Task related cerebral blood flow changes of patients with chronic fatigue syndrome: an arterial spin labeling study

Abstract:

Purpose: One hallmark of chronic fatigue syndrome (ME/CFS) is task related worsening of fatigue. Global brain hypoperfusion, abnormal regional activation, and altered functional connectivity of brain areas associated with cognition and memory have been reported but remain controversial.

Methods: We enrolled 17 female participants fulfilling the CDC Criteria for ME/CFS and 16 matched healthy controls (HC). Using a 3T-Phillips Achieva MRI-scanner, pseudo-continuous arterial spin-labeling (pCASL), was used to study the dynamics of regional cerebral blood flow (rCBF) and their relationship to mental fatigue in ME/CFS patients and HC during a demanding cognitive task, i.e. modified Paced-Auditory-Serial-Addition-Testing (PASAT).

Results: ME/CFS subjects reported more fatigue than HC at baseline (p < .01). Global brain perfusion of ME/CFS and HC subjects was similar at rest. The PASAT resulted in significantly increased fatigue in ME/CFS participants and HC. Although not different between groups, overall CBF significantly increased over the first 3 min of the PASAT and then decreased thereafter. Regional CBF (rCBF) changes were significantly different between groups during the post-task recovery period. Whereas improvement of fatigue of ME/CFS subjects was associated with decreased rCBF in both superior temporal gyri (STG), precuneus, and fusiform gyrus, it was associated with increased rCBF in the same areas in HC.

Conclusions: Our results suggest that ME/CFS is associated with normal global CBF at rest and during a strenuous task (PASAT); however rCBF of several brain regions associated with memory, goal-oriented attention, and visual function was differentially associated with recovery from fatigue in ME/CFS patients and HC.

Source: Roland Staud, Jeff Boissoneault, Jason G. Craggs, Song Lai & Michael E. Robinson (2018) Task related cerebral blood flow changes of patients with chronic fatigue syndrome: an arterial spin labeling study, Fatigue: Biomedicine, Health & Behavior, DOI: 10.1080/21641846.2018.1453919

Small-World Network Analysis of Cortical Connectivity in Chronic Fatigue Syndrome Using Quantitative EEG

Abstract:

The aim of this study was to explore the relationship between complex brain networks in people with Chronic Fatigue Syndrome (CFS) and neurocognitive impairment. Quantitative EEG (qEEG) recordings were taken from 14 people with CFS and 15 healthy controls (HCs) during an eye-closed resting condition.

Exact low resolution electromagnetic tomography (eLORETA) was used to estimate cortical sources and perform a functional connectivity analysis. The graph theory approach was used to characterize network representations for each participant and derive the “small-worldness” index, a measure of the overall homeostatic balance between local and long-distance connectedness.

Results showed that small-worldness for the delta band was significantly lower for patients with CFS compared to HCs. In addition, delta small-worldness was negatively associated with neurocognitive impairment scores on the DePaul Symptom Questionnaire (DSQ). Finally, delta small-worldness indicated a greater risk of complex brain network inefficiency for the CFS group.

These results suggest that CFS pathology may be functionally disruptive to small-world networks. In turn, small-world characteristics might serve as a neurophysiological indicator for confirming a biological basis of cognitive symptoms, treatment outcome, and neurophysiological status of people with CFS.

Source: Citation: Zinn, M. A., Zinn, M. L., & Jason, L. A. (2017). Small-world network analysis of cortical connectivity in Chronic Fatigue Syndrome using quantitative EEG. NeuroRegulation, 4(3–4), 125–137. http://dx.doi.org/10.15540/nr.4.3-4.125 http://www.neuroregulation.org/article/view/17838/11670 (Full article)

The impact of chronic fatigue syndrome on cognitive functioning in adolescents

Abstract:

Chronic fatigue syndrome (CFS) is characterized by persistent fatigue and severe disability. Most adolescent patients report attention and concentration problems, with subsequent poor performance at school. This study investigated the impact of CFS on intellectual capacity by (1) assessing discrepancies between current intelligence quotient (IQ) and school level and (2) exploring differences in current IQ and pre-CFS school performance, compared with healthy individuals. Current data was cross-sectionally gathered and compared with retrospective pre-CFS school performance data. Fifty-nine CFS adolescents and 40 controls were evaluated on performance on age-appropriate intelligence tests and school level. Current IQ scores of CFS adolescents were lower than expected on the basis of their school level. Furthermore, there was a difference in intelligence performance across time when current IQ scores were compared with pre-CFS cognitive achievement. Healthy controls did not show any discrepancies.

