Searching for the neural basis of reserve against memory decline: intellectual enrichment linked to larger hippocampal volume in multiple sclerosis

Effects of mindfulness-based interventions on cognition in people with multiple sclerosis: a systematic review and meta-analysis of randomized controlled trials

Introduction

Cognitive impairment affects up to 65% of people with multiple sclerosis (PwMS), undermining functional independence and quality of life. The objective of this study is to synthesize existing randomized controlled trial (RCT) evidence on the effects of Mindfulness-based interventions (MBIs) on cognitive function in PwMS.

Methods

A systematic literature search was conducted to identify RCTs assessing MBIs effects on cognitive functioning in PwMS. Using pre-defined criteria, two independent reviewers screened titles, abstracts, and extracted data from included studies. Meta-analysis was performed, where possible, using a random effects model. Narrative synthesis was undertaken. Preferred Reporting Items for Systematic Reviews and Meta-analysis guidance was followed. PROSPERO_ID:(CRD42021286429).

Results

Twelve eligible RCTs were identified, n=700 PwMS. MBIs included both standardized and tailored interventions, in-person and virtually. A variety of measures of cognitive functioning were reported. Five studies (n=254 PwMS) were included in meta-analysis; pooled results suggested MBIs effectively improved scores on the Paced Auditory Serial Addition Test (PASAT)-2 (SMD=0.38; 95% CI 0.06-0.71; I2 63%; p=0.02), whereas improvements were of borderline significance on the PASAT-3 (SMD=0.32; 95% CI -0.01-0.64; I2 65%; p=0.06), and, although trending to positive, were statistically insignificant on the Perceived Deficits Questionnaire (SMD=0.34; 95 CI -0.05-0.74; I2 0%; p=0.09) and Symbol Digits Modality Test (SMD=0.25; 95% CI -0.15-0.66; I2 0%; p=0.21).

Conclusion

Preliminary findings in meta-analysis are inconsistent but suggest potential benefits from MBI training on cognitive functioning in PwMS. High quality RCTs are necessary to test more definitively the impact of MBIs on cognitive functioning in PwMS.

Systematic review registration

PROSPERO, identifier CRD42021286429.

Towards new perspectives: A scoping review and meta-synthesis to redefine brain health for multiple sclerosis

BACKGROUND AND PURPOSE

Research promoting the health of the brain has increased exponentially over the last decade. The importance of 'brain health' for multiple sclerosis (MS), as one example, is a high priority. However, as research into the concept increases, so does varied use of the term.

METHODS

A scoping review, guided by the methodological framework of the Joanna Briggs Institute, was conducted to collate the evidence relating to brain health for MS. A comprehensive literature search incorporated six search strategies to retrieve both scientific and grey literature sources. All evidence sources were qualitatively charted and synthesized (meta-synthesis) according to their definition of brain health used, outcome measures and brain-healthy lifestyle elements.

RESULTS

Seventy evidence sources (34 peer reviewed, 36 grey literature) were eligible for inclusion. Of these, just over half (n = 40, 57%) provided a definition of brain health. The most common definition alluded to the biomedical model of neurological reserve (n = 22, 55%), a self-remodelling theory described to retain optimal brain function. Twenty-nine outcome measures of brain health were identified, the most frequent being magnetic resonance imaging metrics (n = 25, 83%). Physical activity was the most prevalent brain-healthy lifestyle element (n = 44), followed by avoidance of smoking (n = 26) and diet (n = 24).

CONCLUSIONS

Brain health should be considered a primary target for optimal disease and lifestyle management across the MS disease course. A working definition reflecting a shift from a medical lens towards broader biopsychosocial contexts that may influence brain health for people living with MS is proposed.

Systematic review of cognitive reserve in multiple sclerosis: Accounting for physical disability, fatigue, depression, and anxiety

BACKGROUND

Cognitive reserve (CR) describes an individual's ability to adapt cognitive processes in response to brain atrophy, and has been reported to explain some of the discrepancy between brain atrophy and cognitive functioning outcomes in multiple sclerosis (MS). CR in MS is typically investigated by assessing an individual's pre- and/or post-diagnosis enrichment, which includes premorbid intellectual abilities, educational level, occupational attainment, and engagement in cognitively enriching leisure activities. Common MS symptoms (e.g., physical disability, fatigue, depression, anxiety) may impact an individual's ability to engage in various CR-enhancing activities post-diagnosis. It is unknown to what extent these MS symptoms have been taken into account in MS research on CR. As such, we identified whether studies assessed CR using measures of premorbid or continuous (including post-diagnosis) enrichment. For studies investigating continuous enrichment, we identified whether studies accounted for MS-impact, which MS symptoms were accounted for, and how, and whether studies acknowledged MS symptoms as potential CR-confounds.

