Detection of ventricular enlargement in patients at the earliest clinical stage of MS

Chronic experimental autoimmune encephalomyelitis is an excellent model to study neuroaxonal degeneration in multiple sclerosis

Animal models of multiple sclerosis (MS), specifically experimental autoimmune encephalomyelitis (EAE), have been used extensively to develop anti-inflammatory treatments. However, the similarity between MS and one particular EAE model does not end at inflammation. MS and chronic EAE induced in C57BL/6 mice using myelin oligodendrocyte glycoprotein (MOG) peptide 35-55 share many neuropathologies. Beyond both having white matter lesions in spinal cord, both also have widespread neuropathology in the cerebral cortex, hippocampus, thalamus, striatum, cerebellum, and retina/optic nerve. In this review, we compare neuropathologies in each of these structures in MS with chronic EAE in C57BL/6 mice, and find evidence that this EAE model is well suited to study neuroaxonal degeneration in MS.

Linear brain atrophy measures in multiple sclerosis and clinically isolated syndromes: a 30-year follow-up

OBJECTIVE

To determine 30-year brain atrophy rates following clinically isolated syndromes and the relationship of atrophy in the first 5 years and clinical outcomes 25 years later.

METHODS

A cohort of 132 people who presented with a clinically isolated syndrome suggestive of multiple sclerosis (MS) were recruited between 1984-1987. Clinical and MRI data were collected prospectively over 30 years. Widths of the third ventricle and the medulla oblongata were used as linear atrophy measures.

RESULTS

At 30 years, 27 participants remained classified as having had a clinically isolated syndrome, 34 converted to relapsing remitting MS, 26 to secondary progressive MS and 16 had died due to MS. The mean age at baseline was 31.7 years (SD 7.5) and the mean disease duration was 30.8 years (SD 0.9). Change in medullary and third ventricular width within the first 5 years, allowing for white matter lesion accrual and Expanded Disability Status Scale increases over the same period, predicted clinical outcome measures at 30 years. 1 mm of medullary atrophy within the first 5 years increased the risk for secondary progressive MS or MS related death by 30 years by 583% (OR 5.83, 95% CI 1.74 to 19.61, p<0.005), using logistic regression.

CONCLUSIONS

Our findings show that brain regional atrophy within 5 years of a clinically isolated syndrome predicts progressive MS or a related death, and disability 25 years later.

Brain Atrophy Is Associated with Disability Progression in Patients with MS followed in a Clinical Routine

BACKGROUND AND PURPOSE

The assessment of brain atrophy in a clinical routine is not performed routinely in multiple sclerosis. Our aim was to determine the feasibility of brain atrophy measurement and its association with disability progression in patients with MS followed in a clinical routine for 5 years.

MATERIALS AND METHODS

A total of 1815 subjects, 1514 with MS and 137 with clinically isolated syndrome and 164 healthy individuals, were collected retrospectively. Of 11,794 MR imaging brain scans included in the analysis, 8423 MRIs were performed on a 3T, and 3371 MRIs, on a 1.5T scanner. All patients underwent 3D T1WI and T2-FLAIR examinations at all time points of the study. Whole-brain volume changes were measured by percentage brain volume change/normalized brain volume change using SIENA/SIENAX on 3D T1WI and percentage lateral ventricle volume change using NeuroSTREAM on T2-FLAIR.

RESULTS

Percentage brain volume change failed in 36.7% of the subjects; percentage normalized brain volume change, in 19.2%; and percentage lateral ventricle volume change, in 3.3% because of protocol changes, poor scan quality, artifacts, and anatomic variations. Annualized brain volume changes were significantly different between those with MS and healthy individuals for percentage brain volume change (P < .001), percentage normalized brain volume change (P = .002), and percentage lateral ventricle volume change (P = .01). In patients with MS, mixed-effects model analysis showed that disability progression was associated with a 21.9% annualized decrease in percentage brain volume change (P < .001) and normalized brain volume (P = .002) and a 33% increase in lateral ventricle volume (P = .004).

CONCLUSIONS

All brain volume measures differentiated MS and healthy individuals and were associated with disability progression, but the lateral ventricle volume assessment was the most feasible.

The role of MRI as a surrogate outcome measure in multiple sclerosis

The need for more specific and more sensitive outcome measures for use in testing new therapies in multiple sclerosis (MS) is generally accepted. This need has been accentuated by the realization that the ability to conduct large placebo-controlled trials will be limited in the future. From the first use of magnetic resonance imaging (MRI) to study MS, the ability of this imaging technique to identify areas of the central nervous system damage by the disease process in MS has been impressive. Thus, the possibility that MRI could serve as a surrogate outcome measure in clinical trials in MS has been attractive. The use of MRI as a surrogate outcome measure has been examined by an international group of investigators with expertise in clinical aspects of MS, the use of MRI in MS, and in experimental therapeutics. The group agreed that MRI does not represent a validated surrogate in any clinical form of MS. It was also agreed, however, that MRI does provide a reflection of the underlying pathology in the disease, but no single MRI measurement in isolation was seen as sufficient to monitor disease. The use for multiple imaging techniques, especially new, emerging techniques that may better reflect the underlying pathology, was seen as particularly important in monitoring studies of patients with either secondary or primary progressive MS. The choice of MRI techniques used to monitor new therapies needs to be consistent with the proposed mechanisms of the new therapy and phase of the disease. It was also noted, however, that additional validation is required for nonconventional imaging techniques. Finally, the participants noted that clinical trials using MRI as a primary outcome measure may fail to fully identify the effects of the therapy on clinical measures and that the risk and cost-benefit ratio of the treatment might be unresolved. Thus, before MRI is used as a primary outcome measure, new approaches to trial design must be given careful consideration. Multiple Sclerosis (2002)8, 40-51

