Increased functional connectivity within memory networks following memory rehabilitation in multiple sclerosis

Rationale and methodology for examining the combination of aerobic exercise and cognitive rehabilitation on new learning and memory in persons with multiple sclerosis and mobility disability: Protocol for a randomized controlled trial

BACKGROUND

This paper describes the protocol for a Phase I/II, parallel-group, single-blind randomized controlled trial (RCT). The RCT investigates the combined effects of 12-weeks of aerobic exercise training (AET) integrated with virtual reality (VR) and cognitive rehabilitation (CR) on new learning and memory in 78 persons with multiple sclerosis (MS) who have mobility disability and objective impairments in learning and memory.

METHODS

Participants will undergo baseline assessments consisting of neuropsychological testing, neuroimaging, self-report questionnaires, and cardiorespiratory fitness. Participants will then be randomized into one of two conditions using concealed allocation: aerobic cycling exercise that incorporates VR combined with CR or stretching and toning (i.e., active control; S/T) combined with CR. Participants will be masked regarding the intent of the conditions. After 7-weeks of exercise alone, the 5-week Kessler Foundation modified Story Memory Technique (KF-mSMT®) will be integrated into the training. After the 12-week training period, participants will complete the same measures as at baseline administered by treatment-blinded assessors. Primary study outcomes include new learning and memory (NLM) measured by a small battery of neuropsychological assessments that assess list learning (California Verbal Learning Test-II), prose memory (Memory Assessment Scale), visuospatial memory (Brief Visuospatial Memory Test-Revised), and everyday memory (Ecological Memory Simulations). Secondary study outcomes include neuroimaging outcomes of hippocampal structure, function, and connectivity.

CONCLUSION

If successful, this trial will provide the first Class I evidence supporting the unique combination of aerobic cycling exercise with VR and CR for treating MS-related learning and memory impairments in persons with mobility disability.

Advanced neuroimaging techniques to explore the effects of motor and cognitive rehabilitation in multiple sclerosis

INTRODUCTION

Progress in magnetic resonance imaging (MRI) technology and analyses is improving our comprehension of multiple sclerosis (MS) pathophysiology. These advancements, which enable the evaluation of atrophy, microstructural tissue abnormalities, and functional plasticity, are broadening our insights into the effectiveness and working mechanisms of motor and cognitive rehabilitative treatments.

AREAS COVERED

This narrative review with selected studies discusses findings derived from the application of advanced MRI techniques to evaluate structural and functional neuroplasticity modifications underlying the effects of motor and cognitive rehabilitative treatments in people with MS (PwMS). Current applications as outcome measure in longitudinal trials and observational studies, their interpretation and possible pitfalls and limitations in their use are covered. Finally, we examine how the use of these techniques could evolve in the future to improve monitoring of motor and cognitive rehabilitative treatments.

EXPERT COMMENTARY

Despite substantial variability in study design and participant characteristics in rehabilitative studies for PwMS, improvements in motor and cognitive functions accompanied by structural and functional brain modifications induced by rehabilitation can be observed. However, significant enhancements to refine rehabilitation strategies are needed. Future studies in this field should strive to implement standardized methodologies regarding MRI acquisition and processing, possibly integrating multimodal measures. This will help identifying relevant markers of treatment response in PwMS, thus improving the use of rehabilitative interventions at individual level. The combination of motor and cognitive strategies, longer periods of treatment, as well as adequate follow-up assessments will contribute to enhance the quality of evidence in support of their routine use.

Is implicit memory associated with the hippocampus?

According to the traditional memory-systems view, the hippocampus is critical during explicit (conscious) long-term memory, whereas other brain regions support implicit (nonconscious) memory. In the last two decades, some fMRI studies have reported hippocampal activity during implicit memory tasks. The aim of the present discussion paper was to identify whether any implicit memory fMRI studies have provided convincing evidence that the hippocampus is associated with nonconscious processes without being confounded by conscious processes. Experimental protocol and analysis parameters included the stimulus type(s), task(s), measures of subjective awareness, explicit memory accuracy, the relevant fMRI contrast(s) or analysis, and confound(s). A systematic review was conducted to identify implicit memory studies that reported fMRI activity in the hippocampus. After applying exclusion criteria, 13 articles remained for analysis. We found that there were no implicit memory fMRI studies where subjective awareness was absent, explicit memory performance was at chance, and there were no confounds that could have driven the observed hippocampal activity. The confounds included explicit memory (including false memory), imbalanced attentional states between conditions (yielding activation of the default-mode network), imbalanced stimuli between conditions, and differential novelty. As such, not a single fMRI study provided convincing evidence that implicit memory was associated with the hippocampus. Neuropsychological evidence was also considered, and implicit memory deficits were caused by factors known to disrupt brain regions beyond the hippocampus, such that the behavioral effects could not be attributed to this region. The present results indicate that implicit memory is not associated with the hippocampus.

The effects of cognitive rehabilitation combined with aerobic exercise or stretching-and-toning on new learning and memory in persons with moderate-to-severe TBI: Protocol for a randomized controlled trial

This paper describes the protocol for a Phase I/II, parallel-group, blinded randomized controlled trial that compares the effects of 12-weeks of combined learning and memory rehabilitation with either aerobic cycling exercise or stretching on cognitive, neuroimaging, and everyday life outcomes in 60 persons with moderate-to-severe traumatic brain injury (TBI) who demonstrate impairments in new learning. Briefly, participants will undergo baseline testing consisting of neuropsychological testing, neuroimaging, daily life measures, and cardiorespiratory fitness. Following baseline testing, participants will be randomized to one of 2 conditions (30 participants per condition) using concealed allocation. Participants will be masked as to the intent of the conditions. The conditions will both involve supervised administration of an enhanced, 8-week version of the Kessler Foundation modified Story Memory Technique, embedded within either 12-weeks of supervised and progressive aerobic cycling exercise training (experimental condition) or 12-weeks of supervised stretching-and-toning (active control condition). Following the 12-week intervention period, participants will complete the same measures as at baseline that will be administered by treatment-blinded assessors. The primary study outcome is new learning and memory impairment based on California Verbal Learning Test (CVLT)-III slope, the secondary outcomes include neuroimaging measures of hippocampal volume, activation, and connectivity, and the tertiary outcomes involve measures of daily living along with other cognitive outcomes. We further will collect baseline sociodemographic data for examining predictors of response heterogeneity. If successful, this trial will provide the first Class I evidence supporting combined memory rehabilitation and aerobic cycling exercise training for treating TBI-related new learning and memory impairment.

Graph-Based Analysis of Brain Connectivity in Multiple Sclerosis Using Functional MRI: A Systematic Review

(1) Background: Multiple sclerosis (MS) is an immune system disease in which myelin in the nervous system is affected. This abnormal immune system mechanism causes physical disabilities and cognitive impairment. Functional magnetic resonance imaging (fMRI) is a common neuroimaging technique used in studying MS. Computational methods have recently been applied for disease detection, notably graph theory, which helps researchers understand the entire brain network and functional connectivity. (2) Methods: Relevant databases were searched to identify articles published since 2000 that applied graph theory to study functional brain connectivity in patients with MS based on fMRI. (3) Results: A total of 24 articles were included in the review. In recent years, the application of graph theory in the MS field received increased attention from computational scientists. The graph-theoretical approach was frequently combined with fMRI in studies of functional brain connectivity in MS. Lower EDSSs of MS stage were the criteria for most of the studies (4) Conclusions: This review provides insights into the role of graph theory as a computational method for studying functional brain connectivity in MS. Graph theory is useful in the detection and prediction of MS and can play a significant role in identifying cognitive impairment associated with MS.

