Cognitive fatigue: an impaired cortical inhibitory replenishment

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.

Prospective analyses of alertness, sleep, and fitness to drive one year after de novo multiple sclerosis diagnosis

BACKGROUND

The prevalence and functional burden of the chronic demyelinating disease multiple sclerosis (MS) are well documented; however, little is known about the initial clinical course of alertness, sleep, cognitive, and psychological symptoms.

OBJECTIVES

This exploratory, prospective, longitudinal study multidimensionally investigated the development and progression of alertness, sleep, fitness to drive, and psychological symptoms in the first year after de novo MS diagnosis.

METHODS

Twenty-five people with MS (pwMS) were assessed cognitively, psychologically, and using polysomnography soon after diagnosis and one year later, with outcomes compared to matched healthy controls.

RESULTS

In the early stage of the disease, psychological symptoms of pwMS were comparable with those of controls, and patient conditions did not deteriorate within the first disease year. A small percentage of pwMS experienced increased levels of anxiety and depression after diagnosis. Alertness, sustained attention, and fitness to drive were comparable between both groups, and fatigue levels remained low over the course of the year.

CONCLUSIONS

This study highlights patient experiences within the initial clinical course of MS in a small group of patients. Further research is needed to understand the progression of symptoms and impairments in MS over a longer period and in different stages of the disease.

Co-design of a therapeutic virtual reality tool to increase awareness and self-management of cognitive fatigue after traumatic brain injury

PURPOSE

The symptom of cognitive fatigue is reported as one of the longest lasting and most debilitating symptoms of traumatic brain injury (TBI). Virtual reality may be one of the most suitable technologies for neurorehabilitation, able to integrate evidence-based neuroscientific principles into motivating rehabilitation simulations. The purpose of this study was to seek perspectives of individuals with lived experience of TBI and experienced rehabilitation clinicians in the co-design of a novel technology-based tool for cognitive fatigue after TBI.

MATERIALS AND METHOD

Co-design focus groups with a sample of clinicians and individuals with lived experience of TBI were used to identify the design parameters. A prototype was developed using inter-disciplinary design iterations. Focus groups were repeated with participants testing the prototype. Qualitative data were analysed using a general inductive approach.

RESULTS

Feasibility of VR in this population was well tolerated. The focus groups guided development of domains including environment, tasks, level progression, outcome measures and considerations about clinical implementation of VR.

CONCLUSIONS

By merging advancements in VR science with a translational approach, a co-designed virtual reality tool to increase awareness and self-management of cognitive fatigue has been developed, suitable for use in persons with TBI.Implications for rehabilitationImmersive virtual reality tools show promise for addressing awareness of cognitive fatigue after traumatic brain injury in rehabilitation settings.Early engagement with consumers is recommended to produce a usable rehabilitation product.

Impact of Sleep Fragmentation on Cognition and Fatigue

Sleep continuity and efficacy are essential for optimal cognitive functions. How sleep fragmentation (SF) impairs cognitive functioning, and especially cognitive fatigue (CF), remains elusive. We investigated the impact of induced SF on CF through the TloadDback task, measuring interindividual variability in working memory capacity. Sixteen participants underwent an adaptation polysomnography night and three consecutive nights, once in a SF condition induced by non-awakening auditory stimulations, once under restorative sleep (RS) condition, counterbalanced within-subject. In both conditions, participants were administered memory, vigilance, inhibition and verbal fluency testing, and for CF the TloadDback, as well as sleep questionnaires and fatigue and sleepiness visual analog scales were administered. Subjective fatigue increased and sleep architecture was altered after SF (reduced sleep efficiency, percentage of N3 and REM, number of NREM and REM phases) despite similar total sleep time. At the behavioral level, only inhibition deteriorated after SF, and CF similarly evolved in RS and SF conditions. In line with prior research, we show that SF disrupts sleep architecture and exerts a deleterious impact on subjective fatigue and inhibition. However, young healthy participants appear able to compensate for CF induced by three consecutive SF nights. Further studies should investigate SF effects in extended and/or pathological disruption settings.

