Mechanisms of poststroke fatigue

Conflict Adaptation in Aphasia: Upregulating Cognitive Control for Improved Sentence Comprehension

PURPOSE

This study investigated conflict adaptation in aphasia, specifically whether upregulating cognitive control improves sentence comprehension.

METHOD

Four individuals with mild aphasia completed four eye tracking sessions with interleaved auditory Stroop and sentence-to-picture matching trials (critical and filler sentences). Auditory Stroop congruency (congruent/incongruent across a male/female voice saying "boy"/"girl") was crossed with sentence congruency (syntactically correct sentences that are semantically plausible/implausible), resulting in four experimental conditions (congruent auditory Stroop followed by incongruent sentence [CI], incongruent auditory Stroop followed by incongruent sentence [II], congruent auditory Stroop followed by congruent sentence [CC], and incongruent auditory Stroop followed by congruent sentence [IC]). Critical sentences were always preceded by auditory Stroop trials. At the end of each session, a five-item questionnaire was administered to assess overall well-being and fatigue. We conducted individual-level mixed-effects regressions on reaction times and growth curve analyses on the proportion of eye fixations to target pictures during incongruent sentences.

RESULTS

One participant showed conflict adaptation indicated by faster reaction times on active sentences and more rapid growth in fixations to target pictures on passive sentences in the II condition compared to the CI condition. Incongruent auditory Stroop also modulated active-sentence processing in an additional participant, as indicated by eye movements.

CONCLUSIONS

This is the first study to observe conflict adaptation in sentence comprehension in people with aphasia. The extent of adaptation varied across individuals. Eye tracking revealed subtler effects than overt behavioral measures. The results extend the study of conflict adaptation beyond neurotypical adults and suggest that upregulating cognitive control may be a potential treatment avenue for some individuals with aphasia.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.27056149.

Functional Recovery in Acute and Subacute Stroke Patients With or Without Post-stroke Fatigue

This study analyzed the impact of post-stroke fatigue (PSF) on functional recovery in acute and subacute stroke patients during inpatient rehabilitation. Medical records of 177 patients were retrospectively reviewed. PSF was assessed using the Fatigue Severity Scale (FSS)-9. Patients were classified into two groups: a PSF group (mean FSS ≥ 4) and a non-PSF group (mean FSS < 4). Stroke severity was measured with the National Institutes of Health Stroke Scale, and functional outcomes were evaluated using Functional Ambulation Category (FAC), Berg Balance Test, Korean version of the Modified Barthel Index (K-MBI), and Mini-Mental State Examination-Korean version (MMSE-K). Statistical significance was set at p < 0.05. The prevalence of PSF was 52.5%. The repeated measures of analysis of variance showed significant "time" effects on FAC (F = 29.726, p < 0.001) and K-MBI (F = 15.348, p < 0.001). A significant "group" effect was observed on MMSE-K (F = 4.571, p = 0.035), and a "time × group" interaction on only K-MBI (F = 4.284, p = 0.041). Multivariable logistic regression analysis showed that improvements in K-MBI scores were independent of initial severity, depression, and age (p = 0.043). PSF affects the recovery of activities of daily living (ADL) in stroke patients, suggesting that regulating early fatigue after stroke positively affects functional recovery.

Post-stroke fatigue severity is associated with executive dysfunction in chronic stroke

Following stroke, fatigue is highly prevalent and managing fatigue is consistently rated a key unmet need by stroke survivors and professionals. Domain-specific cognitive impairments have been associated with greater fatigue severity in earlier stages of stroke recovery, but it is unclear whether these associations hold in chronic (>2 years) stroke. The present cross-sectional observational study evaluates the relationship between domain-specific cognitive functioning and the severity of self-reported fatigue among chronic stroke survivors. Participants (N = 105; mean age = 72.92, 41.90% female; mean years post-stroke = 4.57) were assessed in domains of attention (Hearts Cancellation test), language (Boston Naming Test), episodic memory (Logical Memory Test), working memory (Digit Span Backwards task), and executive functioning (set-shifting: Trail Making Test, Part B), as part of the OX-CHRONIC study, a longitudinal stroke cohort. Fatigue was assessed using the Fatigue Severity Scale. In a multiple linear regression analysis inclusive of above cognitive domains, only poorer executive functioning was associated with increased fatigue severity. This provides insight into the cognitive impairment profile of post-stroke fatigue long-term after stroke, with executive functioning deficits as the key hallmark.

Somatosensory processing in long COVID fatigue and its relations with physiological and psychological factors

Fatigue is prevalent amongst people with long COVID, but is poorly understood. The sensory attenuation framework proposes that impairments in sensory processing lead to heightened perception of effort, driving fatigue. This study aims to investigate the role of somatosensory processing impairments in long COVID fatigue and quantify how sensory processing relates to other prominent symptoms of long COVID including autonomic dysfunction, mood and illness beliefs in driving the experience of fatigue. We will recruit 44 individuals with long COVID fatigue and 44 individuals with neither long COVID nor fatigue (controls). Our primary objective is to compare baseline somatosensory processing between individuals with long COVID fatigue and controls. Additionally, we will explore the associations between somatosensory processing, fatigability and the level of fatigue induced by cognitive and physical exertion. Due to the complex nature of fatigue, we will also investigate how long COVID, state fatigue, perceived effort, mood, illness beliefs, autonomic symptoms and autonomic nervous system function interact to predict trait fatigue. This comprehensive investigation aims to elucidate how sensory processing and other prominent symptoms interact to impact the experience of fatigue.

A systematic review of post-stroke fatigue measurement scale based on COSMIN guidelines

Objective

This study aimed to evaluate the methodological quality and measurement attribute quality of the post-stroke fatigue measurement scale, so as to provide some basis for the clinical application and promotion of related scales.

Methods

The Chinese National Knowledge Infrastructure, the Wanfang Data Knowledge Service Platform, the China Science and Technology Journal Database, the Chinese Medical Journal Full-text Database, the Chinese Biology Medicine, PubMed, Embase, Medline, the Cochrane Library, the Web of Science, CINAHL, and PsycINFO databases were searched for literature on the post-stroke fatigue measurement scale up to June 2022. Literature screening and data extraction were carried out independently by two researchers, and in the case of disagreement, discussions were held with a third investigator to reach an agreement, and the COSMIN checklist and criteria were used to systematically evaluate the attributes of the measurement scale.

Results

A total of 17 studies were included, involving 10 post-stroke fatigue measurement scales. The content validity of FSS-7, FACIT-F, NRS-FRS, and MFI-20 was "not mentioned," and the remaining scales were "uncertain." In terms of construct validity, MFS was "adequate"; FSS-7, FACIT-F, and NRS-FRS were "not mentioned"; and the remaining scales were "uncertain." In terms of internal consistency, NRS-FRS was "not mentioned"; FSS and MFS were "adequate"; and the remaining scales were "uncertain." In terms of hypothesis testing, CIS and FACIT-F were "not mentioned," NRS-FRS was "adequate," and the remaining scales were "uncertain." The stability of FSS-7, CIS, FACIT-F, and MFI-20 was "not mentioned," and the remaining scales were "adequate." The cross-cultural validity of FSS-7 was "adequate," and the remaining scales were "not mentioned." All 10 scales were given a recommendation grade of "B".

Conclusion

For the time being, the FSS can be recommended to measure post-stroke fatigue, but it still needs to be tested for more relevant measurement properties in order to gain more support from high-quality evidence. For a more comprehensive assessment of post-stroke fatigue, the FIS, FAS, and NFI-stroke should perhaps be considered, as the FSS is a one-dimensional scale that can only measure physical fatigue in patients; however, these scales also need to be tested for more relevant measurement properties to verify their clinical applicability.

Exploring post-stroke fatigue from the perspective of stroke survivors: what strategies help? A qualitative study

PURPOSE

Post-stroke fatigue is a research priority for stroke survivors and health professionals but there is limited evidence to guide management. We aimed to explore (1) the experience of post-stroke fatigue from the perspective of stroke survivors and their caregivers and (2) fatigue management strategies that are used.

MATERIALS AND METHODS

This was a qualitative study using semi-structured interviews. People with self-reported post-stroke fatigue and caregivers were recruited using maximum variation sampling. Analysis was done via the framework approach.

RESULTS

We recruited 17 stroke survivors, nine male (53%), most under 65 years (n = 12, 76%), and greater than 1-year post-stroke (n = 16, 94%, range 10-months to 22-years). One-third of participants self-reported having aphasia (n = 5, 36%). We also recruited eight caregivers, most of whom were female (n = 7, 88%). We identified four themes: (1) fatigue is unexpected after stroke and symptoms vary; (2) the individual experience of fatigue is complex, influenced by multifactorial and biopsychosocial factors; (3) learning to adapt and accept fatigue; and (4) Strategies to manage fatigue and personal approaches to rest.

