Chronic fatigue syndrome and fibromyalgia in diagnosed sleep disorders: a further test of the ‘unitary’ hypothesis

Abstract:

BACKGROUND: Since chronic fatigue syndrome (CFS) and fibromyalgia (FM) often co-exist, some believe they reflect the same process, somatization. Against that hypothesis are data suggesting FM but not CFS was common in patients with sleep-disordered breathing (SDB). The presence of discrete case definitions for CFS and FM allowed us to explore rates of CFS alone, CFS with FM, and FM alone in SDB patients compared to those with sleep complaints that fulfilled criteria for insomnia.

METHODS: Participants were 175 sequential patients with sleep-related symptoms (122 had SDB and 21 had insomnia) and 39 healthy controls. Diagnoses were made by questionnaires, tender point count, and rule out labs; sleepiness was assessed with Epworth Sleepiness Scale and mood with Beck Depression Inventory.

RESULTS: Rates of CFS, FM or CFS + FM were high: 13% in SDB and 48% in insomnia. CFS occurred frequently in SDB and insomnia, but FM occurred frequently only in insomnia. SDB patients with CFS and/or FM had higher daytime sleepiness than those without these disorders.

CONCLUSION: CFS patients should complete Epworth scales, and sleep evaluation should be considered for those with scores ≥ 16 before receiving the diagnosis of CFS; the coexistence of depressed mood in these patients suggests some may be helped by treatment of their depression. That FM was underrepresented in SDB suggests FM and CFS may have different underlying pathophysiological causes.

 

Source: Pejovic S, Natelson BH, Basta M, Fernandez-Mendoza J, Mahr F, Vgontzas AN. Chronic fatigue syndrome and fibromyalgia in diagnosed sleep disorders: a further test of the ‘unitary’ hypothesis. BMC Neurol. 2015 Apr 12;15:53. doi: 10.1186/s12883-015-0308-2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4405866/ (Full article)

 

The association between daytime napping and cognitive functioning in chronic fatigue syndrome

Abstract:

OBJECTIVES: The precise relationship between sleep and physical and mental functioning in chronic fatigue syndrome (CFS) has not been examined directly, nor has the impact of daytime napping. This study aimed to examine self-reported sleep in patients with CFS and explore whether sleep quality and daytime napping, specific patient characteristics (gender, illness length) and levels of anxiety and depression, predicted daytime fatigue severity, levels of daytime sleepiness and cognitive functioning, all key dimensions of the illness experience.

METHODS: 118 adults meeting the 1994 CDC case criteria for CFS completed a standardised sleep diary over 14 days. Momentary functional assessments of fatigue, sleepiness, cognition and mood were completed by patients as part of usual care. Levels of daytime functioning and disability were quantified using symptom assessment tools, measuring fatigue (Chalder Fatigue Scale), sleepiness (Epworth Sleepiness Scale), cognitive functioning (Trail Making Test, Cognitive Failures Questionnaire), and mood (Hospital Anxiety and Depression Scale).

RESULTS: Hierarchical Regressions demonstrated that a shorter time since diagnosis, higher depression and longer wake time after sleep onset predicted 23.4% of the variance in fatigue severity (p <.001). Being male, higher depression and more afternoon naps predicted 25.6% of the variance in objective cognitive dysfunction (p <.001). Higher anxiety and depression and morning napping predicted 32.2% of the variance in subjective cognitive dysfunction (p <.001). When patients were classified into groups of mild and moderate sleepiness, those with longer daytime naps, those who mainly napped in the afternoon, and those with higher levels of anxiety, were more likely to be in the moderately sleepy group.

CONCLUSIONS: Napping, particularly in the afternoon is associated with poorer cognitive functioning and more daytime sleepiness in CFS. These findings have clinical implications for symptom management strategies.

 

Source: Gotts ZM, Ellis JG, Deary V, Barclay N, Newton JL. The association between daytime napping and cognitive functioning in chronic fatigue syndrome. PLoS One. 2015 Jan 9;10(1):e0117136. doi: 10.1371/journal.pone.0117136. ECollection 2015. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4289075/ (Full article)

 

Heart rate variability during sleep and subsequent sleepiness in patients with chronic fatigue syndrome

Abstract:

We determined whether alterations in heart rate dynamics during sleep in patients with chronic fatigue syndrome (CFS) differed from controls and/or correlated with changes of sleepiness before and after a night in the sleep laboratory. We compared beat-to-beat RR intervals (RRI) during nocturnal sleep, sleep structure, and subjective scores on visual analog scale for sleepiness in 18 CFS patients with 19 healthy controls aged 25-55 after excluding subjects with sleep disorders. A short-term fractal scaling exponent (α1) of RRI dynamics, analyzed by the detrended fluctuation analysis (DFA) method, was assessed after stratifying patients into those who reported more or less sleepiness after the night’s sleep (a.m. sleepier or a.m. less sleepy, respectively).