Development of a behavioural intervention for cognitive fatigability in multiple sclerosis: Protocol for a pilot and feasibility study

Background

Up to 90% of people with multiple sclerosis (PwMS) subjectively report fatigue as one of their worst symptoms. Fatigability is an objectively measured component of fatigue. Cognitive fatigability (CF) is a breakdown in task performance following sustained cognitive effort. There is a paucity of interventions targeting CF in MS. The prior success of behavioural interventions at improving subjective fatigue suggests that their adaptation may yield similar results for CF. Given the relationship between CF, sleep quality, and mood, a behavioural intervention targeting these factors, such as cognitive behavioural therapy (CBT), is warranted. Given the multidimensional nature of fatigue, a multifaceted approach targeting lifestyle factors and coping (e.g., fatigue management education supplemented by CBT for insomnia and exercise) might prove efficacious.

Aim

We describe a protocol for a pilot feasibility study to design and implement a multi-dimensional behavioural intervention to improve CF in PwMS.

Methods

Stage 1: development of a multi-dimensional group-based videoconference-delivered behavioural intervention based on a previously successful fatigue management program for PwMS. A facilitator manual will be drafted. Course material will focus on four themes: body (sleep and physical activity), mood (impact of depression and anxiety), mind (cognitive contributions), and context (pacing and communication). Stage 2: a needs assessment survey will be completed by 100 PwMS for input on what factors are important contributors to their CF. Modifications will be made to the course material and manual. Stage 3: the facilitator-delivered intervention will include 20 PwMS. After baseline assessment, participants will attend weekly 70-min videoconference group sessions for 8 weeks, including homework assignments. Follow-up assessment will re-evaluate outcomes. Stage 4: analysis and dissemination of results. The primary outcome is improvement in CF. Additional feasibility outcomes will determine if a randomized control trial (RCT) is pursued. Stage 5: refine the intervention based on outcomes and feedback from participants. Determining which aspects participants felt were most effective will help inform RCT design.

Conclusion

The long-term goal is to ensure that PwMS have access to effective interventions in real-world settings to improve quality of life and enhance their ability to participate in cognitively demanding activities that they enjoy.

Three Pathways Into Chronic Lack of Energy as a Mental Health Complaint

Abstract. Many disturbances of physical, social, and mental health have conditions involving lack of energy, difficulty in making decisions, and low interest or motivation. Laboratory studies of willpower depletion have produced similar states in a temporary fashion. The present review uses extant literature to develop and test three theories about how temporary states of low willpower could become chronic. The first is ongoing and repeated exposure to depleting circumstances, such as caregiver fatigue, burdensome financial debts, and high-stress jobs. The second focuses on inadequate recoveries, such as poor sleep, insufficient nutrition, or unsatisfying vacations. The third invokes dispositional vulnerabilities that predispose some people to become depleted more frequently than others. A wide-ranging search for evidence concluded that the first two theories have more support than the third, though all further merit research. Additional possible contributions to chronicity are discussed, such as the emergence of vicious circles.

Validation of Discrete and Regression-Based Performance and Cognitive Fatigability Normative Data for the Paced Auditory Serial Addition Test in Multiple Sclerosis

Cognitive fatigability is an objective performance decrement that occurs over time during a task requiring sustained cognitive effort. Although cognitive fatigability is a common and debilitating symptom in multiple sclerosis (MS), there is currently no standard for its quantification. The objective of this study was to validate the Paced Auditory Serial Addition Test (PASAT) discrete and regression-based normative data for quantifying performance and cognitive fatigability in an Ontario-based sample of individuals with MS. Healthy controls and individuals with MS completed the 3″ and 2″ versions of the PASAT. PASAT performance was measured with total correct, dyad, and percent dyad scores. Cognitive fatigability scores were calculated by comparing performance on the first half (or third) of the task to the last half (or third). The results revealed that the 3″ PASAT was sufficient to detect impaired performance and cognitive fatigability in individuals with MS given the increased difficulty of the 2″ version. In addition, using halves or thirds for calculating cognitive fatigability scores were equally effective methods for detecting impairment. Finally, both the discrete and regression-based norms classified a similar proportion of individuals with MS as having impaired performance and cognitive fatigability. These newly validated discrete and regression-based PASAT norms provide a new tool for clinicians to document statistically significant cognitive fatigability in their patients.

