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

Cognitive rehabilitation effects on grey matter volume and Go-NoGo activity in progressive multiple sclerosis: results from the CogEx trial

BACKGROUND

Research on cognitive rehabilitation (CR) and aerobic exercise (EX) to improve cognition in progressive multiple sclerosis (PMS) remains limited. CogEx trial investigated the effectiveness of CR and EX in PMS: here, we present MRI substudy volumetric and task-related functional MRI (fMRI) findings.

METHODS

Participants were randomised to: 'CR plus EX', 'CR plus sham EX (EX-S)', 'EX plus sham CR (CR-S)' and 'CR-S plus EX-S' and attended 12-week intervention. All subjects performed physical/cognitive assessments at baseline, week 12 and 6 months post intervention (month 9). All MRI substudy participants underwent volumetric MRI and fMRI (Go-NoGo task).

RESULTS

104 PMS enrolled at four sites participated in the CogEx MRI substudy; 84 (81%) had valid volumetric MRI and valid fMRI. Week 12/month 9 cognitive performances did not differ among interventions; however, 25-62% of the patients showed Symbol Digit Modalities Test improvements. Normalised cortical grey matter volume (NcGMV) changes at week 12 versus baseline were heterogeneous among interventions (p=0.05); this was mainly driven by increased NcGMV in 'CR plus EX-S' (p=0.02). Groups performing CR (ie, 'CR plus EX' and 'CR plus EX-S') exhibited increased NcGMV over time, especially in the frontal (p=0.01), parietal (p=0.04) and temporal (p=0.04) lobes, while those performing CR-S exhibited NcGMV decrease (p=0.008). In CR groups, increased NcGMV (r=0.36, p=0.01) at week 12 versus baseline correlated with increased California Verbal Learning Test (CVLT)-II scores. 'CR plus EX-S' patients exhibited Go-NoGo activity increase (p<0.05, corrected) at week 12 versus baseline in bilateral insula.

CONCLUSIONS

In PMS, CR modulated grey matter (GM) volume and insular activity. The association of GM and CVLT-II changes suggests GM plasticity contributes to cognitive improvements.

TRIAL REGISTRATION NUMBER

NCT03679468.

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.

Natalizumab Treatment for Relapsing Multiple Sclerosis Stabilises Normal-Appearing White Matter Microstructure: A One-Year Prospective Ultra-High-Field Quantitative Imaging Study

(1) Background: Natalizumab dramatically reduces relapses and MRI inflammatory activity (new lesions and enhancing lesions) in multiple sclerosis (MS). Chemical exchange saturation transfer (CEST) MRI can explore brain tissue in vivo with high resolution and sensitivity. We investigated if natalizumab can prevent microstructural tissue damage progression measured with MRI at ultra-high field (7 Tesla) over the first year of treatment. (2) Methods: In this one-year prospective longitudinal study, patients with active relapsing-remitting MS were assessed clinically and scanned at ultra-high-field MRI at the time of their first natalizumab infusion, at 6 and 12 months, with quantitative imaging aimed to detect microstructural changes in the normal-appearing white matter (NAWM), including sequences sensitive to magnetisation transfer (MT) effects from amide proton transfer (MTRAPT) and the nuclear Overhauser effect (MTRNOE). (3) Results: 12 patients were recruited, and 10 patients completed the study. The difference in the T1 relaxation times at month 6 and month 12 of natalizumab treatment was not significant, suggesting the lack of accumulation of tissue damage, while improvements were seen in MTR (MTRAPT and MTRNOE measures) at month 12, suggesting a tissue repair effect. This paralleled the expected lack of clinical and radiological worsening of conventional MRI measures of disease activity (new lesions or gadolinium-enhancing lesions). (4) Conclusion: Natalizumab prevents microstructural brain damage and has effects suggesting an improved white matter microstructure measured at ultra-high field during the first year of treatment.