CONCLUSIONS

Post-stroke fatigue experience varies presenting cognitively, physically, and psychologically according to a complex interplay of biopsychosocial factors and personal triggers. Self-management strategies are individualised and include organisation, medications, lifestyle modifications, and peer support.

Causal associations of fatigue and functional outcome after ischemic stroke: a mediation Mendelian randomization study

Background and objectives

Fatigue has been associated with adverse effects on recovery from ischemic stroke based on previous observational research. The purpose of our study was to explore the potential causal association of fatigue with poor functional outcome after ischemic stroke by employing Mendelian randomization (MR).

Methods

A set of instrumental variables, comprising 36 single-nucleotide polymorphisms (SNPs) that are only related to fatigue, were derived from a genome-wide association study (GWAS) that included 449,019 general individuals. The functional outcomes after ischemic stroke were derived from a GWAS (Genetics of Ischemic Stroke Functional Outcome Network) involving 6,021 survivors. Two-sample MR methods were used to assess the causal effect, including inverse variance weighted, MR-Egger, weighted median, simple mode, and weighted mode. In bidirectional MR analysis, the reverse causal association was analyzed using the Wald ratio method. The mediation effects of lipid metabolites were analyzed using two-step MR analysis.

Results

Genetic liability to fatigue was causally associated with the poor functional outcome (modified Rankin Scale ≥3 at 3 months) after ischemic stroke (OR = 4.20, 95%CI [1.11-15.99], p < 0.05). However, genetic predicted poor functional outcome after ischemic stroke was not associated with fatigue (OR = 1.00, 95%CI [0.99-1.02], p > 0.05). The results of the two-step MR showed that cholesteryl esters to total lipids ratio in large very low-density lipoprotein (VLDL) (ME = -0.13, p < 0.05); concentration of very large VLDL particles (ME = -0.13, p < 0.05); free cholesterol in large VLDL (ME = -0.13, p < 0.05); free cholesterol to total lipids ratio in very large VLDL (ME = -0.22, p < 0.05); phospholipids in large VLDL (ME = -0.15, p < 0.05); phospholipids in very large VLDL (ME = -0.13, p < 0.05); phospholipids to total lipids ratio in large high-density lipoprotein (HDL) (ME = -0.17, p < 0.05); total lipids in very large VLDL (ME = -0.14, p < 0.05); triglycerides in small VLDL (ME = -0.11, p < 0.05); and triglycerides to total lipids ratio in large HDL (ME = -0.10, p < 0.05) assumed a pivotal role in mediating the association between fatigue and poor functional outcome after ischemic stroke.

Conclusion

Our study provides evidence supporting the causal association between fatigue and the poor functional outcome after ischemic stroke, which emphasizes the importance of implementing interventions aimed at addressing fatigue. This could offer a therapeutic target to improve recovery after ischemic stroke and warrant exploration in a clinical context. One potential mechanism by which fatigue affects functional outcomes after ischemic stroke is through the action of lipid metabolites.

Disentangling pain and fatigue in chronic fatigue syndrome: a resting state connectivity study before and after cognitive behavioral therapy

BACKGROUND

Fatigue is a central feature of myalgic encephalomyelitis or chronic fatigue syndrome (ME/CFS), but many ME/CFS patients also report comorbid pain symptoms. It remains unclear whether these symptoms are related to similar or dissociable brain networks. This study used resting-state fMRI to disentangle networks associated with fatigue and pain symptoms in ME/CFS patients, and to link changes in those networks to clinical improvements following cognitive behavioral therapy (CBT).

METHODS

Relationships between pain and fatigue symptoms and cortico-cortical connectivity were assessed within ME/CFS patients at baseline (N = 72) and after CBT (N = 33) and waiting list (WL, N = 18) and compared to healthy controls (HC, N = 29). The analyses focused on four networks previously associated with pain and/or fatigue, i.e. the fronto-parietal network (FPN), premotor network (PMN), somatomotor network (SMN), and default mode network (DMN).

RESULTS

At baseline, variation in pain and fatigue symptoms related to partially dissociable brain networks. Fatigue was associated with higher SMN-PMN connectivity and lower SMN-DMN connectivity. Pain was associated with lower PMN-DMN connectivity. CBT improved SMN-DMN connectivity, compared to WL. Larger clinical improvements were associated with larger increases in frontal SMN-DMN connectivity. No CBT effects were observed for PMN-DMN or SMN-PMN connectivity.

CONCLUSIONS

These results provide insight into the dissociable neural mechanisms underlying fatigue and pain symptoms in ME/CFS and how they are affected by CBT in successfully treated patients. Further investigation of how and in whom behavioral and biomedical treatments affect these networks is warranted to improve and individualize existing or new treatments for ME/CFS.

Effect of high-definition transcranial direct current stimulation among late-subacute and chronic stroke survivors with fatigue: A randomized-controlled crossover trial protocol

Post-stroke fatigue (PSF) is a commonly overlooked symptom that impacts daily functioning and quality of life. It is caused by altered functional connectivity within the brain networks, which can potentially be influenced by neuromodulation. Multiple cortical regions have been targeted to reduce PSF, but the most efficient ones remain uncertain. Therefore, we aim to identify the most appropriate cortical stimulation site to reduce PSF. Twenty participants with PSF will be included in this cross-over trial. Each participant will receive one session of active anodal high definition- transcranial direct current stimulation (HD-tDCS) over three different cortical areas and one session of sham tDCS in a cross-over manner, with a two-week of washout period in between. Pre- and post- fatigue will be assessed using Fatigue Severity Scale and fatigability using electromyography by determining the time to task failure. Resting-state electroencephalography will be performed before and after each stimulation session to determine the functional connectivity of the cortical areas stimulated.

Feasibility of a novel blended-care intervention for fatigue after acquired brain injury: a pilot study of the Tied by Tiredness intervention

PURPOSE

Evidence-based treatments for fatigue after brain injury are scarce and often not personalized. An approach to foster personalization is Experience Sampling Methodology (ESM), consisting of repeated daily measurements of fatigue and related factors in daily life. We investigated the feasibility and usability of a novel six-week ESM-based intervention for fatigue after brain injury.

MATERIALS AND METHODS

Ten individuals with acquired brain injury (six men; four women) aged between 36-70 years (M = 53.3, SD = 12.9) used a mHealth application for three days each week during six-weeks; seven completed the intervention. Momentary fatigue, activities, mood, worrying, and social context were assessed with ESM and participants received weekly personalized feedback by a therapist..

RESULTS

56% of ESM-questionnaires (568/1008) were completed, providing detailed insights into individual fatigue patterns. No statistically significant decrease in response rate was found over the course of treatment. Qualitative feedback from participants revealed increased insight into factors underlying fatigue, and no problems with treatment duration or difficulties using the app. Five participants showed a decline in fatigue level during treatment.

CONCLUSIONS

This pilot study provides initial support for the feasibility and usability of this novel blended-care intervention, aimed at alleviating fatigue through personalized feedback and treatment strategies.

The immunomodulatory mechanism of acupuncture treatment for ischemic stroke: research progress, prospects, and future direction

Ischemic stroke (IS) is one of the leading causes of death and disability. Complicated mechanisms are involved in the pathogenesis of IS. Immunomodulatory mechanisms are crucial to IS. Acupuncture is a traditional non-drug treatment that has been extensively used to treat IS. The exploration of neuroimmune modulation will broaden the understanding of the mechanisms underlying acupuncture treatment. This review summarizes the immune response of immune cells, immune cytokines, and immune organs after an IS. The immunomodulatory mechanisms of acupuncture treatment on the central nervous system and peripheral immunity, as well as the factors that influence the effects of acupuncture treatment, were summarized. We suggest prospects and future directions for research on immunomodulatory mechanisms of acupuncture treatment for IS based on current progress, and we hope that these will provide inspiration for researchers. Additionally, acupuncture has shown favorable outcomes in the treatment of immune-based nervous system diseases, generating new directions for research on possible targets and treatments for immune-based nervous system diseases.

Why does malaise/fatigue occur? Underlying mechanisms and potential relevance to treatments in rheumatoid arthritis

INTRODUCTION

Fatigue and malaise are commonly associated with a wide range of medical conditions, including rheumatoid arthritis (RA). Evidence suggests that fatigue and malaise can be overwhelming for patients, yet these symptoms remain inadequately-managed, largely due to an incomplete elucidation of the underlying causes.