Imag(in)ing multiple sclerosis: Time to take better pictures

Magnetic resonance imaging (MRI) has led to the identification of widespread brain abnormalities in multiple sclerosis (MS) that extend far beyond the classic white matter lesion. These findings have generated the idea that MS should be understood as a disease of the whole brain, not just the white matter. While it is no doubt the case that many different pathways are ultimately involved in the destruction of brain tissue that occurs in MS, the implications of the accumulated evidence for understanding disease pathophysiology - and hence the overall significance of these imaging findings - are doubtful. Here, I argue that the principled use of imaging can, in fact, address questions about the genesis of these whole-brain abnormalities, rather than simply describe them.

Thalamus Degeneration and Inflammation in Two Distinct Multiple Sclerosis Animal Models

There is a broad consensus that multiple sclerosis (MS) represents more than an inflammatory disease: it harbors several characteristic aspects of a classical neurodegenerative disorder, i.e., damage to axons, synapses, and nerve cell bodies. While several accepted paraclinical methods exist to monitor the inflammatory-driven aspects of the disease, techniques to monitor progression of early and late neurodegeneration are still in their infancy and have not been convincingly validated. It was speculated that the thalamus with its multiple reciprocal connections is sensitive to inflammatory processes occurring in different brain regions, thus acting as a "barometer" for diffuse brain parenchymal damage in MS. To what extent the thalamus is affected in commonly applied MS animal models is, however, not known. In this article we describe direct and indirect damage to the thalamus in two distinct MS animal models. In the cuprizone model, we observed primary oligodendrocyte stress which is followed by demyelination, microglia/astrocyte activation, and acute axonal damage. These degenerative cuprizone-induced lesions were found to be more severe in the lateral compared to the medial part of the thalamus. In MOG35-55-induced EAE, in contrast, most parts of the forebrain, including the thalamus were not directly involved in the autoimmune attack. However, important thalamic afferent fiber tracts, such as the spinothalamic tract were inflamed and demyelinated on the spinal cord level. Quantitative immunohistochemistry revealed that this spinal cord inflammatory-demyelination is associated with neuronal loss within the target region of the spinothalamic tract, namely the sensory ventral posterolateral nucleus of the thalamus. This study highlights the possibility of trans-neuronal degeneration as one mechanism of secondary neuronal damage in MS. Further studies are now warranted to investigate involved cell types and cellular mechanisms.

Individual Assessment of Brain Tissue Changes in MS and the Effect of Focal Lesions on Short-Term Focal Atrophy Development in MS: A Voxel-Guided Morphometry Study

We performed voxel-guided morphometry (VGM) investigating the mechanisms of brain atrophy in multiple sclerosis (MS) related to focal lesions. VGM maps detect regional brain changes when comparing 2 time points on high resolution T1-weighted (T1w) magnetic resonace imaging (MRI). Two T1w MR datasets from 92 relapsing-remitting MS patients obtained 12 months apart were analysed with VGM. New lesions and volume changes of focal MS lesions as well as in the surrounding tissue were identified by visual inspection on colour coded VGM maps. Lesions were dichotomized in active and inactive lesions. Active lesions, defined by either new lesions (NL) (volume increase > 5% in VGM), chronic enlarging lesions (CEL) (pre-existent T1w lesions with volume increase > 5%), or chronic shrinking lesions (CSL) (pre-existent T1w lesions with volume reduction > 5%) in VGM, were accompanied by tissue shrinkage in surrounding and/or functionally related regions. Volume loss within the corpus callosum was highly correlated with the number of lesions in its close proximity. Volume loss in the lateral geniculate nucleus was correlated with lesions along the optic radiation. VGM analysis provides strong evidence that all active lesion types (NL, CEL, and CSL) contribute to brain volume reduction in the vicinity of lesions and/or in anatomically and functionally related areas of the brain.

