Epileptic spasms with terror during sleep in CDKL5 encephalopathy.

Study Objectives: To describe early diagnostic clues in Cyclin-Dependent Kinase-Like 5 (CDKL5) refractory encephalopathy, to improve treatment strategies.

Methods: We retrospectively studied 35 patients (25 females, 10 males) with gene mutations or deletion, focusing on their early seizure semiology, the electroencephalogram (EEG) pattern, the effect of treatment, and developmental outcome.

Results: The first seizures were recognizable and consisted of tonic, then clonic, and spasms phases, occurring in sleep at a median age of 6 weeks.