AREAS COVERED

In this assessment of the published literature relating to the pathogenesis of fatigue or malaise in chronic conditions, four key mechanistic themes were identified. Each theme (inflammation, hypothalamic-pituitary-adrenal axis, dysautonomia, and monoamines) is discussed, as well as the complex network of interconnections between themes which suggests a key role for inflammatory cytokines in the development and persistence of fatigue.

EXPERT OPINION

Fatigue is multifaceted, poorly defined, and imperfectly comprehended. Moreover, the cause and severity of fatigue may change over time, as a consequence of the natural disease course or pharmacologic treatment. This detailed synthesis of available evidence permits us to identify avenues for current treatment optimization and future research, to improve the management of fatigue and malaise in RA. Within the development pipeline, several new anti-inflammatory therapies are currently under investigation, and we anticipate that the next five years will herald much-needed progress to reduce the debilitating nature of fatigue in patients with RA.

A Comparison of Sensorimotor Integration and Motor Fitness Components between Collegiate Athletes with and without Long COVID: A Cross-Sectional Study with Pair-Matched Controls

Background: Long COVID presents a concern for collegiate athletes, potentially impacting sensorimotor processing and motor fitness. This study aimed to assess these effects. Methods: This cross-sectional study involved 60 athletes diagnosed with Long COVID and 60 controls. Sensorimotor processing and integration were evaluated using neurophysiological variables (N13, P14, N20, P27, and N30), while motor fitness was assessed through balance, agility, and vertical jump testing. T-tests compared groups, and Pearson's correlations explored relationships. Results: Significant differences (p < 0.001) were observed in neurophysiological variables and motor fitness between Long COVID and control groups. Fatigue correlated positively (p < 0.001) with neurophysiological variables in Long COVID cases but not with motor fitness (p = 0.08, p = 0.07, p = 0.09). Conclusions: Collegiate athletes with Long COVID exhibit abnormal sensorimotor processing, integration, and diminished motor fitness compared to uninfected peers. The fatigue severity of Long COVID correlates with neurophysiological changes, suggesting a link between sensorimotor deficits and fatigue. Targeted interventions for sensorimotor deficits and fatigue management are crucial for athletes recovering from Long COVID. This study underscores the importance of addressing these issues to optimize the recovery and performance of collegiate athletes affected by Long COVID.

Influence of Perceptual Load on Attentional Orienting in Post-Stroke Fatigue: A Study of Auditory Evoked Potentials

OBJECTIVE

Increasing perceptual load alters behavioral outcomes in post-stroke fatigue (PSF). While the effect of perceptual load on top-down attentional processing is known, here we investigate if increasing perceptual load modulates bottom-up attentional processing in a fatigue dependent manner.

METHODS

In this cross-sectional observational study, in 29 first-time stroke survivors with no clinical depression, an auditory oddball task consisting of target, standard, and novel tones was performed in conditions of low and high perceptual load. Electroencephalography was used to measure auditory evoked potentials. Perceived effort was rated using the visual analog scale at regular intervals during the experiment. Fatigue was measured using the fatigue severity scale. The effect of fatigue and perceptual load on behavior (response time, accuracy, and effort rating) and auditory evoked potentials (amplitude and latency) was examined using mixed model ananlysis of variances (ANOVA).

RESULTS

Response time was prolonged with greater perceptual load and fatigue. There was no effect of load or fatigue on accuracy. Greater effort was reported with higher perceptual load both in high and low fatigue. p300a amplitude of auditory evoked potentials (AEP) for novel stimuli was attenuated in high fatigue with increasing load when compared to low fatigue. Latency of p300a was longer in low fatigue with increasing load when compared to high fatigue. There were no effects on p300b components, with smaller N100 in high load conditions.

INTERPRETATION

High fatigue specific modulation of p300a component of AEP with increasing load is indicative of distractor driven alteration in orienting response, suggestive of compromise in bottom-up selective attention in PSF.

Fatigue in patients with acquired brain damage

Fatigue is a complex, multidimensional syndrome that is prevalent in patients with acquired brain damage and has a negative impact on the neurorehabilitation process. It presents from early stages after the injury, and may persist over time, regardless of whether sequelae have resolved. Fatigue is conditioned by upper neuronal circuits, and is defined as an abnormal perception of overexertion. Its prevalence ranges from 29% to 77% after stroke, from 18% to 75% after traumatic brain injury, and from 47% to 97% after brain tumours. Fatigue is associated with factors including female sex, advanced age, dysfunctional families, history of specific health conditions, functional status (eg, fatigue prior to injury), comorbidities, mood, secondary disability, and the use of certain drugs. Assessment of fatigue is fundamentally based on such scales as the Fatigue Severity Scale (FSS). Advances have recently been made in imaging techniques for its diagnosis, such as in functional MRI. Regarding treatment, no specific pharmacological treatment currently exists; however, positive results have been reported for some conventional neurorehabilitation therapies, such as bright light therapy, neurofeedback, electrical stimulation, and transcranial magnetic stimulation. This review aims to assist neurorehabilitation professionals to recognise modifiable factors associated with fatigue and to describe the treatments available to reduce its negative effect on patients.

Lesioned hemisphere-specific phenotypes of post-stroke fatigue emerge from motor and mood characteristics in chronic stroke

BACKGROUND AND PURPOSE

Post-stroke fatigue commonly presents alongside several comorbidities. The interaction between comorbidities and their relationship to fatigue is not known. In this study, we focus on physical and mood comorbidities, alongside lesion characteristics. We predict the emergence of distinct fatigue phenotypes with distinguishable physical and mood characteristics.

METHODS

In this cross-sectional observational study, in 94 first time, non-depressed, moderate to minimally impaired chronic stroke survivors, the relationship between measures of motor function (grip strength, nine-hole peg test time), motor cortical excitability (resting motor threshold), Hospital Anxiety and Depression Scale and Fatigue Severity Scale-7 (FSS-7) scores, age, gender and side of stroke was established using Spearman's rank correlation. Mood and motor variables were then entered into a k-means clustering algorithm to identify the number of unique clusters, if any. Post hoc pairwise comparisons followed by corrections for multiple comparisons were performed to characterize differences among clusters in the variables included in k-means clustering.

RESULTS

Clustering analysis revealed a four-cluster model to be the best model (average silhouette score of 0.311). There was no significant difference in FSS-7 scores among the four high-fatigue clusters. Two clusters consisted of only left-hemisphere strokes, and the remaining two were exclusively right-hemisphere strokes. Factors that differentiated hemisphere-specific clusters were the level of depressive symptoms and anxiety. Motor characteristics distinguished the low-depressive left-hemisphere from the right-hemisphere clusters.

CONCLUSION

The significant differences in side of stroke and the differential relationship between mood and motor function in the four clusters reveal the heterogenous nature of post-stroke fatigue, which is amenable to categorization. Such categorization is critical to an understanding of the interactions between post-stroke fatigue and its presenting comorbid deficits, with significant implications for the development of context-/category-specific interventions.

Study protocol of a double-blind randomized control trial of transcranial direct current stimulation in post-stroke fatigue

Rationale

Post-stroke fatigue (PSF) is a frequent problem in stroke survivors and often hinders their rehabilitation. PSF is difficult to treat, and pharmacological therapy is often ineffective. Transcranial direct current stimulation (tDCS) can modulate motor, sensory, cognitive and behavioral responses, as it alters neuronal activity by delivering a small amount of current via the scalp to the cortex, resulting in prolonged alterations to brain function. tDCS has been studied for the treatment of fatigue associated with other neurological diseases, namely, multiple sclerosis, Parkinson's disease and post-polio syndrome.

Aims

This proposed project will examine the effect of tDCS on PSF.

Sample size estimates

We will recruit 156 participants aged 18 to 80 with chronic stroke and allocate them equally to two groups (i.e., n = 78 per group).

Methods and design

This proposed project will be a double-blind randomized control trial. The participants will be randomly divided into two groups. The control group will receive sham tDCS, and the treatment group will receive active tDCS. The latter treatment will involve application of a constant 2-mA current via one 5 × 5-cm anodal electrode positioned on the scalp over the C3 or C4 positions (motor cortex) of the lesioned hemisphere and one cathodal electrode positioned at the ipsilateral shoulder in two 20-min sessions per day for 5 days. The period of follow-up will be 4 weeks.

Study outcomes

The primary outcome measure will be a change in fatigue severity, as measured using the modified fatigue impact scale (MFIS). The participants' scores on the MFIS (total score and physical, cognitive and psychosocial subscores) will be collected before treatment (T0), after 10 treatment sessions, i.e., 1 day after the fifth treatment day (T1), and 1 week (T2), 2 weeks (T3) and 4 weeks (T4) thereafter. Both per-protocol analysis and intention-to-treat analysis will be performed.

