Theta bursts in patients with sleep-related hypermotor epilepsy: potential marker of impaired inhibitory control and its mitigation through musical stimulation

Sleep-related hypermotor epilepsy (SHE) is associated with severe cognitive deficits. The condition involves impaired inhibitory control, and whether music therapy can be effective against it is unclear. Here we analyzed various pathophysiological markers of impaired inhibitory control and identified some that improved after music therapy. We assessed cognitive function in 41 patients with SHE in the Go/NoGo task and electroencephalographic activity before and after a single exposure to Mozart's K. 448. The same assessments were performed in two types of controls, 41 patients with nocturnal epilepsy and 40 healthy individuals. SHE showed significantly longer reaction time, lower accuracy, later onset of theta bursts in the mid-frontal region. Severity of them correlated positively with reaction time. During music exposure, theta activity synchronized with the rhythm. Music significantly shortened reaction time and increased accuracy in patients with SHE, while also shortening the interval until the onset of theta bursts. Our results suggest that SHE involves frontal network damage affecting inhibitory control, and that music therapy can mitigate this damage by facilitating onset of theta bursts. It also indicates that theta bursts may be useful for assessing therapeutic efficacy and for exploring ways to mitigate cognitive deficits in epilepsy patients with frontal network deficits.