Category: Symptoms

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

 

Sleep quality and psychological adjustment in chronic fatigue syndrome

Abstract:

Without specific etiology or effective treatment, chronic fatigue syndrome (CFS) remains a contentious diagnosis. Individuals with CFS complain of fatigue and poor sleep–symptoms that are often attributed to psychological disturbance.

To assess the nature and prevalence of sleep disturbance in CFS and to investigate the widely presumed presence of psychological maladjustment we examined sleep quality, sleep disorders, physical health, daytime sleepiness, fatigue, and psychological adjustment in three samples. individuals with CFS; a healthy control group; and individuals with a definite medical diagnosis: narcolepsy. Outcome measures included physiological evaluation (polysomnography), medical diagnosis, structured interview, and self-report measures.

Results indicate that the CFS sample had a very high incidence (58%) of previously undiagnosed primary sleep disorder such as sleep apnea/hypopnea syndrome and restless legs/periodic limb movement disorder. They also had very high rates of self-reported insomnia and nonrestorative sleep.

Narcolepsy and CFS participants were very similar on psychological adjustment: both these groups had more psychological maladjustment than did control group participants. Our data suggest that primary sleep disorders in individuals with CFS are underdiagnosed in primary care settings and that the psychological disturbances seen in CFS may well be the result of living with a chronic illness that is poorly recognized or understood.

 

Source: Fossey M, Libman E, Bailes S, Baltzan M, Schondorf R, Amsel R, Fichten CS. Sleep quality and psychological adjustment in chronic fatigue syndrome. J Behav Med. 2004 Dec;27(6):581-605. http://www.ncbi.nlm.nih.gov/pubmed/15669445

 

Gastric emptying is slow in chronic fatigue syndrome

Abstract:

BACKGROUND: Gastrointestinal symptoms are common in patients with Chronic Fatigue Syndrome (CFS). The objective of this study was to determine the frequency of these symptoms and explore their relationship with objective (radionuclide) studies of upper GI function.

METHODS: Thirty-two (32) patients with CFS and 45 control subjects completed a questionnaire on upper GI symptoms, and the 32 patients underwent oesophageal clearance, and simultaneous liquid and solid gastric emptying studies using radionuclide techniques compared with historical controls.

RESULTS: The questionnaires showed a significant difference in gastric (p > 0.01) symptoms and swallowing difficulty. Nocturnal diarrhoea was a significant symptom not previously reported.5/32 CFS subjects showed slightly delayed oesophageal clearance, but overall there was no significant difference from the control subjects, nor correlation of oesophageal clearance with symptoms. 23/32 patients showed a delay in liquid gastric emptying, and 12/32 a delay in solid gastric emptying with the delay significantly correlated with the mean symptom score (for each p < 0.001).

CONCLUSIONS: GI symptoms in patients with chronic fatigue syndrome are associated with objective changes of upper GI motility.

 

Source: Burnet RB, Chatterton BE. Gastric emptying is slow in chronic fatigue syndrome. BMC Gastroenterol. 2004 Dec 26;4:32. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC544348/ (Full article)

 

Neuropathology in rhinosinusitis

Abstract:

Pathophysiologic differences in neural responses to hypertonic saline (HTS) were investigated in subjects with acute sinusitis (n = 25), subjects with chronic fatigue syndrome (CFS) with nonallergic rhinitis (n = 14), subjects with active allergic rhinitis (AR; n = 17), and normal (n = 20) subjects. Increasing strengths of HTS were sprayed into their nostrils at 5-minute intervals. Sensations of nasal pain, blockage, and drip increased with concentration and were significantly elevated above normal. These parallels suggested activation of similar subsets of afferent neurons.

Urea and lysozyme secretion were dose dependent in all groups, suggesting that serous cell exocytosis was one source of urea after neural stimulation. Only AR and normal groups had mucin dose responses and correlations between symptoms and lysozyme secretion (R(2) = 0.12-0.23). The lysozyme dose responses may represent axon responses in these groups. The neurogenic stimulus did not alter albumin (vascular) exudation in any group. Albumin and mucin concentrations were correlated in sinusitis, suggesting that nonneurogenic factors predominated in sinusitis mucous hypersecretion. CFS had neural hypersensitivity (pain) but reduced serous cell secretion. HTS nasal provocations identified significant, unique patterns of neural and mucosal dysregulation in each rhinosinusitis syndrome.

 

Source: Baraniuk JN, Petrie KN, Le U, Tai CF, Park YJ, Yuta A, Ali M, Vandenbussche CJ, Nelson B. Neuropathology in rhinosinusitis. Am J Respir Crit Care Med. 2005 Jan 1;171(1):5-11. Epub 2004 Oct 11. http://www.ncbi.nlm.nih.gov/pubmed/15477496

 

Subjective and objective sleepiness in monozygotic twins discordant for chronic fatigue syndrome

Abstract:

STUDY OBJECTIVE: To examine the association of chronic fatigue syndrome (CFS) with measures of objective and subjective sleepiness.