Discussion

This proposed project will provide proof-of-concept, i.e., demonstrate the benefits of tDCS for the treatment of PSF. The beneficiaries are the subjects participated in the study. This will stimulate further research to optimize tDCS parameters for the treatment of PSF.

Clinical trial registration

www.Chictr.org.cn, identifier: ChiCTR2100052515.

Mechanisms of Post-Stroke Fatigue: A Follow-Up From the Third Stroke Recovery and Rehabilitation Roundtable

BACKGROUND

Post-stroke fatigue (PSF) is a significant and highly prevalent symptom, whose mechanisms are poorly understood. The third Stroke Recovery and Rehabilitation Roundtable paper on PSF focussed primarily on defining and measuring PSF while mechanisms were briefly discussed. This companion paper to the main paper is aimed at elaborating possible mechanisms of PSF.

METHODS

This paper reviews the available evidence that potentially explains the pathophysiology of PSF and draws parallels from fatigue literature in other conditions. We start by proposing a case for phenotyping PSF based on structural, functional, and behavioral characteristics of PSF. This is followed by discussion of a potentially significant role of early inflammation in the development of fatigue, specifically the impact of low-grade inflammation and its long-term systemic effects resulting in PSF. Of the many neurotransmitter systems in the brain, the dopaminergic systems have the most evidence for a role in PSF, along with a role in sensorimotor processing. Sensorimotor neural network dynamics are compromised as highlighted by evidence from both neurostimulation and neuromodulation studies. The double-edged sword effect of exercise on PSF provides further insight into how PSF might emerge and the importance of carefully titrating interventional paradigms.

CONCLUSION

The paper concludes by synthesizing the presented evidence into a unifying model of fatigue which distinguishes between factors that pre-dispose, precipitate, and perpetuate PSF. This framework will help guide new research into the biological mechanisms of PSF which is a necessary prerequisite for developing treatments to mitigate the debilitating effects of post-stroke fatigue.

Persian version of the Chalder Fatigue Questionnaire and Multidimensional Fatigue Symptom Inventory-Short Form: psychometric properties in Iranian chronic stroke survivors

BACKGROUND

Post-stroke fatigue is a disturbing condition with various physical and psychological facets, which needs to be assessed by meaningful and psychometrically valid and reliable tools. The Chalder Fatigue Questionnaire (CFQ) and Multidimensional Fatigue Symptom Inventory-Short Form (MFSI-SF) have been designed to assess diverse dimensions of fatigue.

OBJECTIVES

The present study aimed to investigate the psychometric properties of the CFQ and MFSI-SF in people with chronic stroke.

METHODS

Both measures were translated according to forward-backward standard protocol. This cross-sectional study was conducted with 130 first-time stroke survivors. The multidimensional fatigue inventory, checklist individual strength, fatigue assessment scale, fatigue subscale of profiles of mood state, fatigue severity scale, visual analogue scale-fatigue, beck anxiety inventory, center for epidemiologic studies of depression scale, and 36-item short-form health survey were administered in addition to the CFQ and MFSI-SF. Reliability, precision, known-groups validity, and convergent validity were examined for the CFQ and MFSI-SF.

RESULTS

The results showed an acceptable (Cronbach's alpha = 0.81-0.97) internal consistency and test-retest reliability (intra-class correlation = 0.75-0.97). The CFQ and MFSI-SF revealed good ability (P < 0.001) to differentiate chronic stroke survivors with different disability levels. Significant high correlation (P = -0.61-0.87) was found between CFQ and MFSI-SF and other fatigue scales.

CONCLUSIONS

The results of this study showed that the CFQ and MFSI-SF have high reliability and validity for chronic stroke survivors.

The Utility of Methylphenidate for Fatigue in Long-Term Neurological Conditions: A Meta-analytical Review

OBJECTIVE

Fatigue is a chronic and debilitating symptom of many long-term neurological conditions (LTNCs). Although methylphenidate provides some promise in alleviating fatigue in other clinical groups, little work has explored its potential utility within LTNCs. The current systematic review and meta-analysis evaluates the utility of methylphenidate for symptoms of fatigue in LTNCs.

METHODS

Five databases (PsycINFO, MEDLINE, Embase, Scopus, and Cochrane Library) were searched for relevant articles from their inception to February 2022. A purpose-developed evaluation tool was used to assess each study's research quality (QuEST:F).

RESULTS

Of the 1698 articles identified, 11 articles were included within this review (n = 370). Meta-analytical findings reported an overall significant benefit of methylphenidate for symptoms of fatigue across a mixed neurological sample ( g = -0.44; 95% confidence interval, -0.77 to -0.11). Subgroup analyses identified a significantly greater benefit ( P < 0.001) of methylphenidate for fatigue in LTNCs with static pathogenic trajectories (eg, traumatic brain injury) (number needed to treat = 2.5) compared with progressive conditions (eg, multiple sclerosis) (number needed to treat = 40.2).

CONCLUSIONS

Methylphenidate may pose an effective intervention for the treatment of fatigue in a number of LTNCs. Nonetheless, given the quality of the current evidence base, there exists a clear need for further robust assessment of the utility of methylphenidate-with a focus on subgroup-specific variability.

Fatigue Experiences in People With Stroke

PURPOSE

Fatigue is a major symptom in patients with stroke. Because fatigue is an overarching multidimensional phenomenon, it is important to understand how the characteristics of fatigue change over time. The purpose of this study was to explore how fatigue characteristics change over time in patients with stroke.

DESIGN

This study used a mixed-method observational design.

METHODS

This study is a secondary analysis of data from a previous study, the results of which indicated fatigue to be a prominent symptom. Participants in that study were patients with stroke who met eligibility criteria and provided informed consent. This secondary analysis used data from numeric rating scale scores for fatigue, Functional Assessment of Chronic Illness Therapy-Fatigue Scale scores, fatigue descriptors, and participant comments about fatigue gleaned from transcribed interviews.

RESULTS

Twenty-two patients participated in the study. Thirteen characteristics of fatigue were evaluated. Seven characteristics showed significant improvement ( p < .05) from admission to 1 month follow-up, and six characteristics did not change significantly.

CONCLUSIONS

Fatigue experiences vary over time and have both physical and mental aspects to them.

CLINICAL RELEVANCE TO REHABILITATION NURSING

Nurses may consider providing a quiet environment for physical rest, which may allow the brain to not be distracted by multiple stimuli.

Daily patterns of fatigue after subarachnoid haemorrhage: an ecological momentary assessment study

OBJECTIVE

To examine the daily course of, and factors associated with, momentary fatigue after subarachnoid haemorrhage, and to explore subgroups of patients with distinct diurnal patterns of fatigue.

DESIGN

Observational study using ecological momentary assessment.

SUBJECTS

A total of 41 participants with subarachnoid haemorrhage.

METHODS

Patients with fatigue were included within one year post-onset. Momentary fatigue (scale 1-7) was assessed with repeated measurements (10-11 times/day) during 7 consecutive days. Multilevel-mixed-model analyses and latent-class trajectory modelling were conducted.

RESULTS

Mean (standard deviation; SD) age of the group was 53.9 (13.0) years, 56% female, and mean (SD) time post-subarachnoid haemorrhage onset was 9.3 (3.2) months. Mean (SD) momentary fatigue over all days was 3.22 (1.47). Fatigue increased significantly (p < 0.001) over the day, and experiencing more burden of fatigue and day type (working day vs weekend day) were significantly (p < 0.05) associated with higher momentary fatigue. Three subgroups could be distinguished based on diurnal patterns of fatigue. The largest group (n = 17, 41.5%) showed an increasing daily pattern of fatigue.

CONCLUSION

Momentary fatigue in patients with subarachnoid haemorrhage increases over the day, and diurnal patterns of fatigue differ between  participants. In addition to conventional measures, momentary measures of fatigue might provide valuable information for physicians to optimize personalized management of fatigue after subarachnoid haemorrhage.

