The putative role of oxidative stress and inflammation in the pathophysiology of sleep dysfunction across neuropsychiatric disorders: Focus on chronic fatigue syndrome, bipolar disorder and multiple sclerosis

Abstract:

Sleep and circadian abnormalities are prevalent and burdensome manifestations of diverse neuro-immune diseases, and may aggravate the course of several neuropsychiatric disorders. The underlying pathophysiology of sleep abnormalities across neuropsychiatric disorders remains unclear, and may involve the inter-play of several clinical variables and mechanistic pathways.

In this review, we propose a heuristic framework in which reciprocal interactions of immune, oxidative and nitrosative stress, and mitochondrial pathways may drive sleep abnormalities across potentially neuroprogressive disorders. Specifically, it is proposed that systemic inflammation may activate microglial cells and astrocytes in brain regions involved in sleep and circadian regulation. Activated glial cells may secrete pro-inflammatory cytokines (for example, interleukin-1 beta and tumour necrosis factor alpha), nitric oxide and gliotransmitters, which may influence the expression of key circadian regulators (e.g., the Circadian Locomotor Output Cycles Kaput (CLOCK) gene). Furthermore, sleep disruption may further aggravate oxidative and nitrosative, peripheral immune activation, and (neuro) inflammation across these disorders in a vicious pathophysiological loop.

This review will focus on chronic fatigue syndrome, bipolar disorder, and multiple sclerosis as exemplars of neuro-immune disorders. We conclude that novel therapeutic targets exploring immune and oxidative & nitrosative pathways (p.e. melatonin and molecular hydrogen) hold promise in alleviating sleep and circadian dysfunction in these disorders.

Source: Morris G, Stubbs B, Köhler CA, Walder K, Slyepchenko A, Berk M, Carvalho AF. The putative role of oxidative stress and inflammation in the pathophysiology of sleep dysfunction across neuropsychiatric disorders: Focus on chronic fatigue syndrome, bipolar disorder and multiple sclerosis. Sleep Med Rev. 2018 Apr 4. pii: S1087-0792(17)30152-1. doi: 10.1016/j.smrv.2018.03.007. [Epub ahead of print]  https://www.ncbi.nlm.nih.gov/pubmed/29759891

Pharmacological activation of AMPK and glucose uptake in cultured human skeletal muscle cells from patients with ME/CFS

Abstract:

Background: Skeletal muscle fatigue and post-exertional malaise are key symptoms of Myalgic Encephalomyelitis (ME/CFS). We have previously shown that AMPK activation and glucose uptake are impaired in primary human skeletal muscle cell cultures derived from patients with ME/CFS in response to electrical pulse stimulation, a method which induces contraction of muscle cells in vitro. The aim of this study was to assess if AMPK could be activated pharmacologically in ME/CFS.

Methods: Primary skeletal muscle cell cultures from patients with ME/CFS and healthy controls were treated with either metformin or 991. AMPK activation was assessed by Western blot and glucose uptake measured.

Results: Both metformin and 991 treatment significantly increased AMPK activation and glucose uptake in muscle cell cultures from both controls and ME/CFS. Cellular ATP content was unaffected by treatment although ATP content was significantly decreased in ME/CFS compared to controls.

Conclusions: Pharmacological activation of AMPK can improve glucose uptake in muscle cell cultures from patients with ME/CFS. This suggests that the failure of electrical pulse stimulation to activate AMPK in these muscle cultures is due to a defect proximal to AMPK. Further work is required to delineate the defect and determine whether pharmacological activation of AMPK improves muscle function in patients with ME/CFS.

Source: Brown AE, Dibnah B, Fisher E, Newton JL, Walker M. Pharmacological activation of AMPK and glucose uptake in cultured human skeletal muscle cells from patients with ME/CFS. Biosci Rep. 2018 Apr 13. pii: BSR20180242. doi: 10.1042/BSR20180242. [Epub ahead of print]  https://www.ncbi.nlm.nih.gov/pubmed/29654166/

 

Systemic exertion intolerance disease/chronic fatigue syndrome is common in sleep centre patients with hypersomnolence: A retrospective pilot study

Abstract:

Symptoms of the central disorders of hypersomnolence extend beyond excessive daytime sleepiness to include non-restorative sleep, fatigue and cognitive dysfunction. They share much in common with myalgic encephalomyelitis/chronic fatigue syndrome, recently renamed systemic exertion intolerance disease, whose additional features include post-exertional malaise and orthostatic intolerance. We sought to determine the frequency and correlates of systemic exertion intolerance disease in a hypersomnolent population.