Neuroimaging Technology in Exercise Neurorehabilitation Research in Persons with MS: A Scoping Review

There is increasing interest in the application of neuroimaging technology in exercise neurorehabilitation research among persons with multiple sclerosis (MS). The inclusion and focus on neuroimaging outcomes in MS exercise training research is critical for establishing a biological basis for improvements in functioning and elevating exercise within the neurologist's clinical armamentarium alongside disease modifying therapies as an approach for treating the disease and its consequences. Indeed, the inclusion of selective neuroimaging approaches and sensor-based technology among physical activity, mobility, and balance outcomes in such MS research might further allow for detecting specific links between the brain and real-world behavior. This paper provided a scoping review on the application of neuroimaging in exercise training research among persons with MS based on searches conducted in PubMed, Web of Science, and Scopus. We identified 60 studies on neuroimaging-technology-based (primarily MRI, which involved a variety of sequences and approaches) correlates of functions, based on multiple sensor-based measures, which are typically targets for exercise training trials in MS. We further identified 12 randomized controlled trials of exercise training effects on neuroimaging outcomes in MS. Overall, there was a large degree of heterogeneity whereby we could not identify definitive conclusions regarding a consistent neuroimaging biomarker of MS-related dysfunction or singular sensor-based measure, or consistent neural adaptation for exercise training in MS. Nevertheless, the present review provides a first step for better linking correlational and randomized controlled trial research for the development of high-quality exercise training studies on the brain in persons with MS, and this is timely given the substantial interest in exercise as a potential disease-modifying and/or neuroplasticity-inducing behavior in this population.

Lessons from immunotherapies in multiple sclerosis

The improved understanding of multiple sclerosis (MS) neurobiology alongside the development of novel markers of disease will allow precision medicine to be applied to MS patients, bringing the promise of improved care. Combinations of clinical and paraclinical data are currently used for diagnosis and prognosis. The addition of advanced magnetic resonance imaging and biofluid markers has been strongly encouraged, since classifying patients according to the underlying biology will improve monitoring and treatment strategies. For example, silent progression seems to contribute significantly more than relapses to overall disability accumulation, but currently approved treatments for MS act mainly on neuroinflammation and offer only a partial protection against neurodegeneration. Further research, involving traditional and adaptive trial designs, should strive to halt, repair or protect against central nervous system damage. To personalize new treatments, their selectivity, tolerability, ease of administration, and safety must be considered, while to personalize treatment approaches, patient preferences, risk-aversion, and lifestyle must be factored in, and patient feedback used to indicate real-world treatment efficacy. The use of biosensors and machine-learning approaches to integrate biological, anatomical, and physiological parameters will take personalized medicine a step closer toward the patient's virtual twin, in which treatments can be tried before they are applied.

Does Ocrelizumab Limit Multiple Sclerosis Progression? Current Evidence from Clinical, MRI, and Fluid Biomarkers

Multiple sclerosis (MS) is a chronic inflammatory, demyelinating, and neurodegenerative disease affecting the central nervous system, often characterized by the accumulation of irreversible clinical disability over time. In recent years, there has been a dramatic evolution in several key concepts of MS treatment. The demonstration of the effects of ocrelizumab, a selective monoclonal antibody against CD20+ B cells, has significantly modified our knowledge of the immune-pathophysiology of MS and has provided a new therapeutic target for relapsing and progressive MS patients. Emerging findings suggest that, besides its strong anti-inflammatory activity, ocrelizumab may limit disability progression and may exert beneficial effects on cognitive function, fatigue, and quality of life of MS patients. The significant reductions of the rate of global and regional brain atrophy and of serum neurofilament light chain levels, which were found to be partially independent of overt inflammatory activity, suggest that this treatment may also limit neuro-axonal damage. By discussing the most recent evidence regarding the effects of ocrelizumab on clinical measures as well as on magnetic resonance imaging and fluid biomarkers, this review summarizes current knowledge on the possible mechanisms underlying the effects of ocrelizumab in limiting MS progression and neurodegeneration.

Early use of high-efficacy disease‑modifying therapies makes the difference in people with multiple sclerosis: an expert opinion

