Chronic fatigue syndrome impairs circadian rhythm of activity level

Some of the symptoms of chronic fatigue syndrome (CFS) are the same as for disrupted circadian rhythm. Activity level is frequently used to study circadian rhythm. Continuous waist activity measurements taken every minute 24 h/day for from 5 to 7 days in 10 controls and from 2 to 7 days in 8 patients with CFS yielded two primary findings: (a) lower daytime activity and (b) less regular activity-rest cycles in persons with CFS than in controls.     

高血压病血压昼夜节律与心肌缺血的关系

目的 探讨高血压病患者血压昼夜节律改变与心肌缺血之间的关系及临床意义。方法对90例高血压病患者,根据动态心电图上有无心肌缺血(MI)分为MI组(40例)和无MI组(50例),并与20例健康体检者进行对照,观察3组的动态血压变化,同时分析血压昼夜节律正常组和异常组的心肌缺血的发生情况。结果 高血压病伴有MI的患者中,除dSBP、24hDBPL、dSBPL、dDBPL与无MI组比较无统计学差异外,其余各项动态血压指标均明显高于无MI组(P<0.01);高血压病血压昼夜节律异常组发生MI者明显高于血压昼夜节律正常组(P<0.05)。结论 高血压病患者中伴有血压昼夜节律异常者更易导致心肌缺血的发生。对高血压病患者的治疗,除积极控制血压外,还应注意检测和逆转异常的昼夜血压节律,对减少心肌缺血的发生和靶器官损害具有重要意义。     

Circadian rhythm of wrist temperature in normal-living subjects A candidate of new index of the circadian system

Most circadian rhythms are under the control of a major pacemaker located in the hypothalamic suprachiasmatic nucleus. Some of these rhythms, called marker rhythms, serve to characterize the timing of the internal temporal order. A marker rhythm, (e.g., one used in chronotherapy) has to be periodic and easy to measure over long periods using non-invasive methods. The most frequent reference variables for human chronotherapy include salivary melatonin or cortisol, urinary 6-sulfatoximelatonin, actimetry and core body temperature (CBT). Recent evidence suggests that sleepiness may be more closely linked to increased peripheral skin temperature than to a core temperature drop, and that distal skin temperature seems to be correlated and phase-advanced with respect to CBT, suggesting that heat loss from the extremities may drive the circadian CBT rhythm.The aim of the present study was to evaluate whether the wrist skin temperature rhythm could be used as a possible index of the human circadian system. To this end, wrist skin temperature (WT1), as determined by a wireless data logger in healthy normal living subjects, was correlated with sleep-wake diaries and oral temperature (OT) recordings. WT and sleep habits were studied in 99 university students. Each subject wore a wireless iButton sensor attached to the inner side of a sport wristband. Our results show that the WT rhythm exhibits an inverse phase relationship with OT, and it is phase-advanced by 60 min with respect to OT. WT started to increase in association to bed time and dropped sharply after awakening. A secondary WT increase, independent of feeding, was observed in the early afternoon.In conclusion, WT wireless recording can be considered a reliable procedure to evaluate circadian rhythmicity, and an index to establish and follow the effects of chronotherapy in normal living subjects.     

The effects of continuous illumination (LL) and continuous darkness (DD) on the daily rhythms of membrane-bound and microsomal enzymes in the adrenal gland and kidney of the rat

A daily rhythm was demonstrated in levels of specific activity for the Na, K-ATPase and glucose-6-phosphatase enzymes in adrenal and renal subcellular fractions in the rat. A bimodal daily rhythm was observed for 5′-nucleotidase in a renal subcellular fraction. The rats were maintained on a 12:12 light-dark (LD) regimen. Animals were killed at approximately 4-hour intervals. The daily rhythm in Na, K-ATPase and glucose-6-phosphatase activities persisted in animals maintained under continuous illumination (LL) and continuous darkness (DD). The 5′nucleotidase activity persisted under LL, and under DD. The data from the enzyme assays were analyzed by fitting to a cosinor regression model designed to assess the rhythmic nature of the findings. A linear transformation method was applied to assess the closeness of fit to the cosinor regression model. The Na, K-ATPase and glucose-6-phosphatase activities appeared to be endogenous circadian rhythms. Glucose-6-phosphatase activity in renal fractions appeared to be influenced by the feeding cycle. The 5′-nucleotidase enzyme appeared to have an ultradian rhythm. The ultimate derivation and significance of these observed rhythms remains to be determined; however, they appear to be independent of the light-dark cycle.     

