Category: Symptoms

Power spectral analysis of sleep EEG in twins discordant for chronic fatigue syndrome

Abstract:

OBJECTIVE: The purpose of the study was to evaluate quantitative sleep electroencephalogram (EEG) frequencies in monozygotic twins discordant for chronic fatigue syndrome.

METHODS: Thirteen pairs of female twins underwent polysomnography. During the first night, they adapted to the sleep laboratory, and during the second night, their baseline sleep was assessed. Visual stage scoring was conducted on sleep electroencephalographic records according to standard criteria, and power spectral analysis was used to quantify delta through beta frequency bands, processed in 6-s blocks. Data were averaged across sleep stage within each twin and coded for sleep stage and the presence or absence of chronic fatigue syndrome (CFS). A completely within-subjects repeated measure multivariate analysis of variance evaluated twin pairs by frequency band by sleep stage interactions and simple effects. The relationship between alpha and delta EEG was also assessed across twin pairs.

RESULTS: No significant differences in spectral power in any frequency band were found between those with CFS and their nonfatigued cotwins. Phasic alpha activity, coupled with delta was noted in five subjects with CFS but was also present in 4/5 healthy twins, indicating this finding likely reflects genetic influences on the sleep electroencephalogram rather than disease-specific sleep pathology.

CONCLUSIONS: The genetic influences on sleep polysomnography and microarchitecture appear to be stronger than the disease influence of chronic fatigue syndrome, despite greater subjective sleep complaint among the CFS twins. EEG techniques that focus on short duration events or paradigms that probe sleep regulation may provide a better description of sleep abnormalities in CFS.

 

Source: Armitage R, Landis C, Hoffmann R, Lentz M, Watson N, Goldberg J, Buchwald D. Power spectral analysis of sleep EEG in twins discordant for chronic fatigue syndrome. J Psychosom Res. 2009 Jan;66(1):51-7. doi: 10.1016/j.jpsychores.2008.08.004. Epub 2008 Nov 25. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2634600/ (Full article)

 

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)

 

Evidence for T-helper 2 shift and association with illness parameters in chronic fatigue syndrome (CFS)

Abstract:

Few immunological markers have been consistently reported in CFS. However, a shift to a T-helper 2 (Th2) type immune response has been hypothesized for individuals with CFS. The current study investigated whether individuals with CFS who exhibited a stronger shift towards a Th2 type of immune response would also exhibit more severe symptoms, poorer neurocognitive functioning, and poorer physical and psychosocial functioning.

The current investigation measured the percentage of Th1-like and Th2-like memory cells using cell surface flow cytometry in 114 individuals with CFS. The associations between the ratio of Th1 and Th2 memory cells and various illness parameters measures were then examined, including symptom severity, psychiatric functioning, neurocognitive functioning, salivary cortisol levels, and chronic pain status.

Results indicated that individuals who exhibited a more extreme shift towards a Th2 immune response also exhibited poorer sleep and high levels of basal salivary cortisol. The implications of these findings are discussed.

 

Source: Torres-Harding S, Sorenson M, Jason LA, Maher K, Fletcher MA. Evidence for T-helper 2 shift and association with illness parameters in chronic fatigue syndrome (CFS). Bull IACFS ME. 2008 Fall;16(3):19-33. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3018761/ (Full article)

 

Postural orthostatic tachycardia syndrome is an under-recognized condition in chronic fatigue syndrome

Abstract:

BACKGROUND: It has been suggested that postural orthostatic tachycardia syndrome (POTS) be considered in the differential diagnosis of those with chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME). Currently, measurement of haemodynamic response to standing is not recommended in the UK NICE CFS/ME guidelines.

OBJECTIVES: To determine prevalence of POTS in patients with CFS/ME.

DESIGN: Observational cohort study.

METHODS: Fifty-nine patients with CFS/ME (Fukuda criteria) and 52 age- and sex-matched controls underwent formal autonomic assessment in the cardiovascular laboratory with continuous heart rate and beat-to-beat blood pressure measurement (Task Force, CNSystems, Graz Austria). Haemodynamic responses to standing over 2 min were measured. POTS was defined as symptoms of orthostatic intolerance associated with an increase in heart rate from the supine to upright position of >30 beats per minute or to a heart rate of >120 beats per minute on standing.

