Epileptic encephalopathy: What to know

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Generally, the term encephalopathy describes any condition that affects the structure or function of the brain. This can occur due to all types of epilepsy.

According to a 2012 article, experts recognize eight epileptic syndromes commonly associated with encephalopathy, including:

• West syndrome: This condition causes spasms and atypical brain activity that can affect a person’s intellectual capacity. The spasms usually occur in newborns but can occur at any age. Medications can help manage this condition in some. There are several known causes of West syndrome.
• Dravet syndrome: This severe type of epilepsy causes frequent seizures lasting 15–30 minutes or longer. Seizures can occur due to high body temperature or without a trigger. Specific gene mutations cause Dravet syndrome, but it can also occur without a recognized mutation. It begins in the first year of life and can lead to:
  • developmental delays
  • speech impairments
  • coordination and balance issues
  • decreased muscle tone
  • other health issues
• Landau Kleffner syndrome: This syndrome is very rare. It affects a person’s ability to understand and express language. Additionally, atypical brain activity and seizures occur during sleep. These seizures usually begin at around 3–8 years old and can stop before the individual is 15.
• Early myoclonic encephalopathy (EME): EME is a rare condition that typically begins during the newborn period. It causes frequent seizures that doctors cannot manage with medication. Someone with EME can have a shorter life expectancy.
• Ohtahara syndrome: Also known as early infantile myoclonic encephalopathy, this usually occurs within the first 3 months of life. It causes frequent seizures that can result in brain damage. Changes to the structure of the brain can lead to Ohtahara syndrome.
• Myoclonic status in nonprogressive encephalopathies (MSNPE): This condition causes myoclonic seizures to occur in clusters that go on for an extended period. Motor, cognitive, and behavioral impairments can also occur with MSNPE.
• Lennox-Gastaut syndrome (LGS): LGS usually presents in early childhood or infancy. It sometimes occurs due to an underlying condition, though the cause is not always known. This severe type of epilepsy causes seizures, as well as the following:
  • cognitive impairments
  • developmental delays
  • behavioral issues
• Continuous spike wave of sleep (CSWS): This is a rare condition that may affect children and adolescents. CSWS presents as seizures of different types, usually occurring during sleep. A gradual cognitive decline follows the seizure onset. While certain genetic mutations have links with CSWS, the exact cause is unknown.

For many of the epileptic encephalopathy syndromes mentioned above, the cause is unknown. Various factors, such as underlying conditions, can contribute.

Some syndromes have links with specific genetic mutations. For example, a mutation in the SCN1A gene can cause Dravet syndrome. Other syndromes, such as West Syndrome, can have multiple possible causes, including:

• brain injury
• genetic causes
• atypical brain development

Symptoms of epileptic encephalopathy vary greatly depending on the syndrome. However, several epileptic encephalopathy syndromes share symptoms, including:

• seizures, which can be atonic, tonic, or myoclonic
• sleep disturbances
• behavioral difficulties, such as hyperactivity, aggression, and issues with attention
• motor impairment
• cognitive impairment
• developmental delays

Learn more about what a seizure looks like.

The first step to diagnosing epileptic encephalopathy is to identify the underlying cause.

Alongside taking a medical history and performing a physical exam, a doctor may use various tests to determine the specific syndrome a person has. Tests may include a combination of the following:

• electroencephalogram (EEG) to measure brain activity
• other imaging tests, such as an MRI scan, PET scan, or magnetoencephalography scans
• genetic testing
• blood tests
• urine tests
• spinal fluid tests

A doctor may also need to find out more about the seizures. Family or carergivers can help document or gather information on seizure activity. This includes information on the following:

• the type of seizure someone has
• the duration of the seizure
• possible triggers
• the frequency of seizures

Epileptic encephalopathy syndromes are often very resistant to treatment.

Doctors usually aim to manage seizures. Options will depend on the individual’s underlying condition and unique circumstances but can include:

• anti-seizure medications
• hormone therapy
• corticosteroids
• ketogenic diets, which are high in fat and low in carbohydrates
• vagus nerve stimulation
• surgery

It may be possible to reduce or stop the progression of symptoms associated with epileptic encephalopathy only if doctors can treat seizures and other atypical brain activity effectively.

Some people with epileptic encephalopathy experience complications that may be lifelong even if the person stops having seizures.

Common complications include:

• intellectual disabilities
• movement disorders
• respiratory difficulties
• sleep issues
• gastrointestinal issues

Epileptic encephalopathy can be life threatening. This is generally due to a complication rather than seizures themselves.

In some cases, people can experience what doctors refer to as sudden unexpected death in epilepsy (SUDEP). Estimates suggest that SUDEP occurs in 1 in 1,000 individuals with epilepsy every year.

A person’s outlook varies greatly and depends on their unique circumstances.

According to a 2016 paper, reversing some impairments that seizures and epileptiform activity can cause may be possible when doctors treat seizures effectively. Epileptiform activity is a pattern of brain activity that occurs in seizures but does not always cause them.

However, treating this condition is challenging. Those living with epileptic encephalopathy are likely to have some intellectual or physical impairment.

Life expectancy

According to research from 2020, epileptic encephalopathy has a mortality rate of around 25% by age 20. Each epileptic encephalopathy syndrome may have a different life expectancy.

Epileptic encephalopathy is a term that refers to a range of conditions in which epileptic seizures and other atypical brain activity cause behavioral and cognitive impairments. This can happen with any form of epilepsy. However, it is commonly associated with certain conditions called epileptic encephalopathy syndromes.

Symptoms and treatments vary between underlying conditions, but epileptic encephalopathy can be resistant to medication and is often challenging to treat. A person with the condition will likely experience some intellectual or physical impairment for life.

When doctors can effectively manage seizures through treatment, reducing or stopping the progress of other more severe symptoms may be possible.