Is a full recovery possible after cognitive behavioural therapy for chronic fatigue syndrome?

BACKGROUND: Cognitive behavioural therapy (CBT) for chronic fatigue syndrome (CFS) leads to a decrease in symptoms and disabilities. There is controversy about the nature of the change following treatment; some suggest that patients improve by learning to adapt to a chronic condition, others think that recovery is possible. The objective of this study was to find out whether recovery from CFS is possible after CBT. METHODS: The outcome of a cohort of 96 patients treated for CFS with CBT was studied. The definition of recovery was based on the absence of the criteria for CFS set up by the Center for Disease Control (CDC), but also took into account the perception of the patients' fatigue and their own health. Data from healthy population norms were used in calculating conservative thresholds for recovery. RESULTS: After treatment, 69% of the patients no longer met the CDC criteria for CFS. The percentage of recovered patients depended on the criteria used for recovery. Using the most comprehensive definition of recovery, 23% of the patients fully recovered. Fewer patients with a co-morbid medical condition recovered. CONCLUSION: Significant improvement following CBT is probable and a full recovery is possible. Sharing this information with patients can raise the expectations of the treatment, which may enhance outcomes without raising false hopes.     

Hypoxia‐induced changes in recovery sleep,core body temperature,urinary 6‐sulphatoxymelatonin and free cortisol after a simulated long‐duration flight

Fatigue and sleep disorders often occur after long‐haul flights, even when no time zones are crossed. In this controlled study, we assessed the effects of two levels of hypoxia (at 8000 ft and 12 000 ft) on recovery sleep. Core body temperature (CBT), a circadian marker, urinary 6‐sulphatoxymelatonin and free cortisol were studied in 20 young healthy male volunteers exposed for 8 h (08:00–16:00 hours) in a hypobaric chamber to a simulated cabin altitude of 8000 ft and, 4 weeks later, 12 000 ft. Each subject served as his own control. Sleep was recorded by polysomnography for three consecutive nights for each exposure. CBT was monitored by telemetry during the three 24‐h cycles (control, hypoxic exposure and recovery). Free urinary cortisol and 6‐sulphatoxymelatonin levels were assayed twice daily between 08:00 and 20:00 hours (day) and between 20:00 and 08:00 hours (night). We showed significant changes in circadian patterns of CBT at both altitudes, suggesting a phase delay, and changes in recovery sleep but only at 12 000 ft. We observed an increase in sleep onset latency which correlated positively with the increase in CBT levels during the first recovery night and a decrease in the duration of stage N₂ (formerly S₂), which correlated negatively with the mid‐range crossing time, a reliable phase marker of CBT rhythm. This study shows clearly the impact of hypobaric hypoxia on circadian time structure during air flights leading to a phase delay of CBT, independent of jet lag and consequences on sleep during recovery.     

Cognitive Behavioral Therapy and Graded Exercise for Chronic Fatigue Syndrome: A Meta‐Analysis

[Clin Psychol Sci Prac 18: 311–324, 2011] Several reviews have concluded that graded exercise therapy (GET) and cognitive behavioral therapy (CBT) may be the most efficacious treatments for chronic fatigue syndrome (CFS). The current review extends the evidence for overall and outcome‐specific effects of CBT and GET by directly comparing the treatments and addressing the methodological limitations of previous reviews. GET (n = 5) and CBT (n = 16) randomized controlled trials were meta‐analyzed. Overall effect sizes suggested that GET (g = 0.28) and CBT (g = 0.33) were equally efficacious. However, CBT effect sizes were lower in primary care settings and for treatments offering fewer hours of contact. The results suggested that both CBT and GET are promising treatments for CFS, although CBT may be a more effective treatment when patients have comorbid anxiety and depressive symptoms.     

Circadian patterns of sleep, sleepiness, and performance in older and younger adults

