Electroencephalographic patterns during sleep in children with chromosome 15q11.2-13.1 duplications (Dup15q)

Our objective was to define the EEG features during sleep of children with neurodevelopmental disorders due to copy number gains of 15q11-q13 (Dup15q). We retrospectively reviewed continuous EEG recordings of 42 children with Dup15q (mean age: eight years, 32 with idic15), and data collected included background activity, interictal epileptiform discharges, sleep organization, and ictal activity. Three patterns were recognized:Pattern 1: Alpha–delta sleep was noted in 14 children (33%), not associated with any clinical changes.Pattern 2: Electrical status epilepticus in sleep was noted in 15 children (35%), all diagnosed with treatment-resistant epilepsy. Thirteen of the 15 children had clinical seizures.Pattern 3: Frequent bursts of high amplitude bifrontal predominant, paroxysmal fast activity (12–15Hz) during non-REM sleep was noted in 15 children (35%). All 15 children had treatment-resistant epilepsy.