Kessler Foundation Strategy-Based Training to Enhance Memory (KF-STEM™): Study protocol for a single site double-blind randomized, clinical trial in Multiple Sclerosis

New learning and memory impairments are common in Multiple Sclerosis (MS) and negatively impact everyday life, including occupational and social functioning. Despite the demand for learning and memory treatments, few cognitive rehabilitation protocols are supported by Class I research evidence, limiting the degree to which effective treatments may be utilized with persons with MS. The present double-blind, placebo controlled randomized clinical trial (RCT) examines the efficacy of an 8-session cognitive rehabilitation protocol encompassing training in the application of three strategies with the strongest empirical evidence (self-generation, spaced learning and retrieval practice) to treat impaired learning and memory in persons with MS, Kessler Foundation Strategy-based Training to Enhance Memory (KF-STEM™). A sample of 120 participants with clinically definite MS who have impairments in new learning and memory will be enrolled. Outcomes will be assessed via three mechanisms, an Assessment of Global Functioning, which examines everyday functioning and quality of life, a Neuropsychological Evaluation to examine objective cognitive performance, and functional Magnetic Resonance Imaging to examine the impact of treatment on patterns of cerebral activation. We will additionally evaluate the longer-term efficacy of KF-STEM™ on everyday functioning and neuropsychological assessment through a 6-month follow-up evaluation and evaluate the impact of booster sessions in maintaining the treatment effect over time. The methodologically rigorous design of the current study will provide Class I evidence for the KF-STEM™ treatment protocol for persons with MS.

Early remission in multiple sclerosis is linked to altered coherence of the Cerebellar Network

BACKGROUND

The development of permanent disability in multiple sclerosis (MS) is highly variable among patients, and the exact mechanisms that contribute to this disability remain unknown.

METHODS

Following the idea that the brain has intrinsic network organization, we investigated changes of functional networks in MS patients to identify possible links between network reorganization and remission from clinical episodes in MS. Eighteen relapsing-remitting MS patients (RRMS) in their first clinical manifestation underwent resting-state functional MRI and again during remission. We used ten template networks, identified from independent component analysis, to compare changes in network coherence for each patient compared to those of 44 healthy controls from the Human Connectome Project test-retest dataset (two-sample t-test of pre-post differences). Combining a binomial test with Monte Carlo procedures, we tested four models of how functional coherence might change between the first clinical episode and remission: a network can change its coherence (a) with itself ("one-with-self"), (b) with another network ("one-with-other"), or (c) with a set of other networks ("one-with-many"), or (d) multiple networks can change their coherence with respect to one common network ("many-with-one").

RESULTS

We found evidence supporting two of these hypotheses: coherence decreased between the Executive Control Network and several other networks ("one-with-many" hypothesis), and a set of networks altered their coherence with the Cerebellar Network ("many-with-one" hypothesis).

CONCLUSION

Given the unexpected commonality of the Cerebellar Network's altered coherence with other networks (a finding present in more than 70% of the patients, despite their clinical heterogeneity), we conclude that remission in MS may result from learning processes mediated by the Cerebellar Network.

Task- and resting-state fMRI studies in multiple sclerosis: From regions to systems and time-varying analysis. Current status and future perspective

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Functional MRI is able to detect adaptive and maladaptive abnormalities at different MS stages.

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Increased fMRI activity is a feature of early MS, while progressive exhaustion of adaptive mechanisms is detected later on in the disease.

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Collapse of long-range connections and impaired hub integration characterize MS network reorganization.

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Time-varying connectivity analysis provides useful and complementary pieces of information to static functional connectivity.

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New perspectives might be the use of multimodal MRI and artificial intelligence.

Multiple sclerosis (MS) is a neurological disorder affecting the central nervous system and features extensive functional brain changes that are poorly understood but relate strongly to clinical impairments. Functional magnetic resonance imaging (fMRI) is a non-invasive, powerful technique able to map activity of brain regions and to assess how such regions interact for an efficient brain network. FMRI has been widely applied to study functional brain changes in MS, allowing to investigate functional plasticity consequent to disease-related structural injury. The first studies in MS using active fMRI tasks mainly aimed to study such plastic changes by identifying abnormal activity in salient brain regions (or systems) involved by the task. In later studies the focus shifted towards resting state (RS) functional connectivity (FC) studies, which aimed to map large-scale functional networks of the brain and to establish how MS pathology impairs functional integration, eventually leading to the hypothesized network collapse as patients clinically progress. This review provides a summary of the main findings from studies using task-based and RS fMRI and illustrates how functional brain alterations relate to clinical disability and cognitive deficits in this condition. We also give an overview of longitudinal studies that used task-based and RS fMRI to monitor disease evolution and effects of motor and cognitive rehabilitation. In addition, we discuss the results of studies using newer technologies involving time-varying FC to investigate abnormal dynamism and flexibility of network configurations in MS. Finally, we show some preliminary results from two recent topics (i.e., multimodal MRI analysis and artificial intelligence) that are receiving increasing attention. Together, these functional studies could provide new (conceptual) insights into disease stage-specific mechanisms underlying progression in MS, with recommendations for future research.

Developing the Rationale for Including Virtual Reality in Cognitive Rehabilitation and Exercise Training Approaches for Managing Cognitive Dysfunction in MS

Cognitive impairment is a common and detrimental consequence of multiple sclerosis (MS) and current rehabilitation methods are insufficient. Cognitive rehabilitation (CR) and exercise training (ET) are the most promising behavioral approaches to mitigate cognitive deficits, but effects are small and do not effectively translate to improvements in everyday function. This article presents a conceptual framework supporting the use of virtual reality (VR) as an ideal, common adjuvant traditional CR and ET in MS. VR could strengthen the effects of CR and ET by increasing sensory input and promoting multisensory integration and processing during rehabilitation. For ET specifically, VR can also help incorporate components of CR into exercise sessions. In addition, VR can enhance the transfer of cognitive improvements to everyday functioning by providing a more ecologically valid training environment. There is a clear interest in adding VR to traditional rehabilitation techniques for neurological populations, a stronger body of evidence of this unique approach is needed in MS. Finally, to better understand how to best utilize VR in rehabilitation for cognitive deficits in MS, more systematic research is needed to better understand the mechanism(s) of action of VR with CR and ET.

Memory rehabilitation for people with multiple sclerosis

BACKGROUND

Problems with cognition, particularly memory, are common in people with multiple sclerosis (MS) and can affect their ability to complete daily activities and can negatively affect quality of life. Over the last few years, there has been considerable growth in the number of randomised controlled trials (RCTs) of memory rehabilitation in MS. To guide clinicians and researchers, this review provides an overview of the effectiveness of memory rehabilitation for people with MS.

OBJECTIVES

To determine whether people with MS who received memory rehabilitation compared to those who received no treatment, or an active control showed better immediate, intermediate, or longer-term outcomes in their: 1. memory functions, 2. other cognitive abilities, and 3. functional abilities, in terms of activities of daily living, mood, and quality of life.

SEARCH METHODS

We searched CENTRAL which includes Clinicaltrials.gov, World Health Organization (The Whoqol) International Clinical Trials Registry Portal, Embase and PubMed (MEDLINE), and the following electronic databases (6 September 2020): CINAHL, LILACS, the NIHR Clinical Research Network Portfolio database, The Allied and Complementary Medicine Database, PsycINFO, and CAB Abstracts.

SELECTION CRITERIA

We selected RCTs or quasi-RCTs of memory rehabilitation or cognitive rehabilitation for people with MS in which a memory rehabilitation treatment group was compared with a control group. Selection was conducted independently first and then confirmed through group discussion. We excluded studies that included participants whose memory deficits were the result of conditions other than MS, unless we could identify a subgroup of participants with MS with separate results.

DATA COLLECTION AND ANALYSIS

Eight review authors were involved in this update in terms of study selection, quality assessment, data extraction and manuscript review. We contacted investigators of primary studies for further information where required. We conducted data analysis and synthesis in accordance with Cochrane methods. We performed a 'best evidence' synthesis based on the methodological quality of the primary studies included. Outcomes were considered separately for 'immediate' (within the first month after completion of intervention), 'intermediate' (one to six months), and 'longer-term' (more than six months) time points.

