Category: Symptoms

Patterns of abnormal visual attention in myalgic encephalomyelitis

Abstract:

PURPOSE: To experimentally assess visual attention difficulties commonly reported by those with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

METHODS: Twenty-nine ME/CFS patients and 29 controls took part in the study. Performance was assessed using the Useful Field of View (UFOV), a spatial cueing task and visual search.

RESULTS: Patients and controls performed similarly on the processing speed subtest of the UFOV. However, patients exhibited marginally worse performance compared with controls on the divided attention subtest and significantly worse performance on the selective attention subtest. In the spatial cueing task, they were slower than controls to respond to the presence of the target, particularly when cues were invalid. They were also impaired, relative to controls, on visual search tasks.

CONCLUSIONS: We have provided experimental evidence for ME/CFS-related difficulties in directing visual attention. These findings support the subjective reports of those with ME/CFS and could represent a potential means to improve diagnosis.

 

Source: Hutchinson CV, Badham SP. Patterns of abnormal visual attention in myalgic encephalomyelitis. Optom Vis Sci. 2013 Jun;90(6):607-14. doi: 10.1097/OPX.0b013e318294c232. https://www.ncbi.nlm.nih.gov/pubmed/23689679

 

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)

 

Psychological stress contributed to the development of low-grade fever in a patient with chronic fatigue syndrome: a case report

Abstract:

BACKGROUND: Low-grade fever is a common symptom in patients with chronic fatigue syndrome (CFS), but the mechanisms responsible for its development are poorly understood. We submit this case report that suggests that psychological stress contributes to low-grade fever in CFS.

CASE PRESENTATION: A 26-year-old female nurse with CFS was admitted to our hospital. She had been recording her axillary temperature regularly and found that it was especially high when she felt stress at work. To assess how psychological stress affects temperature and to investigate the possible mechanisms for this hyperthermia, we conducted a 60-minute stress interview and observed the changes in the following parameters: axillary temperature, fingertip temperature, systolic blood pressure, diastolic blood pressure, heart rate, plasma catecholamine levels, and serum levels of interleukin (IL)-1β and IL-6 (pyretic cytokines), tumor necrosis factor-α and IL-10 (antipyretic cytokines). The stress interview consisted of recalling and talking about stressful events. Her axillary temperature at baseline was 37.2°C, increasing to 38.2°C by the end of the interview. In contrast, her fingertip temperature decreased during the interview. Her heart rate, systolic and diastolic blood pressures, and plasma levels of noradrenaline and adrenaline increased during the interview; there were no significant changes in either pyretic or antipyretic cytokines during or after the interview.

CONCLUSIONS: A stress interview induced a 1.0°C increase in axillary temperature in a CFS patient. Negative emotion-associated sympathetic activation, rather than pyretic cytokine production, contributed to the increase in temperature induced by the stress interview. This suggests that psychological stress may contribute to the development or the exacerbation of low-grade fever in some CFS patients.

 

Source: Oka T, Kanemitsu Y, Sudo N, Hayashi H, Oka K. Psychological stress contributed to the development of low-grade fever in a patient with chronic fatigue syndrome: a case report. Biopsychosoc Med. 2013 Mar 8;7(1):7. doi: 10.1186/1751-0759-7-7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3599992/ (Full article)

 

A narrative review on the similarities and dissimilarities between myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and sickness behavior

Abstract:

It is of importance whether myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a variant of sickness behavior. The latter is induced by acute infections/injury being principally mediated through proinflammatory cytokines. Sickness is a beneficial behavioral response that serves to enhance recovery, conserves energy and plays a role in the resolution of inflammation.

There are behavioral/symptomatic similarities (for example, fatigue, malaise, hyperalgesia) and dissimilarities (gastrointestinal symptoms, anorexia and weight loss) between sickness and ME/CFS. While sickness is an adaptive response induced by proinflammatory cytokines, ME/CFS is a chronic, disabling disorder, where the pathophysiology is related to activation of immunoinflammatory and oxidative pathways and autoimmune responses.

