Active cognitive reserve influences the regional atrophy to cognition link in multiple sclerosis

Effects of virtual reality-based rehabilitation on cognitive function and mood in multiple sclerosis: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Multiple sclerosis (MS) is a disabling neurological disease that causes cognitive impairment and mental problems that occur in all MS phenotypes but are most common in patients with secondary progressive MS. Various degrees of cognitive impairment and mental health concerns are common among patients with MS (PwMS). Virtual reality (VR)-based rehabilitation is an innovative approach aimed at enhancing cognitive function and mood in PwMS. This study aims to perform a meta-analysis to assess the effects of VR-based rehabilitation on cognitive function and mood in PwMS.

METHODS

Using PubMed, Embase, the Cochrane Library, Web of Science, and the Physiotherapy Evidence Database (PEDro), a thorough database search was performed to identify randomized controlled trials (RCTs) examining the effects of VR on PwMS. Trials published until October 31, 2023, that satisfied our predetermined inclusion and exclusion criteria were included. Data were extracted, literature was examined, and the methodological quality of the included trials was assessed. StataSE version 16 was used for the meta-analysis.

RESULTS

Our meta-analysis included 461 patients from 10 RCTs.

PRIMARY OUTCOMES

The Montreal Cognitive Assessment (MoCA) (weighted mean difference [WMD]=1.93, 95 % confidence interval [CI]=0.51-3.36, P = 0.008, I² = 75.4 %) the Spatial Recall Test (SPART) (WMD=3.57, 95 % CI=1.65-5.50, P < 0.001, I² = 0 %), immediate recall (standard mean difference [SMD]=0.37, 95 % CI=0.10-0.64, P = 0.007, I² = 0 %) and delayed recall ([SMD]=0.30, 95 % CI=0.06-0.54, P = 0.013, I² = 35.4 %) showed improvements in comparison to the control group in terms of global cognitive function immediate recall, delayed recall, and visuospatial abilities.

SECONDARY OUTCOMES

Compared to the control group, anxiety improved (standard mean difference [SMD]=0.36, 95 % CI=0.10-0.62, P = 0.007, I² = 43.1 %). However, there were no significant differences in processing speed, attention, working memory or depression.

CONCLUSIONS

This systematic review provides valuable evidence for improving cognitive function and mood in PwMS through VR-based rehabilitation. In the future, VR-based rehabilitation may be a potential method to treat cognitive function and emotional symptoms of MS.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO; identifier: CRD42023474467.

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.

Do patients with neurological disorders benefit from immersive virtual reality? A scoping review on the emerging use of the computer-assisted rehabilitation environment

INTRODUCTION

Virtual reality (VR) is an advanced technology that creates simulated environments and conditions. By offering the possibility of combining motor, cognitive, and well-being in conjunction with the potential to manipulate multi-sensorial features in a safe environment, VR has emerged as a promising powerful rehabilitation tool. Among advanced VR systems, various authors have highlighted promising effects in the rehabilitation of the computer-assisted rehabilitation environment (CAREN - Motekforce Link; Amsterdam, The Netherlands). In our scoping review, we aimed to map the existing evidence on the use of CAREN in the rehabilitation of neurological patients.

EVIDENCE ACQUISITION

This scoping review was conducted following the PRISMA guidelines. A search was carried out for all peer-reviewed articles published until June 30, 2023, using the following databases: PubMed, Embase, Cochrane Database, PeDro and Web of Science. The following terms have been used: ("Cognitive Rehabilitation" OR "Motor Rehabilitation" OR "CAREN" or "Computer-Assisted Rehabilitation Environment") AND ("Virtual Reality" OR "Rehab").

EVIDENCE SYNTHESIS

From the assessed studies, only seven met the inclusion criteria: 1) one study concerned cognitive rehabilitation in patients suffering from Parkinson's Disease (PD); 2) one was on the usability of CAREN in PD patients; 3) two studies related to the influence of emotional components to CAREN rehabilitation; 4) three studies were related to motor rehabilitation using CAREN, and involved individuals with PD, Multiple Sclerosis, TBI, respectively. Generally, the few assessed studies demonstrate that CAREN is a safe and potentially effective tool to treat different symptoms (including gait and vestibular disturbances, executive function, depressive mood, and anxiety) in patients with different neurological disorders.