Multiple sclerosis (MS) is a chronic and progressive neurological disease that is characterized by neuroinflammation, demyelination and neurodegeneration occurring from the earliest phases of the disease and that may be underestimated. MS patients accumulate disability through relapse-associated worsening or progression independent of relapse activity. Early intervention with high-efficacy disease-modifying therapies (HE-DMTs) may represent the best window of opportunity to delay irreversible central nervous system damage and MS-related disability progression by hindering underlying heterogeneous pathophysiological processes contributing to disability progression. In line with this, growing evidence suggests that early use of HE-DMTs is associated with a significant greater reduction not only of inflammatory activity (clinical relapses and new lesion formation at magnetic resonance imaging) but also of disease progression, in terms of accumulation of irreversible clinical disability and neurodegeneration compared to delayed HE-DMT use or escalation strategy. These beneficial effects seem to be associated with acceptable long-term safety risks, thus configuring this treatment approach as that with the most positive benefit/risk profile. Accordingly, it should be mandatory to treat people with MS early with HE-DMTs in case of prognostic factors suggestive of aggressive disease, and it may be advisable to offer an HE-DMT to MS patients early after diagnosis, taking into account drug safety profile, disease severity, clinical and/or radiological activity, and patient-related factors, including possible comorbidities, family planning, and patients’ preference in agreement with the EAN/ECTRIMS and AAN guidelines. Barriers for an early use of HE-DMTs include concerns for long-term safety, challenges in the management of treatment initiation and monitoring, negative MS patients’ preferences, restricted access to HE-DMTs according to guidelines and regulatory rules, and sustainability. However, these barriers do not apply to each HE-DMT and none of these appear insuperable.

Mapping brain structure and function in professional fencers: A model to study training effects on central nervous system plasticity

Brain magnetic resonance imaging (MRI) studies have shown different patterns of structural and functional reorganization in high‐level athletes compared with controls, but little is known about their relationship with interlimb coordination mechanisms. To this aim, we investigated brain structural and functional differences in high‐level fencers compared with nonathlete controls and the MRI substrates of interlimb coordination in elite athletes. Fourteen right‐handed male fencers (median age = 22.3 years) and 15 right‐handed age‐ and sex‐matched healthy subjects (median age = 22.4 years) underwent structural and functional MRI acquisition during the execution of cyclic bimanual‐movements as well as during in‐phase and antiphase hand/foot‐movements of the dominant‐right limbs. No between‐group differences were found in gray matter volumes and white matter architecture. Active‐fMRI showed that controls versus fencers had higher activations in parietal and temporal areas during bimanual‐task; whereas fencers versus controls had higher activations in the basal ganglia. During in‐phase task, controls versus fencers showed higher activation of right cerebellum, whereas fencers had higher activity mainly in frontal areas. The functional‐connectivity (FC) analysis showed that fencers versus controls had an increased FC between left motor cortex and fronto‐temporal areas as well as bilateral thalami during the different tasks. Intensive and prolonged fencing activity is associated with brain functional changes mainly involving frontal regions related to high‐level motor control and planning of complex tasks. These modifications are likely to reflect an optimization of brain networks involved in motor activities, including interlimb coordination tasks, occurring after intensive training.

No Changes in Functional Connectivity After Dimethyl Fumarate Treatment in Multiple Sclerosis

Introduction

Despite the increased availability of disease-modifying therapies (DMTs) for treating relapsing-remitting multiple sclerosis (RR-MS), only a few studies have evaluated DMT-associated brain functional changes.

Methods

We investigated whether significant resting-state functional connectivity (FC) changes occurred in RR-MS patients after 6 and 12 months of dimethyl fumarate (DMF) treatment using both a seed-based and data-driven approach.

Results

Thirty patients were followed up after 6 months of therapy, and 27 of them reached a 12-month follow-up. Three patients at baseline and only one after 12 months showed gadolinium-enhancing lesions. We did not find any significant FC changes after therapy at either time point. After 12 months of DMF, we observed relatively modest brain volume loss and a significant improvement in Paced Auditory Serial Addition Test 3 s and 25-Foot Walk Test scores.

Conclusion

The absence of FC changes could be due to the low degree of baseline inflammation in our patients, though we cannot exclude that more time may be required to observe such changes. No FC changes may reflect a beneficial effect of DMF therapy, as supported by conventional MRI findings and clinical improvement.

Effects on cognition of DMTs in multiple sclerosis: moving beyond the prevention of inflammatory activity

In this review, we critically summarize recent findings derived from randomized controlled trials (RCTs), observational studies and meta-analyses that have been published in the last 3 years and that included the effects of DMTs on cognitive performances among their outcomes.

Brain atrophy rates in patients with multiple sclerosis on long term natalizumab resembles healthy controls

BACKGROUND

Clinically stable multiple sclerosis (MS) patients often have negligible inflammatory MRI changes. Brain atrophy may provide insight into subclinical disease progression. The objective was to compare brain atrophy rates in stable patients on long term natalizumab treatment vs. age and gender matched healthy non-MS controls (HC) prospectively over two-years examining brain volume, cognition, and patient reported outcomes (PROs).

