Early infantile developmental and epileptic encephalopathy (EIDEE)

Early infantile developmental and epileptic encephalopathy (EIDEE) is a severe, but very rare epilepsy syndrome that can develop in babies under 3 months of age. It causes babies to have many seizures and delayed development.

What would you like to find out about today?

Other names for (EIDEE)

Early-infantile developmental and epileptic encephalopathy (EIDEE) was previously divided into two syndromes: Ohtahara syndrome (or Early infantile epileptic encephalopathy) and Early myoclonic encephalopathy.

Who gets EIDEE?

EIDEE almost always starts when babies are very young, often in the first few weeks of life and always before 3 months of age.

There is usually an underlying problem with the baby’s brain, or a metabolic disorder (affecting chemical processes in the body). This can often be due to a genetic problem – a change (‘mutation’) in a gene that’s passed down from the parents. But there isn’t usually any family history, or any problems that happened during pregnancy or birth. This means there’s no way of knowing that a baby would develop EIDEE, and nothing you could do to prevent it.

In about 1 in 5 babies with EIDEE, no genetic, metabolic or brain problems can be identified.


If your baby has EIDEE, they may get different types of seizures. These can include:

  • Tonic seizures – these cause the baby’s arms and legs to suddenly stiffen
  • Myoclonic seizures – these cause short, jerking movements of the face, arms, legs or sometimes just a single eyebrow, lip or finger
  • Focal motor seizures – these cause jerking (called clonic) movements in one area of your baby’s body
  • Epileptic spasms – when your baby’s body suddenly stiffens – these are shorter than tonic seizures (lasting only 1 or 2 seconds) and usually happen when your baby wakes up. They can happen repeatedly in ‘clusters’.

Your baby may have many seizures throughout the day sometimes with clusters of several seizures at once. They can also have different types of seizure, one after the other.

Ohtahara syndrome, or Early infantile epileptic encephalopathy, used to be the term for babies with EIDEE who mainly had tonic seizures. Early myoclonic encephalopathy was the term used when myoclonic seizures were the main seizure type. As there was a lot of overlap between these two conditions, they’re now just grouped together as EIDEE.

Babies with EIDEE usually have other problems too. Most will have development and learning delays, which can be severe – although this can be hard to assess due to their young age. They can also have movement disorders, which can cause jerking, muscle spasms and tremors separately from seizures. There may also be problems with vision and movement, as well as feeding difficulties.


Your baby should be referred to a specialist doctor called a paediatrician for an assessment. They’ll want to know exactly what happens when your baby has a seizure. It can be helpful to show the doctor a video of the seizures if you have one.

The specialist will do a test called an EEG (electroencephalogram) to help confirm a diagnosis. An EEG looks at electrical activity in the brain. In babies who have EIDEE, the EEG will have an abnormal pattern, called burst-suppression. This means it shows periods with very high activity, alternating with low activity.

The specialist will also look at any other problems your baby is having such as with their movement or vision.

Your baby will usually need a brain scan called an MRI (magnetic resonance imaging) to check for any problems with brain structure. Their doctor will also usually suggest genetic tests and blood and urine tests. These tests can often help to find out exactly what’s caused your baby’s epilepsy, which may affect their treatment and outlook.

If genetic tests reveal any change in a specific gene, including a mutation, this may also help with planning future pregnancies.


If a specific cause has been identified for your baby’s EIDEE, treatment may be directed at this. For example, if they have a metabolic disorder (affecting chemical processes in the body), treatment can aim to correct this. EIDEE caused by certain gene changes may respond better to particular treatments. And if there is a structural change in the brain, surgery may be possible.  These treatments will only be possible in a very small number of children.

Epilepsy medicines usually used to control seizures don’t usually work very well in treating the seizures in EIDEE. One medicine does not seem to be particularly better than any other medicine. But depending on the underlying cause, your child’s specialist may suggest trying one. They may also suggest treatment with steroids (called prednisolone) or hormones (called ACTH). They may also try treatment with the vitamin supplements pyridoxine or biotin, to see if your baby responds to this.

If your child has EIDEE, it’s likely they will have prolonged or repeated seizures. This is known as status epilepticus and is a medical emergency. Your child’s doctor will discuss a ‘rescue’ or emergency care plan with you to treat any prolonged or repeated seizures.


Information about treatments for children can be found on the Medicines for Children website.


Sadly, the severe disabilities and complications associated with EIDEE means that many babies with this condition don’t live longer than a year or two. Those that do survive longer than this will have limited development and severe disabilities. Some babies go on to develop other epilepsy syndromes, such as infantile epileptic spasms (previously known as West syndrome) or Lennox-Gastaut syndrome.

There is care and support available for you if you have a baby with severe disabilities or a life-limiting condition, like EIDEE. We have support available at Epilepsy Action through our Helpline and support groups. You can also get information, advice and support from the organisations listed below.




Contact – for families with disabled children

Freephone helpline: 0808 808 3555
Email: helpline@contact.org.uk


Together for Short Lives

Charity helping families caring for a seriously ill child
Helpline: 0808 8088 100


This information has been produced under the terms of the PIF TICK. The PIF TICK is the UK-wide Quality Mark for Health Information. Please contact website@epilepsy.org.uk if you would like a reference list for this information.
Published: July 2023
Last modified: October 2023
To be reviewed: July 2026
Tracking: A079.01 (previously S036)
Was this article helpful?
Was this article helpful?

Here to support you

a graphic of a headset

Call the Epilepsy Action helpline

If you would like to talk to someone about epilepsy, our trained advisers are here to help.

0808 800 5050
A graphic of a email envolope

Send us your question

Send a question to our trained epilepsy advisers. (We aim to reply within two working days).

Contact us today