METHODS

Three electronic databases (PsycINFO, PubMed, Scopus) were searched. Eligible studies investigated CR proxies (e.g., estimated premorbid intellectual abilities, vocabulary knowledge, educational level, occupational attainment, cognitively enriching leisure activities, or a combination thereof) in relation to cognitive, brain atrophy or connectivity, or daily functioning outcomes in adult participants with MS. We extracted data on methods and measures used, including any MS symptoms taken into account. Objectives were addressed using frequency analyses and narrative synthesis.

RESULTS

115 studies were included in this review. 47.8% of all studies investigated continuous enrichment. Approximately half of the studies investigating continuous enrichment accounted for potential MS-impact in their analyses, with only 31.0% clearly identifying that they treated MS symptoms as potential confounds for CR-enhancement. A narrative synthesis of studies which investigated CR with and without controlling statistically for MS-impact indicated that accounting for MS symptoms may impact findings concerning the protective nature of CR.

CONCLUSION

Fewer than half of the studies investigating CR proxies in MS involved continuous enrichment. Just over half of these studies accounted for potential MS-impact in their analyses. To achieve a more complete and accurate understanding of CR in MS, future research should investigate both pre-MS and continuous enrichment. In doing so, MS symptoms and their potential impact should be considered. Establishing greater consistency and rigour across CR research in MS will be crucial to produce an evidence base for the development of interventions aimed at improving quality of care and life for pwMS.

Cognitive enrichment and education quality moderate cognitive dysfunction in black and white adults with multiple sclerosis

OBJECTIVE

To examine the extent to which three sociobehavioral proxies of cognitive reserve-years of education, education quality, and cognitive enrichment-differ in their prediction of cognitive performance among Black and White people with MS (PwMS).

METHODS

82 PwMS (Black n = 41, White n = 41) underwent a neurological examination and a neuropsychological evaluation that included tests of word recognition (Wechsler Test of Adult Reading) as well as measures of verbal memory, visuospatial memory, and processing speed (the Brief International Cognitive Assessment for MS; BICAMS). Participants rated their lifetime engagement in various cognitively-enriching activities (Cognitive Reserve Scale).

RESULTS

For the full sample, education quality and cognitive enrichment were more strongly associated with cognitive performance than were years of education. Cognitive enrichment was not associated with cognitive performance among participants with high education quality. In contrast, among participants with low education quality, cognitive enrichment was strongly associated with cognitive performance, suggesting that high engagement in cognitively-enriching activities provided similar protection to high education quality. Furthermore, among Black participants, cognitive enrichment and educational quality moderated the relationship between disability level and cognitive performance. In contrast, among White participants, cognitive enrichment did not provide additional protection beyond the buffering effect of education quality.

CONCLUSIONS

PwMS can successfully build reserve through multiple routes, including formal education or informal cognitive enrichment. Treatment for MS should incorporate cognitively-enriching activities to build resilience against cognitive decline, particularly for members of marginalized racial/ethnic groups, who are at greatest risk for poor health outcomes, and for whom years of education may not best reflect education quality.

Prevalence, Influencing Factors, and Clinical Characteristics of Cognitive Impairment in Elderly Patients With Schizophrenia

AIMS

The purpose of this study was to investigate the prevalence, influencing factors, and clinical characteristics of cognitive impairment in elderly patients with chronic schizophrenia.

MATERIALS AND METHODS

A total of 264 elderly patients with chronic schizophrenia and 156 normal controls were enrolled in the current study. The Mini-mental State Examination (MMSE) was used to assess their overall cognitive function, the Positive And Negative Syndrome Scale (PANSS) was used to assess their psychotic symptoms, the Geriatric Depression Scale (GDS) was used to assess their depressive symptoms, while Activity of Daily Living Scale (ADL) was used to assess their daily living ability.