While sickness behavior is a state of energy conservation, which plays a role in combating pathogens, ME/CFS is a chronic disease underpinned by a state of energy depletion. While sickness is an acute response to infection/injury, the trigger factors in ME/CFS are less well defined and encompass acute and chronic infections, as well as inflammatory or autoimmune diseases. It is concluded that sickness behavior and ME/CFS are two different conditions.

 

Source: Morris G, Anderson G, Galecki P, Berk M, Maes M. A narrative review on the similarities and dissimilarities between myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and sickness behavior. BMC Med. 2013 Mar 8;11:64. doi: 10.1186/1741-7015-11-64. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3751187/ (Full article)

 

Dyspnea in Chronic Fatigue Syndrome (CFS): comparison of two prospective cross-sectional studies

Abstract:

Chronic Fatigue Syndrome (CFS) subjects have many systemic complaints including shortness of breath. Dyspnea was compared in two CFS and control cohorts to characterize pathophysiology. Cohort 1 of 257 CFS and 456 control subjects were compared using the Medical Research Council chronic Dyspnea Scale (MRC Score; range 0-5). Cohort 2 of 106 CFS and 90 controls answered a Dyspnea Severity Score (range 0-20) adapted from the MRC Score. Subsets of both cohorts completed CFS Severity Scores, fatigue, and other questionnaires. A subset had pulmonary function and total lung capacity measurements.

Results show MRC Scores were equivalent between sexes in Cohort 1 CFS (1.92 [1.72-2.16]; mean [95% C.I.]) and controls (0.31 [0.23-0.39]; p&lt;0.0001). Receiver-operator curves identified 2 as the threshold for positive MRC Scores in Cohort 1. This indicated 54% of CFS, but only 3% of controls, had significant dyspnea.

In Cohort 2, Dyspnea Score threshold of 4 indicated shortness of breath in 67% of CFS and 23% of controls. Cohort 2 Dyspnea Scores were higher for CFS (7.80 [6.60-9.00]) than controls (2.40 [1.60-3.20]; p&lt;0.0001). CFS had significantly worse fatigue and other complaints compared to controls. Pulmonary function was normal in CFS, but Borg scores and sensations of chest pain and dizziness were significantly greater during testing than controls. General linear model of Cohort 2 CFS responses linked Dyspnea with rapid heart rate, chest pain and dizziness.

In conclusion, sensory hypersensitivity without airflow limitation contributed to dyspnea in CFS. Correlates of dyspnea in controls were distinct from CFS suggesting different mechanisms.

 

Source: Ravindran M, Adewuyi O, Zheng Y, Rayhan RU, Le U, Timbol C, Merck S, Esteitie R, Read C, Cooney M, Baraniuk J. Dyspnea in Chronic Fatigue Syndrome (CFS): comparison of two prospective cross-sectional studies. Glob J Health Sci. 2012 Dec 12;5(2):94-110. doi: 10.5539/gjhs.v5n2p94. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4209305/ (Full article)

 

Fatigue heralding multiple sclerosis

Abstract:

BACKGROUND: Fatigue is a common symptom in multiple sclerosis (MS) and is an important determinant of overall well-being and disability.

OBJECTIVE: To assess the frequency with which fatigue precedes the diagnosis of MS using a retrospective database analysis.

METHODS: Between January 1, 2003 and September 30, 2008, patients diagnosed with fatigue with and without fatigue-related medications within a 3-year period prior to newly diagnosed MS were identified from the MarketScan Databases. All statistical analysis was performed using SAS.

RESULTS: Of the 16,976 patients with MS in the overall population, 5305 (31.3%) were newly diagnosed with MS and had three years of continuous healthcare coverage prior to MS diagnosis. Of these patients, 1534 (28.9%) were labeled with chronic fatigue syndrome (ICD9-780.71) or malaise or fatigue (ICD9-780.79) prior to the diagnosis of MS. One-third of these patients were labeled with fatigue one to two years before the diagnosis; 30.8% were diagnosed only with fatigue and had no other MS symptoms prior to their MS diagnosis. Among the patients diagnosed with fatigue, 10.4% were also prescribed medication for fatigue.

