Impaired cognition is related to microstructural integrity in relapsing remitting multiple sclerosis

Background

Cognitive impairment is common in multiple sclerosis (MS). However, the relationship between cognitive deficits and microstructural abnormalities in Chinese MS patients remains unclear. We aimed to investigate the importance of microstructural abnormalities and the associations with cognitive impairment in Chinese MS patients.

Methods

Three‐dimensional T1‐weighted magnetic resonance imaging (MRI) scans were obtained from 36 relapsing remitting MS patients. Diffusion tensor imaging (DTI) scans were acquired for 29 (81%) patients. Cognitive impairment was assessed using a comprehensive neuropsychological battery. Patients were classified into cognitively impaired (CI) group and cognitively preserved (CP) group. Using volBrain and FSL software, we assessed white matter lesion burden, white matter (WM) and gray matter (GM) volumetric as well as microstructural diffusivity. MRI variables explaining cognitive impairment were analyzed.

Results

Fifteen (42%) patients were classified as CI. Verbal learning and memory was the most commonly impaired domain (n = 16, 44%). CI patients had lower mean skeleton fractional anisotropy (FA) value than CP patients (275.45 vs. 283.61 × 10⁻³, P = 0.023). The final predicting model including demographic variables and global skeleton mean diffusivity (MD) explained 43.6% of variance of the presence of cognitive impairment (β = 0.131, P = 0.041). CI patients showed a widespread change of microstructural integrity comparing to CP patients, which was rarely overlapping with lesion probability map. Microstructural abnormalities in corpus callosum were associated with performance in verbal learning and memory, processing speed and selective attention (P < 0.05).

Conclusion

Loss of microstructural integrity demonstrated by DTI helps explain cognitive dysfunction in Chinese MS patients.

Remyelination alters the pattern of myelin in the cerebral cortex

Destruction of oligodendrocytes and myelin sheaths in cortical gray matter profoundly alters neural activity and is associated with cognitive disability in multiple sclerosis (MS). Myelin can be restored by regenerating oligodendrocytes from resident progenitors; however, it is not known whether regeneration restores the complex myelination patterns in cortical circuits. Here, we performed time lapse in vivo two photon imaging in somatosensory cortex of adult mice to define the kinetics and specificity of myelin regeneration after acute oligodendrocyte ablation. These longitudinal studies revealed that the pattern of myelination in cortex changed dramatically after regeneration, as new oligodendrocytes were formed in different locations and new sheaths were often established along axon segments previously lacking myelin. Despite the dramatic increase in axonal territory available, oligodendrogenesis was persistently impaired in deeper cortical layers that experienced higher gliosis. Repeated reorganization of myelin patterns in MS may alter circuit function and contribute to cognitive decline.

RehaCom rehabilitation training improves a wide-range of cognitive functions in multiple sclerosis patients

Multiple sclerosis (MS) is a chronic neurodegenerative disease that impairs cognitive performance. Attention, response control, working memory, and processing speed are highly impaired in MS. On the other hand, RehaCom is a computerized software that improves cognitive dysfunctions. In this study, we aimed to investigate the effect of RehaCom on attention, response control, processing speed, working memory, visuospatial skills, and verbal/non-verbal executive functions in MS patients. Sixty patients were selected randomly and divided into control (n = 30) and experimental (n = 30) groups. Integrated Auditory Visual-2 (IVA-2), Paced Auditory Serial Addition Test (PASAT), Symbol Digit Modalities Test (SDMT), Judgment of Line Orientation (JLO) and The Delis-Kaplan Executive Function System (DKEFS) were used to assess cognitive functions. Patients in the experimental group were treated by RehaCom for 5 weeks (two 60-min sessions per week). Cognitive performance of all patients in both groups was assessed at weeks 5 and 10 (post-test and follow-up stages, respectively). The results showed that RehaCom treatment improved all studied cognitive functions at the post-test stage. This effect also remained at the follow-up stage for some cognitive functions. In conclusion, treatment with RehaCom may have significant therapeutic effects on cognitive dysfunctions in MS patients.

MRI biomarkers of disease progression and conversion to secondary-progressive multiple sclerosis

INTRODUCTION

Conventional imaging measures remain a key clinical tool for the diagnosis multiple sclerosis (MS) and monitoring of patients. However, most measures used in the clinic show unsatisfactory performance in predicting disease progression and conversion to secondary progressive MS.

AREAS COVERED

Sophisticated imaging techniques have facilitated the identification of imaging biomarkers associated with disease progression, such as global and regional brain volume measures, and with conversion to secondary progressive MS, such as leptomeningeal contrast enhancement and chronic inflammation. The relevance of emerging imaging approaches partially overcoming intrinsic limitations of traditional techniques is also discussed.

EXPERT OPINION

Imaging biomarkers capable of detecting tissue damage early on in the disease, with the potential to be applied in multicenter trials and at an individual level in clinical settings, are strongly needed. Several measures have been proposed, which exploit advanced imaging acquisitions and/or incorporate sophisticated post-processing, can quantify irreversible tissue damage. The progressively wider use of high-strength field MRI and the development of more advanced imaging techniques will help capture the missing pieces of the MS puzzle. The ability to more reliably identify those at risk for disability progression will allow for earlier intervention with the aim to favorably alter the disease course.

Vitamin D, smoking, EBV, and long-term cognitive performance in MS: 11-year follow-up of BENEFIT

OBJECTIVE

To investigate whether vitamin D, smoking, and anti-Epstein-Barr virus (EBV) antibody concentrations predict long-term cognitive status and neuroaxonal injury in multiple sclerosis (MS).

METHODS

This study was conducted among 278 patients with clinically isolated syndrome who participated in the clinical trial BENEFIT (Betaferon/Betaseron in Newly Emerging Multiple Sclerosis for Initial Treatment) and completed the 11-year assessment (BENEFIT-11). We measured serum 25-hydroxyvitamin-D (25(OH)D), cotinine (smoking biomarker), and anti-Epstein-Barr virus nuclear antigen 1 (EBNA-1) immunoglobulin G (IgG) at baseline and at months 6, 12, and 24 and examined whether these biomarkers contributed to predict Paced Auditory Serial Addition Test (PASAT)-3 scores and serum neurofilament light chain (NfL) concentrations at 11 years. Linear and logistic regression models were adjusted for sex, baseline age, treatment allocation, steroid treatment, multifocal symptoms, T2 lesions, and body mass index.

RESULTS

Higher vitamin D predicted better, whereas smoking predicted worse cognitive performance. A 50-nmol/L higher mean 25(OH)D in the first 2 years was related to 65% lower odds of poorer PASAT performance at year 11 (95% confidence intervals [95% CIs]: 0.14-0.89). Standardized PASAT scores were lower in smokers and heavy smokers than nonsmokers (p _trend = 0.026). Baseline anti-EBNA-1 IgG levels did not predict cognitive performance (p _trend = 0.88). Associations with NfL concentrations at year 11 corroborated these findings-a 50-nmol/L higher mean 25(OH)D in the first 2 years was associated with 20% lower NfL (95% CI: -36% to 0%), whereas smokers had 20% higher NfL levels than nonsmokers (95% CI: 2%-40%). Anti-EBNA-1 antibodies were not associated with NfL.

CONCLUSIONS

Lower vitamin D and smoking after clinical onset predicted worse long-term cognitive function and neuronal integrity in patients with MS.

Identification of a predominant cognitive phenotype in patients with multiple sclerosis

BACKGROUND AND PURPOSE

Cognitive impairment occurs frequently in multiple sclerosis (MS). However, the prevalence and clinical characteristics of cognitive MS phenotype are not well established. The aim of the study was to characterize the clinical course and neurocognitive impairment of patients with MS meeting an Expanded Disability Status Scale (EDSS)-defined cognitive phenotype.