RESULTS

The prevalence of cognitive impairment was 77.7% (205/264) in elderly patients with chronic schizophrenia, which was much higher than that [16.7% (26/156)] in normal controls. By using stepwise binary regression analysis, we found that hobbies (p < 0.001, OR = 0.224, 95% CI: 0.114-0.441) might be a protective factor for cognitive impairment, and this relationship remained statistically significant after adjusting for total scores of GDS, ADL and PANSS (model ^b ) (p = 0.016, OR = 0.406, 95% CI: 0.195-0.847). Compared with individuals without cognitive impairment, individuals with cognitive impairment tend to have more depression and psychiatric symptoms as well as worse activities of daily living (p < 0.05). Through linear regression analysis of the mediating model, we found that hobbies may improve cognitive function by improving psychiatric symptoms, and play a partial mediating role (B = -4.789, p < 0.001).

CONCLUSION

Cognitive impairment is a very prominent problem in elderly patients with chronic schizophrenia. Elderly schizophrenia patients with cognitive impairment tended to have more depressive mood, more psychotic symptoms and worse activities of daily living. Hobbies will help prevent cognitive impairment in elderly patients with schizophrenia and may improve their cognitive function by influencing psychiatric symptoms. Therefore, we should encourage elderly patients with chronic schizophrenia to develop their own hobbies. However, the above conclusion still need to be further verified, as we cannot exclude the effects of age and education.

Cultural engagement and incidence of cognitive impairment: A six-year longitudinal follow-up of the Japan Gerontological Evaluation Study (JAGES)

Background

Active engagement in intellectually enriching activities reportedly lowers the risk of cognitive decline; however, few studies have examined this association, including engagement in traditional cultural activities. This study aimed to elucidate the types of cultural engagement associated with lower risk of cognitive impairment.

Methods

We examined the association between cultural engagement and cognitive impairment using Cox proportional hazards models in a cohort of 44,985 participants (20,772 males and 24,213 females) aged 65 years or older of the Japan Gerontological Evaluation Study from 2010 to 2016. Intellectual activities (eg, reading books, magazines, and/or newspapers), creative activities (eg, crafts and painting), and traditional cultural activities (eg, poetry composition [haiku], calligraphy, and tea ceremony/flower arrangement) were included among cultural engagement activities.

Results

Over a follow-up period of 6 years, incident cognitive disability was observed in 4,198 respondents (9.3%). After adjusting for potential confounders, such as depression and social support, intellectual activities were protectively associated with the risk of cognitive impairment (hazard ratio [HR] for those who read and stated that reading was their hobby, 0.75; 95% confidence interval [CI] 0.66–0.85 and HR for those who read but did not consider reading a hobby, 0.72; 95% CI, 0.65–0.80). Engagement in creative activities was also significantly correlated with lower risk of cognitive impairment (crafts: HR 0.71; 95% CI, 0.62–0.81 and painting: HR 0.80; 95% CI, 0.66–0.96). The association between traditional cultural activities and the risk of cognitive impairment was not statistically significant.

Conclusions

Engagement in intellectual and creative activities may be associated with reduced risk of dementia.

Association of lifespan cognitive reserve indicator with the risk of mild cognitive impairment and its progression to dementia

INTRODUCTION

The association of lifespan cognitive reserve (CR) with mild cognitive impairment (MCI) remains controversial. We aimed to examine the association of lifespan CR indicator with the risk of MCI and its progression to dementia, taking brain pathologies into account.

METHODS

In a community-based cohort study (mean age, 79 years) with annual follow-up (median, 5.16 years; maximum, 20 years), a cognitively intact group (n = 1182) and an MCI group (n = 420) were identified at baseline. During the follow-up, 611 participants died and underwent autopsies. CR indicator encompassing education, early life to late-life cognitive and social activities were obtained and tertiled.

RESULTS

The multi-adjusted hazard ratio (HR) of MCI was 0.72 (95% confidence interval [CI] 0.58 to 0.90) in the cognitively intact group, and the HR of dementia was 0.66 (95% CI 0.45 to 0.97) in the MCI group for participants with the highest CR indicator (reference: the lowest CR indicator). Among MCI participants with brain pathologies, dementia incidence was about 50% lower in people with the highest CR indicator than the lowest CR indicator.

DISCUSSION

High lifespan CR indicator reduces risk of MCI, and delays its progression to dementia.