Patients in the a.m. sleepier group showed significantly (p<0.05) higher fractal scaling index α1 during non-rapid eye movement (non-REM) sleep (Stages 1, 2, and 3 sleep) than healthy controls, although standard polysomnographic measures did not differ between the groups. The fractal scaling index α1 during non-REM sleep was significantly (p<0.05) higher than that during awake periods after sleep onset for healthy controls and patients in the a.m. less sleepy group, but did not differ between sleep stages for patients in the a.m. sleepier group. For patients, changes in self-reported sleepiness before and after the night correlated positively with the fractal scaling index α1 during non-REM sleep (p<0.05). These results suggest that RRI dynamics or autonomic nervous system activity during non-REM sleep might be associated with disrupted sleep in patients with CFS.

Copyright © 2013 Elsevier B.V. All rights reserved.

 

Source: Togo F, Natelson BH. Heart rate variability during sleep and subsequent sleepiness in patients with chronic fatigue syndrome. Auton Neurosci. 2013 Jun;176(1-2):85-90. doi: 10.1016/j.autneu.2013.02.015. Epub 2013 Mar 15. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4100066/ (Full article)

 

Subjective sleep quality and daytime sleepiness in a large sample of patients with chronic fatigue syndrome (CFS)

Abstract:

Chronic fatigue syndrome (CFS) is characterised by incapacitating fatigue in combination with a number of minor criteria, including unrefreshing sleep without further specifications, in the absence of psychiatric and internal disease. As little data exist on subjective sleep quality and daytime sleepiness, these parameters were assessed in a large sample of CFS patients.

Consecutive patients with a diagnosis of CFS in a tertiary referral centre filled out the Fatigue Questionnaire (FQ), Medical Outcomes Study 36-Item Short Form Health Survey (MOS SF-36), Epworth Sleepiness Scale (ESS) and Pittsburgh Sleep Quality Index (PSQI). Inclusion comprised 415 individuals (mean age 40.5 yr, SD 7.9, range 18-64; 86% female). Mean FQ (26.90; SD 4.04), mean Global Physical Health from the MOS SF-36 (29.30; SD 12.25) and Global Mental Health from the MOS SF-36 (49.62; SD 18.31) scores corresponded with literature data for similar CFS samples. High mean ESS (10.51; SD 5.52) and global PSQI (10.17; SD 4.02) were observed. No significant relationship was found between ESS and global PSQI.

In contrast, regression analysis demonstrated a significant cubic relation between ESS and ‘PSQI without daytime dysfunction’. A subgroup (n=69) with an insomnia-like phenotype low ESS (<5), high PSQI (mean 11.51; SD 3.86) was observed. The assessment of subjective sleep quality and daytime sleepiness in a large sample of CFS patients indicated high mean PSQI and ESS values. ESS and ‘PSQI without daytime dysfunction’ were inversely related at the spectral ends of ESS. A distinct subgroup with clinical features of insomnia was identified.

 

Source: Mariman A, Vogelaers D, Hanoulle I, Delesie L, Pevernagie D. Subjective sleep quality and daytime sleepiness in a large sample of patients with chronic fatigue syndrome (CFS). Acta Clin Belg. 2012 Jan-Feb;67(1):19-24. https://www.ncbi.nlm.nih.gov/pubmed/22480034

 

Are patients with chronic fatigue syndrome just ‘tired’ or also ‘sleepy’?

Abstract:

It is presently unclear whether chronic fatigue syndrome (CFS) patients exhibit daytime sleepiness in addition to fatigue. Both, fatigue, such as that seen in CFS patients, and excessive daytime sleepiness, such as in sleep apnea-hypopnea syndrome (SAHS), remain poorly understood. Both daytime conditions are generally related to unrefreshing sleep and show affective symptoms. This study’s objective was to contribute to the understanding of the relationship between fatigue and sleepiness in CFS patients not co-morbid for primary sleep or psychiatric disorders.

We compared 16 untreated CFS patients (mean age 32.8, all females) with 13 untreated SAHS (mean age 47.7, all females) patients and 12 healthy controls (mean age 32.2, all females). Objective sleepiness was measured using multiple sleep latency tests (MSLT). Subjective sleepiness and fatigue were assessed with the Epworth Sleepiness Scale and the Fatigue Severity Scale, respectively. Mean Sleep Latency (SL) on the MSLT was significantly shorter in SAHS patients than in CFS patients and CFS patients showed significantly shorter mean SL than matched controls but within normal range.

Subjective sleepiness was greatest in SAHS patients and subjective fatigue was highest in CFS patients. Affective symptoms showed highest intensities in CFS patients. While higher than the control group on all measures, compared to SAHS, the CFS group had higher subjective fatigue and lower subjective and objective sleepiness. Despite possible overlap in symptoms and signs of both daytime conditions, our data indirectly support the clinical distinction between fatigue and sleepiness.

