Ultrahigh field MRI in clinical neuroimmunology: a potential contribution to improved diagnostics and personalised disease management

Conventional magnetic resonance imaging (MRI) at 1.5 Tesla (T) is limited by modest spatial resolution and signal-to-noise ratio (SNR), impeding the identification and classification of inflammatory central nervous system changes in current clinical practice. Gaining from enhanced susceptibility effects and improved SNR, ultrahigh field MRI at 7 T depicts inflammatory brain lesions in great detail. This review summarises recent reports on 7 T MRI in neuroinflammatory diseases and addresses the question as to whether ultrahigh field MRI may eventually improve clinical decision-making and personalised disease management.

Regional Distribution and Evolution of Gray Matter Damage in Different Populations of Multiple Sclerosis Patients

BACKGROUND

Both gray-matter (GM) atrophy and lesions occur from the earliest stages of Multiple Sclerosis (MS) and are one of the major determinants of long-term clinical outcomes. Nevertheless, the relationship between focal and diffuse GM damage has not been clarified yet. Here we investigate the regional distribution and temporal evolution of cortical thinning and how it is influenced by the local appearance of new GM lesions at different stages of the disease in different populations of MS patients.

METHODS

We studied twenty MS patients with clinically isolated syndrome (CIS), 27 with early relapsing-remitting MS (RRMS, disease duration <5 years), 29 with late RRMS (disease duration ≥ 5 years) and 20 with secondary-progressive MS (SPMS). The distribution and evolution of regional cortical thickness and GM lesions were assessed during 5-year follow-up.

RESULTS

The results showed that new lesions appeared more frequently in hippocampus and parahippocampal gyri (9.1%), insula (8.9%), cingulate cortex (8.3%), superior frontal gyrus (8.1%), and cerebellum (6.5%). The aforementioned regions showed the greatest reduction in thickness/volume, although (several) differences were observed across subgroups. The correlation between the appearance of new cortical lesions and cortical thinning was stronger in CIS (r2 = 50.0, p<0.001) and in early RRMS (r2 = 52.3, p<0.001), compared to late RRMS (r2 = 25.5, p<0.001) and SPMS (r2 = 6.3, p = 0.133).

CONCLUSIONS

We conclude that GM atrophy and lesions appear to be different signatures of cortical disease in MS having in common overlapping spatio-temporal distribution patterns. However, the correlation between focal and diffuse damage is only moderate and more evident in the early phase of the disease.

Cell type-specific Nrf2 expression in multiple sclerosis lesions

Oxidative injury appears to play a major role in the propagation of demyelination and neurodegeneration in multiple sclerosis (MS). It has been suggested that endogenous anti-oxidant defense mechanisms within MS lesions are insufficient to prevent spreading of damage. Thus, current therapeutic approaches (e.g., fumarate treatment) target to up-regulate the expression of a key regulator of anti-oxidative defense, the transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf2). In this study, we show that Nrf2 is already strongly up-regulated in active MS lesions. Nuclear Nrf2 expression was particularly observed in oligodendrocytes and its functional activity is indicated by the expression of one of its downstream targets (heme oxygenase 1) in the same cells. In contrast, only a minor number of Nrf2-positive neurons were detected, even in highly inflammatory cortical lesions presenting with extensive oxidative injury. Overall, the most pronounced Nrf2 expression was found in degenerating cells, which showed signs of apoptotic or necrotic cell death. Via whole-genome microarray analyses of MS lesions, we observed a differential expression of numerous Nrf2-responsive genes, also involved in the defense against oxidative stress, predominantly in areas of initial myelin destruction within actively demyelinating white matter lesions. Furthermore, the expression patterns of Nrf2-induced genes differed between the white matter and cortical gray matter. Our study shows that in the MS brain, Nrf2 expression varies in different cell types and is associated with active demyelination in the lesions.

Stable neuropsychiatric status in multiple sclerosis: a 3-year study

Personality changes and neuropsychiatric symptoms are found in multiple sclerosis (MS), but no study has evaluated decline compared to healthy controls. This study assessed personality traits and neuropsychiatric symptoms over 3 years using the NEO Five Factor Inventory and the Neuropsychiatric Inventory. Additional metrics evaluated ambulation, manual dexterity and cognitive function. Contrary to hypothesis, patients showed no significant change in personality or neuropsychiatric status relative to controls. Patients were impaired in motor and cognitive function at baseline and follow-up, but showed only slowing in ambulation over time. The findings indicate that neuropsychiatric status is stable in MS over 3 years.