Early putamen hypertrophy and ongoing hippocampus atrophy predict cognitive performance in the first ten years of relapsing-remitting multiple sclerosis

BACKGROUND

The first years of relapsing-remitting multiple sclerosis (RRMS) constitute the most vulnerable phase for the progression of cognitive impairment (CImp), due to a gradual decrease of compensatory mechanisms. In the first 10 years of RRMS, the temporal volumetric changes of deep gray matter structures must be clarified, since they could constitute reliable cognitive biomarkers for diagnostic, prognostic, and therapeutic purposes.

METHODS

Forty-five cognitively asymptomatic patients with RRMS lasting ≤ 10 years, and with a brain MRI performed in a year from the neuropsychological evaluation (Te-MRI), were included. They performed the Brief International Cognitive Assessment battery for MS. Thirty-one brain MRIs performed in the year of diagnosis (Td-MRI) and 13 brain MRIs of age- and sex-matched healthy controls (HCs) were also included in the study. The relationships between clinical features, cognitive performances, and Te- and Td-MRI volumes were statistically analyzed.

RESULTS

Cognitively preserved (CP) patients had significantly increased Td-L-putamen (P = 0.035) and Td-R-putamen volume (P = 0.027) with respect to cognitively impaired (CI) ones. CI patients had significantly reduced Te-L-hippocampus (P = 0.019) and Te-R-hippocampus volume (P = 0.042) compared, respectively, with Td-L-hippocampus and Td-R-hippocampus volume. Td-L-putamen volume (P = 0.011) and Te-L-hippocampus volume (P = 0.023) were independent predictors of the Symbol Digit Modalities Test score in all patients (r2 = 0.31, F = 6.175, P = 0.001).

CONCLUSION

In the first years of RRMS, putamen hypertrophy and hippocampus atrophy could represent promising indices of cognitive performance and reserve, and become potentially useful tools for diagnostic, prognostic, and therapeutic purposes.

Cognitive Impairment and Brain Reorganization in MS: Underlying Mechanisms and the Role of Neurorehabilitation

Multiple sclerosis (MS) is a chronic, immune-mediated, inflammatory, and degenerative disease of the central nervous system (CNS) that affects both white and gray matter. Various mechanisms throughout its course, mainly regarding gray matter lesions and brain atrophy, result in cognitive network dysfunction and can cause clinically significant cognitive impairment in roughly half the persons living with MS. Altered cognition is responsible for many negative aspects of patients' lives, independently of physical disability, such as higher unemployment and divorce rates, reduced social activities, and an overall decrease in quality of life. Despite its devastating impact it is not included in clinical ratings and decision making in the way it should be. It is interesting that only half the persons with MS exhibit cognitive dysfunction, as this implies that the other half remain cognitively intact. It appears that a dynamic balance between brain destruction and brain reorganization is taking place. This balance acts in favor of keeping brain systems functioning effectively, but this is not so in all cases, and the effect does not last forever. When these systems collapse, functional brain reorganization is not effective anymore, and clinically apparent impairments are evident. It is therefore important to reveal which factors could make provision for the subpopulation of patients in whom cognitive impairment occurs. Even if we manage to detect this subpopulation earlier, effective pharmaceutical treatments will still be lacking. Nevertheless, recent evidence shows that cognitive rehabilitation and neuromodulation, using non-invasive techniques such as transcranial magnetic or direct current stimulation, could be effective in cognitively impaired patients with MS. In this Mini Review, we discuss the mechanisms underlying cognitive impairment in MS. We also focus on mechanisms of reorganization of cognitive networks, which occur throughout the disease course. Finally, we review theoretical and practical issues of neurorehabilitation and neuromodulation for cognition in MS as well as factors that influence them and prevent them from being widely applied in clinical settings.

Association of Lifespan Cognitive Reserve Indicator With Dementia Risk in the Presence of Brain Pathologies

IMPORTANCE

Evidence on the association of lifespan cognitive reserve (CR) with dementia is limited, and the strength of this association in the presence of brain pathologies is unknown.

OBJECTIVE

To examine the association of lifespan CR with dementia risk, taking brain pathologies into account.

DESIGN, SETTING, AND PARTICIPANTS

This study used data from 2022 participants in the Rush Memory and Aging Project, an ongoing community-based cohort study with annual follow-up from 1997 to 2018 (mean follow-up, 6 years; maximum follow-up, 20 years). After excluding 420 individuals who had prevalent dementia, missing data on CR, or dropped out, 1602 dementia-free adults were identified at baseline and evaluated to detect incident dementia. During follow-up, 611 died and underwent autopsies. Data were analyzed from May to September 2018.

