Category: Symptoms

Do patients with “pure” chronic fatigue syndrome (neurasthenia) have abnormal sleep?

Abstract:

OBJECTIVE: To determine whether patients with “pure” chronic fatigue syndrome (neurasthenia) have sleep abnormalities which may contribute to subjective measures of daytime fatigue.

METHOD: Sleep characteristics of 20 patients meeting research criteria for chronic fatigue syndrome (CFS) but not depression, anxiety, or sleep disorder were compared with sleep characteristics of 20 healthy subjects matched for age and sex. Measures of sleep included a) subjective interview reports and sleep diaries and b) home-based polysomnography.

RESULTS: Patients with CFS complained of poor quality unrefreshing sleep. They also napped during the day. Polysomnograph data showed no difference in actual nocturnal sleep time between the two groups although patients with CFS spent significantly longer in bed (p < .01), slept less efficiently (p < .03), and spent longer awake after sleep onset (p < .05). The polysomnographs of seven patients with CFS and one healthy subject were regarded as significantly abnormal. Five patients and one healthy subject had difficulty maintaining sleep. One patient had a disorder of both initiating and maintaining sleep and one patient woke early.

CONCLUSIONS: Patients with “pure” CFS complain of unrefreshing sleep but only a minority have a clearly abnormal polysomnograph. The most common abnormality is of long periods spent awake after initial sleep onset. Although sleep abnormalities may play a role in the etiology of CFS, they seem to be unlikely to be an important cause of daytime fatigue in the majority of patients. However, pharmacological and behavioral methods that improve sleep quality may be an important component of a pragmatically based treatment package for patients who do have abnormal sleep.

 

Source: Sharpley A, Clements A, Hawton K, Sharpe M. Do patients with “pure” chronic fatigue syndrome (neurasthenia) have abnormal sleep? Psychosom Med. 1997 Nov-Dec;59(6):592-6. http://www.ncbi.nlm.nih.gov/pubmed/9407577

 

The chronic fatigue syndrome and hyperventilation

Erratum in: J Psychosom Res 1998 Mar-Apr;44(3-4):517.

 

Abstract:

Chronic fatigue syndrome (CFS) is characterized by severe fatigue, lasting for at least 6 months, for which no somatic explanation can be found. Because hyperventilation can produce substantial fatigue, it seems worthwhile to investigate the relationship between it and CFS. It might be hypothesized that hyperventilation plays a causal or perpetuating role in CFS.

CFS patients, non-CFS patients known to experience hyperventilation, and healthy controls were compared on complaints of fatigue and hyperventilation. CFS patients and non-CFS patients known to experience hyperventilation offered substantial complaints of fatigue and hyperventilation, both to a similar degree. Physiological evidence of hyperventilation was found significantly more often in CFS patients than in healthy controls.

However, no significant differences between CFS patients with and CFS patients without hyperventilation were found on severity of fatigue, impairment, number of complaints, activity level, psychopathology, and depression. It is concluded that hyperventilation in CFS should probably be regarded as an epiphenomenon.

 

Source: Bazelmans E, Bleijenberg G, Vercoulen JH, van der Meer JW, Folgering H. The chronic fatigue syndrome and hyperventilation. J Psychosom Res. 1997 Oct;43(4):371-7. http://www.ncbi.nlm.nih.gov/pubmed/9330236

 

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

 

Sleep anomalies in the chronic fatigue syndrome. A comorbidity study

Abstract:

Polysomnographic findings were compared between a group of patients with the chronic fatigue syndrome (CFS; n = 49) and a matched healthy control (HC) group (n = 20).

Sleep initiation and sleep maintenance disturbances were observed in the CFS group. The percentage of stage 4 was significantly lower in the CFS group. A discriminant analysis allowed a high level of correct classification of CFS subjects and HC. Sleep-onset latency and the number of stage shifts/hour contributed significantly to the discriminant function.

The presence of these anomalies as well as the decrease in stage 4 sleep were not limited to the patients also diagnosed with fibromyalgia or with a psychiatric disorder. No association was found between sleep disorders and the degree of functional status impairment. The mean REM latency and the percentage of subjects with a shortened REM latency were similar in CFS and HC.