Characteristics of lesional and extra-lesional cortical grey matter in relapsing–remitting and secondary progressive multiple sclerosis: A magnetisation transfer and diffusion tensor imaging study

Background:

In multiple sclerosis (MS), diffusion tensor and magnetisation transfer imaging are both abnormal in lesional and extra-lesional cortical grey matter, but differences between clinical subtypes and associations with clinical outcomes have only been partly assessed.

Objective:

To compare mean diffusivity, fractional anisotropy and magnetisation transfer ratio (MTR) in cortical grey matter lesions (detected using phase-sensitive inversion recovery (PSIR) imaging) and extra-lesional cortical grey matter, and assess associations with disability in relapse-onset MS.

Methods:

Seventy-two people with MS (46 relapsing–remitting (RR), 26 secondary progressive (SP)) and 36 healthy controls were included in this study. MTR, mean diffusivity and fractional anisotropy were measured in lesional and extra-lesional cortical grey matter.

Results:

Mean fractional anisotropy was higher and MTR lower in lesional compared with extra-lesional cortical grey matter. In extra-lesional cortical grey matter mean fractional anisotropy and MTR were lower, and mean diffusivity was higher in the MS group compared with controls. Mean MTR was lower and mean diffusivity was higher in lesional and extra-lesional cortical grey matter in SPMS when compared with RRMS. These differences were independent of disease duration. In multivariate analyses, MTR in extra-lesional more so than lesional cortical grey matter was associated with disability.

Conclusion:

Magnetic resonance abnormalities in lesional and extra-lesional cortical grey matter are greater in SPMS than RRMS. Changes in extra-lesional compared with lesional cortical grey matter are more consistently associated with disability.

The Parallel Analysis of Phase Sensitive Inversion Recovery (PSIR) and Double Inversion Recovery (DIR) Images Significantly Improves the Detection of Cortical Lesions in Multiple Sclerosis (MS) since Clinical Onset

BACKGROUND

Double inversion recovery (DIR) detects only a minority (<20%) of cortical lesions (CL) in multiple sclerosis (MS). Phase-sensitive inversion recovery (PSIR) was suggested to be substantially superior to DIR in the detection of cortical lesions (CL). These two sequences might be complementary.

OBJECTIVES

To analyze CL frequency and type in MS patients having different disease duration and disability, including patients at clinical onset, and to discern more correctly the artifacts, by combining DIR and PSIR images.

PATIENTS AND METHODS

40 patients were enrolled in the study: 10 clinically isolated syndrome/early relapsing remitting MS (CIS/eRRMS), 24 relapsing remitting MS (RRMS), 6 secondary progressive MS (SPMS). DIR and PSIR images were jointly used to classify lesions as purely intracortical (IC), leukocortical (LC) and juxtacortical (JC).

RESULTS

PSIR disclosed CL in 100% of the patients and was capable of identifying more than four times lesions (455.5%, p<0.00001), especially IC (mean numbers: 36.5 in CIS/eRRMS, 45.0 in RRMS and 52.3 in SPMS) and LC (mean numbers: 10.9 in CIS/eRRMS, 20.1 in RRMS and 25.3 in SPMS), compared to DIR (p<0.00001). CL number was significantly higher in SPMS compared to RRMS (p<0.0001). Artifacts were more accurately identified by comparing the two sequences.

CONCLUSIONS

Our study confirms the higher ability of PSIR in disclosing and classifying CL. The presence of CL in all CIS patients further points out the relevance of cortical pathology in MS. Whether the parallel analysis of DIR and PSIR images may be useful for diagnostic purposes, especially when a diagnosis of MS is suspected but not confirmed by routine MRI, needs to be evaluated in larger patient series. The analysis of the cortex by DIR and PSIR may also allow a better stratification of the patients for prognostic and counseling purposes, as well as for their inclusion in clinical studies.