STUDY OBJECTIVE: To compare circadian patterns of sleep, subjective sleepiness, and psychomotor performance in older and younger adults. DESIGN: Controlled experimental laboratory study. SETTING: General Clinical Research Center. PARTICIPANTS: Healthy older adults (n = 17, mean age 76 years) and healthy younger adults (n = 19, mean age 23 years). INTERVENTIONS: Subjects lived for 60 consecutive hours on a 90-minute sleep-wake cycle (30 minutes in bed, 60 minutes awake). Electroencephalographic recordings were conducted during bedrest periods. Self-ratings and psychomotor performance tests were conducted during 60-minute wake periods. MEASUREMENTS AND RESULTS: Data were analyzed with cosinor and linear mixed models. Amplitude and phase of the core body temperature rhythm did not significantly differ by age group. Older adults had significantly reduced mean levels and amplitude of rhythms in total sleep time and sleep efficiency and increased mean levels and amplitude of rhythms in sleep latency and wake after sleep onset. Age groups did not differ in mean level of subjective sleepiness, but older adults had reduced amplitude. Older adults had worse overall psychomotor performance, with evidence of larger circadian amplitude in some of these rhythms. Age groups did not differ on the phase position of any rhythm. CONCLUSIONS: Older adults had a lower level and smaller circadian variation of sleep propensity compared with younger adults, whereas wakefulness and psychomotor performance rhythms tended to show increased circadian variation among older subjects. These findings likely result from a combination of age-related changes in cortical function, homeostatic sleep mechanisms, and circadian regulation.     

自主跑轮运动对慢性不可预见性轻度应激大鼠抑郁样行为及神经内分泌因子近日节律的影响

目的:探讨8周自主跑轮运动对慢性不可预见性轻度应激(CUMS)大鼠抑郁样行为及外周神经内分泌因子生物节律表达的影响,从时间生物学方面探讨运动抗抑郁、促进脑康复的作用机制。方法:雄性SD大鼠90只,随机分为对照(control)组、模型(model)组及模型运动(model+exercise)组。采用CUMS方式建立抑郁模型,模型运动组前5周自愿跑轮,从第6周开始,附加21 d慢性复合应激,模型组于同一时点造模21 d。采用糖水偏好实验、旷场行为及高架十字迷宫系统观测大鼠焦虑情绪的行为学变化。行为学检测结束后第2天,连续24 h分6个时点(ZT1、ZT5、ZT9、ZT13、ZT17、ZT21)处死动物取血,每个时点处死5只大鼠,放射免疫法测定上述6个时点血清促肾上腺皮质激素(ACTH)含量,ELISA检测6个相同时点血清皮质酮(CORT)、褪黑素(MT)及血管活性肠肽(VIP)的含量,采用单一余弦法拟合曲线比较慢性应激大鼠各指标的节律周期、振幅、峰相位、中值的变化特点以及运动对其的影响。结果:与对照组相比,21 d的CUMS使模型组大鼠体重增加量明显减少(P0.01),糖水消耗量明显降低(P0.01);旷场实验中爬格数、直立次数及中央格停留时间均显著下降,而粪粒数明显增多(P0.01);高架十字迷宫中开放臂停留时间的百分比和开放臂进入次数的百分比明显降低(P0.01)。运动对CUMS诱导的大鼠抑郁样行为有明显的改善作用。血浆近日节律输出肽及相关激素方面,慢性应激至抑郁样行为充分表达后,模型组大鼠血浆ACTH、CORT的相位与对照组完全相反,表现为时相的大幅度提前、含量波动幅度减小、昼夜分泌节律紊乱;MT的24 h分泌节律完全丧失且整体水平下降,表达量显著低于对照组;VIP虽仍存在24 h节律,但振幅明显低于对照组,峰相位也延迟6 h,表达量显著高于对照组。8周跑轮运动能显著改善应激大鼠的抑郁样行为及激素分泌量的异常,使血浆ACTH、MT、CORT和VIP的近日节律恢复正常。结论:运动可拮抗CUMS致大鼠的抑郁样行为,其作用机制可能与其在一定程度上能够调整外周神经内分泌激素的昼夜节律性和改变激素的分泌量有关。     

Implementing cognitive behavioral therapy for chronic fatigue syndrome in a mental health center: a benchmarking evaluation

OBJECTIVE: This study evaluated the success of implementing cognitive behavioral therapy (CBT) for chronic fatigue syndrome (CFS) in a representative clinical practice setting and compared the patient outcomes with those of previously published randomized controlled trials (RCTs) of CBT for CFS. METHOD: The implementation interventions were the following: spreading information about the new treatment setting to general practitioners and CFS patients; training mental health center (MHC) therapists in CBT for CFS; and organizing changes in the MHC patient workflow. Patient outcomes were documented with validated self-report measures of fatigue and physical functioning before and after treatment. The comparison of the treatment results with RCT results was done following the benchmark strategy. RESULTS: One-hundred forty-three CFS patients were referred to the MHC, of whom 112 started treatment. The implementation was largely successful, but a weak point was the fact that 32% of all referred patients dropped out shortly after or even before starting treatment. Treatment effect sizes were in the range of those found in the benchmark studies. CONCLUSIONS: CBT for CFS can successfully be implemented in an MHC. Treatment results were acceptable, but the relatively large early dropout of patients needs attention.     

