Is psychological stress a predisposing factor for amyotrophic lateral sclerosis (ALS)? An online international case-control study of premorbid life events, occupational stress, resilience and anxiety

Clinician Perspectives Highlight the Need for Early Dyadic Coping Skills for People Living With Amyotrophic Lateral Sclerosis

CONTEXT

A diagnosis of ALS can be challenging, and many people find ways to adapt. At the same time, emotional distress can arise early after an ALS diagnosis even when high quality multidisciplinary care is provided. When emotional distress occurs, it can become chronic over time, and can affect both the person living with ALS and their care-partner (together called a dyad).

OBJECTIVES

We set out to understand ALS multidisciplinary clinicians' perception of the challenges experienced by people with ALS and care-partners who experience emotional distress after diagnosis and potential benefits of a coping skills program to help these patients and their care-partners, Resilient Together-ALS (RT-ALS).

METHODS

We conducted semi-structured focus groups and individual interviews with 17 clinicians at the Sean M. Healey & AMG Center for ALS at MGH (N = 2 focus groups and five interviews) to elicit feedback on four domains: 1) Psychosocial Needs of ALS Dyads seen in the clinic; 2) Clinic Flow and Referral System to RT-ALS; 3) Clinic Partnership Approach in Support of RT-ALS; 4) RT-ALS Program Content and Manual Format. We conducted rapid data analyses for a time-efficient hybrid inductive-deductive thematic approach.

RESULTS

Clinicians noted that dyadic distress (distress experienced by both patient and their care-partner individually and as a unit), though not universal, is often present early after diagnosis. The response to the proposed program content (dyadic and individual coping skills) and structure (6 weekly virtual sessions delivered within about 2 months after diagnosis) was positive. Multidisciplinary clinicians emphasized the importance of a skills-based program for dyads experiencing elevated early emotional distress for which referral can be easily integrated within clinic flow so as not to not increase provider and dyad burden.

CONCLUSION

RT-ALS program content and structure is acceptable to clinicians. It is imperative to next seek further input from dyads about whether this type of program would be of interest and if yes, to pilot and refine the program for feasibility testing and then efficacy.

Stress-related neurodegenerative diseases: Molecular mechanisms implicated in neurodegeneration and therapeutic strategies

Chronic stress is a striking cause of major neurodegenerative diseases disorders (NDDs). These diseases share several common mechanisms regarding to disease pathology, in spite of they have various properties and clinical manifestations. NDDs are defined by progressive cognitive decline, and stress contribute to the promotion and progression of disease. In addition, various pathways such as production of reactive oxygen species (ROS), mitochondrial dysfunction, and neurodegeneration are the main crucial hallmarks to develop common NDDs, resulting in neuronal cell death. Although the exact mechanisms of NDDs are underexplored, the potential neuroprotective critical role of such therapies in neuronal loss the treatment of NDDs are not clear. In this regard, researchers investigate the neuroprotective effects of targeting underlying cascade to introduce a promising therapeutic option to NDDs. Herein, we provide an overview of the role of non-pharmacological treatments against oxidative stress, mitochondrial symbiosis, and neuroinflammation in NDDs, mainly discussing the music, diet, and exercise effects of targeting pathways.

Psychological resilience is protective against cognitive deterioration in motor neuron diseases

OBJECTIVES

Recent studies suggest that psychological resilience (PR) is associated with more well-preserved cognition in healthy subjects (HS), but an investigation of such phenomenon in patients with motor neuron diseases (MNDs) is still lacking. The aim of our study was therefore to evaluate PR and its relationship with baseline cognitive/behavioral and mood symptoms, as well as longitudinal cognitive functioning, in MNDs.

METHODS

94 MND patients and 87 demographically matched HS were enrolled. PR was assessed using the Connor-Davidson Resilience Scale (CD-RISC). Patients were further evaluated both at baseline and every 6 months for cognitive/behavioral disturbances using the Edinburgh Cognitive and Behavioral ALS Screen (ECAS), and for mood symptoms using the Hospital Anxiety and Depression Scale (HADS). CD-RISC scores were compared between patients and HS using the Mann-Whitney U test, and regression models were applied to evaluate the role of CD-RISC scores in predicting baseline cognitive/behavioral and mood measures, as well as longitudinal cognitive performances, in MND patients.

