Why are there so many names?

You might feel confused about why there are so many names for this.

• When my child was first diagnosed, we were told it was CSWS or ESES.

• A year or two later, when I read more, I started seeing DEE-SWAS.

• Now I understand that my child has EE-SWAS.

In online groups, people use different names. This can depend on what their doctor says, or when their child was diagnosed.

All of these names describe very similar conditions.

So what’s going on?

Over time, doctors have named different parts of the same thing:

• ESES / CSWS describe the brain waves seen on an EEG in sleep

• Landau-Kleffner syndrome is a type that mostly affects speech

• Newer names like DEE-SWAS show this is not just epilepsy - it also affects how our children learn, grow and change over time.

Why hasn’t this been made simpler for us?

• Doctors working in this field trained at different times when different names were used - they’ve held on to the name they were taught

• As a result, studies they do also use different terms

• Some doctors prefer more specific labels. e.g. A doctor might use Landau–Kleffner syndrome if speech is the main issue.

How it affects patients and families

This can make it hard families to find clear health information, feel confident the information we find relates to our child’s diagnosis, and make sense of what it means for their day-to-day life.

It can also make it harder to explain to the important people in your child’s life.

For example, your child might be diagnosed with CSWS, but the most helpful online health information to share with their teacher is written under DEE-SWAS.

Educators are busy and the simpler we can make it to support our child, the more confident we feel that our child can get the support they need at school.

1920s to 1930s
Brain waves are discovered

Early EEG research made it possible to recognise this condition.

• 1924 – the first human EEG was recorded
  Hans Berger (1873–1941) and The Discovery of Clinical Electroencephalography
  

• 1935 – this is when the spike–wave activity in epilepsy (including DEE-SWAS) was first described.
  A brief history on the oscillating roles of thalamus and cortex in absence seizures

1970s
Sleep shown to be important

This is when doctors discovered that unusual brain activity during sleep can cause learning, communication and behaviour changes.

• 1971 – Doctors described ESES in children who had lost skills
  Subclinical "Electrical Status Epilepticus" Induced by Sleep in Children

1970s to 2000s
A condition is recognised

Doctors begin to name this as a syndrome linked to:

• abnormal brain activity in sleep

• loss or slowing of skills

• changes in behaviour

ESES and CSWS become the names used. The focus goes from seizures alone to how a child is learning and developing. No clear cause recognised.

Subclinical "Electrical Status Epilepticus" Induced by Sleep in Children

2000s to 2010s
A spectrum is recognised

Doctors see CSWS/ESES is not one condition, but a range, with different ways it shows up and how the child changes over time.

This includes overlap with:

• Landau–Kleffner syndrome (LKS)

• focal epilepsies with sleep activation

  Guidelines for EEG in encephalopathy related to ESES/CSWS in children

2013
First gene link found

In 2013, a gene called GRIN2A was discovered to be a cause in some children with conditions like CSWS and Landau–Kleffner syndrome. This was one of the first clear genetic links.

GRIN2A mutations cause epilepsy-aphasia spectrum disorders

Question: when were other causes identified - perinatal stroke, cortical malformation, other brain injuries, immune system

2010s to present
New names

Earlier names like ESES and CSWS were about what the EEG pattern looked like.
But they didn’t always match the impact in children.

Newer terms focus on how the child is learning and developing in their day-to-day life.
Common names today:

• EE-SWAS - used when a child develops typically at first, then loses or slows skills

• DEE-SWAS - used when there are already differences in a child’s development, and epilepsy adds further impact.

Proposed classification: Syndromes in Children

2020s
Brain networks and connections

The focus is now moving beyond seizures and EEG patterns.

Newer research suggests DEE-SWAS is not just about abnormal activity in one part of the brain. Changes in how brain networks develop and work together over time may help explain changes in learning and development.

Developmental and epileptic encephalopathy with spike–wave activation in sleep: From the ‘functional ablation’ model to a neurodevelopmental network perspective

What the research says

A recent paper, Rebuilding the Tower of Babel: The Current Landscape and Emerging Opportunities in DEE-SWAS, shows that:

• There is still no global agreement on how to diagnose DEE-SWAS.

• The main marker used is the spike-wave index (SWI), measured on an EEG. But experts do not agree on how to use it.

• There is no consistent cut-off for how much of sleep must be affected. There is also no clear evidence that one number is correct.

“The historical 85% cutoff has been predominant, but proposed guidelines in 2009 offered a lower cutoff of ≥50% in NREM sleep. Some groups utilize a 25% cutoff.”

• There is also no standard way to calculate SWI. Different clinicians use different methods, which can give different results.

• There is no clear agreement on what SWI actually means in real life, or how well it reflects what is happening to the child.

Tower of Babel idea

The title of the paper uses the story of the Tower of Babel.

In the story:

• People are trying to build something together

• But they suddenly speak different languages

• They can no longer understand each other

• The project breaks down into confusion.

In this paper, Tower of Babel means:

People are using different terms, definitions and methods, so they cannot clearly communicate or move forward.

