By studying the brain dynamics of 28 subjects with epilepsy, scientists demonstrated there is no evidence for a previously suspected warning sign for seizures known as “critical slowing down.”
In 2013, some of the first seizure-prediction devices were developed and successfully tested. Although extensive research efforts have successfully identified predictors of imminent seizures, the concept of critical slowing down as an index for seizure susceptibility has been controversial and remained unproven.
Critical slowing down refers to characteristic changes in the behavior of a complex system that approaches a theoretical tipping point. When this point is exceeded, it can lead to impactful and devastating changes. An epileptic human brain is considered an excellent example of a system such as this, due to the extreme and distressing nature of a seizure.
In a paper published in Chaos, from AIP Publishing, researchers investigated recordings of brain dynamics that captured 105 epileptic seizures using time-resolved estimates of early warning indicators of the seizures.
Instead of critically slowing down, the researchers discovered the seizures acted oppositely and critically sped up, indicating the brain dynamics were less sensitive to changes and experienced a faster return to an unperturbed state.