slow wave sleep – American ME and CFS Society

Parasympathetic activity is reduced during slow-wave sleep, but not resting wakefulness, in patients with chronic fatigue syndrome

Abstract:

STUDY OBJECTIVES: Physiological dearousal characterized by an increase in parasympathetic nervous system activity is important for good-quality sleep. Previous research shows that nocturnal parasympathetic activity (reflected by heart rate variability [HRV]) is diminished in individuals with chronic fatigue syndrome (CFS), suggesting hypervigilant sleep. This study investigated differences in nocturnal autonomic activity across sleep stages and explored the association of parasympathetic activity with sleep quality and self-reported physical and psychological wellbeing in individuals with CFS.

METHODS: Twenty-four patients with medically diagnosed CFS, and 24 matched healthy control individuals participated. Electroencephalography and HRV were recorded during sleep in participants’ homes using a minimally invasive ambulatory device. Questionnaires were used to measure self-reported wellbeing and sleep quality.

RESULTS: Sleep architecture in patients with CFS differed from that of control participants in slower sleep onset, more awakenings, and a larger proportion of time spent in slow-wave sleep (SWS). Linear mixed-model analyses controlling for age revealed that HRV reflecting parasympathetic activity (normalized high frequency power) was reduced in patients with CFS compared to control participants, particularly during deeper stages of sleep. Poorer self-reported wellbeing and sleep quality was associated with reduced parasympathetic signaling during deeper sleep, but not during wake before sleep, rapid eye movement sleep, or with the proportion of time spent in SWS.

CONCLUSIONS: Autonomic hypervigilance during the deeper, recuperative stages of sleep is associated with poor quality sleep and self-reported wellbeing. Causal links need to be confirmed but provide potential intervention opportunities for the core symptom of unrefreshing sleep in CFS.

Source: Fatt SJ, Beilharz JE, Joubert M, Wilson C, Lloyd AR, Vollmer-Conna U, Cvejic E. Parasympathetic activity is reduced during slow-wave sleep, but not resting wakefulness, in patients with chronic fatigue syndrome. J Clin Sleep Med. 2020 Jan 15;16(1):19-28. doi: 10.5664/jcsm.8114. Epub 2019 Nov 27. https://www.ncbi.nlm.nih.gov/pubmed/31957647

Chronic Fatigue Syndrome Impairs A Person’s Slow Wave Activity During Sleep

Press Release: Chronic fatigue syndrome (CFS) has been associated with altered amounts of slow wave sleep, which could reflect reduced electroencephalograph (EEG) activity and impaired sleep regulation. A study published in the journal SLEEP finds that CFS is also associated with a blunted slow wave activity (SWA) response to sleep challenge, suggesting an impairment of the basic sleep drive and homeostatic response.

The study, authored by Roseanna Armitage, PhD, and colleagues at the University of Michigan, focused on 13 pairs of identical twins discordant for CFS. Analyses, which were restricted to the first four non-REM periods each night in order to show comparability, revealed that SWA, or other sleep EEG measures, did not differ between the CFS and healthy twins during a regular night’s sleep. According to Armitage, it was only after a “challenge” to sleep regulation was introduced (keeping them awake an extra four hours) that the CFS twins exhibited significantly less SWA power in the first non-REM period of recovery sleep and accumulated a smaller percentage of SWA in the first non-REM period than their twin counterparts.

“CFS shares symptoms with depression, and some experts have suggested that it is not a distinctly different disorder,” said Armitage. “We have also conducted studies of SWA response to sleep challenge in depression, and the results are very different. Depressed women did not show a blunted SWA response to sleep challenge. The present CFS study included only women, and none had current depression. Therefore, our results cannot be explained on the basis of depression.”

Experts recommend that adults get between seven and eight hours of sleep each night to maintain good health and optimum performance. Persons who think they might have a sleep disorder are urged to consult with their primary care physician, who will refer them to a sleep specialist.

Article: “The Impact of a Four-Hour Sleep Delay on Slow Wave Activity in Twins Discordant for Chronic Fatigue Syndrome”, Sleep, May 1, 2007.

Source: American Academy of Sleep Medicine. “Chronic Fatigue Syndrome Impairs A Person’s Slow Wave Activity During Sleep.” ScienceDaily. ScienceDaily, 7 May 2007. www.sciencedaily.com/releases/2007/05/070501075253.htm

Slow wave sleep in the chronically fatigued: Power spectra distribution patterns in chronic fatigue syndrome and primary insomnia

Abstract:

OBJECTIVES: To investigate slow wave sleep (SWS) spectral power proportions in distinct clinical conditions sharing non-restorative sleep and fatigue complaints without excessive daytime sleepiness (EDS), namely the chronic fatigue syndrome (CFS) and primary insomnia (PI). Impaired sleep homeostasis has been suspected in both CFS and PI.

