Understanding DEE-SWAS

Developmental and Epileptic Encephalopathy with Spike–Wave Activation in Sleep (DEE-SWAS) is a rare childhood epilepsy syndrome that accounts for approximately 0.5% to 1.3% of all paediatric epilepsies.
It typically begins between ages 2 and 12, most often around ages 4 to 5, and is characterised by developmental regression or loss of skills and abnormal brain activity during sleep.
Prevalence: DEE-SWAS affects roughly 1 in every 200 children with epilepsy.

What happens in the brain

DEE-SWAS is marked by a distinctive EEG pattern called spike-and-wave activation during slow-wave (deep) sleep.
While the child may appear to be sleeping peacefully, the brain may be experiencing near-continuous electrical discharges — sometimes for up to 100% of deep sleep.
These “invisible seizures” interfere with the brain’s nightly process of sorting, storing, and organising information, which is critical for learning, memory, and emotional regulation.

Impact on development

Children with DEE-SWAS may halt or lose previously acquired skills, including:

• understanding and using language

• memory, learning, and attention

• reasoning and social understanding

• movement, coordination, and emotional control

These changes can occur gradually or suddenly. Families often describe watching their child’s skills fade or fluctuate from day to day — as if their child is “there but not there.”
For educators and therapists, this can appear as sudden changes in comprehension, mood, or communication, which may be mistaken for behavioural issues rather than neurological regression.

Causes

DEE-SWAS can arise from genetic causes that alter how the brain develops and functions.
Other contributing factors can include:

• Brain injury or infection

• Metabolic or structural abnormalities

• Unknown causes

Also known as

DEE-SWAS may appear under different names in clinical or research contexts, including:

• EE-SWAS (Epileptic Encephalopathy with Spike–Wave Activation in Sleep)

• CSWS (Continuous Spike-Wave during Slow-Wave Sleep)

• ESES (Electrical Status Epilepticus in Sleep)

• Landau-Kleffner Syndrome

• Atypical Benign Partial Epilepsy / Pseudo-Lennox Syndrome

• Penelope Syndrome

A helpful analogy: the brain as a library

Imagine the brain as a library filled with books that represent knowledge, memories, and skills.
Each night, a “librarian” comes in to sort and shelve what was learned that day.

In DEE-SWAS, the librarian doesn’t show up.
Instead, spike-wave discharges scatter the books across the floor.
When morning comes, the child may not remember what they learned, or may lose access to words or skills they previously had.
The brain remains a library without a librarian — disorganised, inefficient, and unable to build on what it once knew.

Current challenge: missing evidence-based supports

While advances in genetics and neuroimaging are improving medical understanding, there are still no established evidence-based interventions addressing the educational, psychosocial, and community impacts of DEE-SWAS.
This means:

• Educational settings often lack awareness of the fluctuating cognitive and communication challenges these children face.

• Therapists and allied health professionals have little evidence to guide interventions when skills change daily or regress after sleep disruption.

• Families are left navigating major uncertainty about how to support their child’s identity, learning, and wellbeing beyond seizure control.

At present, most research and clinical focus is on seizure suppression, while social participation, learning recovery, and emotional development remain under-researched.
Filling these gaps will require collaboration between families, educators, clinicians, and researchers — so that the focus extends beyond what is lost to what can still grow and reconnect.