METHODS

A total of 2302 patients from the Comprehensive Longitudinal Investigation of Multiple Sclerosis at Brigham and Women's Hospital (CLIMB) study were studied. Predominant cognitive MS phenotype was defined as EDSS Cerebral Functional System (FS) subscore ≥3 and remaining EDSS FS subscores ≤2 on at least one clinical visit. Demographic/clinical characteristics, phenotype stability and neurocognitive domain impairment of these subjects were assessed.

RESULTS

A total of 60 of 2302 (2.6%) patients (age 52.8 ± 10.8 years, 68% female, 82% relapsing MS) met criteria for phenotype designation. A total of 29 of 60 (48%) were designated within 10 years of their presenting MS symptom. The mean cohort annualized relapse rate was 0.38 and EDSS score at last clinical assessment was 3.2 ± 1.3. Cognitive phenotype status was poorly sustained, with only 27% of subjects maintaining Cerebral FS score ≥2 throughout all follow-up. However, predominant cognitive phenotype subjects with clinical neuropsychiatric testing [n = 39/60 (65%)] frequently had cognitive impairment (1.5 SD below mean) in ≥1 domain [n = 30/39 (77%) of subjects] affecting memory, attention/executive function and processing speed. A total of 11 of 39 (28%) patients had severe-range cognitive impairment (3.0 SD below mean). Cognitive phenotype designation was associated with low rate of employment at last clinical assessment.

CONCLUSION

Predominant cognitive MS phenotype is rare, although an EDSS-based definition identifies patients with multidomain cognitive impairment and may serve as a practical screen for identification of patients who might warrant close monitoring of neurocognitive status.

Oligoclonal IgG antibodies in multiple sclerosis target patient-specific peptides

IgG oligoclonal bands (OCBs) are present in the cerebrospinal fluid (CSF) of more than 95% of patients with multiple sclerosis (MS), and are considered to be the immunological hallmark of disease. However, the target specificities of the IgG in MS OCBs have remained undiscovered. Nevertheless, evidence that OCBs are associated with increased levels of disease activity and disability support their probable pathological role in MS. We investigated the antigen specificity of individual MS CSF IgG from 20 OCB-positive patients and identified 40 unique peptides by panning phage-displayed random peptide libraries. Utilizing our unique techniques of phage-mediated real-time Immuno-PCR and phage-probed isoelectric focusing immunoblots, we demonstrated that these peptides were targeted by intrathecal oligoclonal IgG antibodies of IgG1 and IgG3 subclasses. In addition, we showed that these peptides represent epitopes sharing sequence homologies with proteins of viral origin, and proteins involved in cell stress, apoptosis, and inflammatory processes. Although homologous peptides were found within individual patients, no shared peptide sequences were found among any of the 42 MS and 13 inflammatory CSF control specimens. The distinct sets of oligoclonal IgG-reactive peptides identified by individual MS CSF suggest that the elevated intrathecal antibodies may target patient-specific antigens.

Immunoneuropsychiatry - novel perspectives on brain disorders

Immune processes have a vital role in CNS homeostasis, resilience and brain reserve. Our cognitive and social abilities rely on a highly sensitive and fine-tuned equilibrium of immune responses that involve both innate and adaptive immunity. Autoimmunity, chronic inflammation, infection and psychosocial stress can tip the scales towards disruption of higher-order networks. However, not only classical neuroinflammatory diseases, such as multiple sclerosis and autoimmune encephalitis, are caused by immune dysregulation that affects CNS function. Recent insight indicates that similar processes are involved in psychiatric diseases such as schizophrenia, autism spectrum disorder, bipolar disorder and depression. Pathways that are common to these disorders include microglial activation, pro-inflammatory cytokines, molecular mimicry, anti-neuronal autoantibodies, self-reactive T cells and disturbance of the blood-brain barrier. These discoveries challenge our traditional classification of neurological and psychiatric diseases. New clinical paths are required to identify subgroups of neuropsychiatric disorders that are phenotypically distinct but pathogenically related and to pave the way for mechanism-based immune treatments. Combined expertise from neurologists and psychiatrists will foster translation of these paths into clinical practice. The aim of this Review is to highlight outstanding findings that have transformed our understanding of neuropsychiatric diseases and to suggest new diagnostic and therapeutic criteria for the emerging field of immunoneuropsychiatry.

Epidemiology and treatment of multiple sclerosis in elderly populations

The prevalence of multiple sclerosis (MS) and the age of affected patients are increasing owing to increased longevity of the general population and the availability of effective disease-modifying therapies. However, ageing presents unique challenges in patients with MS largely as a result of their increased frequency of age-related and MS-related comorbidities as well as transition of the disease course from an inflammatory to a neurodegenerative phenotype. Immunosenescence (the weakening of the immune system associated with natural ageing) might be at least partly responsible for this transition, which further complicates disease management. Currently approved therapies for MS are effective in preventing relapse but are not as effective in preventing the accumulation of disability associated with ageing and disease progression. Thus, ageing patients with MS represent a uniquely challenging population that is currently underserved by existing therapeutic regimens. This Review focuses on the epidemiology of MS in ageing patients. Unique considerations relevant to this population are discussed, including the immunology and pathobiology of the complex relationship between ageing and MS, the safety and efficacy of disease-modifying therapies, when discontinuation of treatment might be appropriate and the important role of approaches to support wellness and cognition.

Reaching an evidence-based prognosis for personalized treatment of multiple sclerosis

Personalized treatment is ideal for multiple sclerosis (MS) owing to the heterogeneity of clinical features, but current knowledge gaps, including validation of biomarkers and treatment algorithms, limit practical implementation. The contemporary approach to personalized MS therapy depends on evidence-based prognostication, an initial treatment choice and evaluation of early treatment responses to identify the need to switch therapy. Prognostication is directed by baseline clinical, environmental and demographic factors, MRI measures and biomarkers that correlate with long-term disability measures. The initial treatment choice should be a shared decision between the patient and physician. In addition to prognosis, this choice must account for patient-related factors, including comorbidities, pregnancy planning, preferences of the patients and their comfort with risk, and drug-related factors, including safety, cost and implications for treatment sequencing. Treatment response has traditionally been assessed on the basis of relapse rate, MRI lesions and disability progression. Larger longitudinal data sets have enabled development of composite outcome measures and more stringent standards for disease control. Biomarkers, including neurofilament light chain, have potential as early surrogate markers of prognosis and treatment response but require further validation. Overall, attainment of personalized treatment for MS is complex but will be refined as new data become available.

Environmental enrichment improves cognitive symptoms and pathological features in a focal model of cortical damage of multiple sclerosis

Multiple Sclerosis (MS) is a neuroinflammatory disease affecting white and grey matter, it is characterized by demyelination, axonal degeneration along with loss of motor, sensitive and cognitive functions. MS is a heterogeneous disease that displays different clinical courses: relapsing/remitting MS (RRMS), and MS progressive forms: primary progressive (PPMS) and secondary progressive (SPMS). Cortical damage in the progressive MS forms has considerable clinical relevance due to its association with cognitive impairment and disability progression in patients. One treatment is available for the progressive forms of the disease, but none are specific for cognitive deficits. We developed an animal model that reflects most of the characteristics of the cortical damage, such as cortical neuroinflammation, demyelination, neurodegeneration and meningeal inflammation, which was associated with cognitive impairment. Cognitive rehabilitation, exercise and social support have begun to be evaluated in patients and animal models of neurodegenerative diseases. Environmental enrichment (EE) provides exercise as well as cognitive and social stimulation. EE has been demonstrated to exert positive effects on cognitive domains, such as learning and memory, and improving anxiety-like symptoms. We proposed to study the effect of EE on peripherally stimulated cortical lesion induced by the long term expression of interleukin IL-1β (IL-1β) in adult rats. Here, we demonstrated that EE: 1) reduces the peripheral inflammatory response to the stimulus, 2) ameliorates cognitive deficits and anxiety-like symptoms, 3) modulates neurodegeneration, demyelination and glial activation, 4) regulates neuroinflammation by reducing the expression of pro-inflammatory cytokines and enhancing the expression of anti-inflammatory ones. Our findings correlate with the fact that EE housing could be considered an effective non- pharmacological therapeutic agent that can synergistically aid in the rehabilitation of the disease.

