Coexistence of epileptic encephalopathy with continuous spike-and-wave during sleep, atypical benign partial epilepsy, and fixation-off sensitivity in two siblings.

Epileptic encephalopathy with continuous spike-and-wave during sleep is a rare age-related childhood encephalopathy characterized by neuropsychological and motor impairment, epilepsy, and typical EEG findings. Fixation-off sensitivity denotes forms of epilepsy and/or EEG abnormalities that occur during eye closure. The authors describe a girl with developmental regression, electrical status epilepticus during sleep (documented by video/EEG recording), and intermittent myoclonus. Her younger brother was diagnosed with atypical benign partial epilepsy, and his repeated video/EEG recordings unexpectedly showed fixation-off sensitivity.