CONCLUSION: According to their pre-CFS intelligence assessments, CFS patients started with appropriate secondary school levels at the age of 12. Our data suggest that CFS may be accompanied by a decline in general cognitive functioning. Given the critical age for intellectual development, we recommend a timely diagnosis followed by appropriate treatment of CFS in adolescents.

WHAT IS KNOWN: Adolescent chronic fatigue syndrome (CFS) is a debilitating condition with major impact on social and intellectual development. Most patients report concentration problems, with subsequent poor performance at school. Little is known about the influence of CFS on intellectual performances.

WHAT IS NEW: IQ scores of CFS adolescents are lower than the IQ scores of healthy peers with an equivalent school level. There is a decrease in intelligence performance across time when current IQ scores are compared with pre-CFS cognitive achievement. Healthy controls do not show any discrepancies between their current IQ, school level and previous cognitive functioning. This suggest that adolescent CFS may be accompanied by a decline in general cognitive functioning.

 

Source: Nijhof LN, Nijhof SL, Bleijenberg G, Stellato RK, Kimpen JL, Hulshoff Pol HE, van de Putte EM. The impact of chronic fatigue syndrome on cognitive functioning in adolescents. Eur J Pediatr. 2016 Feb;175(2):245-52. doi: 10.1007/s00431-015-2626-1. Epub 2015 Sep 3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4724362/ (Full article)

 

Learning and memorization impairment in childhood chronic fatigue syndrome manifesting as school phobia in Japan

Abstract:

For the last 15 years, we have tried to understand the pathophysiology of childhood chronic fatigue syndrome (CCFS) in Japan. In this condition, two major symptoms are important: easy fatigability and disturbed learning and memorization. In CCFS patients we clinically evaluated autonomic nervous system function, circadian rhythm of hormonal secretion (melatonin, cortisol and 3-endorphin), core body temperature, and sleep-wake pattern.

Most patients showed autonomic nervous system dysfunction and circadian rhythm disturbances, similar to those observed in jet lag. Radiological imaging studies (SPECT, Xe-CT, and MRS) revealed decreased blood flow in the frontal and thalamic areas, and accumulation of choline in the frontal lobe. We analyzed the relationship between the laboratory data and clinical symptoms in CCFS.

 

Source: Miike T, Tomoda A, Jhodoi T, Iwatani N, Mabe H. Learning and memorization impairment in childhood chronic fatigue syndrome manifesting as school phobia in Japan. Brain Dev. 2004 Oct;26(7):442-7. http://www.ncbi.nlm.nih.gov/pubmed/15351079

 

Neurobehavioral deficits associated with chronic fatigue syndrome in veterans with Gulf War unexplained illnesses

Abstract:

Gulf War unexplained illnesses (GWUI) are a heterogeneous collection of symptoms of unknown origin known to be more common among veterans of the Gulf War than among nonveterans. In the present study we focused on one of these unexplained illnesses.

We tested the hypothesis that in a sample of Persian Gulf War veterans chronic fatigue syndrome (CFS) was associated with cognitive deficits on computerized cognitive testing after controlling for the effects of premorbid cognitive differences. We obtained Armed Forces Qualification Test (AFQT) data acquired around the date of induction into the military on 94 veterans of the Gulf War, 32 with CFS and 62 healthy controls. Controls performed better than participants diagnosed with CFS on the AFQT. Cognitive deficits were associated with CFS on 3 of 8 variables after the effect of premorbid AFQT scores was removed with ANCOVA.