One-hundred and eighty-seven hypersomnolent patients completed questionnaires regarding sleepiness and fatigue; questionnaires and clinical records were used to assess for systemic exertion intolerance disease. Sleep studies, hypocretin and cataplexy were additionally used to assign diagnoses of hypersomnolence disorders or sleep apnea. Included diagnoses were idiopathic hypersomnia (n = 63), narcolepsy type 2 (n = 25), persistent sleepiness after obstructive sleep apnea treatment (n = 25), short habitual sleep duration (n = 41), and sleepiness with normal sleep study (n = 33). Twenty-one percent met systemic exertion intolerance disease criteria, and the frequency of systemic exertion intolerance disease was not different across sleep diagnoses (p = .37).

Patients with systemic exertion intolerance disease were no different from those without this diagnosis by gender, age, Epworth Sleepiness Scale, depressive symptoms, or sleep study parameters. The whole cohort reported substantial fatigue on questionnaires, but the systemic exertion intolerance disease group exhibited more profound fatigue and was less likely to respond to traditional wake-promoting agents (88.6% versus 67.7%, p = .01). Systemic exertion intolerance disease appears to be a common co-morbidity in patients with hypersomnolence, which is not specific to hypersomnolence subtype but may portend a poorer prognosis for treatment response.

Source: Maness C, Saini P, Bliwise DL, Olvera V, Rye DB, Trotti LM. Systemic exertion intolerance disease/chronic fatigue syndrome is common in sleep centre patients with hypersomnolence: A retrospective pilot study. J Sleep Res. 2018 Apr 6:e12689. doi: 10.1111/jsr.12689. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/29624767

The etiologic relation between disequilibrium and orthostatic intolerance in patients with myalgic encephalomyelitis (chronic fatigue syndrome)

Abstract:

BACKGROUND: Orthostatic intolerance (OI) causes a marked reduction in the activities of daily living in patients with myalgic encephalomyelitis (ME) or chronic fatigue syndrome. Most symptoms of OI are thought to be related to cerebral hypo-perfusion and sympathetic activation. Because postural stability is an essential element of orthostatic tolerance, disequilibrium may be involved in the etiology of OI.

METHODS AND RESULTS: The study comprised 44 patients with ME (men, 11 and women, 33; mean age, 37±9 years), who underwent neurological examinations and 10-min standing and sitting tests. Symptoms of OI were detected in 40 (91%) patients and those of sitting intolerance were detected in 30 (68%). Among the 40 patients with OI, disequilibrium with instability on standing with their feet together and eyes shut, was detected in 13 (32.5%) patients and hemodynamic dysfunction during the standing test was detected in 19 (47.5%); both of these were detected in 7 (17.5%) patients. Compared with 31 patients without disequilibrium, 13 (30%) patients with disequilibrium more prevalently reported symptoms during both standing (100% vs. 87%, p=0.43) and sitting (92% vs. 58%, p=0.06) tests. Several (46% vs. 3%, p<0.01) patients failed to complete the 10-min standing test, and some (15% vs. 0%, p=0.15) failed to complete the 10-min sitting test. Among the seven patients with both hemodynamic dysfunction during the standing test and disequilibrium, three (43%) failed to complete the standing test. Among the 6 patients with disequilibrium only, 3 (50%) failed while among the 12 patients with hemodynamic dysfunction only, including 8 patients with postural orthostatic tachycardia, none (0%, p=0.02) failed.

CONCLUSIONS: Patients with ME and disequilibrium reported not only OI but also sitting intolerance. Disequilibrium should be recognized as an important cause of OI and appears to be a more influential cause for OI than postural orthostatic tachycardia in patients with ME.