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.

Self- and Parent-Reported Fatigue 7 Years After Severe Childhood Traumatic Brain Injury: Results of the Traumatisme Grave de l'Enfant Prospective Longitudinal Study

OBJECTIVE

To investigate presence of and factors associated with self- and parent-reported fatigue 7 years after severe childhood traumatic brain injury (TBI) in the prospective longitudinal study TGE (Traumatisme Grave de l'Enfant-severe childhood trauma).

METHODS

Self-reports and/or parent reports on the Multidimensional Fatigue Scale were collected for 38 participants (aged 7-22 years) 7 years after severe childhood TBI, and 33 controls matched for age, gender, and parental educational level. The data collected included sociodemographic characteristics, age at injury and injury severity scores, overall disability (Glasgow Outcome Scale Extended), intellectual outcome (Wechsler scales), and questionnaires assessing executive functions, health-related quality of life, behavior, and participation.

RESULTS

Fatigue levels were significantly worse in the TBI than in the control group, especially for cognitive fatigue. Correlations of reported fatigue with age at injury, gender, TBI severity, and intellectual ability were moderate and often not significant. Fatigue was significantly associated with overall level of disability (Glasgow Outcome Scale Extended) and with all questionnaires completed by the same informant.

CONCLUSION

High levels of fatigue were reported by 30% to 50% of patients 7 years after a severe childhood TBI. Reported fatigue explained more than 60% of the variance of reported health-related quality of life by the same informant (patient or parent).

Cognitive Fatigability Interventions in Neurological Conditions: A Systematic Review

INTRODUCTION

Although fatigue is a well-studied concept in neurological disease, cognitive fatigability (CF) is less understood. While most studies measure fatigue using subjective self-report, fewer have measured CF objectively. Given the negative impact of CF on quality-of-life, there is a need for targeted interventions. The objective of this review was to determine which procedural, behavioural and pharmacological treatments for objectively measured CF are available to people living with neurological conditions.

METHODS

In accordance with the PRISMA guidelines, systematic searches for randomized control trials (RCTs), case-controlled studies and case reports/series were conducted across the Ovid Medline, PsycInfo, EMBASE and Cochrane Library databases. English-language articles published between 1980 and February 2019 were considered for eligibility. Included were those that objectively measured CF in individuals with neurological disease/disorder/dysfunction between the ages of 18 and 65 years. Studies were reviewed using a modified Cochrane Data Extraction Template. Risk of bias was assessed using the Cochrane Risk of Bias tool. The review process was facilitated using Covidence software (www.covidence.org). Two authors reviewed articles independently, with a third resolving conflicts regarding article inclusion.

RESULTS

The search identified 450 records. After duplicates were removed and remaining titles/abstracts were screened for eligibility, 28 full-text articles were assessed, and two studies were included in the qualitative synthesis. Studies were a priori divided into those with pharmacological, procedural or behavioural interventions. Two studies met eligibility criteria; both of these included participants with multiple sclerosis. One study utilized a procedural intervention (i.e. transcranial direct current stimulation), while the other utilized a pharmacological intervention (i.e. fampridine-SR). Studies were evaluated for risk of bias, and evidence from both eligible studies was discussed.

CONCLUSION

Despite the positive results of the procedural intervention, the paucity of eligible studies and the nascent nature of the field suggests that more studies are required before firm conclusions can be drawn regarding the amenability of CF to treatment.

TRIAL REGISTRATION

The review was registered with PROSPERO (CRD42019118706).