Functional connectivity pre-post exercise intervention in individuals with relapsing-remitting multiple sclerosis.

OBJECTIVE: Exercise interventions have emerged as a promising approach for managing symptoms associated with multiple sclerosis (MS). However, changes in brain function underlying exercise-related improvements in symptoms of MS have not been fully investigated, and in no instances have they been investigated using a graph theory approach. For the first time, the effects of an exercise intervention on functional brain network connectivity were examined using graph theory analyses of resting-state functional MRI (fMRI) data among individuals with relapsing-remitting MS (RRMS). METHODS: Resting-state fMRI data were obtained from 10 participants before and after 12 weeks of a speeded walking intervention. Functional connectivity data were preprocessed in Data Processing Assistant for Resting-State fMRI Advanced (DPARSF A version 4.2) and analyzed in GraphVar2.02 to compute global and local graph theory metrics. To examine differences in graph metrics before and after the intervention, one-sample permutation tests were performed. RESULTS: There were no significant pre to post exercise intervention changes in global metrics. Changes in local metrics (i.e. clustering coefficient, local efficiency, degree centrality and betweenness centrality) were mixed, with both increases and decreases observed. CONCLUSION: Following a 12-week speeded walking exercise intervention, there were no significant increases or decreases in global graph metrics and results at the level of local metrics were equivocal in individuals with RRMS. Further research with experimental designs that include baseline and longitudinal follow-up, as well as larger sample sizes, is needed to understand the underlying mechanisms of symptom improvement following exercise in RRMS.

Aging in Place: Challenges of Older Adults with Self-Reported Cognitive Decline.

BACKGROUND: An emergent concern related to the aging and the increased risk of cognitive decline is the institutionalization of older adults. Evidence has shown that aging in place leads to many benefits, including higher quality of life. In order to support older adults, it is imperative that we understand the challenges people with changes in cognition face while aging in place. METHODS: A total of sixteen older adults with self-reported cognitive decline and six informal caregivers of individuals reporting cognitive decline, all of whom are living in independent residences, participated. Focus group sessions with semi-structured interviews were conducted, followed by thematic qualitative data analyses. RESULTS: Thematic analyses led to the identification of six challenges to aging in place, including: 1) memory decline, 2) emotional challenges/low mood, 3) social isolation/loneliness, 4) difficulty with mobility and physical tasks, 5) difficulties with activities of daily living/instrumental activities of daily living, and 6) lack of educational resources on cognitive change. CONCLUSION: The themes identified in the current study represent common challenges in aging in place for older adults with self-reported cognitive decline. Identification of these themes allows for important next steps, which can focus on supports through targeted interventions.

Differences in symptoms of depression between females and males with relapsing-remitting multiple sclerosis.

INTRODUCTION: Depressive symptoms are experienced by up to 50% of individuals diagnosed with Multiple Sclerosis (MS). Furthermore, depressive symptoms are sometimes experienced differently for females and males in the general population, but it is unclear if this is true for people with Relapsing-Remitting MS (RRMS). The current study aimed to investigate whether there are differences between females and males with RRMS in overall depression scores as well as the types of depressive symptoms reported (somatic or cognitive). METHOD: Demographic and Beck Depression Inventory, 2nd edition (BDI-II) raw scores for females and males with RRMS were downloaded with permission from the Multiple Sclerosis Outcome Assessments Consortium (MSOAC) Placebo database. A total of 494 individuals (n=354 females) with RRMS were included in analyses. Non-parametric Wilcoxon rank-sum tests were used to compare BDI-II Total Scores, Somatic Scores, and Cognitive Scores between females and males with RRMS. RESULTS: Females reported significantly greater overall symptoms of depression compared to males. Furthermore, females endorsed significantly greater somatic symptoms than males. There were no significant differences in females' reports of cognitive symptoms compared to males. CONCLUSIONS: Depressive symptoms in RRMS are experienced differently for females and males. Females with RRMS report higher levels of overall depression and somatic depressive symptoms compared to males with RRMS; this knowledge may help inform best strategies for treatment planning. Future studies should investigate depressive symptoms in females and males with progressive forms of MS, and track symptom changes longitudinally.