Prevalence and Impact of Poststroke Fatigue on Patient Outcomes in the First 6 Months After Stroke: A Systematic Review and Meta-analysis

ABSTRACT

BACKGROUND: Post-stroke fatigue (PSF) is one of the most pervasive and debilitating symptoms after stroke and has a negative impact on activities of daily living (ADLs) and health-related quality of life (HRQoL) of stroke survivors. However, to date, no study has systematically reviewed the prevalence of PSF at different points in time after stroke. OBJECTIVE: The aim of this study was to investigate the prevalence of PSF and its impact on ADLs and HRQoL in the first 6 months post stroke. METHOD: CINAHL, MEDLINE, Scopus, Google Scholar, and Index to Theses were searched from 1983 to August 2022 for studies published in English. Studies were included if they were conducted on adults 18 years and older, and were observational, correlational, and quantitative components of mixed methods reporting on PSF, ADLs, and HRQoL post stroke. RESULTS: Thirty studies were included in this review, and all had a high methodological quality. The pooled prevalence of PSF at 1 to 6 weeks was 49.5%; at 3 months, it was 41.9%; and at 6 months, it was 43.4%. A negative correlation between PSF and ADLs was observed at 1, 2, and 4 to 6 weeks, and at 3 and 6 months post stroke. A significant negative correlation between PSF and HRQoL was observed within the first week ( r = -0.40, P < .05) and at 3 and 6 months post stroke. The results at 3 and 6 months post stroke were inclusive. CONCLUSION : The prevalence of PSF in the first 6 weeks, particularly in the first 2 weeks after stroke, is high and has a significant negative impact on stroke survivors' ADLs and HRQoL. Only a limited number of studies assessed PSF within the first 2 weeks after stroke.

Reduced ex vivo TNFα synthesis upon whole blood stimulation with endotoxin predicts post-stroke fatigue

OBJECTIVE

Fatigue is a common, debilitating syndrome after stroke. Peripheral inflammation plays a role in the pathogenesis of fatigue of different origin, but its contribution to post-stroke fatigue (PSF) remains unclear. We aimed to determine if there is any association between ex vivo synthesized and circulating cytokines, and risk of PSF.

METHODS

We included 174 patients with ischemic stroke. We stimulated in vitro blood taken on day 3 after stroke with endotoxin. We measured ex vivo released (TNFα, IP-10, IL-1β, IL-6, IL-8, IL-10, IL-12p70) and plasma (TNFα, IL-6, sIL-6R, IL-1Ra) cytokines. We assessed fatigue at month 3 using Fatigue Severity Scale (FSS). We used logistic regression to assess the relationship between cytokines and fatigue scores.

RESULTS

Compared with patients with lower fatigue at month 3 (FSS < 36), patients with higher fatigue (FSS ≥ 36) had lower endotoxin-stimulated TNFα release after 24 h (median: 429 vs 581 pg/mL, P = 0.05). Plasma TNFα tended to be higher in patients who developed fatigue (median: 0.8 vs 0.6 pg/mL, P = 0.06). Other cytokines did not differ between groups. After adjusting for pre-stroke fatigue and depressive symptoms, TNFα release <559.7 pg/mL after 24 h was associated with an increased risk of PSF (OR: 2.61, 95%CI: 1.22-5.57, P = 0.01). Plasma TNFα >0.76 pg/mL was associated with higher risk of PSF in univariable (OR: 2.41, 95%CI: 1.13-5.15, P = 0.02), but not multivariable analysis (OR: 2.41, 95%CI: 0.96-6.00, P = 0.06).

CONCLUSION

Reduced ex vivo TNFα synthesis upon whole blood stimulation with endotoxin in the acute phase of stroke predicted PSF.

Role of selective attention in fatigue in neurological disorders

BACKGROUND

Chronic fatigue is a significant symptom in several diseases including traumatic and degenerative neurological disorders. While several studies have investigated the correlates of chronic fatigue, there is as yet no unifying framework to explain chronic fatigue.

METHODS

In this narrative review, I investigate the role of selective attention in the development of chronic fatigue and discuss results within the framework of the sensory attenuation model of fatigue, which posits that fatigue is the phenomenological output of altered attention to sensory input. Following a short introduction of this framework, I present results from investigations that address attentional mechanisms in fatigue in multiple sclerosis, stroke, traumatic brain injury and Parkinson's disease.

RESULTS

Attention was quantified in all four disease models using a variety of outcome measures, including behavioural, neurophysiological, structural and functional brain connectivity. The range of measures precluded direct comparison of results across disease conditions; however, in all four disease models there was evidence of poor selective attention that explained levels of chronic fatigue, supporting the sensory attenuation model of fatigue as a disease-independent mechanism of fatigue. Evidence was lacking to draw any conclusions about the direction of causality.

CONCLUSION

The role of selective attention in development of fatigue is indicated. Future studies must focus on establishing causality and exploring attentional circuitry as a potential therapeutic target.

Neural dysregulation in post-COVID fatigue

Following infection with SARS-CoV-2, a substantial minority of people develop lingering after-effects known as 'long COVID'. Fatigue is a common complaint with a substantial impact on daily life, but the neural mechanisms behind post-COVID fatigue remain unclear. We recruited 37 volunteers with self-reported fatigue after a mild COVID infection and carried out a battery of behavioural and neurophysiological tests assessing the central, peripheral and autonomic nervous systems. In comparison with age- and sex-matched volunteers without fatigue (n = 52), we show underactivity in specific cortical circuits, dysregulation of autonomic function and myopathic change in skeletal muscle. Cluster analysis revealed no subgroupings, suggesting post-COVID fatigue is a single entity with individual variation, rather than a small number of distinct syndromes. Based on our analysis, we were also able to exclude dysregulation in sensory feedback circuits and descending neuromodulatory control. These abnormalities on objective tests may aid in the development of novel approaches for disease monitoring.

Measurement Properties of the Dutch Multifactor Fatigue Scale in Early and Late Rehabilitation of Acquired Brain Injury in Denmark

Fatigue is a major issue in neurorehabilitation without a gold standard for assessment. The purpose of this study was to evaluate measurement properties of the five subscales of the self-report questionnaire the Dutch Multifactor Fatigue Scale (DMFS) among Danish adults with acquired brain injury. A multicenter study was conducted (N = 149, 92.6% with stroke), including a stroke unit and three community-based rehabilitation centers. Unidimensionality and measurement invariance across rehabilitation settings were tested using confirmatory factor analysis. External validity with Depression Anxiety Stress Scales (DASS-21) and the EQ-5D-5L was investigated using correlational analysis. Results were mixed. Unidimensionality and partial invariance were supported for the Impact of Fatigue, Mental Fatigue, and Signs and Direct Consequences of Fatigue, range: RMSEA = 0.07–0.08, CFI = 0.94–0.99, ω = 0.78–0.90. Coping with Fatigue provided poor model fit, RMSEA = 0.15, CFI = 0.81, ω = 0.46, and Physical Fatigue exhibited local dependence. Correlations among the DMFS, DASS-21, and EQ-5D-5L were in expected directions but in larger magnitudes compared to previous research. In conclusion, three subscales of the DMFS are recommended for assessing fatigue in early and late rehabilitation, and these may facilitate the targeting of interventions across transitions in neurorehabilitation. Subscales were strongly interrelated, and the factor solution needs evaluation.

To engage or not engage: Early incentive motivation prevents symptoms of chronic post-stroke depression - A longitudinal study

BACKGROUND

Although post-stroke depression (PSD) is known to disrupt motor rehabilitation after stroke, PSD is often undertreated and its relationship with motor impairment remains poorly understood.

METHODS

In a longitudinal study design we investigated, which factors at the early post-acute stage may increase the risk for PSD symptoms. We were especially interested in whether interindividual differences in the motivational drive to engage in physically demanding tasks indicate PSD development in patients suffering from motor impairments. Accordingly, we used a monetary incentive grip force task where participants were asked to hold their grip force for high and low rewards at stake to maximize their monetary outcome. Individual grip force was normalized according to the maximal force prior to the experiment. Experimental data, depression, and motor impairment were assessed from 20 stroke patients (12 male; 7.7 ± 6.78 days post-stroke) with mild-to-moderate hand motor impairment and 24 age-matched healthy participants (12 male).

RESULTS

Both groups showed incentive motivation as indicated by stronger grip force for high versus low reward trials and the overall monetary outcome in the task. In stroke patients, severely impaired patients showed stronger incentive motivation, whereas early PSD symptoms were associated with reduced incentive motivation in the task. Larger lesions in corticostriatal tracts correlated with reduced incentive motivation. Importantly, chronic motivational deficits were preceded by initially reduced incentive motivation and larger corticostriatal lesions in the early stage post-stroke.

CONCLUSIONS

More severe motor impairment motivates reward-dependent motor engagement, whereas PSD and corticostriatal lesions potentially disturb incentive motivational behavior, thereby increasing the risk of chronic motivational PSD symptoms. Acute interventions should address motivational aspects of behavior to improve motor rehabilitation post-stroke.