METHODS

MS patients treated with natalizumab for a minimum of 2 years, age 18-60 were recruited and compared with age- and gender-matched healthy controls (HC). Both groups were followed prospectively to obtain two years of consecutive magnetic resonance imaging, clinical and PRO data. Baseline normalized brain volume (NBV), yearly T2 lesion volume (T2LV), and percent brain volume change (PBVC) were measured using SIENAX, JIM 6.0, and SIENA respectively. Neuropsychological tests from the MACFIMS battery were selected to optimize assessments for impairments in the domains of information processing speed and memory. Patient reported outcomes (PROs) for domains of physical, mental and social quality of life were evaluated using the NeuroQol short forms.

RESULTS

Forty-eight natalizumab and 62 HC completed all study visits. At baseline, unadjusted mean NBV (natalizumab=1508.80cm (Popescu et al., 2013) vs. HC=1539.23cm (Popescu et al., 2013); p=0.033) and median baseline T2LV (natalizumab=1724.62mm (Popescu et al., 2013) vs. HC=44.20mm (Popescu et al., 2013); p=<0.0001) were different. The mean PBVC at year 2, adjusted for gender and baseline age was -0.57% (CI: 0.7620, -0.3716) for natalizumab and -0.50% (-0.7208, -0.2831) for HC, but the difference between groups was not statistically significant (0.073%; p=0.62). Over the 2-year period, HC demonstrated mild improvements in some cognitive tests vs. natalizumab subjects. However, PROs were similar between the two groups.

CONCLUSION

Stable MS patients on natalizumab have similar brain volume loss as people who do not have MS, suggesting normalization of brain atrophy.

Effects of Fingolimod and Natalizumab on Brain T1-/T2-Weighted and Magnetization Transfer Ratios: a 2-Year Study

Fingolimod and natalizumab significantly reduce disease activity in relapsing-remitting multiple sclerosis (RRMS) and could promote tissue repair and neuroprotection. The ratio between conventional T1- and T2-weighted sequences (T1w/T2w-ratio) and magnetization transfer ratio (MTR) allow to quantify brain microstructural tissue abnormalities. Here, we compared fingolimod and natalizumab effects on brain T1w/T2w-ratio and MTR in RRMS over 2 years of treatment. RRMS patients starting fingolimod (n = 25) or natalizumab (n = 30) underwent 3T brain MRI scans at baseline (T0), month 6 (M6), month 12 (M12), and month 24 (M24). White matter (WM) lesions, normal-appearing (NA) WM, and gray matter (GM) T1w/T2w-ratio and MTR were estimated and compared between groups using linear mixed models. No baseline demographic, clinical, and MRI difference was found between groups. In natalizumab patients, lesion T1w/T2w-ratio and MTR significantly increased at M6 vs. T0 (p ≤ 0.035) and decreased at subsequent timepoints (p ≤ 0.037). In fingolimod patients, lesion T1w/T2w-ratio increased at M12 vs. T0 (p = 0.010), while MTR gradually increased at subsequent timepoints vs. T0 (p ≤ 0.027). Natalizumab stabilized NAWM and GM T1w/T2w-ratio and MTR. In fingolimod patients, NAWM T1w/T2w-ratio and MTR significantly increased at M24 vs. M12 (p ≤ 0.001). A significant GM T1w/T2w-ratio decrease at M6 vs. T0 (p = 0.014) and increase at M24 vs. M6 (p = 0.008) occurred, whereas GM MTR was significantly higher at M24 vs. previous timepoints (p ≤ 0.017) with significant between-group differences (p ≤ 0.034). Natalizumab may promote an early recovery of lesional damage and prevent microstructural damage accumulation in NAWM and GM during the first 2 years of treatment. Fingolimod enhances tissue damage recovery being visible after 6 months in lesions and after 2 years in NAWM and GM.