 

Source: Binder LM, Storzbach D, Campbell KA, Rohlman DS, Anger WK; Members of the Portland Environmental Hazards Research Center. Neurobehavioral deficits associated with chronic fatigue syndrome in veterans with Gulf War unexplained illnesses. J Int Neuropsychol Soc. 2001 Nov;7(7):835-9. http://www.ncbi.nlm.nih.gov/pubmed/11771626

 

Prognostic factors for persons with idiopathic chronic fatigue

Abstract:

BACKGROUND: The simultaneous examination of a large number of patient characteristics in a prospective study of patients with chronic fatigue.

OBJECTIVE: To compare the relative importance of these characteristics as prognostic factors.

METHODS: The data analyzed were from 199 subjects in a registry of persons who were aged 18 years or older and had idiopathic fatigue for at least 6 months. All subjects completed an extensive baseline questionnaire that provided information about fatigue, demographic characteristics, medical conditions, lifestyle, sleeping habits, psychological characteristics, and the presence of criteria for chronic fatigue syndrome. Changes in fatigue severity from baseline to 2-year follow-up were tested for an association with risk factors at baseline and with changes in symptoms other than fatigue during the follow-up period.

RESULTS: The following characteristics at baseline significantly and independently predicted greater fatigue improvement: less unclear thinking, fewer somatoform symptoms not used to define chronic fatigue syndrome, infrequent awakening, fewer hours sleeping, and being married. Of 29 subjects who at baseline reported no somatoform symptoms unrelated to chronic fatigue syndrome and who thought clearly most of the time, 8 substantially improved, compared with 1 of 29 subjects who had more than 2 somatoform symptoms and never thought clearly (P = .01). Improvements in the following symptoms were significantly and independently associated with improvements in fatigue: unclear thinking, depression, muscle aches, and trouble falling asleep.

CONCLUSIONS: This study identified characteristics of subjects that seem to be of prognostic importance for idiopathic chronic fatigue. Symptoms that change concomitantly with changes in fatigue may be intrinsically linked to fatigue.

 

Source: Hartz AJ, Kuhn EM, Bentler SE, Levine PH, London R. Prognostic factors for persons with idiopathic chronic fatigue. Arch Fam Med. 1999 Nov-Dec;8(6):495-501. http://www.ncbi.nlm.nih.gov/pubmed/10575388

 

The psychotherapeutic effects of estrogens

Abstract:

The effect of estrogens on the central nervous system, particularly mood and behavior, remains a controversial area which needs clarification, not just for understanding of depression in women but to ensure that such commonplace problems in women have efficient and appropriate therapy.

There is now good evidence that estrogens are rapidly effective in the treatment of depression in many women but this information has not found its way through to those health care personnel, psychiatrists and psychologists who are principally involved in the treatment of depression. There is also strong evidence for the benefits of estrogens on cognitive functioning, not only in preventing the onset of dementia but also in improving the symptoms in the established condition.

Recent work has also suggested a benefit for estrogens on mood in women diagnosed as suffering from chronic fatigue syndrome. This article reviews the effect of endogenous estrogen on the female central nervous system and the ever increasing evidence for the diverse psychotherapeutic effects of exogenous estrogens.

 

Source: Panay N, Studd JW. The psychotherapeutic effects of estrogens. Gynecol Endocrinol. 1998 Oct;12(5):353-65. http://www.ncbi.nlm.nih.gov/pubmed/9859029

 

Memory, attention, and executive function in chronic fatigue syndrome

Abstract:

OBJECTIVES: To examine cognitive function in chronic fatigue syndrome.

METHODS: Twenty patients with chronic fatigue syndrome recruited from primary care and 20 matched normal controls were given CANTAB computerised tests of visuospatial memory, attention, and executive function, and verbal tests of letter and category fluency and word association learning.

RESULTS: Patients with chronic fatigue syndrome were impaired, predominantly in the domain of memory but their pattern of performance was unlike that of patients with amnesic syndrome or dementia. They were normal on tests of spatial pattern recognition memory, simultaneous and delayed matching to sample, and pattern-location association learning. They were impaired on tests of spatial span, spatial working memory, and a selective reminding condition of the pattern-location association learning test. An executive test of planning was normal. In an attentional test, eight subjects with chronic fatigue syndrome were unable to learn a response set; the remainder exhibited no impairment in the executive set shifting phase of the test. Patients with chronic fatigue syndrome were also impaired on verbal tests of unrelated word association learning and letter fluency.

