ENCEPHALOPATHY

Developmental and/or epileptic encephalopathy

The term developmental encephalopathy (DE) applies when there is onset of a condition manifesting with cognitive, neurological, or psychiatric impairment, stagnation, or regression, due directly to the underlying etiology. In contrast, an epileptic encephalopathy (EE) is present when the encephalopathy is caused by the epileptic activity. The term developmental and epileptic encephalopathy (DEE) is used when both factors contribute to the patient’s condition.

Progressive neurological deterioration

The term developmental encephalopathy can be challenging to apply in an older individual who has completed all development normally before onset of an epilepsy with cognitive, neurological, or psychiatric impairment, stagnation, or regression. In such individuals the term progressive neurological deterioration can be used instead of DE when this impairment is due directly to the underlying etiology.

Epilepsy syndromes with encephalopathy or progressive neurological deterioration

The following epilepsy syndromes are associated with developmental and/or epileptic encephalopathy or progressive neurological deterioration in all (or nearly all) patients:

Neonate/Infant

• Early-Infantile Developmental and Epileptic Encephalopathy (EIDEE)
• Epilepsy of Infancy with Migrating Focal Seizures (EIMFS)
• Infantile Epileptic Spasms Syndrome (IESS)
• Dravet Syndrome (DS)

Childhood

• Epilepsy with Myoclonic Atonic Seizures (EMAtS)
• Lennox-Gastaut Syndrome (LGS)
• Developmental and/or Epileptic Encephalopathy with Spike-Wave Activation in Sleep (DEE-SWAS, EE-SWAS)
• Febrile Infection-Related Epilepsy Syndrome (FIRES)
• Hemiconvulsion-Hemiplegia-Epilepsy Syndrome (HHE)

Variable Age

• Progressive Myoclonus Epilepsies (PME)
• Rasmussen Syndrome (RS)