CONCLUSIONS

The reviewed literature indicated the potential use of CAREN in improving motor and cognitive skills with conflicting results on emotional aspects. However, since the data comes from few and small sample size studies, further research is needed to confirm the effectiveness of the tool in neurorehabilitation.

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 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.

Cognitive Reserve as an Emerging Concept in Stroke Recovery

Stroke is a leading cause of death and disability. It is a complex and largely heterogeneous condition. Prognosis for variations in impairment and recovery following stroke continues to be challenging and inaccurate, highlighting the need to examine the influence of other currently unknown variables to better predict and understand interindividual differences in stroke impairment and recovery. The concept of "cognitive reserve," a feature of brain function said to moderate the relationship between brain pathology and clinical outcomes, might provide a partial explanation. This review discusses the potential significance of cognitive reserve in the context of stroke, with reference to reduced burden of disability poststroke, health promotion, intervention and secondary prevention of cognitive impairment, ease and challenges of translation into clinical practice, prognosis and prediction of recovery, and clinical decisions and trial stratification. Discussions from the review aim to encourage stroke clinicians and researchers to better consider the role of premorbid, lifestyle-related variables, such as cognitive reserve, in facilitating successful neurological outcomes and recovery following stroke.

Longitudinal Stability of Cognition in Early-Phase Relapsing-Remitting Multiple Sclerosis: Does Cognitive Reserve Play a Role?

Background

Up to 70% of people with multiple sclerosis (MS) experience cognitive impairment. Some remain cognitively intact despite advanced disease. Cognitive reserve (CR) theory postulates that individuals with higher levels of intellectual enrichment can tolerate more pathology than others before exhibiting cognitive impairment.

Methods

Thirty-two individuals with early-phase relapsing-remitting MS with mild physical disability and disease duration less than 10 years and 32 controls were recruited. At baseline and after 3 years, participants completed neuropsychological tests evaluating several cognitive domains. The CR was assessed via a cognitive reserve index (CRI) using educational levels and North American Adult Reading Test scores. Change in cognition was assessed using a reliable change index.

Results

At baseline, people with MS performed worse than controls on visual memory. There were no significant group differences on information processing speed, learning, language, and executive functions. Most cognitive domains showed no change over time, and CRI was not a significant predictor in the regression model.

Conclusions

People with MS performed worse on memory tasks at baseline compared with controls. Cognitive change differed between people with MS and controls in executive functions. Although people with MS and controls improved over time, beyond practice effects, people with MS improved less than controls. Overall, no cognitive deterioration was noted over time, and CR did not predict change in cognition. Sample homogeneity in terms of disease stage and CR may explain these findings.

Brain and cognitive reserve: Translation via network control theory

Traditional approaches to understanding the brain's resilience to neuropathology have identified neurophysiological variables, often described as brain or cognitive "reserve," associated with better outcomes. However, mechanisms of function and resilience in large-scale brain networks remain poorly understood. Dynamic network theory may provide a basis for substantive advances in understanding functional resilience in the human brain. In this perspective, we describe recent theoretical approaches from network control theory as a framework for investigating network level mechanisms underlying cognitive function and the dynamics of neuroplasticity in the human brain. We describe the theoretical opportunities offered by the application of network control theory at the level of the human connectome to understand cognitive resilience and inform translational intervention.

Revisiting cognitive reserve and cognition in multiple sclerosis: A closer look at depression

Background:

The protective effect of cognitive reserve (CR) on cognition in people with multiple sclerosis (PwMS) has been well described.

Objective:

To explore the relationship between aspects of CR, namely, leisure pursuits and depression.

Methods:

In a cross-sectional study, a sample of 155 PwMS and 115 healthy controls (HC) underwent cognitive testing with the Minimal Assessment of Cognitive Function in Multiple Sclerosis (MACFIMS) battery. Leisure activity was retrospectively recorded using the Leisure Activity Scale (LAS). Depression was assessed using the Hospital Anxiety and Depression Scale.

Results:

PwMS demonstrated greater decreases in leisure activity over time compared to the HC group, particularly in the past year ( p < 0.001). Here, depression accounted for 17% of the variance in determining the level of leisure activity ( p < 0.001). Premorbid IQ and leisure activity within the past year emerged as significant predictors of information processing speed, learning, memory and executive function. After controlling for depression, the influence of leisure activity on cognition was insignificant.

