A 20 yo RH woman, followed for 16 years by the same neurologist (PAH), had seizure onset at 1.5 years: afebrile CPSz secondarily generalised with automatisms, duration 5 min, recurrent every 2–4 weeks. Initial treatment consisted of PHT 5 mg/kg/day, then CBZ 30 mg/kg + VPA 18 mg/kg/day with improvement. PMHx: SGA 2.7 kg at birth, 7–8 h labour, “R. leg bent” at birth, in India. FHx negative Szs. Initial development “normal”: walked 12 months, words at 18 months (Gujerati), ESL at 4 years (JK, Can.). EEG #1 (1.5 y) Generalised SWD, L > R, DX. POSZ, not SFC. EEG #2: (4y): Generalised irregular SED2–3 Hz, DBA: secondary generalised epilepsy. EEG #3: (6 y): Epileptic encephalopathy with multiple independent spike foci; PSG c video-EEG (19 y) DIMS, OSA c CPAP; EEG:ESES or CSWSWS pattern >65% sleep. Seizures staring spells, likely atypical absences; LD due to cognitive developmental assessment, IEP. Headaches 2–3/week, x 1–2 h, relieved by sleep. Behaviour: autistic self-stimulatory, asocial. Conclusion An unusual prolonged evolution of epileptic encephalopathy of childhood extending into early adulthood with refractory secondarily generalised epilepsy and a pattern of EEG from irregular generalised spike-wave discharge to ESES or continuous spike-waves of slow-wave sleep pattern. The impact of CSWSWS on cognitive development in childhood should be considered in treatment long-term.