family history of the condition

Lennox-Gastaut syndrome is another rare neurological condition that usually begins in childhood. It is characterized by multiple types of seizures and intellectual disability. This condition can be caused by brain malformations, perinatal asphyxia, severe head injury, central nervous system infection, and inherited degenerative or metabolic conditions. In about one-third of cases, no cause can be found.

Treatment for both Dravet syndrome and Lennox-Gastaut syndrome typically includes anti-epileptic medications. There is usually no single antiepileptic medication that will control seizures. As Dr. Gammaitoni explains, children may improve initially on a medication, but many later show tolerance to it and/or develop uncontrollable seizures. Fortunately, recent data which was presented at the AAN 2021 meeting demonstrated long-term efficacy of fenfluramine for both Dravet syndrome (for which it is already FDA approved) and Lennox-Gastaut syndrome

To learn more about these and other rare neurological disorders, visit