Conclusion:

Depression can cause significant changes in behaviour which can influence indices of CR, such as leisure pursuits. Successfully treating depression may lead to a more active lifestyle thereby offsetting in part the cognitive burden of disease.

Toward mindfulness in quality-of-life research: perspectives on how to avoid rigor becoming rigidity

Background

The field of quality-of-life (QOL) research has matured into a discipline with scientific rigor, sophisticated methods, and guidelines. While this maturation is laudable and needed, it can result in a limiting rigidity. We aim to highlight examples of practices that are based on shared research values and principles that, when dogmatically applied, may limit the potential impact of QOL research.

Methods

By juxtaposing rigorous standards with their rigid application for different stages of the research cycle, we suggest more balanced approaches.

Results

Rigidity in cultivating a research question relates to constraining our thinking, leading to ‘safe’ research focusing on small variations of similar studies. Rigidity in operationalizing key constructs focuses on problems with validation practices that hinder further innovations, the use of static questionnaires when a more flexible approach is needed, dismissing rarely endorsed items that are clinically relevant, use of insensitive generic measures when specific measures are required, and a rigid emphasis on short questionnaires. Rigidity in data analysis relates to an undue emphasis on delineating primary and secondary outcomes and an unquestioned insistence on reducing Type 1 errors regardless of the research context. Rigidity in research infrastructure focuses on the unquestioned validity of patient input on scientific matters, and increasingly rigid guidelines and checklists that end up driving grant applications.

Discussion

It is hoped that this overview will lead to a reconsideration of a more flexible application of research principles while retaining scientific rigor.

Differential effects of aging on motor and cognitive functioning in multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) patients are impaired in motor and cognitive performance, but the extent to which these deficits are magnified by aging is unknown. In one prior study, differences in cognitive processing speed between MS patients and healthy individuals were of similar magnitude across the lifespan. Here, we have improved on this work by expanding assessment to multiple cognitive domains and motor functioning.

OBJECTIVE

To determine whether the degree of cognitive and motor dysfunction in MS is magnified with increasing age.

METHODS

In all, 698 MS patients (aged 29-71 years) and 226 healthy controls (HCs; aged 18-72 years) completed neuroperformance tests covering ambulation, upper extremity function, information processing speed, and memory.

RESULTS

Linear regression models predicting cognitive and motor function revealed main effects of MS/HC diagnosis, age, and education across all measures. There was also an interaction between age and diagnosis on measures of motor function, but not on cognitive outcomes.

CONCLUSION

The progression of motor decline is amplified by aging in MS. However, the degree of cognitive impairment does not vary across the lifespan. Thus, evidence of accelerated cognitive impairment in older adults with MS may signal the presence of other age-related cognitive pathologies.

Synergistic Effects of Reserve and Adaptive Personality in Multiple Sclerosis

OBJECTIVES

Cognitive reserve moderates the effects of gray matter (GM) atrophy on cognitive function in neurological disease. Broadly speaking, Reserve explains how persons maintain function in the face of cerebral injury in cognitive and other functional domains (e.g., physical, social). Personality, as operationalized by the Five Factor Model (FFM), is also implicated as a moderator of this relationship. It is conceivable that these protective mechanisms are related. Prior studies suggest links between Reserve and personality, but the degree to which these constructs overlap and buffer the clinical effects of neuropathology is unclear.

METHODS

We evaluated Reserve and FFM traits-Neuroticism, Extraversion, Openness, Agreeableness, and Conscientiousness-in a cohort of 67 multiple sclerosis (MS) patients. We also examined the extent to which FFM traits and aspects of Reserve interact in predicting cognitive processing speed.

RESULTS

Retrospectively reported educational/occupational achievement was associated with higher Openness, and childhood social engagement was associated with higher Extraversion, Agreeableness, and Conscientiousness. Current involvement in exercise activities and social activities was associated with Extraversion, current involvement in hobbies was associated with Neuroticism, and current receptive behaviors were associated with Agreeableness and Conscientiousness. When tested as predictors, Conscientiousness and childhood enrichment activities interacted in predicting cognitive processing speed after accounting for age, disease duration, disability, and GM volume.

