Sleep Power Spectral Density and Spindles in PTSD and Their Relationship to Symptom Severity

Abstract

Sleep disturbances are common in post-traumatic stress disorder (PTSD), although which sleep microarchitectural characteristics reliably classify those with and without PTSD remains equivocal. Here, we investigated sleep microarchitectural differences (i.e., spectral power, spindle activity) in trauma-exposed individuals that met (n = 45) or did not meet (n = 52) criteria for PTSD and how these differences relate to post-traumatic and related psychopathological symptoms. Using ecologically-relevant home sleep polysomnography recordings, we show that individuals with PTSD exhibit decreased beta spectral power during NREM sleep and increased fast sleep spindle peak frequencies. Contrary to prior reports, spectral power in the beta frequency range (20.31–29.88 Hz) was associated with reduced PTSD symptoms, reduced depression, anxiety and stress and greater subjective ability to regulate emotions. Increased fast frequency spindle activity was not associated with individual differences in psychopathology. Our findings may suggest an adaptive role for beta power during sleep in individuals exposed to a trauma, potentially conferring resilience. Further, we add to a growing body of evidence that spindle activity may be an important biomarker for studying PTSD pathophysiology.

Beta spectral power during sleep is associated with impaired recall of extinguished fear

“…PSD in the range of 0-30 Hz was included in the analysis (e.g. Denis et al, 2021). Separate tests were performed for NREM and REM sleep.…”

“…Theta (∼4-7Hz) oscillatory power during REM sleep has been linked to emotional memory processing during sleep in some studies (Kim et al, 2019; Marquis et al, 2017; Nishida et al, 2009; Schäfer et al, 2020; Sopp et al, 2017), though this association has not been found (Davidson et al, 2021). Theta power has been shown to be elevated in trauma-exposed individuals who were resilient to, compared to those diagnosed with, PTSD (Cowdin et al, 2014; though see Denis et al, 2021). Similarly, electroencephalographic spectral power in in the beta frequency range (∼20-30Hz) during sleep has also been shown to be elevated in PTSD compared to those without PTSD (de Boer et al, 2020; Germain et al, 2006; Wang et al, 2020; Woodward et al, 2000), and has been theorized as a marker of hyperarousal (Hall et al, 2007; Krystal et al, 2002; Perlis et al, 2001; Riedner et al, 2016; Spiegelhalder et al, 2012).…”

“…Similarly, electroencephalographic spectral power in in the beta frequency range (∼20-30Hz) during sleep has also been shown to be elevated in PTSD compared to those without PTSD (de Boer et al, 2020; Germain et al, 2006; Wang et al, 2020; Woodward et al, 2000), and has been theorized as a marker of hyperarousal (Hall et al, 2007; Krystal et al, 2002; Perlis et al, 2001; Riedner et al, 2016; Spiegelhalder et al, 2012). In contrast however, beta power during sleep has also been associated with reduced risk of PTSD development (Mellman et al, 2007) and reduced symptomatology in healthy participants and those with PTSD (Denis et al, 2021). The role of beta power in the consolidation of extinction memories is yet to be investigated.…”

High-density EEG sleep correlates of cognitive and affective impairment at 12-month follow-up after COVID-19

“…In major depression, sleep spindles increase density and shift toward frontal and parietal cortices ( Plante et al, 2013 , Ferrarelli et al, 2019 ). In PTSD, fast sleep spindles increase peak frequencies ( Denis et al, 2021 ). Indeed, we observed a shift of fast spindles toward parietal regions in people discharged from non-ICU and towards anterior areas in people discharged from ICU.…”

“…In major depression, sleep spindles have an increased density and distribution over frontal and parietal cortices ( Plante et al, 2013 ). In post-traumatic stress disorder (PTSD), fast sleep spindles apparently increase peak frequencies ( Denis et al, 2021 ). The study of cortical generators of neural activity has further extended our knowledge of the neurophysiology of cognition and sleep.…”