The role of immune cells, glia and neurons in white and gray matter pathology in multiple sclerosis

Multiple sclerosis is one of the most common causes of chronic neurological disability beginning in early to middle adult life. Multiple sclerosis is idiopathic in nature, yet increasing correlative evidence supports a strong association between one's genetic predisposition, the environment and the immune system. Symptoms of multiple sclerosis have primarily been shown to result from a disruption in the integrity of myelinated tracts within the white matter of the central nervous system. However, recent research has also highlighted the hitherto underappreciated involvement of gray matter in multiple sclerosis disease pathophysiology, which may be especially relevant when considering the accumulation of irreversible damage and progressive disability. This review aims at providing a comprehensive overview of the interplay between inflammation, glial/neuronal damage and regeneration throughout the course of multiple sclerosis via the analysis of both white and gray matter lesional pathology. Further, we describe the common pathological mechanisms underlying both relapsing and progressive forms of multiple sclerosis, and analyze how current (as well as future) treatments may interact and/or interfere with its pathology. Understanding the putative mechanisms that drive disease pathogenesis will be key in helping to develop effective therapeutic strategies to prevent, mitigate, and treat the diverse morbidities associated with multiple sclerosis.

Clinical and imaging assessment of cognitive dysfunction in multiple sclerosis

In patients with multiple sclerosis (MS), grey matter damage is widespread and might underlie many of the clinical symptoms, especially cognitive impairment. This relation between grey matter damage and cognitive impairment has been lent support by findings from clinical and MRI studies. However, many aspects of cognitive impairment in patients with MS still need to be characterised. Standardised neuropsychological tests that are easy to administer and sensitive to disease-related abnormalities are needed to gain a better understanding of the factors affecting cognitive performance in patients with MS than exists at present. Imaging measures of the grey matter are necessary, but not sufficient to fully characterise cognitive decline in MS. Imaging measures of both lesioned and normal-appearing white matter lend support to the hypothesis of the existence of an underlying disconnection syndrome that causes clinical symptoms to trigger. Findings on cortical reorganisation support the contribution of brain plasticity and cognitive reserve in limiting cognitive deficits. The development of clinical and imaging biomarkers that can monitor disease development and treatment response is crucial to allow early identification of patients with MS who are at risk of cognitive impairment.

[Meningeal tertiary lymphoid organs: Major actors in intrathecal autoimmunity]

Multiple sclerosis (MS) is characterized by an intrathecal synthesis of immunoglobulins synthesized by B-cell clones and by a brain infiltrate of clonal T-cells. The clonal maturation of these lymphocytes takes place in tertiary lymphoid organs (TLO) developed in the intrathecal compartment. TLO are acquired lymphoid organs able to develop in the vicinity of the inflammatory sites, where they mount a complete antigen-driven immune response. We here review TLO pathophysiology in animal models of MS and human MS. Several pieces of evidence suggest that intrathecal TLO may play a major role in the clinical impairment. Potential therapeutic applications are examined.

Late-onset multiple sclerosis presenting with cognitive dysfunction and severe cortical/infratentorial atrophy

Objective:

Although cognitive dysfunction is a relevant aspect of multiple sclerosis (MS) from the earliest disease phase, cognitive onset is unusual thus jeopardizing early and accurate diagnosis. Here we describe 12 patients presenting with cognitive dysfunction as primary manifestation of MS with either mild or no impairment in non-cognitive neurological domains.

Methods:

Twelve patients with cognitive onset who were subsequently diagnosed with MS (CI-MS) were included in this retrospective study. Twelve cognitively normal MS patients (CN-MS), 12 healthy controls and four patients having progressive supranuclear palsy (PSP) served as the reference population.

Results:

Ten CI-MS patients had progressive clinical course and all patients had late disease onset (median age = 49 years; range = 40–58 years). Among cognitive functions, frontal domains were the most involved. Compared to CN-MS and healthy controls, significant cortical and infratentorial atrophy characterized CI-MS patients. Selective atrophy of midbrain tegmentum with relative sparing of pons, known as “The Hummingbird sign,” was observed in eight CI-MS and in three PSP patients.

Discussion:

Our observation suggests that MS diagnosis should be taken into consideration in case of cognitive dysfunction, particularly when associated with slowly progressive disease course and severe cortical, cerebellar and brainstem atrophy even in the absence of other major neurological symptoms and signs.