A pilot study of the impact of an exercise intervention on brain structure, cognition, and psychosocial symptoms in individuals with relapsing-remitting multiple sclerosis.

BACKGROUND: Despite pharmacological treatment, many individuals with multiple sclerosis (MS) continue to experience symptoms and medication side effects. Exercise holds promise for MS, but changes in brain structure following exercise have not been thoroughly investigated, and important cognitive and psychosocial variables are rarely primary outcomes. The aim of this pilot study was to investigate whether a 12-week exercise intervention would improve white matter integrity in the brain, or cognition, symptoms of fatigue, and depressed mood for individuals with relapsing-remitting MS (RRMS). METHOD: Thirteen participants completed 12 weeks of speeded walking. Baseline and post-intervention testing included 3T diffusion tensor imaging (DTI) to assess white matter and neuropsychological testing to assess cognition, fatigue, and mood. Image pre-processing and analyses were performed in functional magnetic resonance imaging of the Brain Software Library. RESULTS: Post-intervention, there were no significant changes in white matter compared to baseline. Post-intervention, individuals with RRMS performed significantly better on the Symbol Digit Modalities Test (SDMT), reported fewer perceived memory problems, and endorsed less fatigue. Performance was not significantly different on Trails or Digit Span, and there were no significant changes in reports of mood. CONCLUSION: Although 12 weeks of speeded walking did not improve white matter integrity, exercise may hold promise for managing some symptoms of RRMS in the context of this study population.

Identifying Barriers to and Facilitators of Health Service Access Encountered by Individuals with Multiple Sclerosis.

BACKGROUND: The symptoms of multiple sclerosis (MS) can be diverse, complex, and progressive, creating a need for frequent and long-standing health care services. The purpose of this scoping review was to identify the barriers people with MS encounter when attempting to access multidisciplinary health services and the reported facilitators for better access to health services. METHODS: The MEDLINE, Embase, and CINAHL databases were searched, without date or geographic restrictions, using the following terms: multiple sclerosis, health services accessibility, health care access, health care delivery, and delivery of health care. After screening based on exclusion criteria, 23 articles were included in the final review. RESULTS: Five main themes were identified as barriers and facilitators to accessing health services: 1) information (information available to people with MS, health care provider knowledge of and familiarity with MS), 2) interactions (interactions between health care providers and people with MS, social networks and support of people with MS, collaboration among health care providers), 3) beliefs and skills (personal values and beliefs, perceived time to travel to and attend appointments, and self-assessment of symptoms and needs of people with MS), 4) practical considerations (wait times, physical barriers, affordability of services), and 5) nature of MS (complexity and unpredictability of disease symptoms). CONCLUSIONS: People with MS and their health care providers may benefit from structured and comprehensive MS-specific education to address barriers to accessing health care services. The education can ultimately facilitate the process of addressing unmet health care needs and contribute to a greater quality of life for people with MS.

The relationship between physical activity and symptoms of fatigue, mood, and perceived cognitive impairment in adults with multiple sclerosis.

