Dravet Syndrome

Many children with Dravet syndrome are initially misdiagnosed, since the diagnosis depends on the child's history of seizures and other symptoms that emerge as seizures progress. Another complication is that the usual tests used to evaluate epilepsy — magnetic resonance imaging (MRI) and electroencephalography (EEG) — appear normal at first in babies with Dravet syndrome. Experts believe some children are never correctly diagnosed.

In particular, Dravet syndrome may be first mistaken for febrile seizures, a common type of childhood seizure triggered by a fever. Unfortunately, medications used to treat febrile seizures can worsen seizures in children with Dravet.

Experts recommend genetic testing for children who have had any of the following:

  • Two or more prolonged (more than 10 minutes) seizures by age 1
  • One prolonged seizure and a hemi-clonic seizure (seizure causing rhythmic jerking in one side of the body) by age 1
  • Two seizures that affect alternating sides of the body
  • Seizure onset before 18 months of age, followed by myoclonic seizures (isolated jerking of a muscle or muscle group), absence seizures (brief periods when the child appears to stare into space, also called petit mal seizures) or both types

Genetic blood tests can screen for SCN1A mutations and a few other mutations linked to Dravet syndrome. However, these tests are not 100 percent conclusive, since they do not screen for all mutations that cause Dravet syndrome and because SCN1A mutations can also cause other, less severe forms of epilepsy. Some cases of Dravet syndrome do not have a clear genetic cause.

There is a strong chance that children who meet most of the following criteria have Dravet syndrome, even if they do not have an SCN1A mutation:

  • Normal development before the first seizure
  • Two or more seizures, with or without fever, before age 1
  • Two or more seizures that last more than 10 minutes
  • Myoclonic, hemi-clonic or tonic-clonic seizures
  • Seizures that do not respond to epilepsy medications, with seizures continuing past age 2

Reviewed by health care specialists at UCSF Benioff Children's Hospital.

Related Information

UCSF Clinics & Centers

Pediatric Epilepsy Center of Excellence
1825 Fourth St., Fifth Floor
San Francisco, CA 94158
Phone: (415) 353-2437
Fax: (415) 353-2400
Appointment information

Neurosurgery Clinic
1825 Fourth St., Fifth Floor, 5A
San Francisco, CA 94158
Phone: (415) 353-7500
Fax: (415) 353-2889
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