Therapeutic strategies for relapsing-remitting multiple sclerosis: a special focus on reduction of grey matter damage as measured by brain atrophy

In the past two decades, several pathological and radiological findings convincingly demonstrated that damage of the cortical and deep grey matter is a key issue in multiple sclerosis with a significant impact on physical and cognitive disability. Moreover, it has become increasingly evident that the effect of available therapies on the inflammatory white matter damage is not a guarantee of a meaningful effect on the neurodegenerative process mainly affecting the grey matter. Despite the efficacy of all approved disease-modifying drugs should be measured considering such a relevant aspect of the disease, data from clinical trials are few, scattered and heterogeneous. The aim of this review is to summarize the evidence so far acquired on the effect of reducing grey matter damage produced by current and emerging disease-modifying therapies for multiple sclerosis.

Cognitive impairment in paediatric multiple sclerosis patients is not related to cortical lesions

We investigated the contribution of cortical lesions to cognitive impairment in 41 paediatric MS patients. Thirteen (32%) paediatric MS patients were considered as cognitively impaired. T2-hyperintense and T1-hypointense white matter lesion volumes did not differ between cognitively impaired and cognitively preserved MS patients. Cortical lesions number, cortical lesions volume and grey matter volume did not differ between cognitively impaired and cognitively preserved patients, whereas white matter volume was significantly lower in cognitively impaired versus cognitively preserved MS patients ( p=0.01). Contrary to adult MS, cortical lesions do not seem to contribute to cognitive impairment in paediatric MS patients, which is likely driven by white matter damage.

MRI correlates of disability progression in patients with CIS over 48 months

Background

Gray matter (GM) and white matter (WM) pathology has an important role in disease progression of multiple sclerosis (MS).

Objectives

To investigate the association between the development of GM and WM pathology and clinical disease progression in patients with clinically isolated syndrome (CIS).

Methods

This prospective, observational, 48-month follow-up study examined 210 CIS patients treated with 30 µg of intramuscular interferon beta-1a once a week. MRI and clinical assessments were performed at baseline, 6, 12, 24, 36 and 48 months. Associations between clinical worsening [24-weeks sustained disability progression (SDP) and occurrence of a second clinical attack] and longitudinal changes in lesion accumulation and brain atrophy progression were investigated by a mixed-effect model analysis after correction for multiple comparisons.

Results

SDP was observed in 32 (15.2%) CIS patients, while 146 (69.5%) were stable and 32 (15.2%) showed sustained disability improvement. 112 CIS patients (53.3%) developed clinically definite MS (CDMS). CIS patients who developed SDP showed increased lateral ventricle volume (p < .001), and decreased GM (p = .011) and cortical (p = .001) volumes compared to patients who remained stable or improved in disability. Converters to CDMS showed an increased rate of accumulation of number of new/enlarging T2 lesions (p < .001), decreased whole brain (p = .007) and increased lateral ventricle (p = .025) volumes.

Conclusions

Development of GM pathology and LVV enlargement are associated with SDP. Conversion to CDMS in patients with CIS over 48 months is dependent on the accumulation of new lesions, LVV enlargement and whole brain atrophy progression.

•

We examined 210 clinically isolated syndrome patients on interferon beta.

•

MRI and clinical assessments were performed at 0, 6, 12, 24, 36 and 48 months.

•

15.2% of patients developed disability progression and 53.3 % converted to MS.

•

Gray matter atrophy was strongly associated with sustained disability progression.

Progesterone and nestorone promote myelin regeneration in chronic demyelinating lesions of corpus callosum and cerebral cortex

Multiple Sclerosis affects mainly women and consists in intermittent or chronic damages to the myelin sheaths, focal inflammation, and axonal degeneration. Current therapies are limited to immunomodulators and antiinflammatory drugs, but there is no efficient treatment for stimulating the endogenous capacity of myelin repair. Progesterone and synthetic progestins have been shown in animal models of demyelination to attenuate myelin loss, reduce clinical symptoms severity, modulate inflammatory responses and partially reverse the age-dependent decline in remyelination. Moreover, progesterone has been demonstrated to promote myelin formation in organotypic cultures of cerebellar slices. In the present study, we show that progesterone and the synthetic 19-nor-progesterone derivative Nestorone® promote the repair of severe chronic demyelinating lesions induced by feeding cuprizone to female mice for up to 12 weeks. Progesterone and Nestorone increase the density of NG2(+) oligodendrocyte progenitor cells and CA II(+) mature oligodendrocytes and enhance the formation of myelin basic protein (MBP)- and proteolipid protein (PLP)-immunoreactive myelin. However, while demyelination in response to cuprizone was less marked in corpus callosum than in cerebral cortex, remyelination appeared earlier in the former. The remyelinating effect of progesterone was progesterone receptor (PR)-dependent, as it was absent in PR-knockout mice. Progesterone and Nestorone also decreased (but did not suppress) neuroinflammatory responses, specifically astrocyte and microglial cell activation. Therefore, some progestogens are promising therapeutic candidates for promoting the regeneration of myelin.