Introduction: Multiple Sclerosis (MS) is achronic neurological condition that requires costly treatment for aconstellation of motor and sensory symptoms, as well as fatigue, depression, and cognitive problems. Given that this pharmacological treatment often results in side effects, there is acrucial need for low-costbehavioral treatments that are effective in further reducing MS symptoms. It has been hypothesized that physical activity may slow the neurodegenerative progression of MS. The aim of the current study was to investigate the relationship between physical activity and commonly reported MS symptoms, including fatigue, depression, and perceived cognitive impairment. Method: 86 individuals with MS responded to amail-outquestionnaire. Physical activity, fatigue, mood, and perceived cognitive impairment were assessed using the following measures: Godin Leisure-TimeExercise Questionnaire (GLTEQ), Modified Fatigue Impact Scale (MFIS), Patient Health Questionnaire (PHQ-9), and Patient Deficit Questionnaire (PDQ). Descriptive and correlational statistics were calculated to investigate the relationship between scores on the GLTEQ and scores on the MFIS, PHQ-9, and PDQ. Results: Overall, there was asignificant negative relationship between physical activity (GLTEQ) and fatigue (MFIS; r= -.34, p= .002) and depression (PHQ-9; r= -.23, p= .034) in individuals with MS. There was not asignificant relationship between physical activity and overall perceived cognitive dysfunction (PDQ; r= -.19, p= .08), but when the PDQ subscales were examined, there was asignificant relationship with perceived retrospective (r = 0.24, p= .03) and prospective memory abilities (r = -.22, p= .04). When the RRMS and progressive subtypes were examined separately, we observed asimilar pattern of results for the RRMS group, but the progressive MS group did not reach significance. Conclusions: Individuals with MS who reported more strenuous and/or frequent physical activity, reported fewer problems with fatigue, depression, and perceived memory abilities.

Neuropsychological assessment of traumatic brain injury: Current ethical challenges and recommendations for future practice.

Numerous ethical challenges may arise over the course of neuropsychological assessment. This paper highlights the ethical considerations associated with neuropsychological assessment of individuals with traumatic brain injury. Issues regarding professional competency, providing and obtaining informed consent, neuropsychological test selection and administration, effectively communicating assessment results, and working as part of a multidisciplinary team are discussed with practical recommendations. Ultimately, a comprehensive understanding of these issues as well as an integration of resources to guide clinical practice will contribute to ethical decision-making and strong professional practice.

Relationship Between DTI Metrics and Cognitive Function in Alzheimer's Disease.

Introduction: Alzheimer's disease (AD) is a neurodegenerative disorder with a clinical presentation characterized by memory impairment and executive dysfunction. Our group previously demonstrated significant alterations in white matter microstructural metrics in AD compared to healthy older adults. We aimed to further investigate the relationship between white matter microstructure in AD and cognitive function, including memory and executive function. Methods: Diffusion tensor imaging (DTI) and neuropsychological data were downloaded from the AD Neuroimaging Initiative database for 49 individuals with AD and 48 matched healthy older adults. The relationship between whole-brain fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AxD), radial diffusivity (RD), and composite scores of memory and executive function was examined. We also considered voxel-wise relationships using Tract-Based Spatial Statistics. Results: As expected, individuals with AD had lower composite scores on tests of memory and executive function, as well as disrupted white matter integrity (low FA, high MD, AxD, and RD) relative to healthy older adults in widespread regions, including the hippocampus. When the AD and healthy older adult groups were combined, we found significant relationships between DTI metrics (FA/MD/AxD/RD) and memory scores across widespread regions of the brain, including the medial temporal regions. We also found significant relationships between DTI metrics (FA/MD/AxD/RD) and executive function in widespread regions, including the frontal areas in the combined group. However, when the groups were examined separately, no significant relationships were found between DTI metrics (FA/MD/AxD/RD) and memory performance for either group. Further, we did not find any significant relationships between DTI metrics (FA/MD/AxD/RD) and executive function in the AD group, but we did observe significant relationships between FA/RD, and executive function in healthy older adults. Conclusion: White matter integrity is disrupted in AD. In a mixed sample of AD and healthy elderly persons, associations between measures of white matter microstructure and memory and executive cognitive test performance were evident. However, no significant linear relationship between the degree of white matter disruption and level of cognitive functioning (memory and executive abilities) was found in those with AD. Future longitudinal studies of the relations between DTI metrics and cognitive function in AD are required to determine whether DTI has potential to measure progression of AD and/or treatment efficacy.

Functional Magnetic Resonance Imaging and Functional Near-Infrared Spectroscopy: Insights from Combined Recording Studies.

