Defining the occurrence and influence of alpha-delta sleep in chronic fatigue syndrome

Abstract:

BACKGROUND: Patients with chronic fatigue syndrome (CFS) present a disordered sleep pattern and frequently undergo polysomnography to exclude a primary sleep disorder. Such studies have shown reduced sleep efficiency, a reduction of deep sleep, prolonged sleep initiation, and alpha-wave intrusion during deep sleep. Deregulation of the 2-5A synthetase/RNase L antiviral pathway and a potential acquired channelopathy are also found in a subset of CFS patients and could lead to sleep disturbances. This article compiles a large sleep study database on CFS patients and correlates these data with a limited number of immune parameters as it has been thought that RNase L could be associated with these sleep disturbances.

METHODS: Forty-eight patients who fulfilled 1994 Centers for Disease Control and Prevention criteria for CFS underwent extensive medical evaluation, routine laboratory testing, and a structured psychiatric interview. Subjects then completed a complaint checklist and a two-night polysomnographic investigation. RNase L analysis was performed by gel electrophoresis using a radiolabeled 2′,5′-oligoadenylate trimer. Basic descriptive statistical parameters were calculated.

RESULTS: Patients experienced a prolonged sleep latency, showed a low sleep efficiency index, and had a low percentage of slow wave sleep. The present alpha-delta intrusion correlated with anxiety; no correlations appeared, however, between alpha-delta sleep and immunologic parameters, including RNase L.

CONCLUSIONS: The main findings are 1) validation of sleep latency problems and other sleep disturbances as already suggested by several authors; 2) alpha-delta intrusion seems associated with anxiety; and 3) elevated RNase L did not correlate with alpha-delta sleep.

 

Source: Van Hoof E, De Becker P, Lapp C, Cluydts R, De Meirleir K. Defining the occurrence and influence of alpha-delta sleep in chronic fatigue syndrome. Am J Med Sci. 2007 Feb;333(2):78-84. https://www.ncbi.nlm.nih.gov/pubmed/17301585

 

Central sensitization: a biopsychosocial explanation for chronic widespread pain in patients with fibromyalgia and chronic fatigue syndrome

Abstract:

In addition to the debilitating fatigue, the majority of patients with chronic fatigue syndrome (CFS) experience chronic widespread pain. These pain complaints show the greatest overlap between CFS and fibromyalgia (FM). Although the literature provides evidence for central sensitization as cause for the musculoskeletal pain in FM, in CFS this evidence is currently lacking, despite the observed similarities in both diseases. The knowledge concerning the physiological mechanism of central sensitization, the pathophysiology and the pain processing in FM, and the knowledge on the pathophysiology of CFS lead to the hypothesis that central sensitization is also responsible for the sustaining pain complaints in CFS.

This hypothesis is based on the hyperalgesia and allodynia reported in CFS, on the elevated concentrations of nitric oxide presented in the blood of CFS patients, on the typical personality styles seen in CFS and on the brain abnormalities shown on brain images. To examine the present hypothesis more research is required. Further investigations could use similar protocols to those already used in studies on pain in FM like, for example, studies on temporal summation, spatial summation, the role of psychosocial aspects in chronic pain, etc.

 

Source: Meeus M, Nijs J. Central sensitization: a biopsychosocial explanation for chronic widespread pain in patients with fibromyalgia and chronic fatigue syndrome. Clin Rheumatol. 2007 Apr;26(4):465-73. Epub 2006 Nov 18. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1820749/ (Full article)

 

Sleep characteristics of persons with chronic fatigue syndrome and non-fatigued controls: results from a population-based study

Abstract:

BACKGROUND: The etiology and pathophysiology of chronic fatigue syndrome (CFS) remain inchoate. Attempts to elucidate the pathophysiology must consider sleep physiology, as unrefreshing sleep is the most commonly reported of the 8 case-defining symptoms of CFS. Although published studies have consistently reported inefficient sleep and documented a variable occurrence of previously undiagnosed primary sleep disorders, they have not identified characteristic disturbances in sleep architecture or a distinctive pattern of polysomnographic abnormalities associated with CFS.