MAIN RESULTS

We added 29 studies during this update, bringing the total to 44 studies, involving 2714 participants. The interventions involved various memory retraining techniques, such as computerised programmes and training on using internal and external memory aids. Control groups varied in format from assessment-only groups, discussion and games, non-specific cognitive retraining, and attention or visuospatial training. The risk of bias amongst the included studies was generally low, but we found eight studies to have high risk of bias related to certain aspects of their methodology. In this abstract, we are only reporting outcomes at the intermediate timepoint (i.e., between one and six months). We found a slight difference between groups for subjective memory (SMD 0.23, 95% CI 0.11 to 0.35; 11 studies; 1045 participants; high-quality evidence) and quality of life (SMD 0.30, 95% CI 0.02 to 0.58; 6 studies; 683 participants; high-quality evidence) favoring the memory rehabilitation group. There was a small difference between groups for verbal memory (SMD 0.25, 95% CI 0.11 to 0.40; 6 studies; 753 participants; low-quality evidence) and information processing (SMD 0.27, 95% CI 0.00 to 0.54; 8 studies; 933 participants; low-quality evidence), favoring the memory rehabilitation group.  We found little to no difference between groups for visual memory (SMD 0.20, 95% CI -0.11 to 0.50; 6 studies; 751 participants; moderate-quality evidence), working memory (SMD 0.16, 95% CI -0.09 to 0.40; 8 studies; 821 participants; moderate-quality evidence), or activities of daily living (SMD 0.06, 95% CI -0.36 to 0.24; 4 studies; 400 participants; high-quality evidence).  AUTHORS' CONCLUSIONS: There is evidence to support the effectiveness of memory rehabilitation on some outcomes assessed in this review at intermediate follow-up. The evidence suggests that memory rehabilitation results in between-group differences favoring the memory rehabilitation group at the intermediate time point for subjective memory, verbal memory, information processing, and quality of life outcomes, suggesting that memory rehabilitation is beneficial and meaningful to people with MS. There are differential effects of memory rehabilitation based on the quality of the trials, with studies of high risk of bias inflating (positive) outcomes. Further robust, large-scale, multi-centre RCTs, with better quality reporting, using ecologically valid outcome assessments (including health economic outcomes) assessed at longer-term time points are still needed to be certain about the effectiveness of memory rehabilitation in people with MS.

Cognitive recovery in people with relapsing/remitting multiple sclerosis: A randomized clinical trial on virtual reality-based neurorehabilitation

BACKGROUND

Multiple sclerosis (MS) can adversely affect several domains of cognitive function, including attention, information processing, memory and learning, executive functions and visuospatial skills. In recent years, technological innovations have proven effective in improving motor and cognitive impairment in neurological patients, including those affected by MS.

OBJECTIVE

The study aims to evaluate cognitive outcomes after rehabilitation training with the Virtual Reality rehabilitation system (VRRS) in patients suffering from MS.

METHODS

All patients were randomized into either the control group (CG: 15 patients) receiving conventional cognitive rehab or the experimental group (EG) using virtual reality (VR) (15 patients). Both groups underwent the same amount of cognitive training, 3 times a week for 8 weeks. They were submitted to neuropsychological assessment before (T0) and after the rehabilitation treatment (T1).

RESULTS

Our data showed that both conventional and VR cognitive rehabilitation approaches improved mood (p < 0.001) and visuospatial skills. However, only in the EG a significant improvement in specific cognitive domains (p < 0.001), including learning ability, short-term verbal memory, lexical access ability, as well as quality of life related to mental states, was found.

CONCLUSIONS

The present study demonstrated that VR can be a motivational and effective tool for cognitive recovery in MS patients.

Structural and Functional Connectivity Substrates of Cognitive Impairment in Multiple Sclerosis

Cognitive impairment (CI) occurs in 43 to 70% of multiple sclerosis (MS) patients at both early and later disease stages. Cognitive domains typically involved in MS include attention, information processing speed, memory, and executive control. The growing use of advanced magnetic resonance imaging (MRI) techniques is furthering our understanding on the altered structural connectivity (SC) and functional connectivity (FC) substrates of CI in MS. Regarding SC, different diffusion tensor imaging (DTI) measures (e.g., fractional anisotropy, diffusivities) along tractography-derived white matter (WM) tracts showed relevance toward CI. Novel diffusion MRI techniques, including diffusion kurtosis imaging, diffusion spectrum imaging, high angular resolution diffusion imaging, and neurite orientation dispersion and density imaging, showed more pathological specificity compared to the traditional DTI but require longer scan time and mathematical complexities for their interpretation. As for FC, task-based functional MRI (fMRI) has been traditionally used in MS to brain mapping the neural activity during various cognitive tasks. Analysis methods of resting fMRI (seed-based, independent component analysis, graph analysis) have been applied to uncover the functional substrates of CI in MS by revealing adaptive or maladaptive mechanisms of functional reorganization. The relevance for CI in MS of SC–FC relationships, reflecting common pathogenic mechanisms in WM and gray matter, has been recently explored by novel MRI analysis methods. This review summarizes recent advances on MRI techniques of SC and FC and their potential to provide a deeper understanding of the pathological substrates of CI in MS.

Neurological update: cognitive rehabilitation in multiple sclerosis

Cognitive impairment is a common and debilitating symptom in multiple sclerosis (MS). There is limited evidence that disease-modifying therapies are effective in treating cognitive dysfunction. Cognitive rehabilitation is a promising approach to treat cognitive dysfunction in MS, gaining empirical support over the last 10 years. The current review will provide a brief overview of cognitive rehabilitation in MS. Overall, there is evidence that cognitive rehabilitation programs (either restorative or compensatory) are efficacious in treating MS-related cognitive dysfunction. Clinicians should consider this low-cost, low-risk, yet effective treatment approach for their patients.

Enhanced frontoparietal connectivity in multiple sclerosis patients and healthy controls in response to an intensive computerized training focused on working memory

BACKGROUND

Working memory (WM) deficits are common in multiple sclerosis (MS) patients. Computerized cognitive training may enhance WM capabilities but its efficacy in MS patients has not been sufficiently explored.

METHODS

This study examines the effects of n-back training on cognitive performance and functional connectivity (FC) in 29 MS patients and 29 healthy controls (HC). Baseline (S1) performance on 2- and 3-back tasks and FC within the fronto-parietal network were assessed before randomly splitting the sample into four subgroups: trained MS (MSt, n = 15), trained HC (HCt, n = 14), untrained MS (MSu, n = 14), and untrained HC (HCu, n = 15). The trained subgroups underwent adaptive n-back training (60 min/day; 4 days) and n-back task performance and FC were reassessed in a second session (S2).

RESULTS

As revealed by mixed two-way ANOVAs, trained participants (MSt and HCt) exhibited a significant increase in the number of correct responses and significantly reduced reaction times in S2. These performance improvements were accompanied by an increase in FC in the fronto-parietal pathways and statistically significant correlations between both effects were found.

CONCLUSIONS

Computerised WM training results in behavioural and neuroplasticity positive effects that may be useful when trying to prevent or attenuate cognitive decline in MS patients.

