This epilepsy is also known as CSWS or epilepsy with continuous spike-wave during slow wave sleep.

  • This syndrome is a very rare form of epilepsy, affecting 1 out of 200 (0.5%) children with epilepsy.
  • CSWS may start in children between 2 and 12 years of age, most often between 4 and 5 years of age.
  • Children can be developing normally before the onset of CSWS.
  • Boys seem to be affected more often than girls.
  • The cause of CSWS is often found to be brain malformations (when an area of brain forms differently at birth), genetic variant, or metabolic conditions.

Seizures begin first, followed by a slow cognitive decline that often is not noticed by caregivers at first. Types of cognitive problems depend on where abnormalities are found in the brain.

  • If an electroencephalogram (EEG) shows abnormalities in the frontal lobes, behavioral problems, such as attention deficit hyperactivity disorder (ADHD), aggression, or impulsivity, are more common.
  • If abnormalities are more commonly seen on an EEG in the posterior region of the brain (back of the head), language or other cognitive abilities may be impaired.
  • The most common seizure type seen in CSWS is focal motor seizure (only one part of the body is affected).
  • Focal seizures can progress to affect both sides of the brain. When this happens, the seizure is called a bilateral seizure and looks like tonic-clonic seizures or convulsions.
  • Other seizure types include absence (staring), atypical absence, and atonic (drop attack) seizures.
  • Seizures usually happen during sleep.
  • The cause of CSWS is unknown. New (de novo) genetic mutations (changes in how genes work) have been found in some children. A gene called GRIN2A has been associated with this epilepsy.
  • A family history of seizures or epilepsy is usually not seen.
  • Doctors diagnose CSWS after taking a thorough history with a description of all seizure types and of the child’s development and behavior.
    • Find forms to help you describe seizures in our Toolbox.
  • An EEG (electroencephalogram) is needed to diagnose CSWS.
    • In many instances, a prolonged EEG that includes sleep or video EEG (overnight admission to the hospital) is also needed.
    • The EEG in children with this epilepsy syndrome is abnormal, especially as they enter sleep.
    • The spike discharges seen in CSWS tend to become much more frequent during sleep as compared to wakefulness.
    • Almost continuous slow-spike-wave is seen during the slow sleep cycle. Your physician might use the term ESES, which stands for electrical status epilepticus during slow sleep.
    • These EEG changes may happen in more than 85% of the child’s sleep time. The EEG changes improve during the REM sleep cycle.
  • Genetic and metabolic tests may be ordered.
  • MRI (magnetic resonance imaging) scans can be normal, but they are needed to see if a structural problem in the brain is present.

Seizures in children with CSWS are treated with anti-seizure medications. In rare instances, surgery may be recommended.

  • Medications often used are steroids or high dose diazepam at night. Other medications that have been used to treat this epilepsy syndrome include clobazam (Onfi), ethosuximide (Zarontin), valporic acid (Depakote/Depakene), acetazolamide (Diamox), and levetiracetam (Keppra). Often, more than one medicine is used at once.
  • Medications can be used together or by themselves, depending on what works for each child.
  • If seizures persist despite medication, a surgery called multiple subpial transections may be done. This type of surgery makes multiple small cuts in the brain cortex where the seizures begin.
  • If a brain abnormality is present in a child with CSWS, a resective brain surgery can be considered.
  • Children may be developing normally when seizures first start. A progressive decline in cognitive and behavioral functioning starts up to 1-2 years later.
  • Children with CSWS may improve during the teenage years. Seizures often improve or stop and cognitive and behavioral functioning may get better.
  • While cognitive and behavioral functioning may improve, rarely do children return to normal functioning and can be left with severe impairment.
  • For some children, the abnormalities on EEG may continue into the adult years.

Authored By:

Charuta Joshi MD
Michael Ciliberto MD


on Monday, February 17, 2020

Reviewed By:

Elaine Wirrell MD


on Sunday, February 16, 2020
Charles Anderson