METHODS: This study recruited CFS cases and non-fatigued controls from a population based study of CFS in Wichita, Kansas. Participants spent two nights in the research unit of a local hospital and underwent overnight polysomnographic and daytime multiple sleep latency testing in order to characterize sleep architecture.

RESULTS: Approximately 18% of persons with CFS and 7% of asymptomatic controls were diagnosed with severe primary sleep disorders and were excluded from further analysis. These rates were not significantly different. Persons with CFS had a significantly higher mean frequency of obstructive apnea per hour (p = .003); however, the difference was not clinically meaningful. Other characteristics of sleep architecture did not differ between persons with CFS and controls.

CONCLUSION: Although disordered breathing during sleep may be associated with CFS, this study generally did not provide evidence that altered sleep architecture is a critical factor in CFS. Future studies should further scrutinize the relationship between subjective sleep quality relative to objective polysomnographic measures.

 

Source: Reeves WC, Heim C, Maloney EM, Youngblood LS, Unger ER, Decker MJ, Jones JF, Rye DB. Sleep characteristics of persons with chronic fatigue syndrome and non-fatigued controls: results from a population-based study. BMC Neurol. 2006 Nov 16;6:41. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1660569/ (Full article)

 

beta-Alanine and gamma-aminobutyric acid in chronic fatigue syndrome

Abstract:

BACKGROUND: Due to the occurrence of sleep disturbances and fatigue in chronic fatigue syndrome (CFS), an investigation was performed to examine if there is an abnormal excretion of gamma-aminobutyric acid (GABA) and/or its structural analogue beta-alanine in the urine from CFS patients. Both GABA and beta-alanine are inhibitory neurotransmitters in the mammalian central nervous system.

METHODS: The 24 h urine excretion of GABA and beta-alanine was determined by isotope dilution gas chromatography mass spectrometry in 33 CFS patients and 43 healthy controls. The degree of symptoms in both patients and controls was measured by grading of three typical CFS symptoms using a Visual Analogue Scale.

RESULTS: Men had a significantly higher excretion of both beta-alanine and GABA than women. Comparing CFS patients with healthy controls showed no significant difference in excretion of neither beta-alanine nor GABA. No correlation was found between the excretion of beta-alanine or GABA and any of the three characteristic CFS symptoms measured. However, two female and two male CFS patients excreted considerably higher amounts of beta-alanine in their 24 h urine samples than control subjects.

CONCLUSIONS: Increased excretion of beta-alanine was found in a subgroup of CFS patients, indicating that there may be a link between CFS and beta-alanine in some CFS patients.

 

Source: Hannestad U, Theodorsson E, Evengård B. beta-Alanine and gamma-aminobutyric acid in chronic fatigue syndrome. Clin Chim Acta. 2007 Feb;376(1-2):23-9. Epub 2006 Jul 14. https://www.ncbi.nlm.nih.gov/pubmed/16934791

 

Menopausal transition symptoms in midlife women living with fibromyalgia and chronic fatigue

Abstract:

We aimed to determine how menopausal transition symptoms cluster across 216 midlife women with fibromyalgia, chronic fatigue syndromes (FMS/CFS), or both and subsequently to compare symptom factor severity scores by menopausal status among these women and compare symptom reporting with prior community-based samples of women without obvious illness.

We designed a cross-sectional telephone survey of 216 women aged 35 to 55, diagnosed with FMS/CFS, symptomatic in the prior 6 months, and without hysterectomy. Thirty-six of 61 symptoms loaded on five factors: aroused/anxious mood, depressed mood/withdrawal, musculoskeletal, gastrointestinal (GI), and vasomotor. Peri- and postmenopausal women had higher symptom severity scores for musculoskeletal, GI, and vasomotor factors but not mood factors.

Symptoms for the women we studied who had FMS/CFS clustered similar to those in previous community-based samples of midlife women without major illness; however, the number of women experiencing symptoms was much higher among our sample.

 

Source: Wilbur J, Shaver J, Kogan J, Buntin M, Wang E. Menopausal transition symptoms in midlife women living with fibromyalgia and chronic fatigue. Health Care Women Int. 2006 Aug;27(7):600-14. https://www.ncbi.nlm.nih.gov/pubmed/16844673

 

Chronic musculoskeletal pain in patients with the chronic fatigue syndrome: a systematic review

Abstract:

BACKGROUND: In addition to debilitating fatigue the majority of patients with chronic fatigue syndrome (CFS) experience chronic widespread pain.