Relationship between MRI perfusion and clinical severity in multiple sclerosis

Perfusion alterations within several brain regions have been shown in multiple sclerosis patients using different magnetic resonance imaging (MRI) techniques. Furthermore, MRI-derived brain perfusion metrics have been investigated in association with multiple sclerosis phenotypes, physical disability, and cognitive impairment. However, a review focused on these aspects is still missing. Our aim was to review all the studies investigating the relationship between perfusion MRI and clinical severity during the last fifteen years to understand the clinical relevance of these findings. Perfusion differences among phenotypes were observed both with 1.5T and 3T scanners, with progressive multiple sclerosis presenting with lower perfusion values than relapsing-remitting multiple sclerosis patients. However, only 3T scanners showed a statistically significant distinction. Controversial results about the association between MRI-derived perfusion metrics and physical disability scores were found. However, the majority of the studies showed that lower brain perfusion and longer transit time are associated with more severe physical disability and worse cognitive performances.

Meningeal inflammation changes the balance of TNF signalling in cortical grey matter in multiple sclerosis

Background

Recent studies of cortical pathology in secondary progressive multiple sclerosis have shown that a more severe clinical course and the presence of extended subpial grey matter lesions with significant neuronal/glial loss and microglial activation are associated with meningeal inflammation, including the presence of lymphoid-like structures in the subarachnoid space in a proportion of cases.

Methods

To investigate the molecular consequences of pro-inflammatory and cytotoxic molecules diffusing from the meninges into the underlying grey matter, we carried out gene expression profiling analysis of the motor cortex from 20 post-mortem multiple sclerosis brains with and without substantial meningeal inflammation and 10 non-neurological controls.

Results

Gene expression profiling of grey matter lesions and normal appearing grey matter not only confirmed the substantial pathological cell changes, which were greatest in multiple sclerosis cases with increased meningeal inflammation, but also demonstrated the upregulation of multiple genes/pathways associated with the inflammatory response. In particular, genes involved in tumour necrosis factor (TNF) signalling were significantly deregulated in MS cases compared with controls. Increased meningeal inflammation was found to be associated with a shift in the balance of TNF signalling away from TNFR1/TNFR2 and NFkB-mediated anti-apoptotic pathways towards TNFR1- and RIPK3-mediated pro-apoptotic/pro-necroptotic signalling in the grey matter, which was confirmed by RT-PCR analysis. TNFR1 was found expressed preferentially on neurons and oligodendrocytes in MS cortical grey matter, whereas TNFR2 was predominantly expressed by astrocytes and microglia.

Conclusions

We suggest that the inflammatory milieu generated in the subarachnoid space of the multiple sclerosis meninges by infiltrating immune cells leads to increased demyelinating and neurodegenerative pathology in the underlying grey matter due to changes in the balance of TNF signalling.

Cognitive trajectories in relapsing-remitting multiple sclerosis: A longitudinal 6-year study

BACKGROUND

Information concerning longitudinal cognitive trajectories in multiple sclerosis (MS) is relatively scarce. Moreover, it is unclear which factors are associated with cognitive decline and what is the clinical impact of cognitive impairment (CI) in the long run.

OBJECTIVE

To investigate cognitive trajectories in relapsing-remitting multiple sclerosis (RRMS) patients, analyzing clinical and magnetic resonance imaging (MRI) predictors of cognitive decline.

METHODS

We enrolled 42 patients and 30 controls. They underwent brain MRI and clinical/neuropsychological evaluation at baseline and after 1, 2, and 6 years. We evaluated cognitive domains with principal component analysis and performed multivariable regression analyzing predictors of clinical/cognitive deterioration. We also performed repeated measures analysis to assess whether clinical progression was different according to CI at baseline.

RESULTS

A total of 23 (62.2%) patients deteriorated in combined cognitive domains after 6 years, most in processing speed and memory. The number of baseline impaired cognitive domains was strongly associated with 6-year cognitive (R² = 0.452; p < 0.001) and Expanded Disability Status Scale (EDSS) deterioration (R² = 0.263; p < 0.001). Patients with baseline CI in combined domains had worse clinical progression.

CONCLUSION

Isolated CI tends to become more widespread, affecting memory and processing speed alongside. The extent of baseline CI was the best predictor of both clinical and cognitive deterioration after 6 years.

Cortical and meningeal pathology in progressive multiple sclerosis: a new therapeutic target?

Multiple sclerosis (MS) is an inflammatory and neurodegenerative disease that involves an intricate interaction between the central nervous system and the immune system. Nevertheless, its etiology is still unknown. MS exhibits different clinical courses: recurrent episodes with remission periods ('relapsing-remitting') that can evolve to a 'secondary progressive' form or persistent progression from the onset of the disease ('primary progressive'). The discovery of an effective treatment and cure has been hampered due to the pathological and clinical heterogeneity of the disease. Historically, MS has been considered as a disease exclusively of white matter. However, patients with progressive forms of MS present with cortical lesions associated with meningeal inflammation along with physical and cognitive disabilities. The pathogenesis of the cortical lesions has not yet been fully described. Animal models that represent both the cortical and meningeal pathologies will be critical in addressing MS pathogenesis as well as the design of specific treatments. In this review, we will address the state-of-the-art diagnostic and therapeutic alternatives and the development of strategies to discover new therapeutic approaches, especially for the progressive forms.

Inflammatory intrathecal profiles and cortical damage in multiple sclerosis

OBJECTIVE

Gray matter (GM) damage and meningeal inflammation have been associated with early disease onset and a more aggressive disease course in multiple sclerosis (MS), but can these changes be identified in the patient early in the disease course?

METHODS

To identify possible biomarkers linking meningeal inflammation, GM damage, and disease severity, gene and protein expression were analyzed in meninges and cerebrospinal fluid (CSF) from 27 postmortem secondary progressive MS and 14 control cases. Combined cytokine/chemokine CSF profiling and 3T magnetic resonance imaging (MRI) were performed at diagnosis in 2 independent cohorts of MS patients (35 and 38 subjects) and in 26 non-MS patients.

RESULTS

Increased expression of proinflammatory cytokines (IFNγ, TNF, IL2, and IL22) and molecules related to sustained B-cell activity and lymphoid-neogenesis (CXCL13, CXCL10, LTα, IL6, and IL10) was detected in the meninges and CSF of postmortem MS cases with high levels of meningeal inflammation and GM demyelination. Similar proinflammatory patterns, including increased levels of CXCL13, TNF, IFNγ, CXCL12, IL6, IL8, and IL10, together with high levels of BAFF, APRIL, LIGHT, TWEAK, sTNFR1, sCD163, MMP2, and pentraxin III, were detected in the CSF of MS patients with higher levels of GM damage at diagnosis.

INTERPRETATION

A common pattern of intrathecal (meninges and CSF) inflammatory profile strongly correlates with increased cortical pathology, both at the time of diagnosis and at death. These results suggest a role for detailed CSF analysis combined with MRI as a prognostic marker for more aggressive MS. Ann Neurol 2018 Ann Neurol 2018;83:739-755.