RESULTS

MND cases showed significantly greater PR compared to HS (p from <0.001 to 0.02). In MNDs, higher PR levels were significant predictors of both greater cognitive performance (p from 0.01 to 0.05) and milder mood symptoms (p from <0.001 to 0.04) at baseline, as well as less severe memory decline (p from 0.001 to 0.04) longitudinally.

CONCLUSIONS

PR is an important protective factor against the onset and evolution of cognitive/mood disturbances in MNDs, suggesting the usefulness of resilience enhancement psychological interventions to prevent or delay cognitive and mood disorders in these neurodegenerative conditions.

Acute stress differently modulates interneurons excitability and synaptic plasticity in the primary motor cortex of wild-type and SOD1G93A mouse model of ALS

Primary motor cortex (M1) network stability depends on activity of inhibitory interneurons, for which susceptibility to stress was previously demonstrated in limbic regions. Hyperexcitability in M1 following changes in the excitatory/inhibitory balance is a key pathological hallmark of amyotrophic lateral sclerosis (ALS). Using electrophysiological approaches, we assessed the impact of acute restraint stress on inhibitory interneurons excitability and global synaptic plasticity in M1 of the SOD1G93A ALS mouse model at a late pre-symptomatic stage (10-12.5 weeks). Based on their firing type (continuous, discontinuous, with accommodation or not) and electrophysiological characteristics (resting potential, rheobase, firing frequency), interneurons from M1 slices were separated into four clusters, labelled from 1 to 4. Among them, only interneurons from the first cluster, presenting continuous firing with few accommodations, tended to show increased excitability in wild-type (WT) and decreased excitability in SOD1G93A animals following stress. In vivo analyses of evoked field potentials showed that stress suppressed the theta burst-induced plasticity of an excitatory component (N1) recorded in the superficial layers of M1 in WT, with no impact on an inhibitory complex (N2-P1) from the deeper layers. In SOD1G93A mice, stress did not affect N1 but suppressed the N2-P1 plasticity. These data suggest that stress can alter M1 network functioning in a different manner in WT and SOD1G93A mice, possibly through changes of inhibitory interneurons excitability and synaptic plasticity. This suggests that stress-induced activity changes in M1 may therefore influence ALS outcomes. KEY POINTS: Disruption of the excitatory/inhibitory balance in the primary motor cortex (M1) has been linked to cortical hyperexcitability development, a key pathological hallmark of amyotrophic lateral sclerosis (ALS). Psychological stress was reported to influence excitatory/inhibitory balance in limbic regions, but very little is known about its influence on the M1 functioning under physiological or pathological conditions. Our study revealed that acute stress influences the excitatory/inhibitory balance within the M1, through changes in interneurons excitability along with network plasticity. Such changes were different in pathological (SOD1G93A ALS mouse model) vs. physiological (wild-type) conditions. The results of our study help us to better understand how stress modulates the M1 and highlight the need to further characterize stress-induced motor cortex changes because it may be of importance when evaluating ALS outcomes.

Sports and trauma as risk factors for Motor Neurone Disease: New Zealand case-control study

Objectives

To assess whether sports, physical trauma and emotional trauma are associated with motor neurone disease (MND) in a New Zealand case–control study (2013–2016).

Methods

In total, 321 MND cases and 605 population controls were interviewed collecting information on lifetime histories of playing sports, physical trauma (head injury with concussion, spine injury) and emotional trauma (14 categories). ORs were estimated using logistic regression adjusting for age, sex, ethnicity, socioeconomic status, education, smoking status, alcohol consumption and mutually adjusting for all other exposures.

Results

Head injury with concussion ≥3 years before diagnosis was associated with MND (OR 1.51, 95% CI: 1.09–2.09), with strongest associations for two (OR 4.01, 95% CI: 1.82–8.86), and three or more (OR 2.34, 95% CI: 1.00–5.45) head injuries. Spine injury was not associated with MND (OR 0.81, 95% CI: 0.48–1.36). Compared to never playing sports, engaging in sports throughout childhood and adulthood increased MND risk (OR 1.81, 95% CI: 1.01–3.25), as was more than 12 years playing football/soccer (OR 2.35, 95% CI: 1.19–4.65). Reporting emotionally traumatic events in more than three categories was associated with MND (OR 1.88, 95% CI: 1.17–3.03), with physical childhood abuse the only specific emotional trauma associated with MND (OR 1.82, 95% CI: 1.14–2.90), particularly for those reporting longer abuse duration (OR_{(5–8 years)} 2.26, 95% CI: 1.14–4.49; OR_(>8 years) 3.01, 95% CI: 1.18–7.70). For females, having witnessed another person being killed, seriously injured or assaulted also increased MND risk (OR 2.68, 95% CI: 1.06–6.76).