AIMS: Conducting a systematic review to critically assess the existing knowledge on chronic pain in CFS. We focussed on the definition, the prevalence and incidence, the aetiology, the relevance and the therapy strategy for chronic musculoskeletal pain and post-exertional pain in CFS.

METHODS: To identify relevant articles, we searched eight medical search engines. The search terms “chronic fatigue syndrome” AND “pain”, “nociception”, “arthralgia” and “myalgia”, were used to identify articles concerning pain in CFS. Included articles were reviewed by two blinded researchers.

RESULTS: Twenty-five articles and two abstract were identified and selected for further appraisal. Only 11 search results focussed on musculoskeletal pain in CFS patients. Regarding the standardized review of the articles, a 96% agreement between the researchers was observed. There is no consensus in defining chronic widespread pain in CFS, and although there is little or no strong proof for the exact prevalence, chronic pain is strongly disabling in CFS. Aetiological theories are proposed (sleep abnormalities, tryptophan, parovirus-B, hormonal and brain abnormalities and central sensitisation) and a reduction of pain threshold after exercise has been shown. Furthermore depression seemed not related to pain in CFS and a staphylococcus toxoid vaccine caused no significant pain reduction.

CONCLUSIONS: The results from the systematic review highlight the clinical importance of chronic pain in CFS, but only few studies addressing the aetiology or treatment of chronic pain in CFS are currently available.

 

Source: Meeus M, Nijs J, Meirleir KD. Chronic musculoskeletal pain in patients with the chronic fatigue syndrome: a systematic review. Eur J Pain. 2007 May;11(4):377-86. Epub 2006 Jul 13. https://www.ncbi.nlm.nih.gov/pubmed/16843021

 

Chronic musculoskeletal pain in chronic fatigue syndrome: recent developments and therapeutic implications

Abstract:

Patients with chronic fatigue syndrome (CFS) experience chronic musculoskeletal pain which is even more debilitating than fatigue. Scientific research data gathered around the world enables clinicians to understand, at least in part, chronic musculoskeletal pain in CFS patients. Generalized joint hypermobility and benign joint hypermobility syndrome appear to be highly prevalent among CFS sufferers, but they do not seem to be of any clinical importance.

On the other hand, pain catastrophizing accounts for a substantial portion of musculoskeletal pain and is a predictor of exercise performance in CFS patients. The evidence concerning pain catastrophizing is supportive of the indirect evidence of a dysfunctional pain processing system in CFS patients with musculoskeletal pain. CFS sufferers respond to incremental exercise with a lengthened and accentuated oxidative stress response, explaining muscle pain, postexertional malaise, and the decrease in pain threshold following graded exercise in CFS patients.

Applying the scientific evidence to the manual physiotherapy profession, pacing self-management techniques and pain neurophysiology education are indicated for the treatment of musculoskeletal pain in CFS patients. Studies examining the effectiveness of these strategies for CFS patients are warranted.

 

Source: Nijs J, Meeus M, De Meirleir K. Chronic musculoskeletal pain in chronic fatigue syndrome: recent developments and therapeutic implications. Man Ther. 2006 Aug;11(3):187-91. Epub 2006 Jun 14. https://www.ncbi.nlm.nih.gov/pubmed/16781183

 

How fatigue is related to other somatic symptoms

Abstract:

AIMS: To assess the relation between fatigue and somatic symptoms in healthy adolescents and adolescents with chronic fatigue syndrome/myalgic encephalopathy (CFS/ME).

METHODS: Seventy two adolescents with CFS were compared within a cross-sectional study design with 167 healthy controls. Fatigue and somatic complaints were measured using self-report questionnaires, respectively the subscale subjective fatigue of the Checklist Individual Strength (CIS-20) and the Children’s Somatization Inventory.

RESULTS: Healthy adolescents reported the same somatic symptoms as adolescents with CFS/ME, but with a lower score of severity. The top 10 somatic complaints were the same: low energy, headache, heaviness in arms/legs, dizziness, sore muscles, hot/cold spells, weakness in body parts, pain in joints, nausea/upset stomach, back pain. There was a clear positive relation between log somatic symptoms and fatigue (linear regression coefficient: 0.041 points log somatic complaints per score point fatigue, 95% CI 0.033 to 0.049) which did not depend on disease status.