CONCLUSIONS

Childhood enrichment activities and Conscientiousness have a synergistic effect on cognitive processing speed. Current findings have implications for using psychological interventions to foster both Reserve and adaptive personality characteristics to stave off clinical symptoms in MS. (JINS, 2016, 22, 920-927).

Reserve-related activities and MRI metrics in multiple sclerosis patients and healthy controls: an observational study

BACKGROUND

To examine whether past and current reserve-related activities make the brain less susceptible to MS pathology (i.e., lesions or disease-related atrophy).

METHODS

This secondary analysis of a cohort study included 276 healthy controls (HC), and 65 clinically isolated syndrome (CIS), 352 relapsing-remitting MS (RR) and 109 secondary- progressive MS (SPMS) patients. Past reserve-related activities comprised educational and occupational attainment. Current reserve-related activities comprised strenuous and non-strenuous activities. MRI was performed on 3 T scanner. Regression and non-parametric analysis examined relationships between MRI metrics and reserve-related activities.

RESULTS

Multivariate models (HC as referent) revealed significant interactions in predicting strenuous reserve-related activities with chronic lesion burden (for CIS), brain- (for RR & SPMS), subcortical- (for CIS, RR, & SPMS) and amygdala- (for RR) volumes. Maximal Lifetime Brain Growth was higher for RR patients who engaged in running before and after diagnosis, rather than only before or never. Residual Brain Volume was higher in RR patients who did weights-exercise before and after diagnosis, as compared to only before.

CONCLUSIONS

Reserve-related activities are related to brain health cross-sectionally in all MS subgroups, and longitudinally in RR patients. Consistent with reserve theory, RR patients who maintained strenuous activities had higher Maximal Lifetime Brain Growth and Residual Brain Volume. The study's limitations are discussed, including the potential for recall bias and design limitations that preclude causal inference.

Information processing speed in multiple sclerosis: Past, present, and future

BACKGROUND

Information processing speed (IPS) is a prevalent cognitive impairment in multiple sclerosis (MS).

OBJECTIVES

This review aims to summarize the methods applied to assess IPS in MS and its theoretical conceptualization. A PubMed search was performed to select articles published between 1 January 2004 and 31 December 2013, resulting in 157 articles included.

RESULTS

The majority (54%) of studies assessed IPS with heterogeneous samples (several disease courses). Studies often report controlling for presence of other neurological disorders (60.5%), age (58.6%), education (51.6%), alcohol history (47.8%), or use of steroids (39.5%). Potential confounding variables, such as recent relapses (50.3%), history of developmental disorders (19.1%), and visual problems (29.9%), were often neglected. Assessments used to study IPS were heterogeneous (ranging from simple to complex tasks) among the studies under review, with 62 different tasks used. Only 9.6% of articles defined the construct of IPS and 22.3% discussed IPS in relation to a theoretical model.

FUTURE DIRECTIONS

The challenges for the upcoming decade include clarification of the definition of IPS as well as its theoretical conceptualization and a consensus on assessment. Based on the results obtained, we propose a new theoretical model, the tri-factor model of IPS.

Impact of Pharmacotherapy on Cognitive Dysfunction in Patients with Multiple Sclerosis

Cognitive impairment is a common symptom of multiple sclerosis (MS), adversely impacting many spheres of daily functioning. Yet the effectiveness of pharmacological interventions for cognitive impairment in MS is unclear. Clinicians and patients alike would benefit from formal guidelines regarding effective management of cognitive symptoms. We reviewed the background on the measurement, pathophysiology and risk factors for cognitive dysfunction in MS, and then examined the published clinical trials of pharmacotherapy, including both disease-modifying treatments (DMTs) and symptom-management therapies (SMTs). Our review of DMTs revealed only a single well-designed, randomized, controlled trial where intramuscular interferon (IFN)-β1a, administered once weekly, was compared with placebo. The results showed significant benefits in terms of cognitive processing speed and memory. Less convincing but promising data have shown the potential benefits of IFN-β1b and natalizumab. The literature on SMTs is replete with placebo-controlled, single-centre studies, with a failure to replicate initially promising results. The results for SMTs such as acetylcholinesterase inhibitors and psychostimulants are mixed. Some encouraging data show promise but not to a threshold of indication for standard clinical use. Numerous methodological factors hamper research in this area. Acknowledging the lack of firm conclusions, we argue that all DMTs are likely to benefit cognition and that, if otherwise safe, SMTs with some empirical support may be attempted at the discretion of the treating clinician. We offer some guidance on the assessment and monitoring of cognitive function to inform off-license treatment of cognitive impairment in MS patients.