Copyright © 2018 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Source: Miwa K, Inoue Y. The etiologic relation between disequilibrium and orthostatic intolerance in patients with myalgic encephalomyelitis (chronic fatigue syndrome). J Cardiol. 2018 Mar 24. pii: S0914-5087(18)30058-3. doi: 10.1016/j.jjcc.2018.02.010. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/29588088

Negative Affectivity, Depression, and Resting Heart Rate Variability (HRV) as Possible Moderators of Endogenous Pain Modulation in Functional Somatic Syndromes

Abstract:

Background: Several studies have shown that patients with functional somatic syndromes (FSS) have, on average, deficient endogenous pain modulation (EPM), as well as elevated levels of negative affectivity (NA) and high comorbidity with depression and reduced resting heart rate variability (HRV) compared to healthy controls (HC). The goals of this study were (1) to replicate these findings and (2) to investigate the moderating role of NA, depression, and resting HRV in EPM efficiency within a patient group with fibromyalgia and/or chronic fatigue syndrome (CFS). Resting HRV was quantified as the root mean square of successive differences between inter-beat intervals (RMSSD) in rest, a vagally mediated time domain measure of HRV.

Methods: Seventy-eight patients with fibromyalgia and/or CFS and 33 HC completed a counter-irritation paradigm as a measure of EPM efficiency. Participants rated the painfulness of electrocutaneous stimuli (of individually calibrated intensity) on the ankle before (baseline phase), during (counter-irritation phase) and after (recovery phase) the application of a cold pain stimulus on the forearm. A larger reduction in pain in the counter-irritation phase compared to the baseline phase reflects a more efficient EPM.

Results: In contrast to our expectations, there was no difference between pain ratings in the baseline compared to counter-irritation phase for both patients and HC. Therefore, reliable conclusions on the moderating effect of NA, depression, and RMSSD could not be made. Surprisingly, patients reported more pain in the recovery compared to the counter-irritation and baseline phase, while HC did not. This latter effect was more pronounced in patients with comorbid depression, patients who rated the painfulness of the counter-irritation stimulus as high and patients who rated the painfulness of the electrocutaneous stimuli as low. We did not manage to successfully replicate the counter-irritation effect in HC or FSS patients. Therefore, no valid conclusions on the association between RMSSD, depression, NA and EPM efficiency can be drawn from this study. Possible reasons for the lack of the counter-irritation effect are discussed.

Source: Van Den Houte M, Van Oudenhove L, Van Diest I, Bogaerts K, Persoons P, De Bie J, Van den Bergh O. Negative Affectivity, Depression, and Resting Heart Rate Variability (HRV) as Possible Moderators of Endogenous Pain Modulation in Functional Somatic Syndromes. Front Psychol. 2018 Mar 6;9:275. doi: 10.3389/fpsyg.2018.00275. eCollection 2018. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5845717/ (Full article)

Balance deficits in Chronic Fatigue Syndrome with and without fibromyalgia

Abstract:

OBJECTIVE: Chronic Fatigue Syndrome (CFS) is a disorder of unknown etiology associated with debilitating fatigue. One symptom commonly reported is disequilibrium. The goal of this study was to determine if CFS patients demonstrated verified balance deficits and if this was effected by comorbid fibromyalgia (FM).

METHODS: Twenty-seven patients with CFS (12 with comorbid FM) and 22 age and gender matched controls performed posturography.

RESULTS: Balance scores were significantly correlated with physical functional status in the CFS group (R2 = 0.43, P < 0.001), which was not found for mental functional status (R2 = 0.06, P > 0.5). CFS patients (regardless of FM) had significantly higher anxiety subscale of the vertigo symptom scale scores. CFS patients, regardless of FM status, demonstrated significantly lower overall composite balance scores (Controls – 78.8±1.5; CFS – 69.0±1.4, P < 0.005) even when controlling for anxiety and also had worse preference scores, indicating they relied on visual information preferentially even when visual information was incorrect. Interestingly, the CFS+FM group, not CFS only, demonstrated significantly worse vestibular scores (Controls – 70.2±2.4; CFS only – 67.9±3.8; CFS with FM – 55.4±4.6, P = 0.013).