RESULTS: Maximum heart rate on standing was significantly higher in the CFS/ME group compared with controls (106 +/- 20 vs. 98 +/- 13; P = 0.02). Of the CFS/ME group, 27% (16/59) had POTS compared with 9% (5) in the control population (P = 0.006). This difference was predominantly related to the increased proportion of those in the CFS/ME group whose heart rate increased to >120 beats per minute on standing (P = 0.0002). Increasing fatigue was associated with increase in heart rate (P = 0.04; r(2) = 0.1).

CONCLUSION: POTS is a frequent finding in patients with CFS/ME. We suggest that clinical evaluation of patients with CFS/ME should include response to standing. Studies are needed to determine the optimum intervention strategy to manage POTS in those with CFS/ME.

 

Source: Hoad A, Spickett G, Elliott J, Newton J. Postural orthostatic tachycardia syndrome is an under-recognized condition in chronic fatigue syndrome. QJM. 2008 Dec;101(12):961-5. doi: 10.1093/qjmed/hcn123. Epub 2008 Sep 19. http://qjmed.oxfordjournals.org/content/101/12/961.long (Full article)

 

Diffuse noxious inhibitory control is delayed in chronic fatigue syndrome: an experimental study

Abstract:

Deficient endogenous pain inhibition, e.g. Diffuse noxious inhibitory controls (DNIC), or hormonal abnormalities like hypocortisolism, could be responsible for chronic widespread pain in Chronic Fatigue Syndrome (CFS). Thirty-one CFS-patients with chronic pain and 31 healthy controls were subjected to spatial summation of thermal noxious stimuli by gradual immersion (ascending or descending) of the arm in warm water (46 degrees C). They rated pain intensity every 15s. Every immersion took 2 min, alternated with 5 min rest. Before and after immersion, salivary cortisol was assessed.

Overall pain ratings were higher in CFS-patients, but the evolution was not different between patients and controls, during both ascending and descending immersion. Pain intensity and immersed surface were only correlated during the descending session in both patients (r=.334) and controls (r=.346). When comparing the first and the last 15s of every emersion, it was found that pain inhibition starts slower for CFS-patients in comparison to healthy subjects. Both pre- or post-values and cortisol response did not differ between controls and patients. The drop in cortisol was significantly correlated to pain intensity in CFS (r between .357 and .402).

In addition to the hyperalgesia in CFS, DNIC react slower to spatial summation of thermal noxious stimuli. We found no evidence for hypocortisolism in CFS, and the cortisol response to nociception was not different in CFS compared to healthy subjects. In conclusion, delayed pain inhibition may play a role in chronic widespread pain in CFS but further research is required.

 

Source: Meeus M, Nijs J, Van de Wauwer N, Toeback L, Truijen S. Diffuse noxious inhibitory control is delayed in chronic fatigue syndrome: an experimental study. Pain. 2008 Oct 15;139(2):439-48. doi: 10.1016/j.pain.2008.05.018. Epub 2008 Jul 9. https://www.ncbi.nlm.nih.gov/pubmed/18617327

 

Sleep structure and sleepiness in chronic fatigue syndrome with or without coexisting fibromyalgia

Abstract:

INTRODUCTION: We evaluated polysomnograms of chronic fatigue syndrome (CFS) patients with and without fibromyalgia to determine whether patients in either group had elevated rates of sleep-disturbed breathing (obstructive sleep apnea or upper airway resistance syndrome) or periodic leg movement disorder. We also determined whether feelings of unrefreshing sleep were associated with differences in sleep architecture from normal.

METHODS: We compared sleep structures and subjective scores on visual analog scales for sleepiness and fatigue in CFS patients with or without coexisting fibromyalgia (n = 12 and 14, respectively) with 26 healthy subjects. None had current major depressive disorder, and all were studied at the same menstrual phase.