Determinants of disability in multiple sclerosis: an immunological and MRI study

Multiple sclerosis (MS) is characterized by a wide interpatient clinical variability and available biomarkers of disease severity still have suboptimal reliability. We aimed to assess immunological and MRI-derived measures of brain tissue damage in patients with different motor impairment degrees, for in vivo investigating the pathogenesis of MS-related disability. Twenty-two benign (B), 26 secondary progressive (SP), and 11 early, nondisabled relapsing-remitting (RR) MS patients and 37 healthy controls (HC) underwent conventional and diffusion tensor brain MRI and, as regards MS patients, immunophenotypic and functional analysis of stimulated peripheral blood mononuclear cells (PBMC). Corticospinal tract (CST) fractional anisotropy and grey matter volume were lower and CST diffusivity was higher in SPMS compared to RRMS and BMS patients. CD14+IL6+ and CD4+IL25+ cell percentages were higher in BMS than in SPMS patients. A multivariable model having EDSS as the dependent variable retained the following independent predictors: grey matter volume, CD14+IL6+ and CD4+IL25+ cell percentages. In patients without motor impairment after long-lasting MS, the grey matter and CST damage degree seem to remain as low as in the earlier disease stages and an immunological pattern suggestive of balanced pro- and anti-inflammatory activity is observed. MRI-derived and immunological measures might be used as complementary biomarkers of MS severity.

Validating predictors of disease progression in a large cohort of primary-progressive multiple sclerosis based on a systematic literature review

BACKGROUND

New agents with neuroprotective or neuroregenerative potential might be explored in primary-progressive Multiple Sclerosis (PPMS)--the MS disease course with leading neurodegenerative pathology. Identification of patients with a high short-term risk for progression may minimize study duration and sample size. Cohort studies reported several variables as predictors of EDSS disability progression but findings were partially contradictory.

OBJECTIVE

To analyse the impact of published predictors on EDSS disease progression in a large cohort of PPMS patients.

METHODS

A systematic literature research was performed to identify predictors for disease progression in PPMS. Individual case data from the Sylvia Lawry Centre (SLC) and the Hamburg MS patient database (HAPIMS) was pooled for a retrospective validation of these predictors on the annualized EDSS change.

RESULTS

The systematic literature analysis revealed heterogeneous data from 3 prospective and 5 retrospective natural history cohort studies. Age at onset, gender, type of first symptoms and early EDSS changes were available for validation. Our pooled cohort of 597 PPMS patients (54% female) had a mean follow-up of 4.4 years and mean change of EDSS of 0.35 per year based on 2503 EDSS assessments. There was no significant association between the investigated variables and the EDSS-change.

CONCLUSION

None of the analysed variables were predictive for the disease progression measured by the annualized EDSS change. Whether PPMS is still unpredictable or our results may be due to limitations of cohort assessments or selection of predictors cannot be answered. Large systematic prospective studies with new endpoints are needed.

Pharmacokinetic evaluation of fingolimod for the treatment of multiple sclerosis

INTRODUCTION

Fingolimod is a sphingosine 1-phosphate receptor modulator with a novel mechanism of action and the first oral drug approved for the treatment of relapsing forms of multiple sclerosis (MS). Fingolimod reduces relapses more effectively than intramuscular interferon β1a and delays disability progression. Associated safety risks are bradyarrhythmia and atrioventricular block following the initial dose, requiring monitoring.

AREAS COVERED

This article examines the characteristics of fingolimod, its pharmacokinetic properties and the efficacy and tolerability in MS. Information on the pharmacology and mechanisms of action is also provided.

EXPERT OPINION

Fingolimod is an effective therapy for relapsing forms of MS in a convenient oral dose. Fingolimod may target not only inflammation but potentially also neurodegeneration. Antagonizing astrocyte sphingosine signaling may help explain the reduction in cerebral atrophy observed in Phase III trials. Long-term data about the safety of fingolimod are needed.