 

Source: Neu D, Hoffmann G, Moutrier R, Verbanck P, Linkowski P, Le Bon O. Are patients with chronic fatigue syndrome just ‘tired’ or also ‘sleepy’? J Sleep Res. 2008 Dec;17(4):427-31. doi: 10.1111/j.1365-2869.2008.00679.x. Epub 2008 Oct 17. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2869.2008.00679.x/full (Full article)

 

The relation of sleep difficulties to fatigue, mood and disability in chronic fatigue syndrome

Abstract:

The relationship of sleep complaints to mood, fatigue, disability, and lifestyle was examined in 69 chronic fatigue syndrome (CFS) patients without psychiatric disorder, 58 CFS patients with psychiatric disorder, 38 psychiatric out-patients with chronic depressive disorders, and 45 healthy controls. The groups were matched for age and gender.

There were few differences between the prevalence or nature of sleep complaints of CFS patients with or without current DSM-IIIR depression, anxiety or somatization disorder. CFS patients reported significantly more naps and waking by pain, a similar prevalence of difficulties in maintaining sleep, and significantly less difficulty getting off to sleep compared to depressed patients.

Sleep continuity complaints preceded fatigue in only 20% of CFS patients, but there was a strong association between relapse and sleep disturbance. Certain types of sleep disorder were associated with increased disability or fatigue in CFS patients. Disrupted sleep appears to complicate the course of CFS. For the most part, sleep complaints are either attributable to the lifestyle of CFS patients or seem inherent to the underlying condition of CFS. They are generally unrelated to depression or anxiety in CFS.

 

Source: Morriss RK, Wearden AJ, Battersby L. The relation of sleep difficulties to fatigue, mood and disability in chronic fatigue syndrome. J Psychosom Res. 1997 Jun;42(6):597-605. http://www.ncbi.nlm.nih.gov/pubmed/9226607

 

Consideration of narcolepsy in the differential diagnosis of chronic fatigue syndrome

Abstract:

OBJECTIVE: To justify the inclusion of narcolepsy in the differential diagnosis of patients with chronic fatigue.

CLINICAL FEATURES: We report three patients aged 17 (two women and one man) and one woman aged 45 who had been diagnosed as having chronic fatigue syndrome (CFS). They had no psychiatric illness. Their main problem was severe daytime sleepiness, presenting as “tiredness and fatigue”. The history, sleep study and multiple sleep latency test suggested a diagnosis of narcolepsy.

INTERVENTION: Treatment with methylphenidate resulted in complete resolution of symptoms in two patients and significant improvement in the other two.

CONCLUSIONS: The differential diagnosis of CFS requires the exclusion of other conditions. If daytime sleepiness is a major complaint, other symptoms of narcolepsy should be sought and the diagnosis confirmed with sleep study and a multiple sleep latency test.

 

Source: Ambrogetti A, Olson LG. Consideration of narcolepsy in the differential diagnosis of chronic fatigue syndrome. Med J Aust. 1994 Apr 4;160(7):426-9. http://www.ncbi.nlm.nih.gov/pubmed/8007866

 

Insomnia in the chronic fatigue syndrome

Editor,-Iain Duncan is mistaken in his assertion that the results of our study of patients with the chronic fatigue syndrome can be explained by daytime dozing. According to data from the diaries kept by the subjects in the study, the patients with the chronic fatigue syndrome slept for a mean of 11 minutes during the day and the healthy controls for 0 minutes. There was no association between either the time spent asleep or the time spent resting in bed during the day and the presence of any sleep disorder (or the time spent awake after the onset of sleep at night) in the patients with the chronic fatigue syndrome or the normal controls. Furthermore, in the few patients with the syndrome who wore their polysomnograph for the whole 24 hours there was no association between time spent asleep during the day and the time spent awake after the onset of sleep.

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1678179/pdf/bmj00031-0056a.pdf

 

Source: Morriss R. Insomnia in the chronic fatigue syndrome. BMJ. 1993 Jul 24;307(6898):264. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1678179/

 

Sleep disturbance in chronic fatigue syndrome

Abstract:

Sleep and fatigue characteristics were evaluated in 72 patients who met major criteria for the chronic fatigue syndrome (CFS), 57 multiple sclerosis (MS) patients preselected for fatigue complaints, and 40 healthy controls.

Using previously validated rating scales, CFS patients had significant elevations in fatigue and sleep disturbance compared to the MS and healthy control groups. To confirm these subjective measures, polysomnography was carried out in a subgroup of CFS patients who included sleep disturbance as one of their symptoms on initial clinical interview.

In 10 of 16 (62.5%) polysomnography revealed clinically significant and potentially treatable sleep abnormalities. Their sleep disorders included periodic movement disorder (4), excessive daytime sleepiness (3), apnea (2), and narcolepsy (1).

We conclude that subjective sleep disturbance is common in CFS and some CFS patients may have objective sleep disorders.

 

Source: Krupp LB, Jandorf L, Coyle PK, Mendelson WB. Sleep disturbance in chronic fatigue syndrome. J Psychosom Res. 1993 May;37(4):325-31. http://www.ncbi.nlm.nih.gov/pubmed/8510058