Increased Within-Network Functional Connectivity May Predict NEDA Status in Fingolimod-Treated MS Patients

Only a few studies have evaluated the brain functional changes associated with disease-modifying therapies (DMTs) in multiple sclerosis (MS), though none used a composite measure of clinical and MRI outcomes to evaluate DMT-related brain functional connectivity (FC) measures predictive of short-term outcome. Therefore, we investigated the following: (1) baseline FC differences between patients who showed evidence of disease activity after a specific DMT and those who did not; (2) DMT-related effects on FC, and; (3) possible relationships between DMT-related FC changes and changes in performance. We used a previously analyzed dataset of 30 relapsing MS patients who underwent fingolimod treatment for 6 months and applied the “no evidence of disease activity” (NEDA-3) status as a clinical response indicator of treatment efficacy. Resting-state fMRI data were analyzed to obtain within- and between-network FC measures. After therapy, 14 patients achieved NEDA-3 status (hereinafter NEDA), while 16 did not (EDA). The two groups significantly differed at baseline, with the NEDA group having higher within-network FC in the anterior and posterior default mode, auditory, orbitofrontal, and right frontoparietal networks than the EDA. After therapy, NEDA showed significantly reduced within-network FC in the posterior default mode and left frontoparietal networks and increased between-network FC in the posterior default mode/orbitofrontal networks; they also showed PASAT improvement, which was correlated with greater within-network FC decrease in the posterior default mode network and with greater between-network FC increase. No significant longitudinal FC changes were found in the EDA. Taken together, these findings suggest that NEDA status after fingolimod is related to higher within-network FC at baseline and to a consistent functional reorganization after therapy.

Occurrence and microstructural features of slowly expanding lesions on fingolimod or natalizumab treatment in multiple sclerosis

Background:

In multiple sclerosis (MS), up to 57% of white matter lesions are chronically active. These slowly expanding lesions (SELs) contribute to disability progression.

Objective:

The aim of this study is to compare fingolimod and natalizumab effects on progressive linearly enlarging lesions (i.e. SELs), a putative biomarker of smouldering inflammation.

Methods:

Relapsing-remitting MS patients starting fingolimod ( n = 24) or natalizumab ( n = 28) underwent 3T brain magnetic resonance imaging (MRI) at baseline, months 6, 12 and 24. SELs were identified among baseline-visible lesions showing ⩾ 12.5% of annual increase, calculated by linearly fitting the Jacobian of the nonlinear deformation field between timepoints obtained combining T1- and T2-weighted scans. SEL burden, magnetization transfer ratio (MTR) and T1 signal intensity were compared using linear models.

Results:

The prevalences of fingolimod (75%) and natalizumab patients (46%) with ⩾ 1 SEL were not significantly different (adjusted- p = 0.08). Fingolimod group had higher SEL number and volume (adjusted- p ⩽ 0.047, not false discovery rate (FDR) survived). In both groups, SELs versus non-SELs showed lower MTR and T1 signal intensity (adjusted- p ⩽ 0.01, FDR-survived). Longitudinally, non-SEL MTR increased in both treatment groups (adjusted- p ⩽ 0.005, FDR-survived). T1 signal intensity decreased in SELs with both treatments (adjusted- p ⩽ 0.049, FDR-survived in fingolimod group) and increased in natalizumab non-SELs (adjusted- p = 0.03, FDR-survived).

Conclusion:

The effects of natalizumab and fingolimod on SEL occurrence seem modest, with natalizumab being slightly more effective. Both treatments may promote reparative mechanisms in stable or chronic inactive lesions.

MRI correlates of clinical disability and hand-motor performance in multiple sclerosis phenotypes

Background:

Hand-motor impairment affects a large proportion of multiple sclerosis (MS) patients; however, its substrates are still poorly understood.

Objectives:

To investigate the association between global disability, hand-motor impairment, and alterations in motor-relevant structural and functional magnetic resonance imaging (MRI) networks in MS patients with different clinical phenotypes.

Methods:

One hundred thirty-four healthy controls (HC) and 364 MS patients (250 relapsing-remitting MS (RRMS) and 114 progressive MS (PMS)) underwent Expanded Disability Status Scale (EDSS) rating, nine-hole peg test (9HPT), and electronic finger tapping rate (EFTR). Structural and resting state (RS) functional MRI scans were used to perform a source-based morphometry on gray matter (GM) components, to analyze white matter (WM) tract diffusivity indices and to perform a RS seed-based approach from the primary motor cortex involved in hand movement (hand-motor cortex). Random forest analyses identified the predictors of clinical impairment.