Understanding the pharmacology of stroke and multiple sclerosis through imaging

Stroke and multiple sclerosis (MS) illustrate how clinical imaging can facilitate early phase drug development and most effective medicine use in the clinic. Imaging has enhanced understanding of the dynamics of evolution of disease pathophysiology, better defining treatment targets. Imaging measures can enable stratification of patients for clinical trials and for most cost-effective use in the clinic. In MS, imaging has allowed smaller Phase II clinical trials and contributed to medicine differentiation. It also has led to consideration of suppression of inflammation and neurodegeneration as meaningfully distinct pharmacodynamic concepts. Similar imaging measures can be used in preclinical and clinical studies. Testing translational pharmacological hypotheses using clinical imaging more explicitly could improve the success of the next generation of stroke therapeutics.

Cognitive and affective assessments of multiple sclerosis (MS) and neuromyelitis optica (NMO) patients utilizing computerized touch panel-type screening tests

OBJECTIVE

Cognitive and affective dysfunctions are important aspects for patients with multiple sclerosis (MS) and neuromyelitis optica (NMO).

METHODS

We herein examined the cognitive and affective ability in MS (n=35) and NMO (n=10) patients using computerized touch panel-type screening tests.

RESULTS

While MS patients and normal controls (NC1, n=40) did not significantly differ in their scores from the Hasegawa dementia scale-revised (HDS-R) or the frontal assessment battery, MS patients did score significantly lower on the mini-mental state examination (MMSE). In contrast, NMO patients did not differ from the normal control group 2 (NC2, n=15) in any of the three cognitive assessments. We also examined the affective ability and found that MS patients scored significantly higher on the apathy scale (AS) compared with the NC1 group, while NMO patients scored significantly higher on the geriatric depression scale (GDS) compared with the NC2 group. Although the GDS and AS scores did not correlate with any of the cognitive assessments among MS patients, the AS scores did correlate with the MMSE and HDS-R among NMO patients. Compared with normal controls, the times to complete the flipping cards and arranging pictures games were significantly longer for MS patients but not for NMO patients.

CONCLUSION

These results indicate differences between some features of cognitive and affective dysfunctions between MS and NMO patients. Computerized touch panel-type screening tests may be a more useful and sensitive tool for the cognitive assessment of MS patients than NMO patients.

Intrathecal immune reset in multiple sclerosis: exploring a new concept

Multiple sclerosis impairment is mainly driven by the progressive phase, whose pathology remains elusive. No drug has yet been able to halt this phase so therapeutic management remains challenging. It was recently demonstrated that late disability correlates with the spreading of cortical subpial lesions, and tertiary lymphoid organs (TLO) were identified in close apposition with these lesions. TLO are of crucial importance since they are able to mount a complete local immune response, as observed in the intrathecal compartment from the moment MS is diagnosed (i.e. oligoclonal bands). This article examines the consequences of this intrathecal response: giving a worst clinical prognostic value and bearing arguments for possible direct brain toxicity, intrathecal secretion should be targeted by drugs abating both B-lymphocytes and plasma cells. Another consequence is that intrathecal secretion has value as a surrogate marker of the persistence of an ongoing intrathecal immune reaction after treatment. Although it is still unsure which mechanism or byproduct secreted by TLO triggers cortical lesions, we propose to target TLO components as a new therapeutic avenue in progressive MS. Whereas it was long considered that the inability of therapies to penetrate the blood-brain-barrier was a crucial obstacle, our proposed strategy will take advantage of the properties of the BBB to safely reset the intrathecal immune system in order to halt the slow axonal burning underlying secondary MS. We review the literature in support of the rationale for treating MS with intrathecal drugs dedicated to clearing the local immune response. Since many targets are involved, achieving this goal may require a combination of monoclonal antibodies targeting each cell sub-type. Hope might be rekindled with a one-shot intrathecal multi-drug treatment in progressive MS.

Pharmacological treatment for memory disorder in multiple sclerosis

BACKGROUND

This is an update of the Cochrane review "Pharmacologic treatment for memory disorder in multiple sclerosis" (first published in The Cochrane Library 2011, Issue 10).Multiple sclerosis (MS) is a chronic immune-mediated, inflammatory, demyelinating, neurodegenerative disorder of the central nervous system (CNS) and can cause both neurological and neuropsychological disability. Both demyelination and axonal and neuronal loss are believed to contribute to MS-related cognitive impairment. Memory disorder is one of the most frequent cognitive dysfunctions and presents a considerable burden to people with MS and to society due to the negative impact on function. A number of pharmacological agents have been evaluated in many existing randomised controlled trials for their efficacy on memory disorder in people with MS but the results were not consistent.

