A study published in the journal, Epilepsy and Behavior, suggests that the generation of epileptiform discharges (EDs – distinct patterns of brain activity that can arise in between epileptic seizures) is not a random process but the result of complex interactions controlling sleep-wake cycles. It also highlights that the majority of EDs may, in fact, occur during sleep.On the basis of their findings, the investigators propose that 24-hour electroencephalography (EEG) recordings that capture natural sleep may be more useful than routine EEG in diagnosing genetic generalised epilepsy.During the study, the team, led by Dr Wendyl D’Souza, at the University of Melbourne, studied 24-hour EEG recordings from people diagnosed with genetic generalised epilepsy. They analysed almost 7,000 EDs within 105 abnormal EEGs.The researchers found that there were significant changes in ED counts across the 24-hour period, and that the distribution was largely influenced by the person’s state of arousal. The majority of EDs (67%) occurred during non-REM sleep, peaking from 23:00 through to 07:00, and in 24 people (23%), EDs occurred only in sleep. Overall just 33% of the EDs occurred during wakefulness. In-depth analysis of the EEGs revealed a difference in the nature of the EDs arising in non-REM sleep and in wakefulness.Dr D’Souza and colleagues conclude that EDs are generated as a result of complex interactions among biorhythms. “A deeper understanding of those biorhythms including the intrinsic circadian clock of epilepsy is likely to enhance our knowledge in diagnosis, seizure prediction methods and treatment,” they write.Author: Dr Özge ÖzkayaClick here for more articles about brain science including genetics.