Why this matters for families

The lack of agreement about SWI (for example 85%, 50% or 25%) can affect whether a child:

• is diagnosed

• receives treatment

• is monitored closely

• is seen as having a serious condition.

As one paper states:

“Due to the lack of an established electroclinical phenotype, there has been no standardization of therapy.”

• The same child could be diagnosed in one clinic, and not in another, based only on how SWI is measured or interpreted.

• A child may be diagnosed with DEE-SWAS when their SWI is above a certain level. But if it drops below that level, they may no longer be considered to have it.

This can happen even if:

• thinking and learning are still affected

• cognitive difficulties continue

• behaviour and emotional regulation are still impacted

Questions this raises

• How much do these cut-offs reflect a child’s needs - and how much do they reflect what each health system can support?

• What happens to children who fall just below a cut-off, but are still struggling?

What families experience

Families may face:

• different answers from different clinicians, with no clear way to resolve them

• long delays before changes are recognised or acted on

• ongoing learning and behavioural difficulties without a clear diagnosis

• access to care and support that depends on cut-offs, not need.

Parents and carers often have to advocate again and again just to have concerns taken seriously.

This comes with a real cost in time, energy and emotional load.

Access also depends on where you live

Where a child lives can affect the care they receive.

A child may be seen by:

• a neurologist with deep experience in developmental and epileptic encephalopathies

• or a clinician who has rarely if ever seen DEE-SWAS.

The bottom line

The paper makes this clear:

We still don’t have a shared and reliable way to define, measure and diagnose DEE-SWAS.

Until there is global agreement on SWI:

• diagnosis will continue to vary

• decisions will differ between clinicians and services

• Children may live with lifelong effects from decisions made - or not made - at critical times.

• Families will continue to carry deep uncertainty that affects their child’s care, future planning and daily life.

Developmental and Epileptic Encephalopathy with Spike–Wave Activation in Sleep (DEE-SWAS) is an umbrella term for a rare type of childhood epilepsy, with varying presentations, causes and outcomes.

• It affects around 1 in 200 children with epilepsy.

• It usually starts between ages 2 and 12, most often around 4 to 5 years old.

Children can lose previously learned skills, or their development may slow or stop, meaning they are not gaining new skills as expected.

This is linked to unusual brain activity during sleep.

More information

If you’re looking for more detailed medical information about DEE-SWAS, these pages may help.

They can be technical, but they provide more in-depth explanations of diagnosis, EEG patterns and treatment.

• EpilepsyDiagnosis.org overview (EE-SWAS / CSWS)

• Epilepsy Foundation (DEE-SWAS)

• AboutKidsHealth (DEE-SWAS)

• Treatment of Developmental/Epileptic Encephalopathy With Spike-Wave Activation in Sleep

The less the environment around a child can adapt to their changing needs, the harder life becomes.

Impact on learning, connection and participation

Common challenges families talk about include:

Cognitive

• Regression in thinking, problem-solving and memory

• Difficulty learning and retaining new information

• Impaired attention span and focus

• Poor planning and decision making (executive function)

• Slowed processing speed.

Language and Communication

• Delayed or halted speech

• Loss of previously acquired words or sentences

• Difficulty understanding spoken language (receptive language)

• Difficulty expressing thoughts verbally (expressive language)

• Limited vocabulary

• Trouble with articulation and clarity of speech

• Social communication challenges (e.g conversations, social cues)

Emotional wellbeing

• Hyperactivity or impulsiveness

• Mood swings, anxiety, depression

• Difficulty in emotional regulation (e.g., sudden outbursts)

• Social withdrawal and lack of interest in social interactions

• Aggression or irritability

• Repetitive behaviours or routines

• Difficulty adapting to routine changes

• Reduced ability to express emotions.

Movement and coordination

• Coordination and balance difficulties

• Delay or loss of gross motor skills (e.g., walking, running, jumping)

• Fine motor difficulties (e.g., writing, buttoning clothes)

• Tremors or abnormal movements

• Muscle weakness or stiffness (hypertonia)

• Ataxia (uncoordinated movements)

• Gait abnormalities (e.g., walking difficulties, unsteady walking).

Seizures

• Subclinical seizures in sleep, especially in slow wave (deep) sleep (spike-and-wave activity)

• Subclinical seizure activity in the waking hours

• Occasional or frequent clinical seizures, including visible (e.g., tonic-clonic, absence) both day and night

Toileting and continence difficulties

• Bedwetting

• Accidents in the day.

Sensory and Perception

• Sensory processing(hypersensitivity or hyposensitivity)

• Sensory overload or under-reactivity (e.g., to sound, light, touch)

• Difficulty with spatial awareness and body positioning

• Impaired vision or hearing processing (e.g., trouble interpreting visual or auditory stimuli).