Brain dysconnectivity relates to disability and cognitive impairment in multiple sclerosis

The pathophysiology of cognitive dysfunction in multiple sclerosis (MS) is still unclear. This magnetoencephalography (MEG) study investigates the impact of MS on brain resting-state functional connectivity (rsFC) and its relationship to disability and cognitive impairment. We investigated rsFC based on power envelope correlation within and between different frequency bands, in a large cohort of participants consisting of 99 MS patients and 47 healthy subjects. Correlations were investigated between rsFC and outcomes on disability, disease duration and 7 neuropsychological scores within each group, while stringently correcting for multiple comparisons and possible confounding factors. Specific dysconnections correlating with MS-induced physical disability and disease duration were found within the sensorimotor and language networks, respectively. Global network-level reductions in within- and cross-network rsFC were observed in the default-mode network. Healthy subjects and patients significantly differed in their scores on cognitive fatigue and verbal fluency. Healthy subjects and patients showed different correlation patterns between rsFC and cognitive fatigue or verbal fluency, both of which involved a shift in patients from the posterior default-mode network to the language network. Introducing electrophysiological rsFC in a regression model of verbal fluency and cognitive fatigue in MS patients significantly increased the explained variance compared to a regression limited to structural MRI markers (relative thalamic volume and lesion load). This MEG study demonstrates that MS induces distinct changes in the resting-state functional brain architecture that relate to disability, disease duration and specific cognitive functioning alterations. It highlights the potential value of electrophysiological intrinsic rsFC for monitoring the cognitive impairment in patients with MS.

EA, Busatto GF, Bottino CMC. Mnemonic strategy training modulates functional connectivity at rest in mild cognitive impairment: Results from a randomized controlled trial

INTRODUCTION

Mnemonic strategy training (MST) has been shown to improve cognitive performance and increase brain activation in those with mild cognitive impairment (MCI). However, little is known regarding the effects of MST on functional connectivity (FC) at rest. The aim of the present study was to investigate the MST focused on face-name associations effect on resting-state FC in those with MCI.

METHODS

Twenty-six amnestic MCI participants were randomized in MST (N = 14) and Education Program (active control; N = 12). Interventions occurred twice a week over two consecutive weeks (ie, four sessions). Resting-state functional magnetic resonance imaging was collected at pre- and post-intervention. Regions of interest (ROIs) were selected based on areas that previously showed task-related activation changes after MST. Changes were examined through ROI-to-ROI analysis and significant results were corrected for multiple comparisons.

RESULTS

At post-intervention, only the MST group showed increased FC, whereas the control group showed decreased or no change in FC. After MST, there was an increased FC between the left middle temporal gyrus and right orbitofrontal cortex. In addition, a time-by-group interaction indicated that the MST group showed greater increased FC between the right inferior frontal gyrus and left brain regions, such as fusiform gyrus, temporal pole, and orbitofrontal cortex relative to controls.

DISCUSSION

MST enhanced FC in regions that are functionally relevant for the training; however, not in all ROIs investigated. Our findings suggest that MST-induced changes are reflected in task-specific conditions, as previously reported, but also in general innate connectivity. Our results both enhance knowledge about the mechanisms underlying MST effects and may provide neurophysiological evidence of training transfer.

Cognitive impairment in multiple sclerosis: clinical management, MRI, and therapeutic avenues

Multiple sclerosis is a chronic, demyelinating disease of the CNS. Cognitive impairment is a sometimes neglected, yet common, sign and symptom with a profound effect on instrumental activities of daily living. The prevalence of cognitive impairment in multiple sclerosis varies across the lifespan and might be difficult to distinguish from other causes in older age. MRI studies show that widespread changes to brain networks contribute to cognitive dysfunction, and grey matter atrophy is an early sign of potential future cognitive decline. Neuropsychological research suggests that cognitive processing speed and episodic memory are the most frequently affected cognitive domains. Narrowing evaluation to these core areas permits brief, routine assessment in the clinical setting. Owing to its brevity, reliability, and sensitivity, the Symbol Digit Modalities Test, or its computer-based analogues, can be used to monitor episodes of acute disease activity. The Symbol Digit Modalities Test can also be used in clinical trials, and data increasingly show that cognitive processing speed and memory are amenable to cognitive training interventions.

Beyond clinical changes: Rehabilitation-induced neuroplasticity in MS

BACKGROUND

Neural plasticity represents the substrate by which the damaged central nervous system (CNS) re-learns lost behaviors in response to rehabilitation. In persons with multiple sclerosis (MS), rehabilitation can therefore exploit the potential of neural plasticity to restore CNS functions beyond the spontaneous mechanisms of recovery from MS-related damage.

METHODS

Here, we reviewed the currently available evidence on the occurrence of mechanisms of structural and functional plasticity following rehabilitation, motor, and/or cognitive training. We presented both data gained from basic laboratory research on animal models and data on persons with MS obtained by advanced magnetic resonance imaging (MRI) techniques.

RESULTS

Studies on physical and environmental enrichment in experimental MS models showed beneficial effects mediated by both immune modulation and activity-dependent plasticity, lowering tissue destruction and restoring of CNS network function. Translational researches in MS people demonstrated structural and/or functional MRI changes after various interventions, but their heterogeneity and small sample sizes (5-42 patients) raise concerns about the interpretation and generalization of the obtained results.

DISCUSSION

We highlighted the limitations of published studies, focusing on the knowledge gaps to be filled in terms of neuropathological correlations between changes detected in animal models and changes detected in vivo by neuroimaging.

Study protocol: improving cognition in people with progressive multiple sclerosis: a multi-arm, randomized, blinded, sham-controlled trial of cognitive rehabilitation and aerobic exercise (COGEx)

BACKGROUND

Cognitive dysfunction affects up to 70% of people with progressive MS (PMS). It can exert a deleterious effect on activities of daily living, employment and relationships. Preliminary evidence suggests that performance can improve with cognitive rehabilitation (CR) and aerobic exercise (EX), but existing data are predominantly from people with relapsing-remitting MS without cognitive impairment. There is therefore a need to investigate whether this is also the case in people with progressive forms of the disease who have objectively identified cognitive impairment. It is hypothesized that CR and EX are effective treatments for people with PMS who have cognitive impairment, in particular processing speed (PS) deficits, and that a combination of these two treatments is more effective than each individual treatment given alone. We further hypothesize that improvements in PS will be associated with modifications of functional and/or structural plasticity within specific brain networks/regions involved in PS measured with advanced MRI techniques.

METHODS

This study is a multisite, randomized, double-blinded, sham controlled clinical trial of CR and aerobic exercise. Three hundred and sixty subjects from 11 sites will be randomly assigned into one of four groups: CR plus aerobic exercise; CR plus sham exercise; CR sham plus aerobic exercise and CR sham plus sham exercise. Subjects will participate in the assigned treatments for 12 weeks, twice a week. All subjects will have a cognitive and physical assessment at baseline, 12 weeks and 24 weeks. In an embedded sub-study, approximately 30% of subjects will undergo structural and functional MRI to investigate the neural mechanisms underlying the behavioral response. The primary outcome is the Symbol Digit Modalities Test (SDMT) measuring PS. Secondary outcome measures include: indices of verbal and non-verbal memory, depression, walking speed and a dual cognitive-motor task and MRI.

DISCUSSION

The study is being undertaken in 6 countries (11 centres) in multiple languages (English, Italian, Danish, Dutch); with testing material validated and standardized in these languages. The rationale for this approach is to obtain a robustly powered sample size and to demonstrate that these two interventions can be given effectively in multiple countries and in different languages.

TRIAL REGISTRATION

The trial was registered on September 20th 2018 at www.clinicaltrials.gov having identifier NCT03679468. Registration was performed before recruitment was initiated.

The application of Strategy-based Training to Enhance Memory (STEM) in multiple sclerosis: A pilot RCT

New learning and memory (NLM) impairments are common in multiple sclerosis (MS), negatively impacting daily life. Few studies seek to remediate these deficits to improve everyday functioning. Self-generation, spaced learning and retrieval practice have been shown to improve NLM in healthy persons and have been incorporated into an 8-session treatment protocol, Strategy-based Training to Enhance Memory (STEM). STEM teaches participants about each of the techniques, how to apply them in daily life and provides practice. Participants are taught to restructure a memory-demanding situation to optimize self-generation, spaced learning and retrieval practice. This pilot double-blind, placebo-controlled, randomized clinical trial (RCT) tested the efficacy of STEM in 20 learning-impaired participants with clinically definite MS (9 treatment, 11 control). Significant treatment effects were noted on self-report measures of daily functioning (primary outcome). Objective neuropsychological testing approached significance, showing a medium-large effect on verbal NLM. Results suggest that STEM may improve everyday functioning in individuals with MS. A full-scale RCT is warranted to validate findings in a larger sample so that findings may be generalized to the broader MS community.