Conclusions

This study adds to the evidence that repeated head injury with concussion, playing sports in general, and playing football (soccer) in particular, are associated with an increased risk of MND. Emotional trauma, that is physical abuse in childhood, may also play a role.

Organ on a Chip: A Novel in vitro Biomimetic Strategy in Amyotrophic Lateral Sclerosis (ALS) Modeling

Amyotrophic lateral sclerosis is a pernicious neurodegenerative disorder that is associated with the progressive degeneration of motor neurons, the disruption of impulse transmission from motor neurons to muscle cells, and the development of mobility impairments. Clinically, muscle paralysis can spread to other parts of the body. Hence it may have adverse effects on swallowing, speaking, and even breathing, which serves as major problems facing these patients. According to the available evidence, no definite treatment has been found for amyotrophic lateral sclerosis (ALS) that results in a significant outcome, although some pharmacological and non-pharmacological treatments are currently applied that are accompanied by some positive effects. In other words, available therapies are only used to relieve symptoms without any significant treatment effects that highlight the importance of seeking more novel therapies. Unfortunately, the process of discovering new drugs with high therapeutic potential for ALS treatment is fraught with challenges. The lack of a broad view of the disease process from early to late-stage and insufficiency of preclinical studies for providing validated results prior to conducting clinical trials are other reasons for the ALS drug discovery failure. However, increasing the combined application of different fields of regenerative medicine, especially tissue engineering and stem cell therapy can be considered as a step forward to develop more novel technologies. For instance, organ on a chip is one of these technologies that can provide a platform to promote a comprehensive understanding of neuromuscular junction biology and screen candidate drugs for ALS in combination with pluripotent stem cells (PSCs). The structure of this technology is based on the use of essential components such as iPSC- derived motor neurons and iPSC-derived skeletal muscle cells on a single miniaturized chip for ALS modeling. Accordingly, an organ on a chip not only can mimic ALS complexities but also can be considered as a more cost-effective and time-saving disease modeling platform in comparison with others. Hence, it can be concluded that lab on a chip can make a major contribution as a biomimetic micro-physiological system in the treatment of neurodegenerative disorders such as ALS.

Current Views on the Role of Stress in the Pathogenesis of Chronic Neurodegenerative Diseases

The review summarizes the results of studies on the cellular and molecular mechanisms mediating the impact of stress on the pathogenesis of neurodegenerative brain pathologies (Alzheimer's disease, Parkinson's disease, etc.) and presents current information on the role of stress in the hyperphosphorylation of tau protein, aggregation of beta-amyloid, and hyperactivation of the hypothalamic-pituitary-adrenal axis involved in the hyperproduction of factors that contribute to the pathogenetic role of stress in neurodegeneration. The data on the participation of microglia in the effects of stress on the pathogenesis of neurodegenerative diseases are presented.

The Link between Oxidative Stress, Redox Status, Bioenergetics and Mitochondria in the Pathophysiology of ALS

Amyotrophic lateral sclerosis (ALS) is the most common neurodegenerative disease of the motor system. It is characterized by the degeneration of both upper and lower motor neurons, which leads to muscle weakness and paralysis. ALS is incurable and has a bleak prognosis, with median survival of 3-5 years after the initial symptomatology. In ALS, motor neurons gradually degenerate and die. Many features of mitochondrial dysfunction are manifested in neurodegenerative diseases, including ALS. Mitochondria have shown to be an early target in ALS pathophysiology and contribute to disease progression. Disruption of their axonal transport, excessive generation of reactive oxygen species, disruption of the mitochondrial structure, dynamics, mitophagy, energy production, calcium buffering and apoptotic triggering have all been directly involved in disease pathogenesis and extensively reported in ALS patients and animal model systems. Alterations in energy production by motor neurons, which severely limit their survival capacity, are tightly linked to the redox status and mitochondria. The present review focuses on this link. Placing oxidative stress as a main pathophysiological mechanism, the molecular interactions and metabolic flows involved are analyzed. This leads to discussing potential therapeutic approaches targeting mitochondrial biology to slow disease progression.