Cortical grey matter sodium accumulation is associated with disability and secondary progressive disease course in relapse-onset multiple sclerosis

OBJECTIVE

Sodium (²³Na)-MRI is an emerging imaging technique to investigate in vivo changes in tissue viability, reflecting neuroaxonal integrity and metabolism. Using an optimised ²³Na-MRI protocol with smaller voxel sizes and improved tissue contrast, we wanted to investigate whether brain total sodium concentration (TSC) is a biomarker for long-term disease outcomes in a cohort of patients with relapse-onset multiple sclerosis (MS), followed from disease onset.

METHODS

We performed a cross-sectional study in 96 patients followed up ~ 15 years after a clinically isolated syndrome (CIS) and 34 healthy controls. Disease course was classified as CIS, relapsing-remitting MS or secondary progressive MS (SPMS). We acquired ¹H-MRI and ²³Na-MRI and calculated the TSC in cortical grey matter (CGM), deep grey matter, normal-appearing white matter (WM) and WM lesions. Multivariable linear regression was used to identify independent associations of tissue-specific TSC with physical disability and cognition, with adjustment for tissue volumes.

RESULTS

TSC in all tissues was higher in patients with MS compared with healthy controls and patients who remained CIS, with differences driven by patients with SPMS. Higher CGM TSC was independently associated with Expanded Disability Status Scale (R²=0.26), timed 25-foot walk test (R²=0.23), 9-hole peg test (R²=0.23), Paced Auditory Serial Addition Test (R²=0.29), Symbol Digit Modalities Test (R²=0.31) and executive function (R²=0.36) test scores, independent of grey matter atrophy.

CONCLUSIONS

Sodium accumulation in CGM reflects underlying neuroaxonal metabolic abnormalities relevant to disease course heterogeneity and disability in relapse-onset MS. TSC and should be considered as an outcome measure in future neuroprotection trials.

Longitudinal Characterization of Cortical Lesion Development and Evolution in Multiple Sclerosis with 7.0-T MRI

Background Cortical lesions develop early in multiple sclerosis (MS) and play a major role in disease progression. MRI at 7.0 T shows high sensitivity for detection of cortical lesions as well as better spatial resolution and signal-to-noise ratio compared with lower field strengths. Purpose To longitudinally characterize (a) the development and evolution of cortical lesions in multiple sclerosis across the cortical width, sulci, and gyri; (b) their relation with white matter lesion accrual; and (c) the contribution of 7.0-T cortical and white matter lesion load and cortical thickness to neurologic disability. Materials and Methods Twenty participants with relapsing-remitting MS and 13 with secondary progressive MS, along with 10 age-matched healthy controls, were prospectively recruited from 2010 to 2016 to acquire, in two imaging sessions (mean interval, 1.5 years), 7.0-T MRI T2*-weighted gradient-echo images (0.33 × 0.33 × 1.0 mm3) for cortical and white matter lesion segmentation and 3.0-T T1-weighted images for cortical surface reconstruction and cortical thickness estimation. Cortical lesions were sampled through the cortex to quantify cortical lesion distribution. The Expanded Disability Status Scale (EDSS) was used to assess neurologic disability. Nonparametric statistics assessed differences between and within groups in MRI metrics of cortical and white matter lesion burden; regression analysis explored associations of disability with MRI metrics. Results Twenty-five of 31 (81%) participants developed new cortical lesions per year (intracortical, 1.3 ± 1.7 vs leukocortical, 0.7 ± 1.9; P = .04), surpassing white matter lesion accrual (cortical, 2.0 ± 2.8 vs white matter, 0.7 ± 0.6; P = .01). In contrast to white matter lesions, cortical lesion accrual was greater in participants with secondary progressive MS than with relapsing-remitting MS (3.6 lesions/year ± 4.2 vs 1.1 lesions/year ± 0.9, respectively; P = .03) and preferentially localized in sulci. Total cortical lesion volume independently predicted baseline EDSS (β = 1.5, P < .001) and EDSS changes at follow-up (β = 0.5, P = .003). Conclusion Cortical lesions predominantly develop intracortically and within sulci, suggesting an inflammatory cerebrospinal fluid-mediated lesion pathogenesis. Cortical lesion accumulation was prominent at 7.0 T and independently predicted neurologic disability progression. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Filippi and Rocca in this issue.

Characterization of gray-matter multiple sclerosis lesions using double inversion recovery, diffusion, contrast-enhanced, and volumetric MRI

PURPOSE

To investigate gray-matter (GM) lesions in relapsing-remitting multiple sclerosis (MS) using double-inversion recovery (DIR) MRI, determine GM lesions prevalence, spatial distribution and characterize their contrast-enhancement, diffusion characteristics and compare them to white-matter (WM) lesions. This is the first study, to our knowledge, to investigate GM MS lesions using double-inversion recovery MRI, to determine GM lesion prevalence and location, and characterize contrast-enhancement and diffusion characteristics, compared to WM lesion characteristics in the same patients. We also correlated GM lesion counts, volume and apparent diffusion coefficient (ADC) with total brain, WM, and GM volumes, as well as 25-foot walk test as a clinical disability.

MATERIALS AND METHODS

This retrospective study included 44 relapsing-remitting MS patients (12M/32F, 41 ± 13 years) and 24 age-matched healthy controls (14M/10F, 36 ± 13 years). Lesions were segmented based on DIR and grouped into GM, subcortical WM, and periventricular WM lesions. ADC was tabulated for contrast-enhancing and non-enhancing lesions. Unpaired two sample t-tests were used for comparison between groups. Linear regression was used to evaluate the relationship between number of GM lesions, number of total lesions, total GM lesion volume, and total WM lesion volume with brain volumes and clinical data.

RESULTS

GM MS lesions were present in the majority (86.4%, 38/44) of RRMS patients based on DIR, suggesting GM damage plays an important role in MS pathogenesis. The majority of the GM lesions were located in the frontal lobe. The percentage of lesions in GM that were contrast-enhanced was similar to those in WM, suggesting that blood-brain barrier integrity is likely affected similarly in GM and WM. Contrast-enhanced GM lesions showed higher ADC. GM lesion count and volume were correlated with global and regional brain atrophy, and with more severe disability group.

CONCLUSION

This study characterized GM MS lesions using double-inversion recovery, contrast-enhanced and diffusion MRI. Understanding GM lesion pathophysiology using MRI in vivo, may prove useful for improving targeted therapy and monitoring disease progression.

MRI of cortical lesions and its use in studying their role in MS pathogenesis and disease course

Cortical grey matter (GM) demyelination is present from the earliest stages of multiple sclerosis (MS) and is associated with physical deficits and cognitive impairment. In particular, the rate of disability progression in MS, both in the relapsing and progressive phases, appears to be strictly associated with degenerative GM demyelination and diffuse cortical atrophy. In the last decade, several histopathological studies and advanced radiological methodologies have contributed to better identify the exact involvement/load of cortical pathology in MS, even if the specific inflammatory features and the precise cell and molecular mechanisms of GM demyelination and neurodegeneration in MS remain still not fully understood. It has been proposed that a combined neuropathology, imaging and molecular approach may help to define a more detailed characterization and precise assessment of the heterogeneous features of GM injury and inflammation in MS. This, in turn, will possibly identify specific imaging and biohumoral (cerebrospinal fluid/serum) correlates of cortical pathology that may have an important role in predicting and monitor the disease evolution.

The Relevance of Neuroimaging Findings to Physical Disability in Multiple Sclerosis

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system and one of the leading causes of disability in young adults. While some patients with MS have a benign course in which they develop limited disability even after many years, other patients have a rapidly progressive course resulting in severe disability. However, the progression of the disease, particularly disability, is currently a predictable course with neuroimaging features to some extend. Magnetic resonance imaging (MRI) is not only the main diagnostic tool but also used to monitor response to therapies, thanks to its high sensitivity and ability to identify clinically silent lesions. This report presents a literature review which examines in detail the relationship between MRI findings and disability.