Self-reported cognitive and psychiatric symptoms at 3 months predict single-item measures of fatigue and daytime sleep 12 months after ischemic stroke

INTRODUCTION

Post-stroke fatigue and increased need for daytime sleep are multidimensional and insufficiently understood sequelae. Our aim was to study the relationships of self-reported cognitive and psychiatric symptoms at 3 months with fatigue and daytime sleep at 12 months post-stroke.

METHODS

Ischemic stroke patients without reported history of dementia or depression completed postal surveys 3- and 12-months post-stroke. At 3 months, psychiatric symptoms were assessed with the Hospital Anxiety and Depression Scale (HADS), and self-reported changes in cognitive symptoms (concentration and memory) compared to pre-stroke were assessed using single-item measures. At 12 months, single-item questions about changes in self-reported difficulties sleeping at night, fatigue and daytime sleep were included. First, we studied whether self-reported cognitive and/or psychiatric symptoms at 3 months were associated with daytime sleep and fatigue at 12 months using multiple logistic regression. Second, we fitted 2 structural equation models (SEMs) predicting fatigue and 2 models predicting daytime sleep. We compared a model where only age, sex, stroke severity (National Institutes of Health Stroke Scale; NIHSS), and difficulties sleeping at night predicted fatigue and daytime sleep at 12 months to a model where mental distress (i.e., a latent variable built of cognitive and psychiatric symptoms) was included as an additional predictor of fatigue and daytime sleep at 12 months.

RESULTS

Of 156 patients (NIHSS within 24 hours after admission (mean ± SD) = 3.6 ± 4.3, age = 73.0 ± 10.8, 41% female) 37.9% reported increased daytime sleep and 50.0% fatigue at 12 months. Increased psychiatric symptoms and worsened cognitive symptoms were associated with fatigue and daytime sleep at 12 months, after controlling for NIHSS, age, sex, and difficulties sleeping at night. SEM models including mental distress as predictor showed adequate model fit across 3 fit measures (highest RMSEA = 0.063, lowest CFI and TLI, both 0.975). Models without mental distress were not supported.

CONCLUSION

Self-reported cognitive and psychiatric symptoms at 3 months predict increased daytime sleep and fatigue at 12 months. This highlights the relevance of monitoring cognitive and psychiatric symptoms in the subacute phase post-stroke. However, future research using validated measures of self-reported symptoms are needed to further explore these relationships.

The relationship between red blood cell distribution width at admission and post-stroke fatigue in the acute phase of acute ischemic stroke

Introduction

Post-stroke fatigue (PSF) is a common complication in the patients with acute ischemic stroke (AIS). This prospective study aimed to investigate the relationship between red blood cell distribution width (RDW) at admission and PSF in the acute phase.

Methods

The AIS patients were enrolled in Nantong Third People's Hospital, consecutively. PSF in the acute phase was scored according to the Fatigue Severity Scale. Levels of RDW were measured at admission. The associations were analyzed using multivariate regression and restricted cubic splines (RCS).

Results

From April 2021 to March 2022, a total of 206 AIS patients (mean age, 69.3 ± 10.7 years; 52.9% men) were recruited. After the adjustment for potential confounding factors, RDW at admission remained the independent associated factor with PSF in the acute phase (OR [odds ratio], 1.635; 95% CI [confidence interval], 1.153–2.318; P = 0.006). The linear dose-response associations of RDW with PSF in the acute phase were found, based on the RCS model (P for non-linearity = 0.372; P for linearity = 0.037). These results remained significant in other models.

Conclusions

RDW at admission could serve as a novel biomarker of PSF in the acute phase of AIS.

Exploring the management approaches of cytokines including viral infection and neuroinflammation for neurological disorders

Considerable evidence supports that cytokines are important mediators of pathophysiologic processes within the central nervous system (CNS). Numerous studies have documented the increased production of various cytokines in the human CNS in various neurological and neuropsychiatric disorders. Deciphering cytokine actions in the intact CNS has important implications for our understanding of the pathogenesis and treatment of these disorders. The purpose of this study is to discuss the recent research on treating cytokine storm and amyloids, including stroke, Parkinson's disease (PD), Alzheimer's disease (AD), Huntington's condition, Multi-sclerosis (MS), Amyotrophic Lateral Sclerosis (ALS). Neuroinflammation observed in neurological disorders has a pivotal role in exacerbating Aβ burden and tau hyperphosphorylation, suggesting that stimulating cytokines in response to an undesirable external response could be a checkpoint for treating neurological disorders. Furthermore, the pro-inflammatory cytokines help our immune system through a neuroprotective mechanism in clearing viral infection by recruiting mononuclear cells. This study reveals that cytokine applications may play a vital role in providing novel regulation and methods for the therapeutic approach to neurological disorders and the causes of the deregulation, which is responsible for neuroinflammation and viral infection. However, it needs to be further investigated to clarify better the mechanisms of cytokine release in response to various stimuli, which could be the central point for treating neurological disorders.

The association between fatigue severity and risk of falls among middle-aged and older Australian stroke survivors

Background

Fatigue is a common and often debilitating symptom experienced by many stroke survivors. Significant post stroke fatigue may predispose individuals to other health complications, such as falls, which can lead to fractures and soft tissue injuries. Only limited research has examined the association between fatigue and falls in stroke survivors.

Methods

Data were obtained from the Sax Institute’s 45 and Up Study, from a subset of individuals who had experienced a stroke. The Modified Fatigue Impact Scale—5-item version (MFIS-5) was used to measure the level of fatigue. A logistic regression model, adjusted for stroke characteristics and comorbidities, was used to determine the magnitude of association between change in fatigue score and odds of having had a fall.

Results

A total of 576 participants completed the questionnaire. A total of 214 (37.2%) participants reported having had a fall in the previous 12 months. There was a statistically significant association between fatigue scores and fall status (p < 0.001). Specifically, for every 1-point increase in the fatigue score (MFIS-5) (i.e. higher level of fatigue), the odds of a person having a fall is 1.10 times greater (AOR = 1.10; 95% CI 1.05, 1.15; p < 0.001).

Conclusion

This study revealed an association between an increasing risk of falls with increasing severity of post stroke fatigue. Accurate detection and management of fatigue may help reduce the risk of falls and should be the focus of future research.

No add-on effect of tDCS on fatigue and depression in chronic stroke patients: A randomized sham-controlled trial combining tDCS with computerized cognitive training

BACKGROUND

Fatigue and emotional distress rank high among self-reported unmet needs in life after stroke. Transcranial direct current stimulation (tDCS) may have the potential to alleviate these symptoms for some patients, but the acceptability and effects for chronic stroke survivors need to be explored in randomized controlled trials.

METHODS

Using a randomized sham-controlled parallel design, we evaluated whether six sessions of 1 mA tDCS (anodal over F3, cathodal over O2) combined with computerized cognitive training reduced self-reported symptoms of fatigue and depression. Among the 74 chronic stroke patients enrolled at baseline, 54 patients completed the intervention. Measures of fatigue and depression were collected at five time points spanning a 2 months period.

RESULTS

While symptoms of fatigue and depression were reduced during the course of the intervention, Bayesian analyses provided evidence for no added beneficial effect of tDCS. Less severe baseline symptoms were associated with higher performance improvement in select cognitive tasks, and study withdrawal was higher in patients with more fatigue and younger age. Time-resolved symptom analyses by a network approach suggested higher centrality of fatigue items (except item 1 and 2) than depression items.

CONCLUSION

The results reveal no add-on effect of tDCS on fatigue or depression but support the notion of fatigue as a relevant clinical symptom with possible implications for treatment adherence and response.

Reducing fatigue following acquired brain injury: A feasibility study of high intensity interval training for young adults

The aim was to evaluate feasibility of high-intensity interval training (HIIT) in fatigued adults (20-40 years old) with acquired brain injury (ABI). A prospective pre-post single-arm intervention trial was conducted, including 6-8 months follow-up assessment and interview. Intervention was 18 sessions of intermittent exercise on a cycle ergometer over six weeks. Six out of ten participants without motor impairments completed the intervention (all females, mean age = 30.2 years, months post-injury = 22). On average, participants attended 88% of sessions and achieved high intensity (93% of max heart rate). VO_2max improved by 0.53 l/min (SD = 0.29), and participants continued exercising post-intervention. All participants were satisfied with HIIT, were more inclined to exercise, and reported positive effects of exercising for self-management of fatigue. Three sessions a week were demanding to some participants. Findings support feasibility of HIIT as a promising intervention for young adults with post-ABI fatigue.

Association of Lesion Location and Fatigue Symptoms After Ischemic Stroke: A VLSM Study

Background:

Poststroke fatigue (PSF) is a common symptom in stroke survivors, yet its anatomical mechanism is unclear. Our study was aimed to identify which brain lesions are related to the PSF in patients with acute stroke.