CONCLUSION: This study demonstrates that fatigue may herald MS, often by years. A careful history for transient neurological symptoms and a physical examination is warranted in any patient presenting with fatigue.

 

Source: Berger JR, Pocoski J, Preblick R, Boklage S. Fatigue heralding multiple sclerosis. Mult Scler. 2013 Oct;19(11):1526-32. doi: 10.1177/1352458513477924. Epub 2013 Feb 25. https://www.ncbi.nlm.nih.gov/pubmed/23439577

 

Sleep abnormalities in chronic fatigue syndrome/myalgic encephalomyelitis: a review

Abstract:

Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is a chronic, disabling illness that affects approximately 0.2% of the population. Non-restorative sleep despite sufficient or extended total sleep time is one of the major clinical diagnostic criteria; however, the underlying cause of this symptom is unknown.

This review aims to provide a comprehensive overview of the literature examining sleep in CFS/ME and the issues surrounding the current research findings. Polysomnographic and other objective measures of sleep have observed few differences in sleep parameters between CFS/ME patients and healthy controls, although some discrepancies do exist. This lack of significant objective differences contrasts with the common subjective complaints of disturbed and unrefreshed sleep by CFS/ME patients.

The emergence of new, more sensitive techniques that examine the microstructure of sleep are showing promise for detecting differences in sleep between patients and healthy individuals. There is preliminary evidence that alterations in sleep stage transitions and sleep instability, and other physiological mechanisms, such as heart rate variability and altered cortisol profiles, may be evident. Future research investigating the etiology of non-restorative sleep in CFS/ME may also help us to undercover the causes of non-restorative sleep and fatigue in other medical conditions.

 

Source: Jackson ML, Bruck D. Sleep abnormalities in chronic fatigue syndrome/myalgic encephalomyelitis: a review. J Clin Sleep Med. 2012 Dec 15;8(6):719-28. doi: 10.5664/jcsm.2276. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3501671/ (Full article)

 

Modulation of the axon-reflex response to local heat by reactive oxygen species in subjects with chronic fatigue syndrome

Abstract:

Local cutaneous heating causes vasodilation as an initial first peak, a nadir, and increase to plateau. Reactive oxygen species (ROS) modulate the heat plateau in healthy controls. The initial peak, due to C-fiber nociceptor-mediated axon reflexes, is blunted with local anesthetics and may serve as a surrogate for the cutaneous response to peripheral heat. Chronic fatigue syndrome (CFS) subjects report increased perception of pain. To determine the role of ROS in this neurally mediated response, we evaluated changes in cutaneous blood flow from local heat in nine CFS subjects (16-22 yr) compared with eight healthy controls (18-26 yr).

We heated skin to 42°C and measured local blood flow as a percentage of maximum cutaneous vascular conductance (%CVC(max)). Although CFS subjects had significantly lower baseline flow [8.75 ± 0.56 vs. 12.27 ± 1.07 (%CVC(max), CFS vs. control)], there were no differences between groups to local heat. We then remeasured this with apocynin to inhibit NADPH oxidase, allopurinol to inhibit xanthine oxidase, tempol to inhibit superoxide, and ebselen to reduce H(2)O(2). Apocynin significantly increased baseline blood flow (before heat, 14.91 ± 2.21 vs. 8.75 ± 1.66) and the first heat peak (69.33 ± 3.36 vs. 59.75 ± 2.75). Allopurinol and ebselen only enhanced the first heat peaks (71.55 ± 2.48 vs. 61.72 ± 2.01 and 76.55 ± 5.21 vs. 58.56 ± 3.66, respectively). Tempol had no effect on local heating. None of these agents changed the response to local heat in control subjects. Thus the response to heat may be altered by local levels of ROS, particularly H(2)O(2) in CFS subjects, and may be related to their hyperesthesia/hyperalgesia.