A Neuropsychological Rehabilitation Program for Cognitive Impairment in Psychiatric and Neurological Conditions: A Review That Supports Its Efficacy

Neuropsychological rehabilitation has been the focus of much scientific research over the past decades due to its efficacy in different pathologies. Advances in the neuropsychology field have led to improvements and changes in neuropsychological interventions, which in turn have given rise to different approaches and rehabilitation programs. REHACOP is an integrative neuropsychological rehabilitation program designed by specialist neuropsychologists. With an integrated bottom-up and top-down approach, REHACOP includes neurocognition, social cognition, and daily living tasks hierarchically organized on an increasing level of difficulty. Task arrangement is addressed to maximize improvements and transfer effects into participant's daily living. To date, REHACOP has been implemented on different clinical samples such as patients with schizophrenia, multiple sclerosis (MS), and Parkinson's disease (PD). This manuscript presents the efficacy data of REHACOP across these three populations and discusses it in the context of the available literature. Overall, the magnitude of improvements obtained by means of REHACOP ranged from medium to high across samples. These changes were not restricted to specific neurocognitive domains since participants attending the REHACOP program also showed changes in social cognition and daily functioning variables by means of both direct and transfer effects. Results regarding REHACOP's efficacy in psychiatric and neurological conditions have contributed to expanding the existing evidence about the use of structured neuropsychological rehabilitation. In addition, the results obtained after its implementation highlighted the need and importance of designing and implementing integrative neuropsychological rehabilitation programs that are focused not only on cognition per se but also on participants' performance in daily living.

Do people with multiple sclerosis benefit from PC-based neurorehabilitation? A pilot study

Multiple Sclerosis (MS) is an inflammatory degenerative disease of the central nervous system. Cognitive impairment is a frequent feature of MS at both the earlier and later stages of the disease, and it tends to worsen over time. Cognitive rehabilitation (CR) is becoming a standard component of neurorehabilitation in patients with MS. The aim of this study is to evaluate the effect of computerized CR, by using the Italian software ERICA, on cognitive and daily life performance in MS patients with mild to moderate cognitive impairment. We studied 40 individuals affected by MS, randomized into either traditional CR group (TCRG: n = 20), which performed a conventional cognitive training, or the computer-assisted CR group (CCRG: n = 20), which performed PC-based CR. The cognitive dysfunctions were investigated through a complete neuropsychological battery, administered before (T0) and after (T1) each different training. Both the trainings were well-tolerated and led to improvement in cognitive function. Notably, the CCRG had a significant effect in improving memory, attention, and processing speed, as compared to TCRG. ERICA training could be a valuable tool for the CR in patients affected by MS. Further studied are needed to confirm these promising results and evaluate the long-term effects.

Repeated Working Memory Training Improves Task Performance and Neural Efficiency in Multiple Sclerosis Patients and Healthy Controls

BACKGROUND/OBJECTIVE

To explore the effectiveness of a specific working memory (WM) training program in MS patients and healthy controls (HC).

METHOD

29 MS patients and 29 matched HC were enrolled in the study. MS and HC were randomly split into two groups: nontraining groups (15HC/14 MS) and training groups (14 HC/15 MS). Training groups underwent adaptive n-back training (60 min/day; 4 days). Functional magnetic resonance imaging (fMRI) was used to monitor brain activity during n-back performance (conditions: 0-back, 2-back, and 3-back) at 3 time points: (1) baseline, (2) post-training (+7days), and (3) follow-up (+35days).

RESULTS

In post-training and follow-up fMRI sessions, trained groups (HC and MS patients) exhibited significant reaction time (RT) reductions and increases in Correct Responses (CRs) during 2-back and 3-back performance. This improvement of task performance was accompanied by a decrease in brain activation in the WM frontoparietal network. The two effects were significantly correlated.

CONCLUSIONS

After WM training, both cognitively preserved MS patients and HC participants showed task performance improvement made possible by neuroplastic processes that enhanced neural efficiency.

Functional connectivity in multiple sclerosis after robotic rehabilitative treatment: A case report

RATIONALE

Multiple sclerosis (MS) is an inflammatory demyelinating disease of central nervous system and it is associated with an impaired motor function status. The efficacy of rehabilitation in promoting functional recovery and increasing quality of life in MS patients has been demonstrated.

PATIENT CONCERNS

A 47-year-old woman was diagnosed with relapsing-remitting multiple sclerosis (RRMS) in November 2014 because of left upper limb hypoesthesia and weakness with difficulty in hand manipulation skills (there was a 1-point Expanded Disability Status Scale (EDSS) progression, i.e., 2.5 vs 1.5). Magnetic resonance image (MRI) showed a new frontal right cortical high-signal-intensity lesion.

DIAGNOSIS

Neurological and MRI examination were suggestive of MS diagnosis.

INTERVENTIONS

Patient was treated with robotic rehabilitation and evaluated by a Glove Analyzer for fMRI system (GAF). Functional MRI (fMRI) was acquired before and at the end of rehabilitative treatment performed with robotic device (Armeo-power).

OUTCOMES

At the end of the rehabilitation program, most of the behavioral parameters, GAF and fMRI evaluation, showed a significative improvement. Moreover, fMRI showed a significantly increased functional activation within the sensory-motor network in the active, motor task.

LESSONS

Our findings suggest a possible restorative effect of robotics on brain networks. Moreover, we may argue that GAF may be a valuable tool in assessing functional recovery after upper limb rehabilitation, especially of associated to fMRI examination.

Identifying risk factors for cognitive issues in multiple sclerosis

INTRODUCTION

Cognitive impairment (CI) in Multiple Sclerosis (MS) has progressively regained clinical and research interest and is currently recognized as a debilitating and burdensome problem for these patients. Studying risk and protecting factors that may influence the development and course of CI is currently an area of increasing interest, due to the potential for preventive strategies. Areas covered: In this narrative review the authors briefly addressed the physiopathologic basis, assessment and management of CI in MS and then focused on identifying modifiable and not modifiable risk factors for CI in MS, providing an overview of the current knowledge in the field and indicating avenues for future research. Expert opinion: Improving our understanding of potentially modifiable environmental and lifestyle risk factors or protective factors for CI is important in order to prompt preventive strategies and orient patient counselling and clinical management. To this aim, we need to enhance the current level of evidence linking lifestyle factors to cognition and evaluate some factors that were only preliminary addressed in research. Moreover, we need to explore the role of each factor into the subject cognitive outcome, next to the possible interactions between different environmental factors as well as between environmental and genetic factors.

Will behavioral treatments for cognitive impairment in multiple sclerosis become standards-of-care?

Cognitive impairment is common and debilitating in persons with multiple sclerosis (MS), and further is poorly-managed by pharmacotherapy. Cognitive rehabilitation and exercise training have been identified as promising behavioral approaches for managing MS-related cognitive impairment based on systematic reviews and meta-analyses. However, each body of literature is associated with similar sets of methodological shortcomings, as has been identified by periodic systematic reviews and meta-analyses. Thus, there is little generalizability or transportability research supporting either behavioral approach for managing cognitive dysfunction in this population under real-world conditions (i.e., as a standard-of-care). To that end, this paper aims to catalyze the advancement of cognitive rehabilitation and exercise training research in MS, respectively, towards the successful implementation of generalizability/transportability trials. This first involves critical examinations of the respective cognitive rehabilitation and exercise training literatures in MS from a chronological perspective, with particular emphasis on how the fields have each evolved in response to systematic reviews and meta-analyses. Accordingly, the current paper then provides a roadmap for harmonizing research in those areas to systematically and efficiently inform the development of generalizability/transportability trials for behavioral approaches to manage MS-related cognitive dysfunction. This involves the recognition of overlapping facilitators and impediments for progress in each field, including considerations for the implementation of neuroimaging. Ultimately, the provision of such a framework aims to shorten the timeline for research to influence clinical practice and improve the lives of cognitively-impaired persons with MS.