Although blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) is a widely available, non-invasive technique that offers excellent spatial resolution, it remains limited by practical constraints imposed by the scanner environment. More recently, functional near infrared spectroscopy (fNIRS) has emerged as an alternative hemodynamic-based approach that possesses a number of strengths where fMRI is limited, most notably in portability and higher tolerance for motion. To date, fNIRS has shown promise in its ability to shed light on the functioning of the human brain in populations and contexts previously inaccessible to fMRI. Notable contributions include infant neuroimaging studies and studies examining full-body behaviors, such as exercise. However, much like fMRI, fNIRS has technical constraints that have limited its application to clinical settings, including a lower spatial resolution and limited depth of recording. Thus, by combining fMRI and fNIRS in such a way that the two methods complement each other, a multimodal imaging approach may allow for more complex research paradigms than is feasible with either technique alone. In light of these issues, the purpose of the current review is to: (1) provide an overview of fMRI and fNIRS and their associated strengths and limitations; (2) review existing combined fMRI-fNIRS recording studies; and (3) discuss how their combined use in future research practices may aid in advancing modern investigations of human brain function.

Longitudinal changes in microstructural white matter metrics in Alzheimer's disease.

BACKGROUND: Alzheimer's disease (AD) is a progressive neurodegenerative disorder. Current avenues of AD research focus on pre-symptomatic biomarkers that will assist with early diagnosis of AD. The majority of magnetic resonance imaging (MRI) based biomarker research to date has focused on neuronal loss in grey matter and there is a paucity of research on white matter. METHODS: Longitudinal DTI data from the Alzheimer's Disease Neuroimaging Initiative 2 database were used to examine 1) the within-group microstructural white matter changes in individuals with AD and healthy controls at baseline and year one; and 2) the between-group microstructural differences in individuals with AD and healthy controls at both time points. RESULTS: 1) Within-group: longitudinal Tract-Based Spatial Statistics revealed that individuals with AD and healthy controls both had widespread reduced fractional anisotropy (FA) and increased mean diffusivity (MD) with changes in the hippocampal cingulum exclusive to the AD group. 2) Between-group: relative to healthy controls, individuals with AD had lower FA and higher MD in the hippocampal cingulum, as well as the corpus callosum, internal and external capsule; corona radiata; posterior thalamic radiation; superior and inferior longitudinal fasciculus; fronto-occipital fasciculus; cingulate gyri; fornix; uncinate fasciculus; and tapetum. CONCLUSION: The current results indicate that sensitivity to white matter microstructure is a promising avenue for AD biomarker research. Additional longitudinal studies on both white and grey matter are warranted to further evaluate potential clinical utility.

Long-Term Motor Recovery After Severe Traumatic Brain Injury: Beyond Established Limits.

OBJECTIVE: To report neural plasticity changes after severe traumatic brain injury. SETTING: Case-control study. PARTICIPANTS: Canadian soldier, Captain Trevor Greene survived a severe open-traumatic brain injury during a 2006 combat tour in Afghanistan. DESIGN: Longitudinal follow-up for more than 6 years. MAIN MEASURES: Twelve longitudinal functional magnetic imaging (fMRI) examinations were conducted to investigate lower limb activation changes in association with clinical examination. Trevor Greene's lower limb fMRI activation was compared with control fMRI activation of (1) mental imagery of similar movement and (2) matched control subject data. RESULTS: Trevor Greene's motor recovery and corresponding fMRI activation increased significantly over time (F = 32.54, P < .001). Clinical measures of functional recovery correlated strongly with fMRI motor activation changes (r = 0.81, P = .001). By comparison, while Trevor Greene's mental imagery activated similar motor regions, there was no evidence of fMRI activation change over time. While comparable, control motor activation did not change over time and there was no significant mental imagery activation. CONCLUSION: Motor function recovery can occur beyond 6 years after severe traumatic brain injury, both in neural plasticity and clinical outcome. This demonstrates that continued benefits in physical function due to rehabilitative efforts can be achieved for many years following injury. The finding challenges current practices and assumptions in rehabilitation following traumatic brain injury.