OBJECTIVES

To assess the absolute and comparative efficacy, tolerability and safety of pharmacological treatments for memory disorder in adults with MS.

SEARCH METHODS

We searched the Cochrane Multiple Sclerosis and Rare Diseases of the Central Nervous System Group Trials Register (24 July 2013), PsycINFO (January 1980 to 26 June 2013) and CBMdisc (1978 to 24 June 2013), and checked reference lists of identified articles, searched some relevant journals manually, registers of clinical trials and published abstracts of conference proceedings.

SELECTION CRITERIA

All double-blind, randomised controlled parallel trials on pharmacological treatment versus placebo or one or more pharmacological treatments in adults with MS who had at least mild memory impairment (at 0.5 standard deviations below age- and sex-based normative data on a validated memory scale). We placed no restrictions regarding dose, route of administration and frequency; however, we only included trials with an administration duration of 12 weeks or greater.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. We discussed disagreements and resolved them by consensus among review authors. We contacted principal investigators of included studies for additional data or confirmation.

MAIN RESULTS

We included seven randomised controlled trials (RCTs) involving 625 people mostly with relapsing-remitting, secondary-progressive and primary-progressive MS, evaluating the absolute efficacy of donepezil, ginkgo biloba, memantine and rivastigmine versus placebo in improving memory performance with diverse assessment scales. Overall, clinical and methodological heterogeneities existed across these studies. Moreover, most of them had methodological limitations on non-specific selections of targeted sample, non-matched variables at baseline or incomplete outcome data (high attrition bias). Only the two studies on donepezil had clinical and methodological homogeneity and relatively low risks for bias. One RCT evaluating estriol versus placebo is currently ongoing.We could not carry out a meta-analysis due to the heterogeneities across studies and the high attrition bias. A subgroup analysis for donepezil versus placebo showed no treatment effects on total recall on the Selective Reminding Test (mean difference (MD) 1.68; 95% confidence interval (CI) -2.21 to 5.58), total correct scores on the 10/36 Spatial Recall Test (MD -0.93; 95% CI -3.18 to 1.32), the Symbol Digit Modalities Test (MD -1.27; 95% CI -3.15 to 0.61) and the Paced Auditory Serial Addition Test (2+3 sec) (MD 2.23; 95% CI -1.87 to 6.33). Concerning safety, the main adverse events were: diarrhoea (risk ratio (RR) 3.88; 95% CI 1.66 to 9.05), nausea (RR 1.71; 95% CI 0.93 to 3.18) and abnormal dreams (RR 2.91; 95% CI 1.38 to 6.14). However, the results in both studies were subjected to a serious imprecision resulting from the small sample sizes and the low power of test (lower than 80%), which contributed to a moderate quality of the evidence. No serious adverse events were attributed to the treatments in all experimental groups.

AUTHORS' CONCLUSIONS

We found no convincing evidence to support the efficacy of pharmacological symptomatic treatment for MS-associated memory disorder because most of available RCTs had a limited quality. Whether pharmacological treatment is effective for memory disorder in patients with MS remains inconclusive. However, there is moderate-quality evidence that donepezil 10 mg daily was not effective in improving memory in MS patients with mild memory impairment, but had a good tolerability. Adverse events such as nausea, diarrhoea and abnormal dreams were not frequent but were associated with treatment. Ginkgo biloba, memantine and rivastigmine were safe and well tolerated and no serious adverse effects were reported. Future large-scale RCTs with higher methodological quality are needed.

Clinical, MRI, and CSF markers of disability progression in multiple sclerosis

Multiple sclerosis (MS) is a chronic disorder of the central nervous system (CNS) in which the complex interplay between inflammation and neurodegeneration determines varying degrees of neurological disability. For this reason, it is very difficult to express an accurate prognosis based on purely clinical information in the individual patient at an early disease stage. Magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) biomarkers are promising sources of prognostic information with a good potential of quantitative measure, sensitivity, and reliability. However, a comprehensive MS outcome prediction model combining multiple parameters is still lacking. Current relevant literature addressing the topic of clinical, MRI, and CSF markers as predictors of MS disability progression is reviewed here.

