How to choose a practicable duration time for capturing paroxysmal events by prolonged video electroencephalogram monitoring in the elderly?

•Positivity of paroxysmal events is 48.4% in the elderly.•Non-epileptic events, especially PNES, are usually detected on the first day.•Over 98% of first epileptic events are detected during the first 2days with daily or persistent frequency.•There should be different expected monitoring duration in patients with different seizure frequency.