Brain and retinal atrophy in African-Americans versus Caucasian-Americans with multiple sclerosis: a longitudinal study

On average, African Americans with multiple sclerosis demonstrate higher inflammatory disease activity, faster disability accumulation, greater visual dysfunction, more pronounced brain tissue damage and higher lesion volume loads compared to Caucasian Americans with multiple sclerosis. Neurodegeneration is an important component of multiple sclerosis, which in part accounts for the clinical heterogeneity of the disease. Brain atrophy appears to be widespread, although it is becoming increasingly recognized that regional substructure atrophy may be of greater clinical relevance. Patient race (within the limitations of self-identified ancestry) is regarded as an important contributing factor. However, there is a paucity of studies examining differences in neurodegeneration and brain substructure volumes over time in African Americans relative to Caucasian American patients. Optical coherence tomography is a non-invasive and reliable tool for measuring structural retinal changes. Recent studies support its utility for tracking neurodegeneration and disease progression in vivo in multiple sclerosis. Relative to Caucasian Americans, African American patients have been found to have greater retinal structural injury in the inner retinal layers. Increased thickness of the inner nuclear layer and the presence of microcystoid macular pathology at baseline predict clinical and radiological inflammatory activity, although whether race plays a role in these changes has not been investigated. Similarly, assessment of outer retinal changes according to race in multiple sclerosis remains incompletely characterized. Twenty-two African Americans and 60 matched Caucasian Americans with multiple sclerosis were evaluated with brain MRI, and 116 African Americans and 116 matched Caucasian Americans with multiple sclerosis were monitored with optical coherence tomography over a mean duration of 4.5 years. Mixed-effects linear regression models were used in statistical analyses. Grey matter (-0.9%/year versus -0.5%: P =0.02), white matter (-0.7%/year versus -0.3%: P =0.04) and nuclear thalamic (-1.5%/year versus -0.7%/year: P =0.02) atrophy rates were approximately twice as fast in African Americans. African Americans also exhibited higher proportions of microcystoid macular pathology (12.1% versus 0.9%, P =0.001). Retinal nerve fibre layer (-1.1% versus -0.8%: P =0.02) and ganglion cell+ inner plexiform layer (-0.7%/year versus -0.4%/year: P =0.01) atrophy rates were faster in African versus Caucasian Americans. African Americans on average exhibited more rapid neurodegeneration than Caucasian Americans and had significantly faster brain and retinal tissue loss. These results corroborate the more rapid clinical progression reported to occur, in general, in African Americans with multiple sclerosis and support the need for future studies involving African Americans in order to identify individual differences in treatment responses in multiple sclerosis.

Impact of trial design and patient heterogeneity on the identification of clinically effective therapies for progressive MS

Clinically effective immunomodulatory therapies have been developed for relapsing-remitting multiple sclerosis (RRMS), but they have generally not translated to a corresponding slowing of disability accumulation in progressive forms of multiple sclerosis (MS). Since disability is multifaceted, progressive patients are heterogeneous, and the drivers of disease progression are still unclear, it has been difficult to identify the most informative outcome measures for progressive trials. Historically, secondary outcome measures have focused on inflammatory measures, which contributed to the recent identification of immunomodulatory therapies benefiting younger patients with more inflammatory progressive MS. Meanwhile, agents capable of treating late-stage disease have remained elusive. Consequently, measures of neurodegeneration are becoming common. Here, we review completed clinical trials testing immunomodulatory therapies in primary progressive multiple sclerosis (PPMS) or secondary progressive multiple sclerosis (SPMS) and discuss the features contributing to trial design variability in relation to trial outcomes, and how efforts toward better patient stratification and inclusion of reliable progression markers could improve outcomes.

Ultra-high-field arterial spin labelling MRI for non-contrast assessment of cortical lesion perfusion in multiple sclerosis

Objectives

To assess the feasibility of using an optimised ultra-high-field high-spatial-resolution low-distortion arterial spin labelling (ASL) MRI acquisition to measure focal haemodynamic pathology in cortical lesions (CLs) in multiple sclerosis (MS).

Methods

Twelve MS patients (eight female, mean age 50 years; range 35–64 years) gave informed consent and were scanned on a 7 Tesla Philips Achieva scanner. Perfusion data were collected at multiple post-labelling delay times using a single-slice flow-sensitive alternating inversion recovery ASL protocol with a balanced steady-state free precession readout scheme. CLs were identified using a high-resolution Phase-Sensitive Inversion Recovery (PSIR) scan. Significant differences in perfusion within CLs compared to immediately surrounding normal appearing grey matter (NAGM_local) and total cortical normal appearing grey matter (NAGM_cortical) were assessed using paired t-tests.

Results

Forty CLs were identified in PSIR scans that overlapped with the ASL acquisition coverage. After excluding lesions due to small size or intravascular contamination, 27 lesions were eligible for analysis. Mean perfusion was 40 ± 25 ml/100 g/min in CLs, 53 ± 12 ml/100 g/min in NAGM_local, and 53 ± 8 ml/100 g/min in NAGM_cortical. CL perfusion was significantly reduced by 23 ± 9% (mean ± SE, p = 0.013) and 26 ± 9% (p = 0.006) relative to NAGM_local and NAGM_cortical perfusion, respectively.

Conclusion

This is the first ASL MRI study quantifying CL perfusion in MS at 7 Tesla, demonstrating that an optimised ASL acquisition is sensitive to focal haemodynamic pathology previously observed using dynamic susceptibility contrast MRI. ASL requires no exogenous contrast agent, making it a more appropriate tool to monitor longitudinal perfusion changes in MS, providing a new window to study lesion development.

Key Points

• Perfusion can be quantified within cortical lesions in multiple sclerosis using an optimised high spatial resolution arterial spin Labelling MRI acquisition at ultra-high-field.

• The majority of cortical lesions assessed using arterial spin labelling are hypo-perfused compared to normal appearing grey matter, in agreement with dynamic susceptibility contrast MRI literature.

• Arterial spin labelling MRI, which does not involve the injection of a contrast agent, is a safe and appropriate technique for repeat scanning of an individual patient.

Neuropsychology in the Integrated MS Care Setting

The goal of this paper is to describe the role of the neuropsychologist in a Multiple Sclerosis clinic setting. A brief overview of the pathophysiology and neuropsychological deficits in MS is presented. Practical details regarding relations with the neurology team, and the neuropsychologist's focus on assessment are described. Recommendations regarding necessary training and skills, as well as typical clinical practice routines are described. The neuropsychologist's communication with internal and external providers and family members in order to assist implementation of recommendations is described.

Functional Connectivity Alterations Reveal Complex Mechanisms Based on Clinical and Radiological Status in Mild Relapsing Remitting Multiple Sclerosis

Resting state functional MRI (rs-fMRI) has provided important insights into functional reorganization in subjects with Multiple Sclerosis (MS) at different stage of disease. In this cross-sectional study we first assessed, by means of rs-fMRI, the impact of overall T2 lesion load (T2LL) and MS severity score (MSSS) on resting state networks (RSNs) in 62 relapsing remitting MS (RRMS) patients with mild disability (MSSS < 3). Independent Component Analysis (ICA) followed by dual regression analysis confirmed functional connectivity (FC) alterations of many RSNs in RRMS subjects compared to healthy controls. The anterior default mode network (DMNa) and the superior precuneus network (PNsup) showed the largest areas of decreased FC, while the sensory motor networks area M1 (SMNm1) and the medial visual network (MVN) showed the largest areas of increased FC. In order to better understand the nature of these alterations as well as the mechanisms of functional alterations in MS we proposed a method, based on linear regression, that takes into account FC changes and their correlation with T2LL and MSSS. Depending on the sign of the correlation between FC and T2LL, and furthermore the sign of the correlation with MSSS, we suggested the following possible underlying mechanisms to interpret altered FC: (1) FC reduction driven by MS lesions, (2) "true" functional compensatory mechanism, (3a) functional compensation attempt, (3b) "false" functional compensation, (4a) neurodegeneration, (4b) pre-symptomatic condition (damage precedes MS clinical manifestation). Our data shows areas satisfying 4 of these 6 conditions (i.e., 1,2,3b,4b), supporting the suggestion that increased FC has a complex nature that may exceed the simplistic assumption of an underlying compensatory mechanism attempting to limit the brain damage caused by MS progression. Exploring differences between RRMS subjects with short disease duration (MS_short) and RRMS with similar disability but longer disease duration (MS_long), we found that MS_short and MS_long were characterized by clearly distinct pattern of FC, involving predominantly sensory and cognitive networks respectively. Overall, these results suggest that the analysis of FC alterations in multiple large-scale networks in relation to radiological (T2LL) and clinical (MSSS, disease duration) status may provide new insights into the pathophysiology of relapse onset MS evolution.