EXPOSURES

Information on CR factors (education; early-life, midlife, and late-life cognitive activities; and social activities in late life) was obtained at baseline. Based on these factors, lifespan CR scores were captured using a latent variable from a structural equation model and was divided into tertiles (lowest, middle, and highest).

MAIN OUTCOMES AND MEASURES

Dementia was diagnosed following international criteria. Neuropathologic evaluations for Alzheimer disease and other brain pathologies were performed in autopsied participants. The association of lifespan CR with dementia or brain pathologies was estimated using Cox regression models or logistic regression.

RESULTS

Of the 1602 included participants, 1216 (75.9%) were women, and the mean (SD) age was 79.6 (7.5) years. During follow-up, 386 participants developed dementia (24.1%), including 357 participants with Alzheimer disease-related dementia (22.3%). The multiadjusted hazards ratios (HRs) of dementia were 0.77 (95% CI, 0.59-0.99) for participants in the middle CR score tertile and 0.61 (95% CI, 0.47-0.81) for those in the highest CR score tertile compared with those in the lowest CR score tertile. In autopsied participants, CR was not associated with most brain pathologies, and the association of CR with dementia remained significant after additional adjustment for brain pathologies (HR, 0.60; 95% CI, 0.42-0.86). The highest CR score tertile was associated with a reduction in dementia risk, even among participants with high Alzheimer disease pathology (HR, 0.57; 95% CI, 0.37-0.87) and any gross infarcts (HR, 0.34; 95% CI, 0.18-0.62).

CONCLUSIONS AND RELEVANCE

High lifespan CR is associated with a reduction in dementia risk, even in the presence of high brain pathologies. Our findings highlight the importance of lifespan CR accumulation in dementia prevention.

Altered hippocampal GABA and glutamate levels and uncoupling from functional connectivity in multiple sclerosis

There is growing evidence for dysfunctional glutamatergic excitation and/or gamma-aminobutyric acid (GABA)ergic inhibition in patients with multiple sclerosis (MS). Cognitive impairment may occur during the early stages of MS and hippocampal abnormalities have been suggested as biomarkers. However, researchers have not clearly determined whether changes in hippocampal GABA and glutamate (Glu) levels are associated with cognitive impairment and aberrant neural activity in patients with MS. We used magnetic resonance spectroscopy to measure GABA+ and Glu levels in the left hippocampal region of 29 patients with relapsing-remitting MS and 29 healthy controls (HCs). Resting-state functional connectivity (FC) with the hippocampus was also examined. Compared to HCs, patients exhibited significantly lower GABA+ and Glu levels, which were associated with verbal and visuospatial memory deficits, respectively. Patients also showed decreased FC strengths between the hippocampus and several cortical regions, which are located within the default mode network. Moreover, hippocampal GABA+ levels and Glu/GABA+ ratios correlated with the FC strengths in HCs but not in patients with MS. This study describes a novel method for investigating the complex relationships among excitatory/inhibitory neurotransmitters, brain connectivity and cognition in health and disease. Strategies that modulate Glu and GABA neurotransmission may represent new therapeutic treatments for patients with MS.

The Association of Cognitive Reserve in Chronic-Phase Functional and Neuropsychological Outcomes Following Traumatic Brain Injury

OBJECTIVE

Examine the association of cognitive reserve (CR) factors (estimated premorbid intelligence quotient [IQ], years of education, and occupational attainment) and traumatic brain injury (TBI) severity with functional and neuropsychological outcomes 1 to 5 years following TBI.

PARTICIPANTS

Patients with mild (N = 58), moderate (N = 25), or severe (N = 17) TBI.

MAIN MEASURES

Cognitive reserve factors (estimated premorbid IQ, years of education, and occupational attainment); neuropsychological test battery; Glasgow Outcome Scale-Extended; Short Form-36 Health Survey.

ANALYSES

Spearman-Brown correlations, linear regression models, and analyses of covariance were used to analyze the relation between CR factors and outcome measures.