RESULTS: CFS patients had significant differences in polysomnograpic findings from healthy controls and felt sleepier and more fatigued than controls after a night’s sleep. CFS patients as a group had less total sleep time, lower sleep efficiency, and less rapid eye movement sleep than controls. A possible explanation for the unrefreshing quality of sleep in CFS patients was revealed by stratification of patients into those who reported more or less sleepiness after a night’s sleep (a.m. sleepier or a.m. less sleepy, respectively). Those in the sleepier group reported that sleep did not improve their symptoms and had poorer sleep efficiencies and shorter runs of sleep than both controls and patients in the less sleepy group; patients in the less sleepy group reported reduced fatigue and pain after sleep and had relatively normal sleep structures. This difference in sleep effects was due primarily to a decrease in the length of periods of uninterrupted sleep in the a.m. sleepier group.

CONCLUSION: CFS patients had significant differences in polysomnographic findings from healthy controls and felt sleepier and more fatigued than controls after a night’s sleep. This difference was due neither to diagnosable sleep disorders nor to coexisting fibromyalgia but primarily to a decrease in the length of periods of uninterrupted sleep in the patients with more sleepiness in the morning than on the night before. This sleep disruption may explain the overwhelming fatigue, report of unrefreshing sleep, and pain in this subgroup of patients.

Comment in: How much sleep apnea is too much? [Arthritis Res Ther. 2009]

 

Source: Togo F, Natelson BH, Cherniack NS, FitzGibbons J, Garcon C, Rapoport DM. Sleep structure and sleepiness in chronic fatigue syndrome with or without coexisting fibromyalgia. Arthritis Res Ther. 2008;10(3):R56. doi: 10.1186/ar2425. Epub 2008 May 13. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2483445/ (Full article)

 

Breathing retraining in patients with chronic fatigue syndrome: a pilot study

Abstract:

The study aimed to 1) examine the point prevalence of asynchronous breathing in chronic fatigue syndrome (CFS) patients; 2) examine whether CFS patients with an asynchronous breathing pattern present with diminished lung function in comparison with CFS patients with a synchronous breathing pattern; and 3) examine whether one session of breathing retraining in CFS patients with an asynchronous breathing pattern is able to improve lung function.

Twenty patients fulfilling the diagnostic criteria for CFS were recruited for participation in a pilot controlled clinical trial with repeated measures. Patients presenting with an asynchronous breathing pattern were given 20-30 minutes of breathing retraining. Patients presenting with a synchronous breathing pattern entered the control group and received no intervention. Of the 20 enrolled patients with CFS, 15 presented with a synchronous breathing pattern and the remaining 5 patients (25%) with an asynchronous breathing pattern. Baseline comparison revealed no group differences in demographic features, symptom severity, respiratory muscle strength, or pulmonary function testing data (spirometry). In comparison to no treatment, the session of breathing retraining resulted in an acute (immediately postintervention) decrease in respiratory rate (p < 0.001) and an increase in tidal volume (p < 0.001). No other respiratory variables responded to the session of breathing retraining.

In conclusion, the present study provides preliminary evidence supportive of an asynchronous breathing pattern in a subgroup of CFS patients, and breathing retraining might be useful for improving tidal volume and respiratory rate in CFS patients presenting with an asynchronous breathing motion.

 

Source: Nijs J, Adriaens J, Schuermans D, Buyl R, Vincken W. Breathing retraining in patients with chronic fatigue syndrome: a pilot study. Physiother Theory Pract. 2008 Mar-Apr;24(2):83-94. Doi: 10.1080/09593980701429406. https://www.ncbi.nlm.nih.gov/pubmed/18432511

 

Dynamics of sleep stage transitions in healthy humans and patients with chronic fatigue syndrome

Abstract:

Physiological and/or pathological implications of the dynamics of sleep stage transitions have not, to date, been investigated. We report detailed duration and transition statistics between sleep stages in healthy subjects and in others with chronic fatigue syndrome (CFS); in addition, we also compare our data with previously published results for rats.

Twenty-two healthy females and 22 female patients with CFS, characterized by complaints of unrefreshing sleep, underwent one night of polysomnographic recording. We find that duration of deep sleep (stages III and IV) follows a power-law probability distribution function; in contrast, stage II sleep durations follow a stretched exponential and stage I, and REM sleep durations follow an exponential function. These stage duration distributions show a gradually increasing departure from the exponential form with increasing depth of sleep toward a power-law type distribution for deep sleep, suggesting increasing complexity of regulation of deeper sleep stages. We also find a substantial number of REM to non-REM sleep transitions in humans, while this transition is reported to be virtually nonexistent in rats.