The effect of fingolimod on focal and diffuse grey matter damage in active MS patients

INTRODUCTION

The mechanism of action of fingolimod within the central nervous system and its efficacy in reducing/preventing both focal and diffuse grey matter (GM) damage in active multiple sclerosis (MS) are not completely understood.

METHODS

In this longitudinal, 2-year prospective, phase IV, single-blind study, 40 MS patients treated with fingolimod and 39 untreated age, gender, and disability-matched MS patients were enrolled. Each patient underwent a neurological examination every 6 months and a 3T MRI at the beginning of the treatment and after 24 months. The accumulation of new cortical lesions (CLs) and the progression of regional GM atrophy were compared between the two groups.

RESULTS

At the end of the study (T24), the percentage of patients with new CLs (13.5 vs. 89%, p < 0.001) and the percentage of GM volume change was lower in the treated group (p < 0.001). The regional analysis revealed that the treated group had also less volume loss in thalamus, caudatus, globus pallidus, cingulate cortex, and hippocampus (p < 0.001), as well as in, cerebellum, superior frontal gyrus, and insular-long gyrus (p < 0.05). Patients with no evidence of disease activity were 60% in the treated group and 10% in the untreated group (p < 0.001).

CONCLUSIONS

These results suggest a possible protective effect of fingolimod on focal and diffuse GM damage.

Effects of Rhythmic Auditory Cueing in Gait Rehabilitation for Multiple Sclerosis: A Mini Systematic Review and Meta-Analysis

Rhythmic auditory cueing has been shown to enhance gait performance in several movement disorders. The "entrainment effect" generated by the stimulations can enhance auditory motor coupling and instigate plasticity. However, a consensus as to its influence over gait training among patients with multiple sclerosis is still warranted. A systematic review and meta-analysis was carried out to analyze the effects of rhythmic auditory cueing in studies gait performance in patients with multiple sclerosis. This systematic identification of published literature was performed according to PRISMA guidelines, from inception until Dec 2017, on online databases: Web of science, PEDro, EBSCO, MEDLINE, Cochrane, EMBASE, and PROQUEST. Studies were critically appraised using PEDro scale. Of 602 records, five studies (PEDro score: 5.7 ± 1.3) involving 188 participants (144 females/40 males) met our inclusion criteria. The meta-analysis revealed enhancements in spatiotemporal parameters of gait i.e., velocity (Hedge's g: 0.67), stride length (0.70), and cadence (1.0), and reduction in timed 25 feet walking test (-0.17). Underlying neurophysiological mechanisms, and clinical implications are discussed. This present review bridges the gaps in literature by suggesting application of rhythmic auditory cueing in conventional rehabilitation approaches to enhance gait performance in the multiple sclerosis community.

Investigation of grey matter abnormalities in multiple sclerosis patients by combined use of double inversion recovery sequences and diffusion tensor MRI at 3.0 Tesla

AIM

To investigate the grey matter abnormalities in multiple sclerosis (MS) patients by combined use of double inversion recovery (DIR) sequences and diffusion tensor (DTI) magnetic resonance imaging (MRI) at 3 T.

MATERIALS AND METHODS

Twenty relapsing-remitting MS (RRMS) patients and 20 healthy control were enrolled in this study. All participants underwent DIR and DTI MRI and completed the Mini-Mental State Examination (MMSE) and Expanded Disability Status Scale (EDSS). The cortical lesions and normal-appearing grey matter (NAGM) of the patient group, as well as the NAGM of the control group were quantitatively analysed using the DIR and DTI images. The average NAGM mean diffusion (MD) and fractional anisotropy (FA) values of the patient group and control group were measured and compared. The correlation between NAGM MD and FA values and the number of cortical lesions, cognitive impairment, as well as the degree of nerve damage were analysed.

RESULTS

The NAGM of the patient group had average MD and FA values that were significantly different compared with the control group. In addition, the NAGM FA values of the MS patients were negatively correlated with the MMSE score, but positively correlated with the EDSS score. The NAGM MD values of the MS patients were also negatively correlated with the MMSE score, but positively correlated with the EDSS score.

CONCLUSIONS

The NAGM of MS patients has microstructural damages. The extent of such damage was correlated with the number of cortical lesions. The severity of the damage also correlated with increased severity of cognitive impairment and neural defects.

A new focal model resembling features of cortical pathology of the progressive forms of multiple sclerosis: Influence of innate immunity

Multiple sclerosis (MS) is an inflammatory and demyelinating disease of unknown aetiology that causes neurological disabilities in young adults. MS displays different clinical patterns, including recurrent episodes with remission periods ("relapsing-remitting MS" (RRMS)), which can progress over several years to a secondary progressive form (SPMS). However, 10% of patients display persistent progression at the onset of disease ("primary progressive MS" (PPMS)). Currently, no specific therapeutic agents are available for the progressive forms, mainly because the underlying pathogenic mechanisms are not clear and because no animal models have been specifically developed for these forms. The development of MS animal models is required to clarify the pathological mechanisms and to test novel therapeutic agents. In the present work, we overexpressed interleukin 1 beta (IL-1β) in the cortex to develop an animal model reflecting the main pathological hallmarks of MS. The treated animals presented with neuroinflammation, demyelination, glial activation, and neurodegeneration along with cognitive symptoms and MRI images consistent with MS pathology. We also demonstrated the presence of meningeal inflammation close to cortical lesions, with characteristics similar to those described in MS patients. Systemic pro-inflammatory stimulation caused a flare-up of the cortical lesions and behavioural symptoms, including impairment of working memory and the appearance of anxiety-like symptoms. Our work demonstrated induced cortical lesions, reflecting the main histopathological hallmarks and cognitive impairments characterizing the cortical pathology described in MS patients with progressive forms of the disease.

Improved Visualization of Cortical Lesions in Multiple Sclerosis Using 7T MP2RAGE

BACKGROUND AND PURPOSE

Cortical lesions are common and often extensive in multiple sclerosis but are difficult to visualize by MRI, leaving important questions about their clinical implications and response to therapy unanswered. Our aim was to determine whether cortical lesions are better visualized using magnetization prepared 2 rapid acquisition gradient echoes (MP2RAGE) than T2*-weighted imaging on 7T MR imaging.

MATERIALS AND METHODS

Brain MR imaging using T1-weighted MP2RAGE at 500-μm isotropic resolution, T2*-weighted gradient-echo, and T2*-weighted segmented echo-planar imaging sequences were collected for 13 patients with MS and 5 age-matched neurologically healthy controls on a 7T research system. One MS case underwent postmortem MR imaging including gradient-echo and MP2RAGE sequences, after which cortical lesions seen on MR imaging were assessed with immunohistochemistry.