Cortical grey matter demyelination can be induced by elevated pro-inflammatory cytokines in the subarachnoid space of MOG-immunized rats

A substantial proportion of cases with secondary progressive multiple sclerosis have extensive inflammation in the leptomeninges that is associated with increased subpial demyelination, neuronal loss and an exacerbated disease course. However, the mechanisms underlying this extensive subpial pathology are poorly understood. We hypothesize that pro-inflammatory cytokine production within the meninges may be a key to this process. Post-mortem cerebrospinal fluid and dissected cerebral leptomeningeal tissue from patients with multiple sclerosis were used to study the presence of tumour necrosis factor and interferon gamma protein and messenger RNA levels. A novel model of subpial cortical grey matter demyelination was set up in Dark Agouti rats and analysed using quantitative immunohistochemistry. Increased expression of the pro-inflammatory cytokines tumour necrosis factor and interferon gamma was found in the meninges of cases with secondary progressive multiple sclerosis exhibiting tertiary lymphoid-like structures. Injection of tumour necrosis factor and interferon gamma into the subarachnoid space of female Dark Agouti rats pre-immunized with a subclinical dose of myelin oligodendrocyte glycoprotein mimicked the pathology seen in multiple sclerosis, including infiltration of lymphocytes (CD4+ and CD8+ T cells and CD79+ B cells) into the meninges and extensive subpial demyelination. Extensive microglial/macrophage activation was present in a gradient from the pial surface to deeper cortical layers. Demyelination did not occur in control animals immunized with incomplete Freund's adjuvant and injected with cytokines. These results support the hypothesis that pro-inflammatory molecules produced in the meninges play a major role in cortical demyelination in multiple sclerosis, but also emphasize the involvement of an anti-myelin immune response.

The changing clinical course of multiple sclerosis: a matter of gray matter

OBJECTIVE

Clinical and neuroimaging parameters predictive of the changing clinical course of multiple sclerosis (MS) from relapsing-remitting to secondary progressive have not been clarified yet. We specifically designed a prospective 5-year longitudinal study aimed at assessing demographic, clinical, and magnetic resonance imaging (MRI) parameters that could predict the changing clinical course of MS.

METHODS

At study entry and after 5 years, clinical and MRI (ie, gray matter and white matter lesions, including spinal cord lesions, and global and regional cortical thinning) parameters were assessed in a training set of 334 consecutive relapsing-remitting MS patients and in an independent validation set of 84 relapsing-remitting MS patients.

RESULTS

Sixty-six (19.7%) relapsing-remitting MS patients changed their clinical course during the study and entered into the secondary progressive phase. Age (p = 0.001, odds ratio [OR] = 1.2), cortical lesion volume (p < 0.001, OR = 1.7), and cerebellar cortical volume (p < 0.001, OR = 0.2) at study entry were found to predict the changing clinical course. The model including only these 3 variables correctly identified 252 of 268 (94.0%) patients who maintained the relapsing-remitting course and 58 of 66 (87.8%) patients who became secondary progressive (cross-validated error rate = 7.2%). When applied on the validation set, the model obtained a similar error rate (8.4%).

INTERPRETATION

A prediction model based on age, cortical lesion load, and cerebellar cortical volume suitably explains the probability of relapsing-remitting MS patients evolving into the progressive phase. Gray matter damage appears to play a pivotal role in determining the changing clinical course of MS.

Gray Matter Pathology in MS: Neuroimaging and Clinical Correlations

It is abundantly clear that there is extensive gray matter pathology occurring in multiple sclerosis. While attention to gray matter pathology was initially limited to studies of autopsy specimens and biopsies, the development of new MRI techniques has allowed assessment of gray matter pathology in vivo. Current MRI techniques allow the direct visualization of gray matter demyelinating lesions, the quantification of diffuse damage to normal appearing gray matter, and the direct measurement of gray matter atrophy. Gray matter demyelination (both focal and diffuse) and gray matter atrophy are found in the very earliest stages of multiple sclerosis and are progressive over time. Accumulation of gray matter damage has substantial impact on the lives of multiple sclerosis patients; a growing body of the literature demonstrates correlations between gray matter pathology and various measures of both clinical disability and cognitive impairment. The effect of disease modifying therapies on the rate accumulation of gray matter pathology in MS has been investigated. This review focuses on the neuroimaging of gray matter pathology in MS, the effect of the accumulation of gray matter pathology on clinical and cognitive disability, and the effect of disease-modifying agents on various measures of gray matter damage.