CONCLUSION: Patients with chronic fatigue syndrome have reduced attentional capacity resulting in impaired performance on effortful tasks requiring planned or self ordered generation of responses from memory.

Source: Joyce E, Blumenthal S, Wessely S. Memory, attention, and executive function in chronic fatigue syndrome. J Neurol Neurosurg Psychiatry. 1996 May;60(5):495-503. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC486360/ (Full article)

Behavioural effects of infectious mononucleosis

Abstract:

The aim of the present study was to provide preliminary information on the acute and chronic effects of infectious mononucleosis (IM) on memory, attention, psychomotor performance and mood. These issues were examined by comparing individuals with acute IM, those who had the initial illness some months before, and matched healthy controls.

Objective measures of memory, attention, motor skills and visual functions were obtained, as were subjective reports of mood. The results showed selective effects of acute IM on performance and mood, with the profile of impairments being very similar to those observed in previous studies of influenza.

Different impairments were observed in subjects who had the primary illness several months before, and the effects observed in this group were similar to those observed in recent studies of chronic fatigue syndrome patients.

Both acute and chronic IM subjects reported similar levels of symptoms and psychopathology, with both groups having greater scores than the controls. However, the performance impairments did not reflect symptoms or psychopathology. One may conclude that the study of IM will provide important data on both the acute and longer lasting effects of viral infections on the brain and behaviour.

 

Source: Hall SR, Smith AP. Behavioural effects of infectious mononucleosis. Neuropsychobiology. 1996;33(4):202-9. http://www.ncbi.nlm.nih.gov/pubmed/8840344

 

A controlled comparison of multiple chemical sensitivities and chronic fatigue syndrome

Abstract:

The present study had two objectives: 1) to determine the characteristics that differentiated subjects with multiple chemical sensitivities (MCS), chemical sensitivities (CS), and chronic fatigue syndrome (CFS); and 2) to evaluate the psychiatric and neuropsychological complaints of these groups relative to normal controls.

A cross-sectional comparison was made of the following groups matched for age, sex, and education: 1) patients whose sensitivities to multiple low level chemical exposures began with a defined exposure (MCS; N = 23); 2) patients with sensitivities to multiple chemicals without a clear date of onset (CS; N = 13); 3) patients meeting CDC criteria for Chronic Fatigue Syndrome (CFS; N = 18); and 4) normal controls (N = 18).

Subjects with sensitivities to chemicals (MCS and CS) reported significantly more lifestyle changes due to chemical sensitivities and significantly more chemical substances that made them ill compared with chronic fatigue and normal controls. MCS, CS, and CFS patients had significantly higher rates of current psychiatric disorders than normal controls and reported significantly more physical symptoms with no medical explanation.

Seventy-four percent of MCS and 61% of CFS did not qualify for any current Axis I psychiatric diagnosis. Chemically sensitive subjects without a defined date of onset (CS) had the highest rate of Axis I psychiatric disorders (69%). On the MMPI-2, 44% of MCS, 42% of CS, 53% of CFS, and none of the controls achieved clinically significant elevations on scales associated with somatoform disorders.

With the exception of one complex test of visual memory, no significant differences were noted among the groups on tests of neuropsychological function. Standardized measures of psychiatric and neuropsychological function did not differentiate subjects with sensitivities to chemicals from those with chronic fatigue. Subjects with sensitivities to chemicals and no clear date of onset had the highest rate of psychiatric morbidity. Standardized neuropsychological tests did not substantiate the cognitive impairment reported symptomatically. Cognitive deficits may become apparent under controlled exposure conditions.

 

Source: Fiedler N, Kipen HM, DeLuca J, Kelly-McNeil K, Natelson B. A controlled comparison of multiple chemical sensitivities and chronic fatigue syndrome. Psychosom Med. 1996 Jan-Feb;58(1):38-49. http://www.ncbi.nlm.nih.gov/pubmed/8677287