RESULTS

MP2RAGE detected 203 cortical lesions (median, 16 lesions/case; interquartile range, 15), compared to 92 with T2*gradient-echo (median, 7; interquartile range, 8; P < .001) and 81 with T2*EPI (median, 7; interquartile range, 5; P < .001). This increase in lesion number detected on MP2RAGE versus T2* was observed for juxtacortical, leukocortical, and intracortical lesions. Forty-three percent of all cortical lesions were identified only on MP2RAGE. White matter lesion volume correlated with total juxtacortical (r = 0.86, P < .001) and leukocortical lesion volume (r = 0.70, P < .01) but not intracortical lesion volume, suggesting that pathophysiology may differ by lesion type. Of 4 suspected lesions seen on postmortem imaging, 3 were found to be true cortical lesions while 1 represented postmortem tissue damage.

CONCLUSIONS

A combination of MP2RAGE and T2*-weighted imaging at 7T improved detection of cortical lesions and should enable longitudinal studies to elucidate their spatiotemporal dynamics and clinical implications.

Potential neuroprotective effect of Fingolimod in multiple sclerosis and its association with clinical variables

INTRODUCTION

Multiple sclerosis (MS) is a chronic inflammatory, demyelinating disease of the central nervous system affecting both white matter and grey matter in the earliest phases of its course. The crucial role of neurodegeneration in disability progression in MS, regardless of white matter damage, has been confirmed by several imaging and neuropathological studies. Fingolimod is an effective immunomodulator of the sphingosine 1-phosphate receptor, approved in relapsing remitting MS and able to cross the blood-brain barrier and to slow disability progression and brain volume loss. However, it remains unclear whether this neuroprotective action is due to a peripheral anti-inflammatory effect and/or to a direct effect on neuronal cells.

AREAS COVERED

In this review, the authors summarize the published preclinical and clinical studies on the effect of Fingolimod in limiting the focal and diffuse grey matter damage in MS.

EXPERT OPINION

Fingolimod might have a significant neuroprotective effect on relapsing remitting MS based on its modulatory effect on oligodendroglial cells and astrocytes, and on its direct effect on cortical neurons. Future clinical studies including measures of grey matter damage are required to confirm in vivo such neuroprotective effect.

New Approaches to the Diagnosis, Clinical Course, and Goals of Therapy in Multiple Sclerosis and Related Disorders

The diagnosis, categorization, and treatment of multiple sclerosis (MS) and other demyelinating diseases have shifted over the past decade, and many of the fundamental principles of MS pathogenesis and clinical course are being rewritten. Fundamental issues include selecting the right disease-modifying therapy for someone with active disease and how, or even if, patients with purely progressive MS should be treated. This article provides an overview and introduction to the current thinking in MS diagnosis and therapy with an emphasis on the data-driven and proactive approach that has come to define the current state of the art.

Cognition in multiple sclerosis: State of the field and priorities for the future

Cognitive decline is recognized as a prevalent and debilitating symptom of multiple sclerosis (MS), especially deficits in episodic memory and processing speed. The field aims to (1) incorporate cognitive assessment into standard clinical care and clinical trials, (2) utilize state-of-the-art neuroimaging to more thoroughly understand neural bases of cognitive deficits, and (3) develop effective, evidence-based, clinically feasible interventions to prevent or treat cognitive dysfunction, which are lacking. There are obstacles to these goals. Our group of MS researchers and clinicians with varied expertise took stock of the current state of the field, and we identify several important practical and theoretical challenges, including key knowledge gaps and methodologic limitations related to (1) understanding and measurement of cognitive deficits, (2) neuroimaging of neural bases and correlates of deficits, and (3) development of effective treatments. This is not a comprehensive review of the extensive literature, but instead a statement of guidelines and priorities for the field. For instance, we provide recommendations for improving the scientific basis and methodologic rigor for cognitive rehabilitation research. Toward this end, we call for multidisciplinary collaborations toward development of biologically based theoretical models of cognition capable of empirical validation and evidence-based refinement, providing the scientific context for effective treatment discovery.

A potential impact of Helicobacter pylori-related galectin-3 in neurodegeneration

Neurodegeneration represents a component of the central nervous system (CNS) diseases pathogenesis, either as a disability primary source in the frame of prototype neurodegenerative disorders, or as a secondary effect, following inflammation, hypoxia or neurotoxicity. Galectins are members of the lectin superfamily, a group of endogenous glycan-binding proteins, able to interact with glycosylated receptors expressed by several immune cell types. Glycan-lectin interactions play critical roles in the living systems by involving and mediating a variety of biologically important normal and pathological processes, including cell-cell signaling shaping cell communication, proliferation and migration, immune responses and fertilization, host-pathogen interactions and diseases such as neurodegenerative disorders and tumors. This review focuses in the role of Galectin-3 in shaping responses of the immune system against microbial agents, and concretely, Helicobacter pylori (Hp), thereby potentiating effect of the microbe in areas distant from the ordinary site of colonization, like the CNS. We hereby postulate that gastrointestinal Hp alterations in terms of immune cell functional phenotype, cytokine and chemokine secretion, may trigger systemic responses, thereby conferring implications for remote processes susceptible in immunity disequilibrium, namely, the CNS inflammation and/or neurodegeneration.

Long-Term Magnetization Transfer Ratio Evolution in Multiple Sclerosis White Matter Lesions

BACKGROUND AND PURPOSE

Magnetization transfer ratio (MTR), a magnetic resonance imaging technique used to assess tissue integrity, correlates with demyelination and axonal loss in multiple sclerosis (MS) lesions. In acute white matter lesions, short-term MTR changes mainly reflect demyelination and remyelination, in addition to edema and axonal and glial changes. Long-term MTR changes in MS lesions have not been studied extensively.

METHODS

A new quantitative image analysis method was developed to measure long-term MTR changes in MS lesions. The method was applied to a group of 59 patients and 14 healthy control subjects followed for 4 years. MTR changes in white matter lesions were analyzed, where lesion voxels were classified into six categories based on starting MTR and change over time. For each patient, the proportion of lesion voxels in each MTR-change category was calculated. Correlations between long-term MTR evolution, disability progression, and brain atrophy were investigated.

RESULTS

The proportion of lesion voxels in the high stable category correlated with less atrophy progression, while the proportion with low and increasing MTR correlated with increased atrophy. The proportion of lesion voxels in the high and stable MTR lesion category was significantly different between MS disease subgroups. The group with disability progression had a higher proportion of lesion voxels with low and increasing MTR.

CONCLUSIONS

These results suggest that long-term changes in MTR in white matter lesions can be used to distinguish lesion subtypes associated with MS disease progression and improve understanding of the temporal evolution of MS pathology.

The complex relationship between oligoclonal bands, lymphocytes in the cerebrospinal fluid, and immunoglobulin G antibodies in multiple sclerosis: Indication of serum contribution

Introduction

Intrathecal immunoglobulin G (IgG) and oligoclonal bands (OCBs) are the most consistent and characteristic features of Multiple Sclerosis (MS). OCBs in MS are considered products of clonally expanded B cells in the cerebrospinal fluid (CSF), representing the sum of contributions from B cells in the brain. However, large amounts of IgG can be eluted from MS plaques in which lymphocytes are absent, and there is no correlation between levels of plaque-associated IgG and the presence of lymphocytes. It is calculated that it would take 3.2 billion lymphocytes to generate such large amounts of intrathecal IgG (30 mg in 500 ml CSF) in MS patients. Therefore, circulating lymphocytes in CSF could only account for <0.1% of the extra IgG in MS.

Methods

We analyzed clinical laboratory parameters from sera and CSF of 115 patients including 91 patients with MS and 24 patients with other inflammatory central nervous system (CNS) disorders (IC). We investigated the relationship between oligoclonal bands, IgG antibodies, CSF cells, IgG Index, albumin, and total protein.