RESULTS

Analyses revealed significant relations between estimated premorbid IQ and neuropsychological outcomes (P < .004): California Verbal Learning Test, Wechsler Adult Intelligence Scale-Fourth Edition working memory, Booklet Category Test, Trail Making Test B, and Grooved Pegboard Test. There was also a significant correlation between estimated premorbid IQ and Wechsler Adult Intelligence Scale-Fourth Edition processing speed. Years of education had significant relations with California Verbal Learning Test and Wechsler Adult Intelligence Scale-Fourth Edition working memory and processing speed scores. There were significant differences between TBI severity groups and performance on the Trail Making Test A, Grooved Pegboard Test, and Finger Tapping Test.

CONCLUSIONS

Cognitive reserve factors may be associated with outcomes following TBI. Additional alternatives to TBI severity are needed to help guide rehabilitative planning postinjury.

Widespread Volumetric Reductions in Schizophrenia and Schizoaffective Patients Displaying Compromised Cognitive Abilities

OBJECTIVE

Progress toward understanding brain mechanisms in psychosis is hampered by failures to account for within-group heterogeneity that exists across neuropsychological domains. We recently identified distinct cognitive subgroups that might assist in identifying more biologically meaningful subtypes of psychosis. In the present study, we examined whether underlying structural brain abnormalities differentiate these cognitively derived subgroups.

METHOD

1.5T T1 weighted structural scans were acquired for 168 healthy controls and 220 patients with schizophrenia/schizoaffective disorder. Based on previous work, 47 patients were categorized as being cognitively compromised (impaired premorbid and current IQ), 100 as cognitively deteriorated (normal premorbid IQ, impaired current IQ), and 73 as putatively cognitively preserved (premorbid and current IQ within 1 SD of controls). Global, subcortical and cortical volume, thickness, and surface area measures were compared among groups.

RESULTS

Whole cortex, subcortical, and regional volume and thickness reductions were evident in all subgroups compared to controls, with the largest effect sizes in the compromised group. This subgroup also showed abnormalities in regions not seen in the other patient groups, including smaller left superior and middle frontal areas, left anterior and inferior temporal areas and right lateral medial and inferior frontal, occipital lobe and superior temporal areas.

CONCLUSIONS

This pattern of more prominent brain structural abnormalities in the group with the most marked cognitive impairments-both currently and putatively prior to illness onset, is consistent with the concept of schizophrenia as a progressive neurodevelopmental disorder. In this group, neurodevelopmental and neurodegenerative factors may be important for cognitive function.

Cognitive reserve, cognition, and regional brain damage in MS: A 2 -year longitudinal study

BACKGROUND

According to the cognitive reserve (CR) theory, enriching experiences protect against cognitive decline.

OBJECTIVES

To investigate the dynamic interaction between CR and global/regional measures of brain white matter (WM) and gray matter (GM) damage and their effect on cognitive performance in multiple sclerosis (MS).

METHODS

Baseline and 2 -year three-dimensional (3D) T1-weighted scans were obtained from 54 MS patients and 20 healthy controls. Patients' cognitive functions were tested and a cognitive reserve index (CRI) was calculated. Baseline regional atrophy and longitudinal volume changes were investigated using voxel-wise methods. Structural damage and CRI effects on cognitive performance were explored with linear models.

RESULTS

At baseline, MS patients showed atrophy of the deep GM nuclei, GM/WM frontal-temporal-parietal-occipital regions, and left cerebellum. Controlling for atrophy, higher CRI explained significant portions of variance in verbal memory and verbal fluency (∆ R² = 0.07-0.16; p < 0.03). The interaction between thalamic volume and CRI was significant (∆ R² = 0.05; p = 0.03). Longitudinal changes in memory and attention performance were associated with local/global variations of GM/WM and T2 lesions. CRI had no effect on longitudinal cognitive changes.

CONCLUSION

In MS, CR may have a protective role in preserving cognitive functions, moderating the effect of structural damage on cognitive performance. This protective role may diminish with disease progression.

Cognition and fatigue in patients with relapsing multiple sclerosis treated by subcutaneous interferon β-1a: an observational study SKORE

BACKGROUND

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system, which often causes progressive neurological disability. In addition to motor and sensory dysfunction, cognitive decline and fatigue are frequent manifestations of the disease. Fatigue is probably the most common symptom, with up to 90% of MS individuals reporting fatigue at some point. Cognitive impairment affects about 50% of patients and may be present at all MS stages. The aim of this observational study was to evaluate changes in cognition, fatigue, and disability status in 300 relapsing-remitting MS (RRMS) patients, treated with subcutaneous (sc) interferon (IFN) β-1a over 2 years.