The efficacy of the modified Story Memory Technique in progressive MS

Background:

Impairments in new learning and memory are common in individuals with multiple sclerosis (MS), negatively impacting everyday life, including occupational and social functioning.

Objective:

This study examined the efficacy of the modified Story Memory Technique (mSMT) in a progressive multiple sclerosis (PMS) sample through a double-blind, placebo-controlled, randomized clinical trial (RCT).

Methods:

Thirty (30) individuals with PMS, naïve to the mSMT, were randomized to the treatment or placebo control group. The Treatment Group completed mSMT training twice per week for 5 weeks while the Placebo Group met with the therapist at the same frequency, engaging in non-training-oriented tasks to control for professional contact and disease alterations.

Results:

The treatment group showed significant improvements in learning compared with the placebo control group, evident on both objective evaluation of new learning and self-report of functioning in daily life. Increased awareness of cognitive deficits was also noted post-treatment.

Conclusion:

These data provide Class I evidence supporting the efficacy of the mSMT in PMS. A behavioral intervention, targeted to specifically strengthen new learning, can significantly improve memory performance in PMS, and this improvement in memory performance is maintained 3 months later.

Application of advanced MRI techniques to monitor pharmacologic and rehabilitative treatment in multiple sclerosis: current status and future perspectives

Introduction: Advances in magnetic resonance imaging (MRI) technology and analyses are improving our understanding of the pathophysiology of multiple sclerosis (MS). Due to their ability to grade the presence of irreversible tissue loss, microstructural tissue abnormalities, metabolic changes and functional plasticity, the application of these techniques is also expanding our knowledge on the efficacy and mechanisms of action of different pharmacological and rehabilitative treatments. Areas covered: This review discusses recent findings derived from the application of advanced MRI techniques to evaluate the structural and functional substrates underlying the effects of pharmacologic and rehabilitative treatments in patients with MS. Current applications as outcome in clinical trials and observational studies, their interpretation and possible pitfalls in their use are discussed. Finally, how these techniques could evolve in the future to improve monitoring of disease progression and treatment response is examined. Expert commentary: The number of treatments currently available for MS is increasing. The application of advanced MRI techniques is providing reliable and specific measures to better understand the targets of different treatments, including neuroprotection, tissue repair, and brain plasticity. This is a fundamental progress to move toward personalized medicine and individual treatment selection.

Functional Connectivity in Multiple Sclerosis: Recent Findings and Future Directions

Multiple sclerosis is a debilitating disorder resulting from scattered lesions in the central nervous system. Because of the high variability of the lesion patterns between patients, it is difficult to relate existing biomarkers to symptoms and their progression. The scattered nature of lesions in multiple sclerosis offers itself to be studied through the lens of network analyses. Recent research into multiple sclerosis has taken such a network approach by making use of functional connectivity. In this review, we briefly introduce measures of functional connectivity and how to compute them. We then identify several common observations resulting from this approach: (a) high likelihood of altered connectivity in deep-gray matter regions, (b) decrease of brain modularity, (c) hemispheric asymmetries in connectivity alterations, and (d) correspondence of behavioral symptoms with task-related and task-unrelated networks. We propose incorporating such connectivity analyses into longitudinal studies in order to improve our understanding of the underlying mechanisms affected by multiple sclerosis, which can consequently offer a promising route to individualizing imaging-related biomarkers for multiple sclerosis.

Is impaired information processing speed a matter of structural or functional damage in MS?

Objective

Cognitive deficits, especially those of information processing speed (IPS), are common in multiple sclerosis (MS), however, the underlying neurobiological mechanisms remain poorly understood. In this study, we examined structural and functional brain changes separately, but also in an integrative manner, in relation to IPS performance.

Methods

IPS was measured using the symbol digit modalities test (SDMT) in 330 MS patients and 96 controls. Patients with IPS impairment (IPS-I, z-score < −1.5) were compared to patients with preserved IPS performance (IPS-P) on volumetric measures, white matter integrity loss (using diffusion tensor imaging) and the severity of functional connectivity changes (using resting-state fMRI). Significant predictors of IPS performance were used to create groups of mild or severe structural and/or functional damage to determine the relative effect of structural and/or functional changes on IPS.

Results

IPS-I patients, compared to IPS-P patients, showed lower deep gray matter volume and less WM integrity, but stronger increases in functional connectivity. Patients with predominantly structural damage had worse IPS (z-score = −1.49) than patients with predominantly functional changes (z-score = −0.84), although both structural and functional measures remained significant in a regression model. Patients with severe structural and functional changes had worst IPS (z-score = −1.95).

Conclusion

The level of structural damage explains IPS performance better than functional changes. After integrating functional and structural changes, however, we were able to detect more subtle and stepwise decline in IPS. In subgroups with a similar degree of structural damage, more severe functional changes resulted in worse IPS scores than those with only mild functional changes.

•

Impaired information processing in MS relates to structural and functional changes.

•

There is no one-to-one relation between structural and functional damage.

•

MS patients with severe structural and functional changes have the lowest IPS.

•

Structural changes affect information processing more than functional changes.

•

Functional changes seem to mediate the effect of structural damage on IPS.

The hippocampus in multiple sclerosis

Some of the clinical manifestations of multiple sclerosis, such as memory impairment and depression, are, at least partly, related to involvement of the hippocampus. Pathological studies have shown extensive demyelination, neuronal damage, and synaptic abnormalities in the hippocampus of patients with multiple sclerosis, and improvements in MRI technology have provided novel ways to assess hippocampal involvement in vivo. It is now accepted that clinical manifestations related to the hippocampus are due not only to focal hippocampal damage, but also to disconnection of the hippocampus from several brain networks. Evidence suggests anatomical and functional subspecialisation of the different hippocampal subfields, resulting in variability between regions in the extent to which damage and repair occur. The hippocampus also has important roles in plasticity and neurogenesis, both of which potentially contribute to functional preservation and restoration. These findings underline the importance of evaluation of the hippocampus not only to improve understanding of the clinical manifestations of multiple sclerosis, but also as a potential future target for treatment.

Classic Block Design "Pseudo"-Resting-State fMRI Changes After a Neurorehabilitation Program in Patients with Multiple Sclerosis

BACKGROUND AND PURPOSE

The goal of this study was to assess changes in the resting-state networks (RSNs) of patients with multiple sclerosis (MS) after a cognitive rehabilitation program (CRP), by retrospectively analyzing functional magnetic resonance imaging (fMRI) studies using the classical block design.

METHODS

Fifteen patients with MS (2 primary progressive, 3 relapsing-remitting, 10 secondary progressive) were scanned before and after the CRP on a 1.5T MRI scanner. In addition, patients underwent pre- and post-CRP neuropsychological assessment using a battery of standardized tests. Five healthy individuals were scanned at the same time points to confirm the test-retest reliability of the imaging technique. For each study, the individual fMRI blocks of rest were merged to produce a "pseudo"-resting-state (pseudo-RS) of 3 minutes duration. RS studies were analyzed with the MELODIC toolbox. A dual regression analysis was applied to estimate the longitudinal changes in RSNs of patients and test controls relative to a set of predefined RSNs used as templates.

