Generalized Seizures after Experimental Traumatic Brain Injury Occur at the Transition from Slow-Wave to Rapid Eye Movement Sleep.

Sleep disturbances commonly occur after traumatic brain injury (TBI) and may predispose patients to epileptic seizures. We hypothesized that unprovoked seizure occurrence post-TBI depends on the sleep-wake cycle, and that the electrographic characteristics of a given sleep stage provide biomarkers for post-traumatic epilepsy (PTE). We show, in a rat lateral fluid percussion model, that 92% of spontaneous generalized seizures occur during the transition from stage III to rapid eye movement sleep. Moreover, a reduction in spindle duration and dominant frequency during the transition stage present as specific and sensitive noninvasive biomarkers for experimentally induced PTE with generalized electrographic seizures.