DESIGN: Monozygotic co-twin control study.

SETTING: Academic medical center.

PATIENTS AND PARTICIPANTS: Twenty monozygotic twin pairs discordant for CFS.

INTERVENTIONS: N/A.

MEASUREMENTS AND RESULTS: All twins completed an Epworth Sleepiness Scale (ESS), 4 Stanford Sleepiness Scales (SSS), and underwent a standard 4-nap multiple sleep latency test. We compared the ESS scores, average SSS scores, and average sleep latency in CFS and healthy twins. The CFS twins reported more sleepiness as measured by mean scores on the ESS (10.9 vs 8.2; 95% confidence interval [CI] = 0.3-5.5; P = .03) and the SSS (3.4 versus 2.1; 95% CI = 0.7-1.9; P < .001). The mean sleep latency on the Multiple Sleep Latency Test was not significantly different between the CFS and healthy twins (8.9 vs 10.0 minutes; 95% CI -4.4-1.7; P = .33). Mean SSS scores increased among the CFS twins and decreased among healthy twins from nap 1 to nap 4 (P < .001). The individual ESS scores and mean sleep latencies on the Multiple Sleep Latency Test were negatively correlated for all the twins (Pearson’s r = – 0.40; P = .01), with a slightly stronger association among the healthy twins (Pearson’s r = -0.42, P = .07) than the CFS twins (Pearson’s r = -0.36, P = .15).

CONCLUSIONS: CFS twins reported significantly more subjective sleepiness than their healthy co-twins despite similar nonpathologic mean sleep latencies on the Multiple Sleep Latency Test. Patients with CFS may mistake their chronic disabling fatigue for sleepiness.

 

Source: Watson NF, Jacobsen C, Goldberg J, Kapur V, Buchwald D. Subjective and objective sleepiness in monozygotic twins discordant for chronic fatigue syndrome. Sleep. 2004 Aug 1;27(5):973-7. http://www.ncbi.nlm.nih.gov/pubmed/15453557

 

Exercise lowers pain threshold in chronic fatigue syndrome

Abstract:

Post-exertional muscle pain is an important reason for disability in patients who are diagnosed to have Chronic Fatigue Syndrome (CFS). We compared changes in pain threshold in five CFS patients with five age and sex matched controls following graded exercise. Pain thresholds, measured in the skin web between thumb and index finger, increased in control subjects with exercise while it decreased in the CFS subjects. Increased perception of pain and/or fatigue after exercise may be indicative of a dysfunction of the central anti-nociceptive mechanism in CFS patients.

 

Source: Whiteside A, Hansen S, Chaudhuri A. Exercise lowers pain threshold in chronic fatigue syndrome. Pain. 2004 Jun;109(3):497-9. http://www.ncbi.nlm.nih.gov/pubmed/15157711

 

Sleep assessment in a population-based study of chronic fatigue syndrome

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) is a disabling condition that affects approximately 800,000 adult Americans. The pathophysiology remains unknown and there are no diagnostic markers or characteristic physical signs or laboratory abnormalities. Most CFS patients complain of unrefreshing sleep and many of the postulated etiologies of CFS affect sleep. Conversely, many sleep disorders present similarly to CFS. Few studies characterizing sleep in unselected CFS subjects have been published and none have been performed in cases identified from population-based studies.

METHODS: The study included 339 subjects (mean age 45.8 years, 77% female, 94.1% white) identified through telephone screen in a previously described population-based study of CFS in Wichita, Kansas. They completed questionnaires to assess fatigue and wellness and 2 self-administered sleep questionnaires. Scores for five of the six sleep factors (insomnia/hypersomnia, non-restorative sleep, excessive daytime somnolence, sleep apnea, and restlessness) in the Centre for Sleep and Chronobiology’s Sleep Assessment Questionnaire (SAQ) were dichotomized based on threshold. The Epworth Sleepiness Scale score was used as a continuous variable.

RESULTS: 81.4% of subjects had an abnormality in at least one SAQ sleep factor. Subjects with sleep factor abnormalities had significantly lower wellness scores but statistically unchanged fatigue severity scores compared to those without SAQ abnormality. CFS subjects had significantly increased risk of abnormal scores in the non-restorative (adjusted odds ratio [OR] = 28.1; 95% confidence interval [CI]= 7.4-107.0) and restlessness (OR = 16.0; 95% CI = 4.2-61.6) SAQ factors compared to non-fatigued, but not for factors of sleep apnea or excessive daytime somnolence. This is consistent with studies finding that, while fatigued, CFS subjects are not sleepy. A strong correlation (0.78) of Epworth score was found only for the excessive daytime somnolence factor.