Results

MS patients have significantly elevated serum concentrations of IgG antibodies, albumin, and total protein, lower levels of lymphocytes, albumin, and total protein in the cerebrospinal fluid, but no difference in CSF IgG concentration compared to those with other inflammatory neurological disorders. Furthermore, in MS there was no linear relationship between the numbers of OCBs, CSF lymphocytes, CSF IgG, and IgG Index, and between serum IgG and serum albumin, but significant correlation between IgG in CSF and serum, and between CSF IgG and CSF albumin.

Conclusion

There are unique differences between MS and patients with other inflammatory neurological disorders. Our data suggest that in MS patient (a) B cells and their products in the CSF may not be the sole source of intrathecal IgG; (b) oligoclonal bands may not be the products of single B cell clones in the CSF; and (c) there is a strong connection between serum components in the peripheral circulation and the central nervous system.

Fibrin(ogen) and neurodegeneration in the progressive multiple sclerosis cortex

OBJECTIVE

Neuronal loss, a key substrate of irreversible disability in multiple sclerosis (MS), is a recognized feature of MS cortical pathology of which the cause remains unknown. Fibrin(ogen) deposition is neurotoxic in animal models of MS, but has not been evaluated in human progressive MS cortex. The aim of this study was to investigate the extent and distribution of fibrin(ogen) in progressive MS cortex and elucidate its relationship with neurodegeneration.

METHODS

A postmortem cohort of pathologically confirmed MS (n = 47) and control (n = 10) cases was used. The extent and distribution of fibrin(ogen) was assessed and related to measures of demyelination, inflammation, and neuronal density. In a subset of cases (MS, n = 20; control, n = 10), expression of plasminogen activator inhibitor 1 (PAI-1), a key enzyme in the fibrinolytic cascade, was assessed and related to the extent of fibrin(ogen).

RESULTS

Motor cortical fibrin(ogen) deposition was significantly over-represented in MS compared to control cases in all compartments studied (ie, extracellular [p = 0.001], cell body [p = 0.003], and neuritic/glial-processes [p = 0.004]). MS cases with high levels of extracellular fibrin(ogen) had significantly upregulated PAI-1 expression in all cortical layers assessed (p < 0.05) and reduced neuronal density (p = 0.017), including in the functionally-relevant layer 5 (p = 0.001).

INTERPRETATION

For the first time, we provide unequivocal evidence that fibrin(ogen) is extensively deposited in progressive MS motor cortex, where regulation of fibrinolysis appears perturbed. Progressive MS cases with severe fibrin(ogen) deposition have significantly reduced neuronal density. Future studies are needed to elucidate the provenance and putative neurotoxicity of fibrin(ogen), and its potential impact on clinical disability. Ann Neurol 2017;82:259-270.

MRI evidence of acute inflammation in leukocortical lesions of patients with early multiple sclerosis

OBJECTIVE

To identify gadolinium-enhancing lesions affecting the cortex of patients with early multiple sclerosis (MS) and to describe the frequency and evolution of these lesions.

METHODS

We performed a retrospective, observational, longitudinal analysis of MRI scans collected as part of the Betaseron vs Copaxone in Multiple Sclerosis with Triple-Dose Gadolinium and 3T MRI Endpoints (BECOME) study. Seventy-five patients with early-stage MS were scanned monthly, over a period of 12-24 months, using 3T MRI after administration of triple-dose gadolinium. A total of 1,188 scans were included in the analysis. A total of 139 were selected using an image pipeline algorithm that integrated the image information from cortical gray matter masks and gadolinium-enhancing lesion masks. These scans were evaluated to identify gadolinium-enhancing lesions affecting the cortex.

RESULTS

The total number of gadolinium-enhancing lesions was 2,044. The number of gadolinium-enhancing lesions affecting the cortex was 120 (6%), 95% of which were leukocortical. The number of patients who showed gadolinium-enhancing lesions affecting the cortex was 27 (36%). The number of gadolinium-enhancing lesions affecting the cortex at baseline was 25 (21%) and the number of new lesions that developed in follow-up scans was 49 (41%). The number of persistent lesions was 46 (38%).

CONCLUSIONS

The presence of enhancing lesions affecting the cortex and adjacent white matter, although transient and not frequent, suggests that at least some cortical lesions are related to blood-brain barrier disruption. Our data support the concept that there may be an acute inflammatory phase in the development of leukocortical MS lesions.

CLINICALTRIALSGOV IDENTIFIER

NCT00176592.

MRI evidence of acute inflammation in leukocortical lesions of patients with early multiple sclerosis

OBJECTIVE

To identify gadolinium-enhancing lesions affecting the cortex of patients with early multiple sclerosis (MS) and to describe the frequency and evolution of these lesions.

METHODS

We performed a retrospective, observational, longitudinal analysis of MRI scans collected as part of the Betaseron vs Copaxone in Multiple Sclerosis with Triple-Dose Gadolinium and 3T MRI Endpoints (BECOME) study. Seventy-five patients with early-stage MS were scanned monthly, over a period of 12-24 months, using 3T MRI after administration of triple-dose gadolinium. A total of 1,188 scans were included in the analysis. A total of 139 were selected using an image pipeline algorithm that integrated the image information from cortical gray matter masks and gadolinium-enhancing lesion masks. These scans were evaluated to identify gadolinium-enhancing lesions affecting the cortex.

RESULTS

The total number of gadolinium-enhancing lesions was 2,044. The number of gadolinium-enhancing lesions affecting the cortex was 120 (6%), 95% of which were leukocortical. The number of patients who showed gadolinium-enhancing lesions affecting the cortex was 27 (36%). The number of gadolinium-enhancing lesions affecting the cortex at baseline was 25 (21%) and the number of new lesions that developed in follow-up scans was 49 (41%). The number of persistent lesions was 46 (38%).

CONCLUSIONS

The presence of enhancing lesions affecting the cortex and adjacent white matter, although transient and not frequent, suggests that at least some cortical lesions are related to blood-brain barrier disruption. Our data support the concept that there may be an acute inflammatory phase in the development of leukocortical MS lesions.

CLINICALTRIALSGOV IDENTIFIER

NCT00176592.

Protease-activated receptor-1 activation by granzyme B causes neurotoxicity that is augmented by interleukin-1β

Background

The cause of neurodegeneration in progressive forms of multiple sclerosis is unknown. We investigated the impact of specific neuroinflammatory markers on human neurons to identify potential therapeutic targets for neuroprotection against chronic inflammation.

Methods

Surface immunocytochemistry directly visualized protease-activated receptor-1 (PAR1) and interleukin-1 (IL-1) receptors on neurons in human postmortem cortex in patients with and without neuroinflammatory lesions. Viability of cultured neurons was determined after exposure to cerebrospinal fluid from patients with progressive multiple sclerosis or purified granzyme B and IL-1β. Inhibitors of PAR1 activation and of PAR1-associated second messenger signaling were used to elucidate a mechanism of neurotoxicity.

Results

Immunohistochemistry of human post-mortem brain tissue demonstrated cells expressing higher amounts of PAR1 near and within subcortical lesions in patients with multiple sclerosis compared to control tissue. Human cerebrospinal fluid samples containing granzyme B and IL-1β were toxic to human neuronal cultures. Granzyme B was neurotoxic through activation of PAR1 and subsequently the phospholipase Cβ-IP3 second messenger system. Inhibition of PAR1 or IP3 prevented granzyme B toxicity. IL-1β enhanced granzyme B-mediated neurotoxicity by increasing PAR1 expression.

Conclusions

Neurons within the inflamed central nervous system are imperiled because they express more PAR1 and are exposed to a neurotoxic combination of both granzyme B and IL-1β. The effects of these inflammatory mediators may be a contributing factor in the progressive brain atrophy associated with neuroinflammatory diseases. Knowledge of how exposure to IL-1β and granzyme B act synergistically to cause neuronal death yields potential novel neuroprotective treatments for neuroinflammatory diseases.