METHODS

The study was designed as an observational, multicentre, prospective, single-arm, phase IV study carried out in 13 MS centres in the Czech Republic. Cognition status was assessed using the Paced Auditory Serial Addition Task (PASAT), fatigue using the Fatigue Descriptive Scale (FDS), and disability using the Expanded Disability Status Scale (EDSS), at baseline, and after 6, 12 and 24 months. The percentage of patients with changed versus stable cognition, fatigue status and disability was calculated at each time point and the changes in these scores were evaluated.

RESULTS

The proportion of patients with cognitive improvement was higher compared with those with a stable or decreased PASAT scores at all time points, and the average cognitive performance improved during the follow-up period. Also the proportion of patients with stable or improved fatigue and EDSS scores was higher compared with those in which FDS or EDSS scores declined, this was found at all time points of the analysed sample. However, the direct effect of IFN β-1a on cognition and fatigue cannot be concluded from this study.

CONCLUSIONS

The results of this observational study have demonstrated a stable or improved cognitive performance, fatigue status, and disability level in the majority of RRMS patients treated with sc IFN β-1a over a two-year follow-up period, in a real life setting, in the Czech Republic.

Genome research in pre-dementia stages of Alzheimer's disease

Genetic characterization of individuals at risk of Alzheimer's disease (AD), i.e. people having amyloid deposits in the brain without symptoms, people suffering from subjective cognitive decline (SCD) or mild cognitive impairment (MCI), has spurred the interests of researchers. However, their pre-dementia genetic profile remains mostly unexplored. In this study, we reviewed the loci related to phenotypes of AD, MCI and SCD from literature and performed the first meta-analyses evaluating the role of apolipoprotein E (APOE) in the risk of conversion from a healthy status to MCI and SCD. For AD dementia risk, an increased number of loci have been identified; to date, 28 genes have been associated with Late Onset AD. In MCI syndrome, APOE is confirmed as a pheno-conversion factor leading from MCI to AD, and clusterin is a promising candidate. Additionally, our meta-analyses revealed APOE as genetic risk factor to convert from a healthy status to MCI [OR = 1.849 (1.587-2.153); P = 2.80  × 10-15] and to a lesser extent from healthy status to SCD [OR = 1.151 (1.015-1.304); P = 0.028]. Thus, we believe that genetic studies in longitudinal SCD and MCI series may provide new therapeutic targets and improve the existing knowledge of AD. This type of studies must be completed on healthy subjects to better understand the natural disease resistance to brain insults and neurodegeneration.

Reading, writing, and reserve: Literacy activities are linked to hippocampal volume and memory in multiple sclerosis

BACKGROUND

Engagement in cognitive leisure activities during early adulthood has been linked to preserved memory and larger hippocampal volume in persons with multiple sclerosis (MS).

OBJECTIVE

To investigate which specific types of cognitive leisure activities contribute to hippocampal volume and memory.

METHODS

We investigated links between three types of cognitive activities (Reading-Writing, Art-Music, Games-Hobbies) and (a) hippocampal volume within independent samples of Italian (n=187) and American (n=55) MS patients and (b) memory in subsamples of Italian (n=97) and American (n=53) patients.

RESULTS

Reading-Writing was the only predictor of hippocampal volume (rp=.204, p=.002), and the best predictor of memory (rp=.288, p=.001).

CONCLUSIONS

Findings inform the development of targeted evidence-based enrichment programs aiming to bolster reserve against memory decline.

Exercise Training and Cognitive Rehabilitation

The current review develops a rationale and framework for examining the independent and combined effects of exercise training and cognitive rehabilitation on walking and cognitive functions in persons with multiple sclerosis (MS). To do so, we first review evidence for improvements in walking and cognitive outcomes with exercise training and cognitive rehabilitation in MS. We then review evidence regarding cognitive–motor coupling and possible cross-modality transfer effects of exercise training and cognitive rehabilitation. We lastly present a macro-level framework for considering mechanisms that might explain improvements in walking and cognitive dysfunction with exercise and cognitive rehabilitation individually and combined in MS. We conclude that researchers should consider examining the effects of exercise training and cognitive rehabilitation on walking, cognition, and cognitive–motor interactions in MS and the possible physiological and central mechanisms for improving these functions.