Method

Patients with first-ever acute ischemic stroke consecutively admitted from the first affiliated hospital of the University of Science and Technology of China (USTC) between January 2017 and June 2020. Fatigue was scored using the Fatigue Severity Scale. All the participants were assessed by 3.0 T brain MRI including diffusion-weighted imaging. The infarct lesions were delineated manually and transformed into a standard template. Voxel-based lesion-symptom mapping (VLSM) was applied to investigate the association between lesion location and the occurrence and severity of fatigue. The same analyses were carried out by flipping the left-sided lesions. Multivariate logistic regressions were applied to verify the associations.

Results

Of the 361 patients with acute stroke, 142 (39.3%) patients were diagnosed with fatigue in the acute phase and 116 (35.8%) at 6 months after the index stroke. VLSM analysis indicated clusters in the right thalamus which was significantly associated with the occurrence and severity of PSF at 6-month follow-up. In contrast, no significant cluster was found in the acute phase of stroke. The flipped analysis did not alter the results. Multivariate logistic regression verified that lesion load in the right thalamus (OR 2.67, 95% CI 1.46–4.88) was an independent predictor of 6-month PSF.

Conclusion

Our findings indicated that lesions in the right thalamus increased the risk of fatigue symptoms 6 months poststroke.

The Neurobiology of Pathological Fatigue: New Models, New Questions

The last decade has seen the emergence of new theoretical frameworks to explain pathological fatigue, a much neglected, yet highly significant symptom across a wide range of diseases. While the new models of fatigue provide new hypotheses to test, they also raise a number of questions. The primary purpose of this essay is to examine the predictions of three recently proposed models of fatigue, the overlap and differences between them, and the evidence from diseases that may lend support to the models of fatigue. I also present expansions for the sensory attenuation model of fatigue. Further questions examined here are the following: What are the neural substrates of fatigue? How can sensory attenuation, which underpins agency also explain fatigue? Are fatigue and agency related?

UK clinical approaches to address post-stroke fatigue: findings from The Nottingham Fatigue after Stroke study

Background/Aims

Although post-stroke is common and debilitating, there is little published research on how it is managed by clinicians. The aim of this study was to document UK management of post-stroke fatigue and ascertain whether there are any differences in its management compared to fatigue arising from other conditions.

Methods

A cross-sectional survey was used with allied health professionals, psychologists, doctors and nurses working clinically in hospitals, the community or both, who routinely provided information, management or treatment to patients with fatigue. Questionnaires were designed and underwent pilot testing. Recruitment was conducted using healthcare professional networks, professional and condition special interest groups and social media, snowballing and personal emails targeting key professional experts.

Results

A total of 305 questionnaires were analysed; the majority of responses were from occupational therapists (56%, n=171). Although there were different opinions about whether post-stroke fatigue was the same as fatigue resulting from other conditions, the strategies suggested for both were similar. Post-stroke management included pacing (67%, n=204), which is spreading activities out during the day or week, keeping a fatigue diary (39%, n=119) and education (38%, n=117). There were variations in how support was offered, and marked variations in length of follow up; some services were flexible and could retain patients for up to 18 months, while others offered one session and no follow up.

Conclusions

People with post-stroke fatigue and fatigue arising from other conditions experience different levels of support to manage their fatigue, but the main strategies used in management are similar.

Development of the Korean Medicine Core Outcome Set for Stroke Sequelae: Herbal Medicine Treatment of Elderly Patients With Stroke Sequelae in Primary Clinics

Objectives: We developed a Korean medicine core outcome set for stroke sequelae (COS-SS-KM) to evaluate the effectiveness and safety of herbal medicine (HM) for stroke sequelae, especially for elderly stroke patients in primary clinics.

Methods: We identified previously reported outcomes from a literature review and defined the list of outcomes and effect modifiers for the core outcome set (COS) questionnaire. Three rounds of modified Delphi consensus exercises with experts were conducted online for suitability assessment, and one round of a modified Delphi consensus exercise with primary clinicians was conducted for feasibility assessment.

Results: The review identified 17 outcomes and 16 effect modifiers; moreover, six outcomes and one effect modifier were suggested by the experts. The final COS comprised 8 outcomes and 12 effect modifiers for history taking, and experts listed 13 major symptoms of stroke sequelae for symptom assessment. The clinicians agreed on the feasibility of the COS.

Conclusion: This COS will help primary care researchers assess the effectiveness of pharmacotherapy, including HM, for elderly patients with stroke sequelae. Future studies should focus on reflecting the opinions of all stakeholders.

The association of personality traits with poststroke fatigue in daily life: An exploratory experience sampling method and cross-sectional study

Fatigue is a frequently occurring and persistent symptom after stroke. Many biological, psychosocial, and behavioural factors are associated with poststroke fatigue, but research into associations with personality traits is relatively sparse. In this study, we explored whether personality traits were related to poststroke fatigue measured with conventional fatigue questionnaires as well as experience sampling methodology (ESM). Twenty-four individuals with stroke completed 10 daily questionnaires about momentary (here-and-now) fatigue for six consecutive days using the mHealth ESM application PsyMate^TM. Further, they completed questionnaires assessing personality (NEO-FFI and LOR-T) and fatigue (FSS). Results showed that higher extraversion (ß = -.44, SE = .12, p = .001; 95% CI = -.67-.19) and optimism (ß = -.18, SE = .06, p = .007; 95% CI = -.30-.05) were associated with lower momentary fatigue. No association was found between neuroticism and momentary fatigue, but higher neuroticism (r = 0.531, p = .008, 95% CI = .160-.759; r = .574, p = .003, 95% CI = .245-.767) was associated with higher scores on the retrospective FSS scales. We conclude that personality traits differentially influence poststroke fatigue, but this also depends on the way fatigue is measured (with retrospective or with momentary measures). When functional gains are not in line with expected progress during the rehabilitation treatment of fatigue, it may be appropriate to take into account how person characteristics are related to momentary fatigue.

Minimal and robust clinically important difference of three fatigue measures in chronic stroke survivors

BACKGROUND

Fatigue assessment scale (FAS), fatigue subscale of the Profile of Mood States (POMS-F), and vitality subscale of the Short Form Health Survey (SF-36-VT) are among the first and most widely used adapted tools for assessing post-stroke fatigue.

OBJECTIVE

To identify the minimal clinically important difference (MCID) and robust clinically important difference (RCID) of FAS, POMS-F, and SF-36-VT in stroke survivors.

METHODS

Participants completed the FAS, POMS-F, and SF-36-VT before and after receiving 6-week intervention including graded activity training and pacing therapy. MCID was calculated using the distribution-based and anchor-based methods. Further, accuracy, sensitivity, and specificity of calculated values using the distribution-based method were used for determining RCID.

RESULT

A total of 124 stroke survivors participated in this study. MCID for FAS, POMS-F, and SF-36-VT was found to be 4.86, 3.32, and -10.10 (using score change) and 3.5, 2.5, and -10.5 (using ROC analysis), respectively. Using the distribution-based method, the MCID value obtained for the FAS was in the range of 3.16 to 8.76, for the POMS-F was in the range of 1.49 to 5.63, and for the SF-36-VT was in the range of -15.43 to -5.58. ½SD for FAS, ½ SD and 1.96 SEM for POMS-F, and 1.96 SEM and SD for SF-36-VT showed the best discriminative ability to use as the RCID.

CONCLUSIONS

The MCID and RCID were calculated for FAS, POMS-F, and SF-36-VT using different methods. The results can be used by researchers and clinicians for interpreting their findings in subjects similar to those who participated in this study.

Serum Uric Acid Levels at Admission Could Predict the Chronic Post-stroke Fatigue

Background

Post-stroke fatigue (PSF) is a frequent complication of stroke. Serum uric acid (SUA) is frequently thought to be a risk factor for stroke. This study aimed to investigate whether SUA also played a role in PSF.

Methods

Subjects with ischemic stroke were screened from The First Affiliated Hospital of Wenzhou Medical University between January 2020 and October 2020. Patients' fatigue symptoms were assessed by the Fatigue severity scale (FSS). To investigate the relationship between SUA and PSF, binary logistic regression analysis was conducted, with the confounders being controlled. SUA levels were divided into four layers (Q1 ≤ 245 μmol/L; Q2 246–308 μmol/L; Q3 309–365 μmol/L; Q4 ≥366 μmol/L) based on the quartiles.