CONCLUSIONS: SAQ factors describe sleep abnormalities associated with CFS and provide more information than the Epworth score. Validation of these promising results will require formal polysomnographic sleep studies.

 

Source: Unger ER, Nisenbaum R, Moldofsky H, Cesta A, Sammut C, Reyes M, Reeves WC. Sleep assessment in a population-based study of chronic fatigue syndrome. BMC Neurol. 2004 Apr 19;4:6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC419502/  (Full article)

 

Monozygotic twins discordant for chronic fatigue syndrome: objective measures of sleep

Abstract:

PURPOSE: Chronic fatigue syndrome (CFS) is characterized by profound fatigue accompanied by disturbances of sleep, cognition, mood, and other symptoms. Our objective was to describe sleep architecture in CFS-discordant twin pairs.

METHODS: We conducted a co-twin control study of 22 pairs of monozygotic twins where one twin met criteria for CFS and the co-twin was healthy. Twins underwent two nights of polysomnography.

RESULTS: The percentage of Stage 3 and REM sleep was greater among the CFS twins than their healthy co-twins (P< or = .05 for both), but no other differences in sleep architecture including sleep latency, REM latency, and total sleep time were observed. Compared to their co-twins, CFS twins had higher values for the apnea-hypopnea index and apnea-hypopnea arousal index (P< or =.05 for both).

CONCLUSION: These results do not provide strong evidence for a major role for abnormalities in sleep architecture in CFS. Respiration appears impaired in CFS, but these clinical abnormalities cannot alone account for the prominence of sleep complaints in this illness. The co-twin control methodology highlights the importance of selecting well-matched control subjects.

 

Source: Ball N, Buchwald DS, Schmidt D, Goldberg J, Ashton S, Armitage R. Monozygotic twins discordant for chronic fatigue syndrome: objective measures of sleep. J Psychosom Res. 2004 Feb;56(2):207-12. http://www.ncbi.nlm.nih.gov/pubmed/15016580

 

Chronic fatigue syndrome and sexual dysfunction

Abstract:

OBJECTIVE: The study was undertaken to determine if ambulant female patients with the chronic fatigue syndrome (CFS) report problems with their sexual functioning.

METHODS: We studied 35 female CFS patients and 36 healthy female controls. The severity of CFS was measured with a fatigue questionnaire and the presence and severity of sexual dysfunction with a questionnaire about sexual functioning.

RESULTS: The mean fatigue score was 24.8 in the CFS patients and 11.9 in the controls (P=.000). No increase in sexual dysfunction was found in the CFS group. The control group showed negative correlations between the score of the fatigue questionnaire and the frequency of “sexual fantasies,” “(desire for) sexual contact” and “satisfaction with sex life.” Such correlations were absent in the CFS group.

CONCLUSION: The satisfaction with sex life was similar in patients and controls. The results suggest that patients and controls have a different perception of fatigue.

 

Source: Vermeulen RC, Scholte HR. Chronic fatigue syndrome and sexual dysfunction. J Psychosom Res. 2004 Feb;56(2):199-201. http://www.ncbi.nlm.nih.gov/pubmed/15016578

 

Factor analysis of symptoms among subjects with unexplained chronic fatigue: what can we learn about chronic fatigue syndrome?

Abstract:

OBJECTIVE: Chronic fatigue syndrome (CFS) case definitions agree that fatigue must be unexplained, debilitating and present for at least 6 months, but they differ over accompanying symptoms. Our objective was to compare the 1994 CFS case-defining symptoms with those identified by factor analysis.

METHODS: We surveyed the Wichita population and measured the occurrence of 21 symptoms in 1391 chronically fatigued subjects who did not report fatigue-associated medical or psychiatric conditions. We used factor analyses to identify symptom dimensions of fatigue and cluster analysis to assign subjects to subgroups.

RESULTS: Forty-three subjects had CFS. We confirmed three factors: musculoskeletal, infection and cognition-mood-sleep, essentially defined by CFS symptoms. Although factor scores were higher among CFS subjects, CFS and non-CFS distributions overlapped substantially. Three clusters also showed overlap between CFS and non-CFS subjects.

CONCLUSION: CFS symptomatology is a multidimensional phenomenon overlapping with other unexplained fatiguing syndromes and this must be considered in CFS research.

 

Source: Nisenbaum R, Reyes M, Unger ER, Reeves WC. Factor analysis of symptoms among subjects with unexplained chronic fatigue: what can we learn about chronic fatigue syndrome? J Psychosom Res. 2004 Feb;56(2):171-8. http://www.ncbi.nlm.nih.gov/pubmed/15016574