CDKL5-associated developmental and epileptic encephalopathy: A long-term, longitudinal electroclinical study of 22 cases.

CDD is a true developmental and epileptic encephalopathy with a specific etiology characterized by the early appearance of epileptic seizures that quickly become polymorphic and drug resistant in infants that are most often female and already have neurological impairment. Polygraphic video-EEG recordings are important to recognize ictal events of the association of hypermotor seizures, epileptic spasms in clusters, and massive myoclonic jerks, already present at onset.