The relative frequency of this REM to non-REM sleep transition is significantly lower in CFS patients than in controls, resulting in a significantly greater relative transition frequency of moving from both REM and stage I sleep to awake. Such an alteration in the transition pattern suggests that the normal continuation of sleep in light or REM sleep is disrupted in CFS. We conclude that dynamic transition analysis of sleep stages is useful for elucidating yet-to-be-determined human sleep regulation mechanisms with pathophysiological implications.

 

Source: Kishi A, Struzik ZR, Natelson BH, Togo F, Yamamoto Y. Dynamics of sleep stage transitions in healthy humans and patients with chronic fatigue syndrome. Am J Physiol Regul Integr Comp Physiol. 2008 Jun;294(6):R1980-7. doi: 10.1152/ajpregu.00925.2007. Epub 2008 Apr 16. http://ajpregu.physiology.org/content/294/6/R1980.long

 

Sexual dysfunction as related to severity of fatigue in women with CFS

Abstract:

To assess sexual function in women with chronic fatigue syndrome. The study included 27 women, aged 20 to 45 years, with chronic fatigue syndrome (CFS) and 15 healthy female controls. Sexual function was measured with the Golombok Rust Inventory of Sexual Satisfaction (GRISS) questionnaire and five clinical questions. In the patient group, total fatigue impact scale (FIS) score correlated with the GRISS satisfaction (r:-0.471, P < .005), avoidance (r: 0.632, P < .001) and sensuality (r: -0.445, P = .008) subscales. The GRISS satisfaction, avoidance, and sensuality subscale results and the fact of seeing the sexual act as a negative experience correlated with the intensity of fatigue in women with CFS.

 

Source: Blazquez A, Ruiz E, Vazquez A, de Sevilla TF, Garcia-Quintana A, Garcia-Quintana J, Alegre J. Sexual dysfunction as related to severity of fatigue in women with CFS. J Sex Marital Ther. 2008;34(3):240-7. doi: 10.1080/00926230701866232. https://www.ncbi.nlm.nih.gov/pubmed/18398762

 

Alterations in diurnal salivary cortisol rhythm in a population-based sample of cases with chronic fatigue syndrome

Abstract:

OBJECTIVE: To examine diurnal salivary cortisol rhythms and plasma IL-6 concentrations in persons with chronic fatigue syndrome (CFS), persons not fulfilling a diagnosis of CFS (we term them cases with insufficient symptoms or fatigue, ISF) and nonfatigued controls (NF). Previous studies of CFS patients have implicated the hypothalamic-pituitary-adrenal axis and the immune system in the pathophysiology of CFS, although results have been equivocal.

METHODS: Twenty-eight people with CFS, 35 persons with ISF, and 39 NF identified from the general population of Wichita, Kansas, were admitted to a research ward for 2 days. Saliva was collected immediately on awakening (6:30 AM), at 08:00 AM, 12 noon, 4:00 PM, 8:00 PM and at bedtime (10:00 PM) and plasma was obtained at 7:30 AM. Salivary cortisol concentrations were assessed using radioimmunoassay, and plasma IL-6 was measured using sandwich enzyme-linked immunosorbent assay.

RESULTS: People with CFS demonstrated lower salivary cortisol concentrations in the morning and higher salivary cortisol concentrations in the evening compared with both ISF and NF groups indicating a flattening of the diurnal cortisol profile. Mean plasma IL-6 concentrations were highest in CFS compared with the other groups, although these differences were no longer significant after controlling for BMI. Attenuated decline of salivary cortisol concentrations across the day and IL-6 concentration were associated with fatigue symptoms in CFS.

CONCLUSIONS: These results suggest an altered diurnal cortisol rhythm and IL-6 concentrations in CFS cases identified from a population-based sample.

 

Source: Nater UM, Youngblood LS, Jones JF, Unger ER, Miller AH, Reeves WC, Heim C. Alterations in diurnal salivary cortisol rhythm in a population-based sample of cases with chronic fatigue syndrome. Psychosom Med. 2008 Apr;70(3):298-305. doi: 10.1097/PSY.0b013e3181651025. Epub 2008 Mar 31. https://www.ncbi.nlm.nih.gov/pubmed/18378875