Social and Interactive

• Difficulty forming and maintaining friendships

• Struggles with peer relationships and social integration

• Lack of interest in group activities

• Trouble understanding or responding to social cues (e.g., tone of voice, facial expressions)

• Isolation or avoidance of social situations

• Reduced ability to engage in age-appropriate play or interactions

Sleep

• Sleep disturbances (e.g., trouble falling asleep, frequent waking)

• Irregular sleep habits (e.g., staying up late or waking up too early)

• Sleep apnoea or irregular breathing patterns during sleep

• Restlessness or hyperactivity at night

• Poor sleep quality despite adequate hours of sleep.

Co-existing conditions

• Intellectual disability (ranging from mild to severe)

• Autism spectrum disorder (ASD)

• Attention deficit hyperactivity disorder (ADHD)

• Cerebral palsy

• Speech and language disorders

• Sensory processing disorders

• Sleep disorders (e.g., night terrors, insomnia).

IMPORTANT NOTE: These examples reflect a range of experiences, including changes in development, learning and behaviour. You may find parts of them confronting, especially if you are early in your journey. Before reading, you might want to pause and consider whether this is the right time, and whether it is likely to make life feel lighter or heavier right now. Go gently.

These are amalgamations of stories I have come across over time, in articles, case studies, and conversations with other families, alongside my own child’s experience.

DEE-SWAS is used in examples to keep things clear. Many children, including my own, may be diagnosed under other names such as ESES, CSWS or LKS.

If your child’s journey looks different, you are welcome to share it by emailing melanie@voicesofdeeswas.org

These anonymised scenarios can help show the range of DEE-SWAS presentations.

‘Benign’ epilepsy that wasn’t
A child was diagnosed with benign rolandic epilepsy in early primary school. Over time, their speech slowed, learning became harder, and behaviour changed. What first seemed mild was later recognised as part of the DEE-SWAS spectrum.

Stroke, cerebral palsy, then DEE-SWAS
A child had a stroke in their early years. They were left with hemiplegia, cerebral palsy and epilepsy. Years later, subtle changes like tiredness and dribbling led to an EEG and a diagnosis of DEE-SWAS.

Early brain injury and difficult decisions
A child had a brain injury around birth and developed epilepsy early. In the early school years, they were diagnosed with DEE-SWAS. Despite multiple medications, development regressed and surgery was discussed as a possible next step.

Normal development, then sharp decline
A child developed typically until around age 6. Seizures began, followed by noticeable changes in thinking and learning. Later testing showed a significant drop in ability, leading to a diagnosis of DEE-SWAS.

School first notices change
A child was developing typically until around age 6. Their teacher first noticed a shift in behaviour including withdrawal and rigid behaviour. A tonic seizure led to a nocturnal epilepsy diagnosis. Behaviour and learning then declined dramatically. There were more clinical seizures and further testing led to a DEE-SWAS diagnosis. A few years on, the child has autism, ADHD and dyspraxia diagnoses and attends an autism school. There is autism and ADHD in the wider family.

Early epilepsy, then a second wave
A child had seizures in infancy and later improved. After a few stable years, new seizures and regression appeared at school age. They were then diagnosed with DEE-SWAS.

Genetic condition alongside DEE-SWAS
A young child with a known genetic condition developed DEE-SWAS with very high spike-wave activity. Multiple medications were tried to try to reduce it.

Loss of language and emotional control
A child gradually lost speech and the ability to process language. Daily meltdowns and distress followed. After a long search for answers, an EEG showed DEE-SWAS.

Ups and downs over time
A child does not follow a steady decline. Instead, they move through good phases and bad phases over weeks or months. Speech, behaviour and learning go up and down. Diagnosis sits within the DEE-SWAS spectrum.

Improvement in the teen years
A child lost speech and learning skills during childhood with DEE-SWAS. In the teen years, brain activity improved. They regained some skills and independence but still live with ongoing disability.

Illness-triggered epilepsy and developmental change
A child was developing typically until early childhood, when a serious illness led to epilepsy. By around age 7, she showed intellectual delay, impulsivity and reduced emotional regulation. She was later diagnosed with DEE-SWAS. There is a family history of epilepsy.

Medication-related onset or worsening
A child was diagnosed with epilepsy in early childhood and started on medication. After this, seizures, sleep and behaviour worsened. EEG showed near-continuous activity during sleep. The child was later diagnosed with DEE-SWAS, with medication suspected to have contributed to the change.

Structural cause and ongoing high EEG activity
A child with a widespread brain malformation developed ESES with very high sleep activity that persisted over years. Multiple medicines and surgery were tried with limited effect. The focus shifted from resolution to long-term management and quality of life.

Return or persistence in adulthood
A child experienced ESES in early childhood that appeared to settle, then saw a return of significant symptoms in early adulthood. Ongoing sleep-related epileptic activity and cognitive changes continued. Transition to adult care was difficult, with limited specialist knowledge available.

Immune-related pathway and partial response
A child with long-standing ESES showed temporary response to steroids. Further testing suggested brain inflammation. An immune-based treatment reduced EEG activity for the first time, but required careful adjustment due to medication side effects and ongoing uncertainty.

To come

To come

To come

To come