Results

SUA levels were significantly higher in the PSF group (345.96 ± 73.78 μmol/L) than the non-PSF group (295.97 ± 87.8 μmol/L, P < 0.001). There were no differences in any other variables between these two groups. After adjusting the confounders, the risk of PSF in the Q4 layer (≥366 μmol/L) was 6.05 times (95% CI 1.79–20.43, P = 0.004) higher than that in Q1 (≤245 μmol/L).

Conclusion

High SUA at admission was an independent risk factor for fatigue 1 year after stroke onset. High SUA (≥366 μmol/L) during stroke deserves more attention, and active control of high SUA levels may be beneficial to reduce the incidence of PSF in the chronic stage following stroke.

Effect of the Early Administration of Selective Serotonin Reuptake Inhibitors on the Time Course of Poststroke Fatigue: A 2-Year Longitudinal Study

Background

Poststroke fatigue (PSF) is a dynamic process over time. Current evidence for interventions for PSF is limited. Our study investigated the effects of selective serotonin reuptake inhibitors (SSRIs) on the time course of PSF.

Methods

The patients with acute ischaemic stroke were enrolled in this study. All patients were scored with the Fatigue Severity Scale (FSS) at baseline and 6, 12, and 24 months after the index stroke. The time course of PSF was classified as non-PSF, incident PSF, recovered PSF and persistent PSF according to the PSF status at baseline and the 24-month follow-up. Multivariate logistic regression analysis and generalized mixed model were applied to explore the relationships between SSRIs and the time course of PSF.

Results

Eight hundred forty-seven patients were analyzed in this study. No significant association between SSRIs and the time course of PSF was observed in all patients (p = 0.076). The subgroup analyses indicated that SSRI antidepressants reduced the risk of incident PSF [Odds Ratio (OR) 0.23; 95% confidence interval (CI) 0.05–0.96, p = 0.044] and persistent PSF (OR 0.28; 95% CI 0.09–0.90, p = 0.033) in the PSD subgroup, but not in the non-PSD group. In the longitudinal analysis, generalized logistical mixed-effect models indicated that early administration of SSRIs reduced the risk (OR 0.955; 95% CI 0.928–0.984, p = 0.002) and severity (β = −0.018, p = 0.041) of PSF in the PSD subgroup.

Conclusion

No relationship was identified between the use of SSRIs and the time course of PSF in all patients. However, these drugs might be effective in PSF patients with depression.

Neural effective connectivity explains subjective fatigue in stroke

Persistent fatigue is a major debilitating symptom in many psychiatric and neurological conditions, including stroke. Post-stroke fatigue has been linked to low corticomotor excitability. Yet, it remains elusive as to what the neuronal mechanisms are that underlie motor cortex excitability and chronic persistence of fatigue.

In this cross-sectional observational study, in two experiments we examined a total of 59 non-depressed stroke survivors with minimal motoric and cognitive impairments using ‘resting-state’ MRI and single- and paired-pulse transcranial magnetic stimulation.

In the first session of Experiment 1, we assessed resting motor thresholds—a typical measure of cortical excitability—by applying transcranial magnetic stimulation to the primary motor cortex (M1) and measuring motor-evoked potentials in the hand affected by stroke. In the second session, we measured their brain activity with resting-state MRI to assess effective connectivity interactions at rest. In Experiment 2 we examined effective inter-hemispheric connectivity in an independent sample of patients using paired-pulse transcranial magnetic stimulation. We also assessed the levels of non-exercise induced, persistent fatigue using Fatigue Severity Scale (FSS-7), a self-report questionnaire that has been widely applied and validated across different conditions. We used spectral dynamic causal modelling in Experiment 1 and paired-pulse transcranial magnetic stimulation in Experiment 2 to characterize how neuronal effective connectivity relates to self-reported post-stroke fatigue. In a multiple regression analysis, we used the balance in inhibitory connectivity between homologue regions in M1 as the main predictor, and have included lesioned hemisphere, resting motor threshold and levels of depression as additional predictors.

Our novel index of inter-hemispheric inhibition balance was a significant predictor of post-stroke fatigue in Experiment 1 (β = 1.524, P = 7.56 × 10⁻⁵, confidence interval: 0.921 to 2.127) and in Experiment 2 (β = 0.541, P = 0.049, confidence interval: 0.002 to 1.080). In Experiment 2, depression scores and corticospinal excitability, a measure associated with subjective fatigue, also significantly accounted for variability in fatigue.

We suggest that the balance in inter-hemispheric inhibitory effects between primary motor regions can explain subjective post-stroke fatigue. Findings provide novel insights into neural mechanisms that underlie persistent fatigue.

Fatigue in patients with acquired brain damage

Fatigue is a complex, multidimensional syndrome that is prevalent in patients with acquired brain damage and has a negative impact on the neurorehabilitation process. It presents from early stages after the injury, and may persist over time, regardless of whether sequelae have resolved. Fatigue is conditioned by upper neuronal circuits, and is defined as an abnormal perception of overexertion. Its prevalence ranges from 29% to 77% after stroke, from 18% to 75% after traumatic brain injury, and from 47% to 97% after brain tumours. Fatigue is associated with factors including female sex, advanced age, dysfunctional families, history of specific health conditions, functional status (eg, fatigue prior to injury), comorbidities, mood, secondary disability, and the use of certain drugs. Assessment of fatigue is fundamentally based on such scales as the Fatigue Severity Scale (FSS). Advances have recently been made in imaging techniques for its diagnosis, such as in functional MRI. Regarding treatment, no specific pharmacological treatment currently exists; however, positive results have been reported for some conventional neurorehabilitation therapies, such as bright light therapy, neurofeedback, electrical stimulation, and transcranial magnetic stimulation. This review aims to assist neurorehabilitation professionals to recognise modifiable factors associated with fatigue and to describe the treatments available to reduce its negative effect on patients.

Increasing the Clinical Utility of the Paced Auditory Serial Addition Test: Normative Data for Standard, Dyad, and Cognitive Fatigability Scoring

BACKGROUND

No normative data currently exist that would allow clinicians to decide whether the degree of cognitive fatigability (CF) experienced in individuals with neurologic disease is greater than expected when compared with a healthy population.

OBJECTIVE

To establish discrete and regression-based normative data for CF as defined by an objective decrement in performance over the course of a cognitive task; namely, the Paced Auditory Serial Addition Test (PASAT). In addition, to develop discrete and regression-based normative data for PASAT performance scores-dyad and percent dyad-for which data do not currently exist.

METHOD

One hundred and seventy-eight healthy individuals completed the PASAT as part of a larger neuropsychological battery. PASAT performance scores including total correct responses, total dyads, and percent dyad were calculated. CF scores were calculated by comparing the individuals' performance on the first half (or third) of the test to their performance on the last half (or third) in order to capture any within-task performance decrements over time.

RESULTS

Both age- and education-based discrete normative data and demographically adjusted (sex, age, and education) regression-based formulas were established for the PASAT performance scores and the CF scores.

CONCLUSION

The development of these normative data will allow for greater interpretation of an individual's performance on the PASAT, beyond just the total correct score, through the use of dyad and percent dyad scores. With respect to CF, these data will allow clinicians to objectively quantify decrements in cognitive performance over time better in individuals with neurologic diseases.

Risk Factors and Imaging Mechanisms of Fatigue After Mild Ischemic Stroke: An Exploratory Study From a Single Chinese Center

Objective: To explore the biochemical risk factors and imaging mechanisms of post fatigue after mild ischemic stroke among a Chinese population. Methods: Forty consecutive patients with mild ischemic stroke within onset of 14 ± 2 days were enrolled between March and June 2018. The clinical information, scale data, biomarkers in peripheral venous blood, and imaging data during hospitalization and follow-up period were collected. Results: Patient age (range 34-78) was positively correlated with the prevalence of fatigue (p = 0.009). Both blood norepinephrine and serotonin levels during hospitalization were negatively correlated to the prevalence of post-stroke fatigue (model 1 p = 0.009 and model 2 P = 0.043, respectively). Infarct of right cerebral hemisphere is positively correlated with the occurrence of fatigue after mild ischemic stroke (p = 0.020). Compared to non-fatigue patients, amplitude of low-frequency fluctuation (ALFF) was lower in several areas of brain in stroke patients with fatigue, including the right orbital inferior frontal, right inner orbital frontal, right frontal, right triangular frontal inferior, right anterior and lateral cingulate, and right medial frontal gyruses. Analysis of the difference in functional connectivity between the fatigue and non-fatigue groups found no cluster. Conclusions: Frontal lobe-related neural pathways may play an essential role in the regulation of fatigue after mild ischemic stroke. Abnormal neural circuits may reduce the levels of neurotransmitters such as serotonin and norepinephrine and lead to post-stroke fatigue.