High-frequency oscillations across wakefulness and sleep in NREM parasomnia and sleep-related hypermotor epilepsy: A
Bahar Caliskan1, M Kagan Caliskan2, Bengi Gül Türk3
1Sleep and Disorders Unit, Division of Clinical Neurophysiology, Department of Neurology, Cerrahpasa Faculty of Medicine, Istanbul University-Cerrahpasa, Istanbul, Turkiye; Clinic of Neurology, Sancaktepe Şehit Prof.Dr. Ilhan Varank Training and Research Hospital, Istanbul, Turkiye.
Study Objectives:
High-frequency oscillations(HFOs) have recently been defined in patients with epilepsy as electrophysiological markers of the neuronal hyperexcitability. Based on the clinical and pathophysiological similarities between non-rapid eye movements(NREM) parasomnias and sleep-related hypermotor epilepsy(SHE), we aimed to examine HFOs in patients with NREM parasomnias and sleep-related epilepsy.
Methods:
Sixteen patients with NREM arousal parasomnias, fourteen patients with non-refractory SHE, and ten age- and sex-matched healthy controls were prospectively included. HFO analysis was performed in 16-channel electroencephalography in 3-min periods from wakefulness before and after sleep, NREM and REM sleep stages in first and second halves of sleep.
Results:
The ripple and/or fast ripple activities were detected in 50% of the patients with NREM parasomnias, in 71.4% of the patients with SHE, and in 30% of the healthy controls (p = 0.039). While the total ripple and fast ripple rates in sleep and wakefulness were significantly higher in patients with epilepsy compared to the patients with NREM parasomnias and controls, the total ripple rate (p = 0.048) in the second half of sleep, total fast ripple rate occurring in sleep (p = 0.049) and total fast ripple rate in sleep and wakefulness (p = 0.044) were also significantly higher in patients with NREM parasomnias compared to those in healthy controls.
Conclusions:
Our study demonstrated that high-frequency oscillations can be detected in patients with NREM arousal parasomnias. This original and significant finding is needed to be supported by further studies, to better explore the role of HFOs in the pathophysiology of NREM-related parasomnias.
Related Concept Videos
Sleep-Wake Cycles
NREM Sleep
NREM sleep comprises four progressive stages that seamlessly merge:
REM Sleep Behavior Disorder
RBD is significantly associated with...
Brain Waves
Narcolepsy
Stages of Sleep
Before sleep begins, in wakefulness, the brain exhibits primarily beta waves, which are high in frequency and low in amplitude, indicating alertness...