The relationship between 6-sulphatoxymelatonin and polysomnographic sleep in good sleeping controls and wake maintenance insomniacs, aged 55-80 years

The pineal hormone, melatonin, is reported to possess hypnotic properties. This has led to an investigation of the relationship between the endogenous melatonin rhythm and sleep. However, this relationship has yet to be fully examined in aged insomniacs and controls. From media advertisements, 16 good sleeping controls (11F, 5M) and 16 sleep maintenance insomniacs (11F, 5M), aged over 55 years, were recruited to participate in a study involving four nights of polysomnographically (PSG) measured sleep followed by a 26 h constant routine. During the constant routine, 2 h urine samples were collected and analysed for the melatonin metabolite, 6-sulphatoxymelatonin (aMT.6S). This was used to determine total melatonin excretion. As well, the following circadian melatonin parameters were calculated from fifth order polynomial curve fitting analyses, the goodness of the polynomial curve fit, peak melatonin concentration, the phase of the melatonin rhythm, and melatonin and sleep rhythm synchrony. Apart for one control, all subjects showed significant circadian melatonin rhythms. Although insomniacs showed a greater amount of wakefulness, less sleep in total, and lower sleep efficiency, no significant group differences were observed in any of the melatonin parameters. In addition, while subjects with more reliable melatonin curve fits showed shorter sleep latencies and higher sleep efficiencies, correlational analyses revealed no other significant relationships between any melatonin and PSG sleep parameters. Overall, the present results suggest that neither melatonin amplitude nor phase are related to sleep quality in the aged.     

Restructuring mood in cyclothymia using cognitive behavior therapy: an intensive time-sampling study

Hypotheses predicting how cognitive behavioral therapy (CBT) would change the daily pattern of mood and sleep in a patient with cyclothymia were formulated based on circadian processes. Using a prospective single-case experimental design, the patient provided mood ratings every 4 hours and sleep reports daily for 49 weeks, including a 4-week baseline, a 20-session CBT intervention, and a follow-up period. Improvements in mood during and after therapy were accounted for by reduced daily mood variability and extended sleep. The patient's energy at different times of day was explained by adjusting the endogenous rhythm in a mathematical circadian model. Treatment of cyclothymia and related bipolar disorders may be enhanced by integrating understanding of circadian mood regulation into CBT treatment.     

IgE levels are the same in chronic fatigue syndrome (CFS) and control subjects when stratified by allergy skin test results and rhinitis types.

BACKGROUND: Chronic fatigue syndrome (CFS) has an uncertain pathogenesis. Allergies have been suggested as one cause. OBJECTIVE: The aim of this study was to compare serum immunoglobulin (Ig)E in CFS and control subjects to determine whether IgE levels were elevated in CFS. This would be suggestive of increased atopy in CFS. METHODS: IgE was measured by quantitative ELISA (sandwich) immunoassay in 95 CFS and 109 non-CFS control subjects. Subjects were classified by positive or negative allergy skin tests (AST) and rhinitis questionnaires (rhinitis score, RhSc) into four rhinitis types: nonallergic rhinitis (NAR with positive RhSc and negative AST); allergic rhinitis (AR with positive AST and RhSc); atopic/no rhinitis (AST positive/RhSc negative); and nonatopic/no rhinitis (both AST and RhSc negative) subjects. RESULTS: IgE was not significantly different between control (128 +/- 18 IU/mL, mean +/- SEM) and CFS (133 +/- 43 IU/mL) groups, or between control and CFS groups classified into the four rhinitis types. IgE was significantly higher in subjects with positive AST whether or not they had positive RhSc or CFS symptoms. CONCLUSIONS: Elevated IgE and positive AST indicate allergen sensitization, but are not necessarily indicators of symptomatic allergic diseases. There was no association between IgE levels and CFS, indicating that atopy was probably not more prevalent in CFS. Therefore, TH2-lymphocyte and IgE-mast cell mechanisms are unlikely causes of CFS.     

