Continuous spike-wave during sleep is an age-dependent epileptic encephalopathy characterized by the presence of status epilepticus during slow-wave sleep, and significant cognitive-behavioral impact. It is also known as Penelope syndrome. Landau-Kleffner syndrome (or epilepsy-aphasia spectrum) is a subtype of this disease, in which the neurological deficit is a receptive aphasia.

EEG tracing during sleep with ESES.
Characteristic clinical course of the disease.

There is a patient association with POCS that has information available on its website.