CONCLUSIONS: Results suggest a continuum with a gradual transition from fatigue with associated symptoms in healthy adolescents to the symptom complex of CFS/ME.

 

Source: van de Putte EM, Engelbert RH, Kuis W, Kimpen JL, Uiterwaal CS. How fatigue is related to other somatic symptoms. Arch Dis Child. 2006 Oct;91(10):824-7. Epub 2006 Jun 5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2066005/ (Full article)

 

The association between experimental and clinical pain measures among persons with fibromyalgia and chronic fatigue syndrome

Abstract:

Evoked or experimental pain is often used as a model for the study of clinical pain, yet there are little data regarding the relationship between the two. In addition, there are few data regarding the types of stimuli and stimulus intensities that are most closely related to clinical pain. In this study, 36 subjects with fibromyalgia (FM), chronic fatigue syndrome (CFS), or both syndromes were administered measures of clinical pain and underwent a dolorimetry evaluation. Subjects also underwent experimental pain testing utilizing heat and pressure stimulation.

Stimulation levels evoking low, moderate and high sensory intensity, and comparable levels of unpleasantness, were determined for both types of stimuli using random staircase methods. Clinical pain was assessed using visual analogue ratings and the short form of the McGill Pain Questionnaire (MPQ). Ratings of heat pain sensation were not significantly associated with clinical pain ratings, with the exception of unpleasantness ratings at high stimulus intensities. Pain threshold and tolerance as assessed by dolorimetry were significantly associated with average measures of clinical pain.

Both intensity and unpleasantness ratings of pressure delivered using random staircase methods were significantly associated with clinical pain at low, moderate and high levels, and the strength of the association was greater at increasingly noxious stimulus intensities. These findings suggest that random pressure stimulation as an experimental pain model in these populations more closely reflects the clinical pain for these conditions. These findings merit consideration when designing experimental studies of clinical pain associated with FM and CFS.

 

Source: Geisser ME, Gracely RH, Giesecke T, Petzke FW, Williams DA, Clauw DJ. The association between experimental and clinical pain measures among persons with fibromyalgia and chronic fatigue syndrome. Eur J Pain. 2007 Feb;11(2):202-7. Epub 2006 Mar 20. https://www.ncbi.nlm.nih.gov/pubmed/16546424

 

Sub-typing CFS patients on the basis of ‘minor’ symptoms

Abstract:

The diagnosis of chronic fatigue syndrome (CFS), an illness characterized by medically unexplained fatigue, depends on a clinical case definition representing one or more pathophysiological mechanisms. To prepare for studies of these mechanisms, this study sought to identify subtypes of CFS.

In 161 women meeting 1994 criteria for CFS, principal components analysis of the 10 ‘minor’ symptoms of CFS produced three factors interpreted to indicate musculoskeletal, infectious and neurological subtypes. Extreme scores on one or more of these factors characterized about 2/3 of the sample. Those characterized by the neurological factor were at increased risk of reduced scores on cognitive tests requiring attention, working memory, long-term memory or rapid performance.

In addition, the neurological subtype was associated with reduced levels of function. Those characterized by the musculoskeletal factor were at increased risk for the diagnosis of fibromyalgia (chronic widespread pain and mechanical allodynia) and reduced physical function. Those characterized by the infectious factor were less likely to evidence co-occurring fibromyalgia, and showed lesser risk of functional impairment.

The prevalence of disability was increased in those with the highest scores on any of the subtypes, as well as in those with high scores on multiple factors. Depression and anxiety, while frequently present, were not more prevalent in any particular subtype, and did not increase with the severity of specific symptom reports. Results suggest that subtypes of CFS may be identified from reports of the minor diagnostic symptoms, and that these subtypes demonstrate construct validity.

 

Source: Janal MN, Ciccone DS, Natelson BH. Sub-typing CFS patients on the basis of ‘minor’ symptoms. Biol Psychol. 2006 Aug;73(2):124-31. Epub 2006 Feb 10. https://www.ncbi.nlm.nih.gov/pubmed/16473456