Impact of Education on Memory Deficits in Subclinical Depression

Elevated depressive symptoms are associated with cognitive deficits, while higher education protects against cognitive decline. This study was conducted to test if education level moderates the relationship between depressive symptoms and cognitive function. Seventy-three healthy, dementia-free adults aged 18-81 completed neuropsychological tests, as well as depression and anxiety questionnaires. Controlling for age, sex, and state anxiety, we found a significant interaction of depressive symptoms and education for immediate and delayed verbal memory, such that those with a higher education level performed well regardless of depressive symptomatology, whereas those with lower education and high depressive symptoms had worse performance. No effects were found for executive functioning or processing speed. Results suggest that education protects against verbal memory deficits in individuals with elevated depressive symptoms. Further research on cognitive reserve in depression-related cognitive deficits and decline is needed to understand the mechanisms behind this phenomenon.

A new perspective on proxy report: Investigating implicit processes of understanding through patient-proxy congruence

BACKGROUND

Utilizing proxy report is a common solution to gathering quality-of-life information from people who are not capable of reliably answering questionnaires, such as people with dementia. Proxy report could, however, also provide information about patients' implicit processes of understanding, which we define as automatic, schema-driven cognitive processes that allow one to have a better understanding of oneself and of one's body, make oneself known and knowable to members of the social network, and allow one to react proactively in response to cues. We investigated whether implicit processes of understanding explain some of the association between reserve and healthy lifestyle behaviors.

METHODS

We operationalized three implicit processes of understanding: (a) psychosocial understanding; (b) insight into physical disability; and (c) somatic awareness. This secondary analysis involved a cohort of multiple sclerosis patients and their caregiver informants (n = 118 pairs). Measures included a neurologist-administered Expanded Disability Status Scale, patient- and informant-completed survey measures, and a heartbeat perception test (interoception). Patient-other congruence assessed implicit processes of understanding: psychosocial understanding (neurocognitive and personality); physical-disability insight; and somatic awareness (interoception).

RESULTS

Effect sizes (ES) for the inter-correlations between the three implicit processes were small. Psychosocial understanding was associated with higher past reserve-building activities (small ES). Psychosocial understanding explained variance in healthy lifestyle behaviors over and above the variance explained by current reserve-building activities (∆R (2) = 0.04; model R Adjusted (2) = 0.18).

CONCLUSIONS

Proxy versus patient report can provide information about underlying interpretational processes related to insight. These processes are distinct from reserve, predict health outcomes, and can inform lifestyle-changing interventions.

Clinical relevance of brain volume measures in multiple sclerosis

Multiple sclerosis (MS) is a chronic disease with an inflammatory and neurodegenerative pathology. Axonal loss and neurodegeneration occurs early in the disease course and may lead to irreversible neurological impairment. Changes in brain volume, observed from the earliest stage of MS and proceeding throughout the disease course, may be an accurate measure of neurodegeneration and tissue damage. There are a number of magnetic resonance imaging-based methods for determining global or regional brain volume, including cross-sectional (e.g. brain parenchymal fraction) and longitudinal techniques (e.g. SIENA [Structural Image Evaluation using Normalization of Atrophy]). Although these methods are sensitive and reproducible, caution must be exercised when interpreting brain volume data, as numerous factors (e.g. pseudoatrophy) may have a confounding effect on measurements, especially in a disease with complex pathological substrates such as MS. Brain volume loss has been correlated with disability progression and cognitive impairment in MS, with the loss of grey matter volume more closely correlated with clinical measures than loss of white matter volume. Preventing brain volume loss may therefore have important clinical implications affecting treatment decisions, with several clinical trials now demonstrating an effect of disease-modifying treatments (DMTs) on reducing brain volume loss. In clinical practice, it may therefore be important to consider the potential impact of a therapy on reducing the rate of brain volume loss. This article reviews the measurement of brain volume in clinical trials and practice, the effect of DMTs on brain volume change across trials and the clinical relevance of brain volume loss in MS.