 

Source: Medow MS, Aggarwal A, Baugham I, Messer Z, Stewart JM. Modulation of the axon-reflex response to local heat by reactive oxygen species in subjects with chronic fatigue syndrome. J Appl Physiol (1985). 2013 Jan 1;114(1):45-51. doi: 10.1152/japplphysiol.00821.2012. Epub 2012 Nov 8. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3544512/ (Full article)

 

Sleep in the chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is a disabling condition characterized by severe fatigue lasting for more than six months and the presence of at least four out of eight minor criteria. Sleep disturbance presenting as unrefreshing or nonrestorative sleep is one of these criteria and is very common in CFS patients. Biologically disturbed sleep is a known cause of fatigue and could play a role in the pathogenesis of CFS. However, the nature of presumed sleep impairment in CFS remains unclear. Whilst complaints of NRS persist over time, there is no demonstrable neurophysiological correlate to substantiate a basic deficit in sleep function in CFS. Polysomnographic findings have not shown to be significantly different between subjects with CFS and normal controls. Discrepancies between subjectively poor and objectively normal sleep suggest a role for psychosocial factors negatively affecting perception of sleep quality. Primary sleep disorders are often detected in patients who otherwise qualify for a CFS diagnosis. These disorders could contribute to the presence of daytime dysfunctioning. There is currently insufficient evidence to indicate that treatment of primary sleep disorders sufficiently improves the fatigue associated with CFS. Therefore, primary sleep disorders may be a comorbid rather than an exclusionary condition with respect to CFS.

Copyright © 2012 Elsevier Ltd. All rights reserved.

 

Source: Mariman AN, Vogelaers DP, Tobback E, Delesie LM, Hanoulle IP, Pevernagie DA. Sleep in the chronic fatigue syndrome. Sleep Med Rev. 2013 Jun;17(3):193-9. doi: 10.1016/j.smrv.2012.06.003. Epub 2012 Oct 6. https://www.ncbi.nlm.nih.gov/pubmed/23046847

 

Pain in patients with chronic fatigue syndrome: time for specific pain treatment?

Abstract:

BACKGROUND: Besides chronic fatigue, patients with chronic fatigue syndrome (CFS) have debilitating widespread pain. Yet pain from CFS is often ignored by clinicians and researchers.

OBJECTIVES: To examine whether pain is a unique feature of CFS, or does it share the same underlying mechanisms as other CFS symptoms? Second, it is examined whether effective treatments for pain from CFS are currently available.

STUDY DESIGN: Narrative review covering the scientific literature up through December 2011.

SETTING: Several universities.

RESULTS: From the available literature, it is concluded that musculoskeletal factors are unlikely to account for pain from CFS. Pain seems to be one out of many symptoms related to central sensitization from CFS. This idea is supported by the findings of generalized hyperalgesia (including widespread increased responsiveness to painful stimuli) and dysfunctional endogenous analgesia in response to noxious thermal stimuli. Pain catastrophizing and depression partly account for pain from CFS. Pain increases during exercise is probably due to the lack of endogenous analgesia and activation of several genes in response to exercise in CFS. There is currently no evidence in support for the efficacy of complementary medicine in the treatment of pain from CFS. Intensive education about the biology of pain from CFS (within the framework of central sensitization) has positive short-term effects for patients with CFS, and fatigue-targeting cognitive behavioral therapy appears to be effective for pain from CFS as well.

LIMITATIONS: The role of the deficient hypothalamus-pituitary-adrenal axis in relation to pain from CFS, as well as the interactions with immune (dys)functioning require further study.

CONCLUSION: Recent research has increased our understanding of pain from CFS, including its treatment. It is advocated to optimize current CFS treatment protocols by targeting the underlying mechanism for those patients having severe pain.

 

Source: Nijs J, Crombez G, Meeus M, Knoop H, Damme SV, Cauwenbergh V, Bleijenberg G. Pain in patients with chronic fatigue syndrome: time for specific pain treatment? Pain Physician. 2012 Sep-Oct;15(5):E677-86. http://www.painphysicianjournal.com/linkout?issn=1533-3159&vol=15&page=E677 (Full article)