Developmental and Epileptic Encephalopathies

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Developmental and epileptic encephalopathies, or DEEs, refer to a group of severe epilepsies that typically begin early in life, are rare and are refractory. In children with DEEs, getting an accurate and timely diagnosis is important for a number of reasons: developing a proper treatment plan, understanding outcomes and managing expectations, guiding family planning, and often opening up a support network of other impacted families.

Here are some common questions and answers about diagnosis and treatment:

What causes DEEs?

The most common cause of DEEs is a genetic change. This is typically not a genetic change inherited from either parent but is a new change in the affected person (de novo variant).

How are DEEs diagnosed?

History, including past medical history, seizure types and response to medications can help with diagnosis.

  • Early indicators of DEE
    • Epilepsy:
      • Early-onset.
        • Seizures often difficult to control.
        • Specific seizure types (i.e., tonic seizures, epileptic spasms).
  • Development:
    • A regression or plateau with onset of seizures or during periods of poor seizure control.
    • An improvement during periods of better seizure control.
  • Diagnosing DEE:
    • EEG and MRI are often used to diagnose DEE.
    • Genetic testing often confirms and can classify the DEE.

DEE and epilepsy syndromes

Epilepsies can be classified into specific electroclinical syndromes, based on history, seizure types and EEG findings. Here are some epilepsy syndromes that are considered DEEs:

  • Epileptic spasms/West syndrome.
  • Ohtahara syndrome (Early infantile DEE).
  • Epilepsy of Infancy with Migrating Focal Seizures (EIMFS).
  • Dravet syndrome.
  • Epilepsy with Myoclonic-Atonic Seizures (EMAS/EMAtS/Doose syndrome).
  • DEE-SWAS (including continuous spike and wave in sleep and Landau-Kleffner syndrome).
  • Febrile infection-related epilepsy syndrome (FIRES).

Treatment in DEEs

DEEs tend to be poorly responsive to standard antiseizure medications. Sometimes earlier, targeted treatment may be associated with better outcomes.

  • Medications.
  • Ketogenic diet.
  • Surgery (not a good option for all DEEs, i.e., channelopathies).

Your doctor can help you find the best treatment plan, based on your specific DEE and medical history.

Future therapies in DEEs

Precision medicine is a term that means medications and therapies that are designed to help a patient or group of patients, usually based on genetic or metabolic information. Clinical trials are currently taking place using targeting therapies for certain DEEs with additional studies planned to take place in the near future. These include treatments to help impaired genes work better or replacing genes that are not functioning properly.

Learn more about how Mayo Clinics epilepsy experts can help manage your epilepsy

Anthony L. Fine, M.D., is a pediatric neurologist and epileptologist at Mayo Clinic. His clinical and research focus includes the evaluation and treatment of developmental and epileptic encephalopathies, with a particular interest in DEE-SWAS (CSWS and LKS). He also studies the diagnosis and management of genetic epilepsies and fetal and neonatal neurology.