Using the NeuroPace RNS system to monitor long-term epileptic-like activity, researchers have confirmed that there is a uniform circadian pattern to this brain activity. Studying 134 subjects, Spencer et al found the epileptiform activity peaked during normal sleeping hours. They also discovered a monophasic, nocturnally dominant rhythm in the neocortical areas of the brain and a more complex pattern, with a diurnal peak, in limbic sections of the brain. Some volunteers were also found to have a dual oscillator pattern to the brain activity, displaying a circadian and ultradian pattern.
Spencer D, Sun F, Brown S, Jobst, B, Wong V, Mirro E et al. Circadian and ultradian patterns of epileptiform discharges differ by seizure-onset location during long-term ambulatory intracranial monitoring. Epilepsia. 2016;57(9):1495-1502.