RESULTS

In healthy individuals, there were no significant differences in RSN results between the two time points studied. In the group of patients with MS, significant differences were found post-CRP in the visual medial, cerebellar, auditory, and frontal-executive RSNs. Furthermore, synchronization increases in the frontal-executive RSN were associated with cognitive improvement on neuropsychological testing.

CONCLUSIONS

Results obtained using a pseudo-RS approach to analyze data from block-design fMRI studies suggest that a CRP of 5 weeks' duration induces measurable changes in specific RSNs of patients with MS.

Increased brain connectivity and activation after cognitive rehabilitation in Parkinson's disease: a randomized controlled trial

Cognitive rehabilitation programs have demonstrated efficacy in improving cognitive functions in Parkinson's disease (PD), but little is known about cerebral changes associated with an integrative cognitive rehabilitation in PD. To assess structural and functional cerebral changes in PD patients, after attending a three-month integrative cognitive rehabilitation program (REHACOP). Forty-four PD patients were randomly divided into REHACOP group (cognitive rehabilitation) and a control group (occupational therapy). T1-weighted, diffusion weighted and functional magnetic resonance images (fMRI) during resting-state and during a memory paradigm (with learning and recognition tasks) were acquired at pre-treatment and post-treatment. Cerebral changes were assessed with repeated measures ANOVA 2 × 2 for group x time interaction. During resting-state fMRI, the REHACOP group showed significantly increased brain connectivity between the left inferior temporal lobe and the bilateral dorsolateral prefrontal cortex compared to the control group. Moreover, during the recognition fMRI task, the REHACOP group showed significantly increased brain activation in the left middle temporal area compared to the control group. During the learning fMRI task, the REHACOP group showed increased brain activation in the left inferior frontal lobe at post-treatment compared to pre-treatment. No significant structural changes were found between pre- and post-treatment. Finally, the REHACOP group showed significant and positive correlations between the brain connectivity and activation and the cognitive performance at post-treatment. This randomized controlled trial suggests that an integrative cognitive rehabilitation program can produce significant functional cerebral changes in PD patients and adds evidence to the efficacy of cognitive rehabilitation programs in the therapeutic approach for PD.

Multidisciplinary Rehabilitation is Efficacious and Induces Neural Plasticity in Multiple Sclerosis even when Complicated by Progressive Multifocal Leukoencephalopathy

A 48-year-old woman with multiple sclerosis (MS), treated with natalizumab for more than one year without clinical and magnetic resonance imaging (MRI) signs of disease activity, was diagnosed with definite progressive multifocal leukoencephalopathy (PML). She presented with subacute motor deficit of the right upper limb (UL), followed by involvement of the homolateral leg and urinary urgency. The patient was treated with steroids and plasma exchange. On follow-up MRI scans, the PML lesion remained stable and no MS rebounds were observed, but the patient complained of a progressive worsening of the right UL motor impairment, becoming dependent in most activities of daily living. A cycle of multidisciplinary rehabilitation (MDR) was then started, including daily sessions of UL robot therapy and occupational therapy. Functional MRI (fMRI) was acquired before and at the end of the MDR cycle using a motor task which consisted of 2 runs: in one run the patient was asked to observe while the second one consisted of hand grasping movements. At the end of the rehabilitation period, both the velocity and the smoothness of arm trajectories during robot-based reaching movements were significantly improved. After MDR, compared with baseline, fMRI showed significantly increased functional activation within the sensory-motor network in the active, motor task, while no significant differences were found in the observational task. MDR in MS, including robot-assisted UL training, seems to be clinically efficacious and to have a significant impact on brain functional reorganization on a short-term, even in the presence of superimposed tissue damage provoked by PML.

Reporting interventions in trials evaluating cognitive rehabilitation in people with multiple sclerosis: a systematic review

OBJECTIVE

To determine the quantity and quality of description of cognitive rehabilitation for cognitive deficits in people with multiple sclerosis, using a variety of published checklists, and suggest ways of improving the reporting of these interventions.

DATA SOURCES

A total of 10 electronic databases were searched, including MEDLINE, EMBASE, CINAHL and PsycINFO, from inception to May 2017. Grey literature databases, trial registers, reference lists and author citations were also searched.

REVIEW METHODS

Papers were included if participants were people with multiple sclerosis aged 18 years and over and if the effectiveness of cognitive rehabilitation in improving functional ability for memory, attention or executive dysfunction, with or without a control group, was being evaluated.

RESULTS

A total of 54 studies were included in this review. The reporting of a number of key aspects of cognitive rehabilitation was poor. This was particularly in relation to content of interventions (reported completely in 26 of the 54 studies), intervention procedures (reported completely in 16 of the 54 studies), delivery mode (reported completely in 24 of the 54 studies) and intervention mechanism of action (reported completely in 21 of the 54 studies).

CONCLUSION

The quality of reporting of cognitive rehabilitation for memory, attention and executive function for multiple sclerosis, across a range of study designs, is poor. Existing reporting checklists do not adequately cover aspects relevant to cognitive rehabilitation, such as the approaches used to address cognitive deficits. Future checklists could consider these aspects we have identified in this review.

Benefits from an autobiographical memory facilitation programme in relapsing-remitting multiple sclerosis patients: a clinical and neuroimaging study

While the efficacy of mental visual imagery (MVI) to alleviate autobiographical memory (AM) impairment in multiple sclerosis (MS) patients has been documented, nothing is known about the brain changes sustaining that improvement. To explore this issue, 20 relapsing-remitting MS patients showing AM impairment were randomly assigned to two groups, experimental (n = 10), who underwent the MVI programme, and control (n = 10), who followed a sham verbal programme. Besides the stringent AM assessment, the patients underwent structural and functional MRI sessions, consisting in retrieving personal memories, within a pre-/post-facilitation study design. Only the experimental group showed a significant AM improvement in post-facilitation, accompanied by changes in brain activation (medial and lateral frontal regions), functional connectivity (posterior brain regions), and grey matter volume (parahippocampal gyrus). Minor activations and functional connectivity changes were observed in the control group. The MVI programme improved AM in MS patients leading to functional and structural changes reflecting (1) an increase reliance on brain regions sustaining a self-referential process; (2) a decrease of those reflecting an effortful research process; and (3) better use of neural resources in brain regions sustaining MVI. Functional changes reported in the control group likely reflected ineffective attempts to use the sham strategy in AM.

Cognitive impairment in MS: rehabilitation approaches

Cognitive deficits have been reported in 45%-70% of patients with multiple sclerosis (MS). Like other symptoms of MS, cognitive deficits are highly variable. Slowed information processing and memory and learning dysfunction are regarded as the most frequent cognitive deficits in MS. Both white and gray matter damages have been suggested to contribute to cognitive impairments in MS. There is no direct relationship between cognitive deficits and physical disability, disease duration or course of the disease. In addition to cognitive impairments, neuropsychiatric symptoms are observed in MS, the most common being alterations in mood state. Neurobehavioral deficits have multidimensional effects on the activities of daily living and quality of life. Consequently, attention should be paid to early diagnosis and treatment. Based on studies on cognitive retraining and more multimodal neuropsychological rehabilitation, both approaches show promise in the treatment of cognitive impairments and their harmful effects. This review introduces the frequency and characteristics of cognitive impairments, as well as main findings on the effects of neuropsychological rehabilitation in MS.

Hippocampal Neuroinflammation, Functional Connectivity, and Depressive Symptoms in Multiple Sclerosis

BACKGROUND

Depression, a condition commonly comorbid with multiple sclerosis (MS), is associated more generally with elevated inflammatory markers and hippocampal pathology. We hypothesized that neuroinflammation in the hippocampus is responsible for depression associated with MS. We characterized the relationship between depressive symptoms and hippocampal microglial activation in patients with MS using the 18-kDa translocator protein radioligand [(18)F]PBR111. To evaluate pathophysiologic mechanisms, we explored the relationships between hippocampal neuroinflammation, depressive symptoms, and hippocampal functional connectivities defined by resting-state functional magnetic resonance imaging.