Treatment of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), a multisystem disease,should target the pathophysiological aberrations (inflammatory and oxidative and nitrosative stress pathways), not the psychosocial “barriers” for a new equilibrium

In a recent article published by B. van Houdenhove and P. Luyten it is claimed that cognitive behavioral therapy and graded exercise therapy (CBT/GET) are evidence based and are the most adequate treatments to control symptoms and improve quality of life of patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). However, these authors do not disclose that their own treatments at the Belgian CFS Reference Centers with CBT/GET have proven to have no clinical effects. The Belgian minister declared in the parliament that CBT/GET at those centers are no curative therapies. Even more, measured by objective standards the CBT/GET approach has shown to be counterproductive. van Houdenhove and Luyten neglect or deny all scientific findings on the pathophysiology and possible medical treatments of ME/CFS. However, there is now a consensus that inflammatory and oxidative and nitrosative (IO&NS) pathways underpin the pathophysiology of ME/CFS in humans and in animal models as well. Human and animal data show that treatments which target IO&NS pathways are useful in treating ME/CFS. van Houdenhove and Luyten also propose that the time has come to shift treatment research in CFS from efficacy studies to effectiveness studies in ‘real life’. In our opinion, future research should use a high throughput screening, made possible by the translational approach, in order to further examine the IO&NS pathways in detail; further delineate novel drug-targets in the IO&NS pathways and develop new drugs to treat this complex and serious medical disorder.     

Circadian rhythms in depression. Part II: Circadian rhythms in inpatients with various mental disorders

We investigated longitudinally the circadian body temperature rhythms in 65 inpatients with various mental disorders, 38 of whom had major depressive episodes, by estimating the deep body temperature from the skin surface every 2 h for a consecutive 48-h period. To estimate the circadian rhythm, the data obtained were analyzed by the least-squares method and maximum entropy spectral analysis (MEM). Circadian rhythm disturbances in patients with depression were likely to be manifested in phase variability rather than in phase advance. The amplitude of body temperature of the depressed group was significantly less than that of the control group. A positive correlation between the mesor and the severity of the depressive symptoms was found. Moreover, the body temperature of the patients with affective disorders, both in the depressive and in the manic state, tended to fluctuate so much as not only to fit poorly to sinusoid curves, but also to reduce the periodicity of the circadian rhythm. On the basis of these findings, we conclude that the essential feature of the rhythm disturbances in affective disorders is not the phase shift but the instability of the circadian temperature rhythm.     

Social support and the persistence of complaints in chronic fatigue syndrome

BACKGROUND: Several studies suggested that the surroundings of chronic fatigue syndrome (CFS) patients are of importance in the persistence of complaints. Contrary to what was expected, participation in support groups has not led to clinical improvement. The purpose of the present study was to describe social support in CFS patients as compared with other fatigued and non-fatigued groups. Further, changes in social support and the influence of social support on the course of CFS over a period of more than 1 year were studied in patients with and without treatment. METHODS: Baseline data were assessed in 270 CFS patients, 150 disease-free breast cancer patients, 151 fatigued employees on sick-leave and 108 healthy subjects using the Social Support List and Significant Others Scale. CFS patients were followed in cognitive behaviour therapy (CBT), guided support groups and natural course at 8 and 14 months. RESULTS: CFS patients and fatigued employees reported more negative interactions and insufficiency of supporting interactions than cancer patients and healthy controls. No differences in frequency of supporting interactions were found. Negative interactions decreased significantly after treatment with CBT, but did not change in support groups or natural course. In the natural course, higher fatigue severity at 8 months was predicted by more negative interactions at baseline. CONCLUSIONS: In CFS patients and fatigued employees, social support is worse than in disease-free cancer patients and healthy controls. Lack of social support was identified as a new factor in the model of perpetuating factors of fatigue severity and functional impairment in CFS.     

Circadian rhythm of motor restlessness and sensory symptoms in the idiopathic restless legs syndrome

