Electrical status epilepticus during slow-wave sleep (ESESS)

27th March 2019

ESESS is a particularly rare epilepsy syndrome that develops in mid-childhood, around 4-5 years and normally affects children who already have epilepsy. It accounts for just 0.2% – 0.5% of childhood epilepsy syndromes and it’s slightly more common in males than females (62%). The cause of this syndrome is still currently unknown.

What are the symptoms of ESESS?  

There are a number of symptoms that are synonymous with ESESS, one of the first things is that the child’s learning development will slow significantly. This can mean that their ability to understand speech and language is impaired, also known as receptive dysphasia. They can also have trouble expressing their own feelings and thoughts in speech, also known as expressive dysphasia.

There are different types of seizures that can occur, particularly during sleep. However, despite the name, some children will not have any seizures during sleep. Types of seizures may include:

  • Absence (blank) seizures
  • Myoclonic (jerk) seizures
  • Focal (partial) seizures

Click here to read about the different types of seizures and how to recognise the difference between each one. 

One interesting characteristic of ESESS is that even though sleep patterns are often heavily disturbed with seizures, children will usually wake up feeling refreshed and appearing to have slept well.


An electroencephalogram (EEG) test will usually determine ESESS by monitoring the electrical brain patterns during sleep. The test will show a continuous spike and wave pattern, which is especially prevalent during the part of sleep commonly known as ‘slow wave’. It’s this finding that gives the syndrome its name, however, the abnormal patterns will often show whilst the child is awake too.

With ESESS, metabolic tests, such as blood tests and brain scans will often give normal results.

What’s the treatment for ESESS?

If the seizures are a problem, then it may be that epilepsy medicines (AEDs) are prescribed. Common AEDs for this syndrome include sodium valproate, ethosuximide and clobazam. Prednisolone, which is a steroid medication, has proven to be effective at treating ESESS, however, it requires close monitoring. Sulthiame may also be effective, but only a specialist in paediatric epilepsy can prescribe these two medications.

Unfortunately, for some children, ESESS will not respond to any medication. If the child has this syndrome and frequently experiences prolonged or repeated seizures (status epilepticus), then it’s crucial that a rescue plan is put in place.

Find out more about status epilepticus here in one of our other blog posts


For most children who have ESESS, an improvement will be seen during their early teenage years as they enter pubity. In many cases, the EEG results will return to normal and seizures will become less frequent or stop altogether. However, in some cases, ESESS may persist through childhood and into their adult life.

National Epilepsy Training can help

For more information on Electrical status epilepticus during slow-wave sleep (ESESS) or to enquire about our training and care services. Please contact us on 01706 373075 or email admin@nationalepilepsytraining.co.uk.