INTERPRETATION: The major findings are that poor balance may be associated with poorer self-reported physical health. In addition, CFS patients seemed to rely preferentially on visual inputs, regardless of whether it was correct. The finding that vestibular function may be impaired in patients with CFS+FM but not in those with CFS alone suggests that the pathophysiology of CFS+FM may differ as has been suggested by some.

Source: Serrador JM, Quigley K, Zhao C, Findley T, Natelson BH. Balance deficits in Chronic Fatigue Syndrome with and without fibromyalgia. NeuroRehabilitation. 2018;42(2):235-246. doi: 10.3233/NRE-172245.

Markers of non-coeliac wheat sensitivity in patients with myalgic encephalomyelitis/chronic fatigue syndrome

We recently reported in Gut that non-coeliac wheat sensitivity (NCWS) is associated with a state of systemic immune activation in conjunction with a compromised intestinal epithelium.1 Patients with NCWS experience GI symptoms, most commonly including abdominal pain and bloating, as well as extraintestinal symptoms, among which fatigue, headache and cognitive difficulties feature prominently.1 2 A principal component analysis of the generated data from our study, including markers of antibody reactivity to wheat gluten, intestinal cell damage and systemic innate and adaptive immune responses to microbial components, found clustering of the patients and controls into discernible groups and demonstrated the potential utility of the identified biomarkers for identifying patients with NCWS.1

Extreme fatigue, in particular one that does not improve with rest, is a hallmark of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).3 Immune system abnormalities have been found to be associated with symptoms in a substantial number of patients with ME/CFS.4 5 Furthermore, many patients complain of GI symptoms of unknown aetiology.6–8 We considered whether a subset of patients with ME/CFS may exhibit serologic markers associated with NCWS, which might explain some of the corresponding symptoms. We screened serum samples from 131 patients with ME/CFS and 86 healthy controls (table 1), recruited as previously described,9 for the same markers as those in the above-mentioned study on NCWS.1 Questionnaires were used to assess GI symptoms within the past 6 months, including abdominal pain, bloating and nausea. Severity of individual symptoms was scored from 1 to 5 (1=absent; 2=mild; 3=moderate; 4=severe; 5=very severe), and a total score, based on the sum of individual symptom scores, was calculated for each subject.

Read full article HERE.

Source: Melanie Uhde, Alyssa C Indart, Xuechen B Yu, Sophie S Jang, Roberto De Giorgio, Peter H R Green, Umberto Volta, Suzanne D Vernon, Armin Alaedini. Markers of non-coeliac wheat sensitivity in patients with myalgic encephalomyelitis/chronic fatigue syndrome. http://dx.doi.org/10.1136/gutjnl-2018-316133

Perception of induced dyspnea in fibromyalgia and chronic fatigue syndrome

Abstract:

OBJECTIVE: Dyspnea perception is distorted in patients with medically unexplained dyspnea. The goals of this study were 1) to replicate these results in patients with fibromyalgia and/or chronic fatigue syndrome (CFS), and 2) to investigate predictors of distorted symptom perception within the patient group, with a focus on negative affectivity (NA), psychiatric comorbidity and somatic symptom severity.

METHODS: Seventy-three patients diagnosed with fibromyalgia and/or CFS and 38 healthy controls (HC) completed a rebreathing paradigm, consisting of a baseline (60s of room air), a rebreathing phase (150s, gradually increasing ventilation, partial pressure of CO2 in the blood, and self-reported dyspnea), and a recovery phase (150s of room air). Dyspnea, respiratory flow and FetCO2 levels were measured continuously.

RESULTS: Patients reported more dyspnea than HC in the recovery phase (p=0.039), but no differences between patients and HC were found in the baseline (p=0.07) or rebreathing phase (p=0.17). No significant differences between patients and HC were found in physiological reactivity. Within the patient group, the effect in the recovery phase was predicted by somatic symptom severity (p=0.046), but not by negative affectivity or by the number of psychiatric comorbidities.