Association of Stress-Related Disorders With Subsequent Neurodegenerative Diseases

Importance

Posttraumatic stress disorder (PTSD) has been associated with increased risk for dementia. Less is known, however, about other stress-related disorders and their associations with neurodegenerative diseases.

Objective

To examine the association between stress-related disorders and risk for neurodegenerative diseases.

Design, Setting, and Participants

This population-matched and sibling cohort study was conducted in Sweden using data from nationwide health registers, including the Swedish National Patient Register. Individuals who received their first diagnosis of stress-related disorders between January 1, 1987, and December 31, 2008, were identified. Individuals who had a history of neurodegenerative diseases, had conflicting or missing information, had no data on family links, or were aged 40 years or younger at the end of the study were excluded. Individuals with stress-related disorders were compared with the general population in a matched cohort design; they were also compared with their siblings in a sibling cohort. Follow-up commenced from the age of 40 years or 5 years after the diagnosis of stress-related disorders, whichever came later, until the first diagnosis of a neurodegenerative disease, death, emigration, or the end of follow-up (December 31, 2013), whichever occurred first. Data analyses were performed from November 2018 to April 2019.

Exposures

Diagnosis of stress-related disorders (PTSD, acute stress reaction, adjustment disorder, and other stress reactions).

Main Outcomes and Measurements

Neurodegenerative diseases were identified through the National Patient Register and classified as primary or vascular. Alzheimer disease, Parkinson disease, and amyotrophic lateral sclerosis were evaluated separately. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) with 95% CIs after controlling for multiple confounders.

Results

The population-matched cohort included 61 748 exposed individuals and 595 335 matched unexposed individuals. A total of 44 839 exposed individuals and their 78 482 unaffected full siblings were included in the sibling cohort analysis. The median (interquartile range) age at the start of follow-up was 47 (41-56) years, and 24 323 (39.4%) of the exposed individuals were male. The median (interquartile range) follow-up was 4.7 (2.1-9.8) years. Compared with unexposed individuals, individuals with a stress-related disorder were at an increased risk of neurodegenerative diseases (HR, 1.57; 95% CI, 1.43-1.73). The risk increase was greater for vascular neurodegenerative diseases (HR, 1.80; 95% CI, 1.40-2.31) than for primary neurodegenerative diseases (HR, 1.31; 95% CI, 1.15-1.48). A statistically significant association was found for Alzheimer disease (HR, 1.36; 95% CI, 1.12-1.67) but not Parkinson disease (HR, 1.20; 95% CI, 0.98-1.47) or amyotrophic lateral sclerosis (HR, 1.20; 95% CI, 0.74-1.96). Results from the sibling cohort corroborated results from the population-matched cohort.

Conclusions and Relevance

This study showed an association between stress-related disorders and an increased risk of neurodegenerative diseases. The relative strength of this association for vascular neurodegenerative diseases suggests a potential cerebrovascular pathway.

Stress and neurodegeneration

Neurodegenerative diseases are a great concern because of aging worldwide population. Despite substantial effort to advance our understanding of the etiology and potential treatment of neurodegeneration, there remains a paucity of information with respect to this complex disease process. Interestingly, stress has been implicated among the potential mechanisms implicated in neurodegenerative pathology. Given the increase in chronic stress in modern society, this premise warrants further investigation. The aim of this review is to evaluate the influence of stress on neurodegeneration, the effect of neurodegenerative diseases diagnosis on stress, and therapeutic strategies for neurodegenerative diseases with a special focus on stress reduction. Neurodegenerative disorders such as Alzheimer's, Parkinson's and Huntington's Disease showed an acceleration in disease progression and a worsening of symptoms under stress. Some therapies (e.g., yoga, meditation) focused on reducing stress showed beneficial effects against neurodegeneration. Nevertheless, more studies are necessary in order to completely understand the implications of stress in neurodegeneration and the usefulness of stress reduction in the treatment thereof.