Result:

In RRMS, global measures of atrophy and lesions together with measures of structural damage of motor-related regions predicted EDSS (out-of-bag (OOB)- R2 = 0.19, p-range = <0.001–0.04), z9HPT (right: OOB- R2 = 0.14; left: OOB- R2 = 0.24, p-range = <0.001–0.03). No RS functional connectivity (FC) abnormalities were identified in RRMS models. In PMS, cerebellar and sensorimotor regions atrophy, cerebellar peduncles integrity and increased RS FC between left hand-motor cortex and right inferior frontal gyrus predicted EDSS (OBB- R2 = 0.16, p-range = 0.02–0.04).

Conclusion:

In RRMS, only measures of structural damage contribute to explain motor impairment, whereas both structural and functional MRI measures predict clinical disability in PMS. A multiparametric MRI approach could be relevant to investigate hand-motor impairment in different MS phenotypes.

Systematic Review on Exercise Training as a Neuroplasticity-Inducing Behavior in Multiple Sclerosis

Background. Exercise training is associated with functional improvements in persons with multiple sclerosis (MS), perhaps based on neuroplasticity. However, inferences regarding neuroplasticity require observations of exercise-related changes in the central nervous system that explain functional adaptations. This systematic review critically evaluated studies on exercise training, neuroimaging outcomes, and functional outcomes in MS based on consistency with a well-established conceptual model for characterizing exercise training as a possible neuroplasticity-inducing behavior in this population. Methods. We performed targeted and comprehensive searches of multiple databases for papers involving exercise training interventions on functional and neuroimaging outcomes in persons with MS. Acceptable study designs included randomized controlled trials, single-group pre/post designs, and quasi-experimental designs. Four independent reviewers extracted relevant data from each eligible paper on characteristics of participants, exercise interventions, neuroimaging outcomes, functional outcomes, pattern of study results, and potential risks of bias. Results. The literature search returned only 10 papers (involving 8 original interventions) that met eligibility criteria wherein inferences regarding neuroplasticity could be drawn, based on inclusion of neuroimaging and functional endpoints. Within those 10 papers, there is mixed evidence for exercise training as a neuroplasticity-inducing behavior in persons with MS. Conclusions. Such a paucity of evidence supporting exercise-induced neuroplasticity in MS is likely a product of a very small number of papers that do not sufficiently examine hypothesized mechanisms of action. Future research might consider examining specific neural changes that might result from exercise prescriptions that are specifically designed to induce certain functional changes among persons with MS.

Two-year regional grey and white matter volume changes with natalizumab and fingolimod

OBJECTIVE

To compare the efficacy of fingolimod and natalizumab in preventing regional grey matter (GM) and white matter (WM) atrophy in relapsing-remitting multiple sclerosis (RRMS) over 2 years.

METHODS

Patients with RRMS starting fingolimod (n=25) or natalizumab (n=30) underwent clinical examination and 3T MRI scans at baseline (month (M) 0), M6, M12 and M24. Seventeen healthy controls were also scanned at M0 and M24. Tensor-based morphometry and SPM12 were used to assess the longitudinal regional GM/WM volume changes.

RESULTS

At M0, no clinical or GM/WM volume differences were found between treatment groups. At M24, both drugs reduced relapse rate (p<0.001 for both) and stabilised disability. At M6 vs M0, both groups experienced significant atrophy of several areas in the cortex, deep GM nuclei and supratentorial WM. Significant bilateral cerebellar GM and WM atrophy occurred in fingolimod patients only. At M12 vs M6 and M24 vs M12, further supratentorial GM and WM atrophy occurred in both groups. Bilateral GM/WM cerebellar atrophy continued to progress in fingolimod patients only. Compared with natalizumab, fingolimod-treated patients showed a significant cerebellar GM/WM atrophy, mainly at M6 vs M0, but still occurring up to M24. Compared with fingolimod, natalizumab-treated patients had a small number of areas of GM atrophy in temporo-occipital regions at the different time-points.

CONCLUSIONS

Natalizumab and fingolimod are associated with heterogeneous temporal and regional patterns of GM and WM atrophy progression. Compared with natalizumab, fingolimod-treated patients experience accelerated GM and WM atrophy in the cerebellum, while both drugs show minimal regional volumetric differences in supratentorial regions.