STUDY OBJECTIVES: To determine if motor restlessness in the Restless Legs Syndrome (RLS) shows a circadian rhythm with maximum at night, as previously found for subjective discomfort and periodic limb movements (PLMs), and to correlate RLS peak intensity with the core temperature cycle. DESIGN: Subjects underwent two days of normally timed wakefulness and sleep followed by a night and subsequent day of sleep deprivation. Activity was standardized through modified suggested immobilization tests (mSITs). SETTING: The study was conducted in a laboratory environment with a bedroom equipped for polysomnography during sleep and the mSITs. PATIENTS: Nine patients (mean age 59.8+/-11.3 years [range: 33-72]; 4 males, 5 females) with clinically severe idiopathic RLS. INTERVENTIONS: Patients were monitored with continuous ambulatory activity and core temperature recording. The mSITs were performed every three hours while subjects were awake. During the mSITs, subjective discomfort was measured every 15 minutes while motor restlessness was assessed through activity monitoring. MEASUREMENTS AND RESULTS: Subjective discomfort and motor restlessness increased from a trough in the morning to a maximum at night in the hours following midnight. Peak intensity was found on the falling phase of the core temperature cycle, whose circadian rhythm appeared to be within the normal range for age. CONCLUSIONS: An independent circadian factor modulates the intensity of RLS, which seems to peak on the falling phase of the core temperature cycle. Therefore, the diagnostic criteria that RLS occurs with rest and during the night have independent bases. Furthermore, RLS may be partially controlled by some process or substance whose level varies with the normal circadian rhythm.     

Causal attributions for somatic sensations in patients with chronic fatigue syndrome and their partners

BACKGROUND: Patients with chronic fatigue syndrome (CFS) often make somatic attributions for their illness which has been associated with poor outcome. A tendency to make somatic attributions in general may be a vulnerability factor for the development of CFS. METHODS: This cross-sectional study based on self-report questionnaire data aimed to investigate the type of attributions for symptoms made by patients with CFS and to compare this to attributions made by their partners. It was hypothesized that patients with CFS would make more somatic attributions for their own symptoms than control subjects and that partners of patients with CFS would make more somatic attributions for their ill relative's symptoms but would be similar to controls regarding their own symptoms. Fifty patients with CFS were compared to 50 controls from a fracture clinic in the same hospital and 46 relatives living with the patients with CFS. A modified Symptom Interpretation Questionnaire was used to assess causal attributions. RESULTS: CFS patients were more likely to make somatic attributions for their symptoms. The relatives of patients with CFS made significantly more somatic attributions for symptoms in their ill relative. However, they were like the fracture clinic controls in terms of making predominantly normalizing attributions for their own symptoms. CONCLUSIONS: The data support modification of existing cognitive behavioural treatments for CFS to investigate whether addressing partners' attributions for patients' symptoms improves recovery in the patient. Furthermore, a tendency to make somatic attributions for symptoms may be a vulnerability factor for the development of CFS.     

The impact of informational interventions about cognitive behavioral therapy for chronic fatigue syndrome on GPs referral behavior

OBJECTIVE: This study investigated the impact of an informational intervention among general practitioners (GPs) about a new treatment with cognitive behavioral therapy (CBT) for chronic fatigue syndrome (CFS) in a mental health center (MHC). The outcome measures concerned GPs knowledge and attitudes towards CFS and their actual referrals of CFS patients to this new treatment setting. METHODS: Three hundred and one GPs, who all had received written information about CFS four times, and who partly had also visited an informational group session, completed a short questionnaire survey on CFS knowledge and attitudes. Referral data were obtained from the mental health center. RESULTS: During 16 months 22% of all GPs in the concerning region had referred at least one CFS patient. Concerning knowledge and attitude, the survey results showed that 70% of the GPs had remembered the intervention's main message, namely the new treatment possibility. These informed GPs reported better knowledge and more positive attitudes towards CFS than the non-informed GPs, who had not seen and read the intervention's information. CONCLUSION: This study showed that disseminating written materials can be a useful method for stimulating GPs to refer CFS patients for CBT. PRACTICE IMPLICATIONS: In future implementation projects concerning CBT for CFS (or other 'new' treatments for a disputed illness) in a MHC or other institution, the informational intervention evaluated here can be a suitable and efficient method to inform GPs and let them refer patients.     

Circadian motor asymmetries in humans

Previous research studies indicate that motor activity during sleep is lateralized to the non-dominant hand. We put forward the hypothesis that the relative superiority of the non-dominant hand movements during night could arise from a different circadian phase relationship between the two hemispheres, independently of the sleep condition. The present study evaluated whether actigraphic data are consistent with such hypothesis. A total of 58 right-handed university students wore actigraphs (AMI 32K) on both left and right wrist for 3 consecutive days. Mesor and acrophase were computed using cosinor analysis. Moreover, factorial analysis of variances were carried out on side (left versus right) and time of day. The results indicated that the left hand circadian rhythm had a significant phase delay in comparison to the right hand one. The mean activity of the left hand was significantly higher than that of the right hand from 20:00 until 04:00 h. The results are suggestive of a different circadian activation between the two hemispheres and are discussed in relation to models of circadian regulation of sleep/wake cycle.