METHODS: We compared perceived sleep quality, fatigue and sleepiness symptom-intensities, polysomnography (PSG) and SWS spectral power distributions of drug-free CFS and PI patients without comorbid sleep or mental disorders, with a good sleeper control group.

RESULTS: Higher fatigue without EDS and impaired perceived sleep quality were confirmed in both patient groups. PSG mainly differed in sleep fragmentation and SWS durations. Spectral analysis revealed a similar decrease in central ultra slow power (0.3-0.79Hz) proportion during SWS for both CFS and PI and an increase in frontal power proportions of faster frequencies during SWS in PI only. The latter was correlated to affective symptoms whereas lower central ultra slow power proportions were related to fatigue severity and sleep quality impairment.

CONCLUSIONS: In combination with normal (PI) or even increased SWS durations (CFS), we found consistent evidence for lower proportions of slow oscillations during SWS in PI and CFS.

SIGNIFICANCE: Observing normal or increased SWS durations but lower proportions of ultra slow power, our findings suggest a possible quantitative compensation of altered homeostatic regulation.

Source: Neu D, Mairesse O, Verbanck P, Le Bon O. Slow wave sleep in the chronically fatigued: Power spectra distribution patterns in chronic fatigue syndrome and primary insomnia. Clin Neurophysiol. 2015 Oct;126(10):1926-33. doi: 10.1016/j.clinph.2014.12.016. Epub 2015 Jan 10. https://www.ncbi.nlm.nih.gov/pubmed/25620040

Behavioral perturbation and sleep in healthy and virus-infected inbred mice

Abstract:

Murine gammaherpesvirus (MuGHV) is a natural pathogen of wild rodents that has been studied extensively in terms of host immune responses to herpesviruses during acute infection, latency, and reactivation from latency. Although herpesvirus infections in people can be associated with fatigue and excessive sleepiness during both acute and latent infection, MuGHV has not been assessed extensively as a model for studying the behavioral consequences of chronic latent herpesvirus infections.

To assess MuGHV infection as a model for evaluating fatigue and assessing potential mechanisms that underlie the exacerbation of fatigue during chronic viral disease, we evaluated sleep, temperature, and activity after exposure of healthy and latently MuGHV-infected mice to sleep fragmentation and social interaction. Neither treatment nor infection significantly affected temperature. However, at some time points, latently infected mice that underwent sleep fragmentation had less locomotor activity and more slow-wave sleep than did mice exposed to social interaction. In addition, delta-wave amplitude during slow-wave sleep was lower in infected mice exposed to sleep fragmentation compared with uninfected mice exposed to the same treatment.

Both reduced locomotor activity and increased time asleep could indicate fatigue in infected mice after sleep fragmentation; reduced delta-wave amplitude during slow-wave sleep indicates a light plane of sleep from which subjects would be aroused easily. Identifying the mechanisms that underlie sleep responses of mice with chronic latent MuGHV infection may increase our understanding of fatigue during infections and eventually contribute to improving the quality of life for people with chronic viral infections.

Source: Trammell RA, Toth LA. Behavioral perturbation and sleep in healthy and virus-infected inbred mice. Comp Med. 2014 Aug;64(4):283-92. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4170093/ (Full article)

High slow-wave sleep and low-light sleep: chronic fatigue syndrome is not likely to be a primary sleep disorder

Abstract:

The status of chronic fatigue syndrome (CFS) is still under debate. Mainstream views still often consider it as an undetected primary sleep disorder or as the psychosomatic expression of a related anxiety or depression syndrome. Both primary sleep disorder and CFS are often related to unrefreshing sleep and affective daytime symptoms.

The present study compares nonrapid eye movement sleep distribution between patients with a primary sleep disorder and “pure” CFS patients without sleep or mood disorders. Intensity measures of affective symptoms are also analyzed. Sleep variables of 32 pure CFS (mean age, 41.9 +/- 8.7 years; 25 women), 30 Sleep Apnea Hypopnea Syndrome patients (mean age, 43.7 +/- 6.7 years; 13 women), and 14 healthy controls (mean age, 40.2 +/- 7.6 years; 9 women) were compared. Related affective symptoms were assessed using the self-reported Zung anxiety and depression scales.

The study confirms previous reports on increased slow-wave sleep in CFS patients. Both patient groups showed similar sleep duration and efficiency. Sleep efficiency was lower in both patient groups compared with controls. CFS patients showed a higher microarousal index than controls. Anxiety, but not depression symptoms were more intense in the CFS group. The distribution of nonrapid eye movement sleep in CFS differs sizeably from what can be observed in a primary sleep disorder.

Source: Neu D, Cappeliez B, Hoffmann G, Verbanck P, Linkowski P, Le Bon O. High slow-wave sleep and low-light sleep: chronic fatigue syndrome is not likely to be a primary sleep disorder. J Clin Neurophysiol. 2009 Jun;26(3):207-12. doi: 10.1097/WNP.0b013e3181a1841b. https://www.ncbi.nlm.nih.gov/pubmed/19424087