METHODS

The Beck Depression Inventory (BDI) was administered to 11 patients with MS and 22 healthy control subjects before scanning with positron emission tomography and functional magnetic resonance imaging. We tested for higher [(18)F]PBR111 uptake in the hippocampus of patients with MS relative to healthy control subjects and examined the correlations between [(18)F]PBR111 uptake, BDI scores, and hippocampal functional connectivities in the patients with MS.

RESULTS

Patients with MS had an increased hippocampal [(18)F]PBR111 distribution volume ratio relative to healthy control subjects (p = .024), and the hippocampal distribution volume ratio was strongly correlated with the BDI score in patients with MS (r = .86, p = .006). Hippocampal functional connectivities to the subgenual cingulate and prefrontal and parietal regions correlated with BDI scores and [(18)F]PBR111 distribution volume ratio.

CONCLUSIONS

Our results provide evidence that hippocampal microglial activation in MS impairs the brain functional connectivities in regions contributing to maintenance of a normal affective state. Our results suggest a rationale for the responsiveness of depression in some patients with MS to effective control of brain neuroinflammation. Our findings also lend support to further investigation of the role of inflammatory processes in the pathogenesis of depression more generally.

A pilot study of changes in functional brain activity during a working memory task after mSMT treatment: The MEMREHAB trial

BACKGROUND

Working memory deficits are common in multiple sclerosis (MS). The modified Story Memory Technique (mSMT) has been shown to improve new learning and memory in MS, but its effects on working memory (WM) are currently unknown.

OBJECTIVE

The present study presents a secondary analysis of data from a larger double-blind, placebo-controlled, randomized clinical trial and examines changes in cerebral activation on a WM task following mSMT treatment.

METHODS

Sixteen participants with clinically definite MS were randomly assigned to treatment (n=7) or placebo-control groups (n=9) matched for gender, age and education. Baseline and immediate follow-up functional Magnetic Resonance Imaging (fMRI) was obtained for all subjects. During fMRI participants completed an N-back task, consisting of 0-, 1-and 2-back conditions.

RESULTS

Significant increases in cerebral activation were noted in the dorsolateral prefrontal cortex, supplementary motor area and inferior parietal lobule at follow-up in the treatment group. No significant changes were noted in the placebo control group.

CONCLUSION

Due to the small sample size, results of the current study should be interpreted as preliminary. However, the observed pattern of activation of the frontoparietal network involved in WM found in the treatment group, suggests that mSMT training increases recruitment of attention- and WM-related neural networks. We conclude that mSMT treatment leads to changes in WM-related cerebral activation.

Memory rehabilitation for people with multiple sclerosis

BACKGROUND

This is an update of the Cochrane review 'Memory rehabilitation for people with multiple sclerosis' (first published in the Cochrane Library 14 March 2012, Issue 3). Impairments in cognitive function, particularly memory, are common in people with multiple sclerosis (MS) and can potentially affect their ability to complete functional activities. There is evidence from single-case or small group studies that memory rehabilitation can be beneficial for people with MS, but findings from randomised controlled trials (RCTs) and systematic reviews have been inconclusive.

OBJECTIVES

To determine whether people with MS who received memory rehabilitation showed: 1. better outcomes in their memory functions compared to those given no treatment or receiving a placebo control; and 2. better functional abilities, in terms of activities of daily living, mood, and quality of life, than those who received no treatment or a placebo.

SEARCH METHODS

We searched the Trials Specialised Register of the Cochrane Multiple Sclerosis and Rare Diseases of the CNS Group (2 June 2015) and the following electronic databases: The NIHR Clinical Research Network Portfolio database (NIHR CRN) (from 2010 to June 2015), The Allied and Complementary Medicine Database (AMED) (2010 to June 2015), British Nursing Index (BNI) (2010 to June 2015), PsycINFO (2011 to June 2015), and CAB Abstracts (2010 to June 2015). Start dates for the electronic databases coincided with the last search for the previous review. We handsearched relevant journals and reference lists.

SELECTION CRITERIA

We selected RCTs or quasi-randomised trials of memory rehabilitation or cognitive rehabilitation for people with MS in which a memory rehabilitation treatment group was compared to a control group. Selection was conducted independently first and then confirmed through group discussion. We excluded studies that included participants whose memory deficits were the result of conditions other than MS unless we could identify a subgroup of participants with MS with separate results.

DATA COLLECTION AND ANALYSIS

Three review authors were involved in this update in terms of study selection, quality assessment, and data extraction. We contacted investigators of primary studies for further information where required. We conducted data analysis and synthesis in accordance with the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). We performed a 'best evidence' synthesis based on the methodological quality of the primary studies included.

MAIN RESULTS

We added seven studies during this update, bringing the total to 15 studies, involving 989 participants. The interventions involved various memory retraining techniques, such as computerised programmes and training on internal and external memory aids. Control groups varied in format from assessment-only groups, discussion and games, non-specific cognitive retraining, and attention or visuospatial training. The risk of bias of the included studies was generally low, but we found eight studies to have high risk of bias related to certain aspects of their methodology.We found significant effect of intervention on objective assessments of memory in both the immediate and long-term follow-ups: standardised mean difference (SMD) 0.23 (95% confidence interval (CI) 0.05 to 0.41) and SMD 0.26 (95% CI 0.03 to 0.49), respectively. We also found significant effect of intervention for quality of life in the immediate follow-up (SMD 0.23 (95% CI 0.05 to 0.41)). These findings showed that the intervention group performed significantly better than the control group. We also found a significant difference for activities of daily living (ADL) in the long-term follow-up (SMD -0.33 (95% CI -0.63 to -0.03)), showing that the control groups had significantly less difficulty completing ADLs than the intervention groups. We found no significant effects, either immediate or long-term, on subjective reports of memory problems (SMD 0.04 (95% CI -0.19 to 0.27) and SMD 0.04 (95% CI -0.19 to 0.27)); on mood (SMD 0.02 (95% CI -0.16 to 0.20) and SMD -0.01 (95% CI -0.21 to 0.20)); and on immediate follow-up for ADL (SMD -0.13 (95% CI -0.60 to 0.33)) and in the long term for quality of life (SMD 0.16 (95% CI -0.03 to 0.36)). We could not complete a sensitivity analysis of intention-to-treat in comparison with per-protocol analysis, due to insufficient information from the included papers. However, a sensitivity analysis of high- versus low-risk studies suggested that while quality of the trials did not affect most outcomes, differences were seen in the objective memory outcomes (both at immediate and long term) and quality of life (immediate) outcome, with studies with higher risk of bias inflating the overall effect size estimates for these outcomes, and the test of overall effect changing from being statistically significant to not significant when studies at high risk of bias were excluded. This suggests that lower-quality studies may have positively influenced the outcomes.

AUTHORS' CONCLUSIONS

There is some evidence to support the effectiveness of memory rehabilitation on memory function, as well as on quality of life. However, the evidence is limited and does not extend to subjective reports of memory functioning or mood. Furthermore, the objective measures used are not ecologically valid measures, and thus potentially limit generalisability of these findings into daily life. Further robust RCTs of high methodological quality and better quality of reporting, using ecologically valid outcome assessments, are still needed.

Can we define a rehabilitation strategy for cognitive impairment in progressive multiple sclerosis? A critical appraisal

Cognitive impairment (CI) has been shown to be severe in patients with progressive forms of multiple sclerosis (MS), and the most frequently impaired domains are sustained attention, information processing speed, memory, and executive functions. In contrast to relapsing forms of MS, where studies have shown favorable results from cognitive rehabilitation, there is a lack of data on cognitive rehabilitation in progressive forms of MS. A specific approach in assessing CI and in designing and administering rehabilitation training for patients with progressive forms of MS is needed.