 

Source: Fischler B, Le Bon O, Hoffmann G, Cluydts R, Kaufman L, De Meirleir K. Sleep anomalies in the chronic fatigue syndrome. A comorbidity study. Neuropsychobiology. 1997;35(3):115-22. http://www.ncbi.nlm.nih.gov/pubmed/9170115

 

Dissociation of body-temperature and melatonin secretion circadian rhythms in patients with chronic fatigue syndrome

Abstract:

Many patients with chronic fatigue syndrome (CFS) display features of hypothalamic dysfunction. We have investigated aspects of circadian rhythmicity, an important hypothalamic function, in 20 CFS patients and in 17 age- and sex-matched healthy control subjects.

There were no differences between the two groups in the amplitude, mesor (mean value) or timing of the peak (acrophase) of the circadian rhythm of core temperature, or in the timing of the onset of melatonin secretion.

However, the CFS patients showed no significant correlation between the timing of the temperature acrophase and the melatonin onset (P < 0.5), whereas the normal significant correlation was observed in the controls (P < 0.05). Dissociation of circadian rhythms could be due to the sleep deprivation and social disruption, and/or the reduction in physical activity which typically accompany CFS.

By analogy with jet-lag and shift-working, circadian dysrhythmia could be an important factor in initiating and perpetuating the cardinal symptoms of CFS, notably tiredness, impaired concentration and intellectual impairment.

 

Source: Williams G, Pirmohamed J, Minors D, Waterhouse J, Buchan I, Arendt J, Edwards RH. Dissociation of body-temperature and melatonin secretion circadian rhythms in patients with chronic fatigue syndrome. Clin Physiol. 1996 Jul;16(4):327-37. http://www.ncbi.nlm.nih.gov/pubmed/8842569

 

Preliminary determination of the association between symptom expression and urinary metabolites in subjects with chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) patients have a urinary metabolite labeled CFSUM1 with increased incidence (P < 0.004) and relative abundance (P < 0.00003). The relative abundances of urinary CFSUM1 and beta-alanine were associated with alterations in metabolite excretion and symptom incidence.

In 20 CFS patients and 45 non-CFS subjects, symptom/metabolite associations were investigated by assessing symptom sensitivity and specificity, and symptom indices of total symptom incidence, CFS core symptoms, cognitive, neurological, musculoskeletal, gastrointestinal, infection-related and genitourinary symptom indices, as well as a visual analogue pain scale of average pain intensity. Thirty-three symptoms had significant (P < 0.005) sensitivity and specificity in the CFS patients compared to that in the non-CFS controls.

Severe fatigue was the only symptom with 100% sensitivity and specificity and CFSUM1 excretion was the primary metabolite for expression of this symptom. All nine symptom indices had elevated responses in the CFS patients (all P < 0.0000001). Multiple regression analyses indicated that all the symptom indices had significant correlations (R) with changes in the urinary excretion of metabolites (P < 0.0001).

CFSUM1 and beta-alanine were the first and second metabolites correlated with the CFS core symptom index and CFSUM1 was primarily associated with infection-related and musculoskeletal indices whereas beta-alanine was primarily associated with gastrointestinal and genitourinary indices. The strong associations of CFSUM1 and beta-alanine with CFS symptom expression provide a molecular basis for developing an objective test for CFS.

 

Source: McGregor NR, Dunstan RH, Zerbes M, Butt HL, Roberts TK, Klineberg IJ. Preliminary determination of the association between symptom expression and urinary metabolites in subjects with chronic fatigue syndrome. Biochem Mol Med. 1996 Jun;58(1):85-92. http://www.ncbi.nlm.nih.gov/pubmed/8809350

 

‘Seronegative’ Sjögren’s syndrome manifested as a subset of chronic fatigue syndrome

Abstract:

We determined the extent to which chronic fatigue syndrome (CFS) patients with sicca symptoms fulfil the diagnostic criteria for Sjögren’s syndrome (SS). Three sets of diagnostic criteria for SS, formulated by the Japanese, Europeans and Fox, were used. One-third of the CFS patients with sicca symptoms fulfilled the diagnostic criteria for SS. However, they were ‘seronegative’, differing from the ordinary primary SS.

 

Source: Nishikai M1, Akiya K, Tojo T, Onoda N, Tani M, Shimizu K. ‘Seronegative’ Sjögren’s syndrome manifested as a subset of chronic fatigue syndrome. Br J Rheumatol. 1996 May;35(5):471-4. http://rheumatology.oxfordjournals.org/content/35/5/471.long (Full article)

 

Sensory characterization of somatic parietal tissues in humans with chronic fatigue syndrome

Abstract:

Patients with chronic fatigue syndrome (CFS) mainly complain of symptoms in the musculoskeletal domain (myalgias, fatigue). In 21 CFS patients the deep (muscle) versus superficial (skin, subcutis) sensitivity to pain was explored by measuring pain thresholds to electrical stimulation unilaterally in the deltoid, trapezius and quadriceps and overlying skin and subcutis in comparison with normal subjects.