CONCLUSION: This study extended earlier findings in patients with medically unexplained dyspnea to patients with fibromyalgia and CFS. This suggests that altered symptom perception is a non-symptom-specific mechanism underlying functional somatic syndromes in general, particularly in patients with high levels of somatic symptom severity. The results are discussed in a predictive coding framework of symptom perception.

Source: Van Den Houte M, Bogaerts K, Van Diest I, De Bie J, Persoons P, Van Oudenhove L, Van den Bergh O. Perception of induced dyspnea in fibromyalgia and chronic fatigue syndrome. J Psychosom Res. 2018 Mar;106:49-55. doi: 10.1016/j.jpsychores.2018.01.007. Epub 2018 Jan 11. https://www.ncbi.nlm.nih.gov/pubmed/29455899

Energy envelope maintenance among patients with myalgic encephalomyelitis and chronic fatigue syndrome: Implications of limited energy reserves

Abstract:

Objective: The Energy Envelope Theory of myalgic encephalomyelitis and chronic fatigue syndrome postulates that individuals with myalgic encephalomyelitis and chronic fatigue syndrome may experience some increase in functioning if their level of exertion consistently remains within the limits of their available energy. Findings of several studies support this theory; however, the current study is the first to explore how an individual’s initial level of available energy may influence the relation between energy envelope maintenance and level of functioning.

Method:The functioning, activity, and symptomatology of six groups of individuals with myalgic encephalomyelitis and chronic fatigue syndrome were compared. Groups were created based upon level of available energy (higher or lower) and energy envelope adherence (underextended, within, overextended).

Results: Results indicate that, as expected, individuals with myalgic encephalomyelitis and chronic fatigue syndrome who had higher available energy also had better functioning than individuals with lower available energy; however, this relation was less pronounced for individuals who were overexerting themselves.

Discussion: These results are consistent with the Energy Envelope Theory, and they suggest that overexertion was particularly impactful for individuals with higher levels of available energy.

Source: O’connor K, Sunnquist M, Nicholson L, Jason LA, Newton JL, Strand EB. Energy envelope maintenance among patients with myalgic encephalomyelitis and chronic fatigue syndrome: Implications of limited energy reserves. Chronic Illn. 2017 Jan 1:1742395317746470. doi: 10.1177/1742395317746470. [Epub ahead of print]

Inflammation correlates with symptoms in chronic fatigue syndrome

It is not unusual for patients who say they are sick to have normal results on standard laboratory testing. The physician often concludes that there is no “real” illness and that the patients’ symptoms likely stem from a psychological disorder. An alternative conclusion, often honored in the breach, is that the standard laboratory tests are measuring the wrong things.

Chronic fatigue syndrome (CFS)―also called myalgic encephalomyelitis/chronic fatigue syndrome―is such an illness. Often, the condition begins suddenly, following an “infectious-like” illness.

For years, patients do not return to full health. The illness waxes and wanes, and at its worst leads patients to be bedridden or unable to leave their homes. A report from the National Academies estimates that CFS affects up to 2.5 million people in the United States and generates direct and indirect expenses of $17–24 billion annually (1). The most widely used case definition (2) consists only of symptoms. This, along with typically normal results on standard laboratory tests, has raised the question of whether there are any “real” objective, biological abnormalities in CFS. In PNAS, Montoya et al. report the latest evidence that there are such abnormalities.

Indeed, research over the past 30 y has discovered pathology involving the central nervous system (CNS) and autonomic nervous system (ANS), energy metabolism (with associated oxidative and nitrosative stress), and the immune system, as described in a detailed review (4). This Commentary will briefly summarize the evidence, providing citations only to work published since this review. I will then place the report by Montoya et al. (3) in context, and speculate about the pathophysiology of the illness.

Source: Anthony Komaroff. Inflammation correlates with symptoms in chronic fatigue syndrome. PNAS  2017 ; published ahead of print August 15, 2017 doi: 10.1073/pnas.1712475114  http://www.pnas.org/content/early/2017/08/14/1712475114.extract