Other names: Severe Myoclonic Epilepsy of Infancy; SMEI
Dravet syndrome is a rare type of epilepsy that begins in the first year of life in an otherwise healthy child. A syndrome is a combination of specific signs and symptoms that when occur together are diagnosed as a medical condition.
Dravet syndrome patients have a particular type and pattern of epileptic seizures and as the syndrome progresses other issues become apparent including developmental delay or regression, sleep disturbance issues, behaviour problems and mobility concerns such as unsteady gait. The first seizure usually occurs in the first 12 months of life and this often occurs while the child has fever due to illness or vaccination. Following the first seizure more seizures follow with increasing severity, changes in seizure type and often the seizures become unpredictable, frequent and difficult to control.
The seizures often start out as jerky movements (clonic seizures), that are prolonged and more likely to affect one side of the body. As the syndrome progresses the seizures types can include myoclonic seizures (affecting whole or half of the body), atypical absence seizures, focal seizures, serial seizures or status epilepticus. Dravet syndrome patients are more prone status epilepticus, which is when there is a long lasting seizure or when seizures occur close together without recovery between them. With Dravet syndrome there is an increased risk of sudden unexplained death in epilepsy (SUDEP) compared to other types of epilepsy.
Most patients with Dravet syndrome have a change or mutation in the SCN1a gene which causes a faulty protein to be made. This faulty protein reduces the brain’s ability to control electrical messages within the brain and causes seizures.