Thresholds in patients were normal in skin and subcutis but significantly lower than normal (hyperalgesia) in muscles (P < 0.001) in all sites. The selective muscle hypersensitivity corresponded also to fiber abnormalities at muscle biopsy (quadriceps) performed in nine patients which were absent in normal subjects (four cases): morphostructural alterations of the sarchomere, fatty degeneration and fibrous regeneration, inversion of the cytochrome oxidase/succinate dehydrogenase ratio, pleio/polymorphism and monstruosity of mitochondria, reduction of some mitochondrial enzymatic activities and increments of common deletion of 4977 bp of mitochondrial DNA 150-3000 times the normal values.

By showing both sensory (diffuse hyperalgesia) and anatomical (degenerative picture) changes at muscle level, the results suggest a role played by peripheral mechanisms in the genesis of CFS symptoms. They would exclude the heightened perception of physiological signals from all districts hypothesized by some authors, especially as the hyperalgesia is absent in skin/subcutis.

 

Source: Vecchiet L, Montanari G, Pizzigallo E, Iezzi S, de Bigontina P, Dragani L, Vecchiet J, Giamberardino MA. Sensory characterization of somatic parietal tissues in humans with chronic fatigue syndrome. Neurosci Lett. 1996 Apr 19;208(2):117-20. http://www.ncbi.nlm.nih.gov/pubmed/8859904

 

Periodic K-alpha sleep EEG activity and periodic limb movements during sleep: comparisons of clinical features and sleep parameters

Abstract:

The K-alpha sleep electroencephalographic (EEG) phenomenon is characterized by periodic (approximately 20-40 seconds) K-complexes, immediately followed by alpha-EEG activity (7.5-11 Hz) of 0.5- to 5.0-second duration. A group of 14 subjects with the periodic K-alpha anomaly was found to have a similar distribution pattern of interevent intervals as compared with previously published data for sleep-related periodic limb movements during sleep (PLMS). Sleep parameters and somatic symptoms of 30 patients with K-alpha were compared with 30 patients with PLMS. The periodic K-alpha group was predominantly female, younger, exhibiting more slow-wave sleep, gastrointestinal symptoms and muscular complaints and fewer movement arousals on overnight polysomnography. The K-alpha group presented uniformly with complaints of unrefreshing sleep, often associated with fibromyalgia and chronic fatigue syndrome. The PLMS group was predominantly male, showed greater sleep disruption and presented with a variety of sleep-related symptoms.

 

Source: MacFarlane JG, Shahal B, Mously C, Moldofsky H. Periodic K-alpha sleep EEG activity and periodic limb movements during sleep: comparisons of clinical features and sleep parameters. Sleep. 1996 Apr;19(3):200-4. http://www.ncbi.nlm.nih.gov/pubmed/8723376

 

Determination of observer-rated alpha activity during sleep

Abstract:

Patients suffering from chronic fatigue syndrome (CFS) have been described as having alpha intrusion into sleep. In a separate study of the relationship between depression and CFS, we investigated the sleep of CFS patients.

We could not detect any observable alpha anomaly in our group of CFS patients. It is possible that there is a subgroup of CFS patients in whom no alpha anomaly is present. However, the sleep electroencephalogram (EEG) montage used in our study was different to that employed by previous researchers.

This paper investigates the influence of electrode derivations on the outcome of observable alpha ratings. We compared simultaneous recordings of sleep EEG using three commonly employed montages.

Our results indicate that use of the mastoid reference (montage 1) results in the highest observer-related alpha. This may suggest that data regarding alpha intrusion should always be collected using montage 1.

However, there is a possibility that the mastoid electrode is not electrically silent and is contaminating the data of the referenced channels. The implications of these findings are discussed in relation to the validity of alpha intrusion measurement of CFS and fibromyalgia.

 

Source: Flanigan MJ, Morehouse RL, Shapiro CM. Determination of observer-rated alpha activity during sleep. Sleep. 1995 Oct;18(8):702-6. http://www.ncbi.nlm.nih.gov/pubmed/8560138