Thalamus pathology in multiple sclerosis: from biology to clinical application

There is a broad consensus that MS represents more than an inflammatory disease: it harbors several characteristic aspects of a classical neurodegenerative disorder, i.e. damage to axons, synapses and nerve cell bodies. While the clinician is equipped with appropriate tools to dampen peripheral cell recruitment and, thus, is able to prevent immune-cell driven relapses, effective therapeutic options to prevent the simultaneously progressing neurodegeneration are still missing. Furthermore, while several sophisticated paraclinical methods exist to monitor the inflammatory-driven aspects of the disease, techniques to monitor progression of early neurodegeneration are still in their infancy and have not been convincingly validated. In this review article, we aim to elaborate why the thalamus with its multiple reciprocal connections is sensitive to pathological processes occurring in different brain regions, thus acting as a "barometer" for diffuse brain parenchymal damage in MS. The thalamus might be, thus, an ideal region of interest to test the effectiveness of new neuroprotective MS drugs. Especially, we will address underlying pathological mechanisms operant during thalamus degeneration in MS, such as trans-neuronal or Wallerian degeneration. Furthermore, we aim at giving an overview about different paraclinical methods used to estimate the extent of thalamic pathology in MS patients, and we discuss their limitations. Finally, thalamus involvement in different MS animal models will be described, and their relevance for the design of preclinical trials elaborated.

Clinical relevance of brain volume measures in multiple sclerosis

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

Brain atrophy and lesion load predict long term disability in multiple sclerosis

OBJECTIVE

To determine whether brain atrophy and lesion volumes predict subsequent 10 year clinical evolution in multiple sclerosis (MS).

DESIGN

From eight MAGNIMS (MAGNetic resonance Imaging in MS) centres, we retrospectively included 261 MS patients with MR imaging at baseline and after 1-2 years, and Expanded Disability Status Scale (EDSS) scoring at baseline and after 10 years. Annualised whole brain atrophy, central brain atrophy rates and T2 lesion volumes were calculated. Patients were categorised by baseline diagnosis as primary progressive MS (n=77), clinically isolated syndromes (n=18), relapsing-remitting MS (n=97) and secondary progressive MS (n=69). Relapse onset patients were classified as minimally impaired (EDSS=0-3.5, n=111) or moderately impaired (EDSS=4-6, n=55) according to their baseline disability (and regardless of disease type). Linear regression models tested whether whole brain and central atrophy, lesion volumes at baseline, follow-up and lesion volume change predicted 10 year EDSS and MS Severity Scale scores.

RESULTS

In the whole patient group, whole brain and central atrophy predicted EDSS at 10 years, corrected for imaging protocol, baseline EDSS and disease modifying treatment. The combined model with central atrophy and lesion volume change as MRI predictors predicted 10 year EDSS with R(2)=0.74 in the whole group and R(2)=0.72 in the relapse onset group. In subgroups, central atrophy was predictive in the minimally impaired relapse onset patients (R(2)=0.68), lesion volumes in moderately impaired relapse onset patients (R(2)=0.21) and whole brain atrophy in primary progressive MS (R(2)=0.34).

CONCLUSIONS

This large multicentre study points to the complementary predictive value of atrophy and lesion volumes for predicting long term disability in MS.

Clinical use of brain volumetry

Magnetic resonance imaging (MRI)-based brain volumetry is increasingly being used in the clinical setting to assess brain volume changes from structural MR images in a range of neurologic conditions. Measures of brain volumes have been shown to be valid biomarkers of the clinical state and progression by offering high reliability and robust inferences on the underlying disease-related mechanisms. This review critically examines the different scenarios of the application of MRI-based brain volumetry in neurology: 1) supporting disease diagnosis, 2) understanding mechanisms and tracking clinical progression of disease, and 3) monitoring treatment effect. These aspects will be discussed in a wide range of neurologic conditions, with particular emphasis on Alzheimer's disease and multiple sclerosis.

Reduced astrocytic NF-κB activation by laquinimod protects from cuprizone-induced demyelination

Laquinimod (LAQ) is a new oral immunomodulatory compound that reduces relapse rate, brain atrophy and disability progression in multiple sclerosis (MS). LAQ has well-documented effects on inflammation in the periphery, but little is known about its direct activity within the central nervous system (CNS). To elucidate the impact of LAQ on CNS-intrinsic inflammation, we investigated the effects of LAQ on cuprizone-induced demyelination in mice in vivo and on primary CNS cells in vitro. Demyelination, inflammation, axonal damage and glial pathology were evaluated in LAQ-treated wild type and Rag-1-deficient mice after cuprizone challenge. Using primary cells we tested for effects of LAQ on oligodendroglial survival as well as on cytokine secretion and NF-κB activation in astrocytes and microglia. LAQ prevented cuprizone-induced demyelination, microglial activation, axonal transections, reactive gliosis and oligodendroglial apoptoses in wild type and Rag-1-deficient mice. LAQ significantly decreased pro-inflammatory factors in stimulated astrocytes, but not in microglia. Oligodendroglial survival was not affected by LAQ in vitro. Astrocytic, but not microglial, NF-κB activation was markedly reduced by LAQ as evidenced by NF-κB reporter assay. LAQ also significantly decreased astrocytic NF-κB activation in cuprizone-treated mice. Our data indicate that LAQ prevents cuprizone-induced demyelination by attenuating astrocytic NF-κB activation. These effects are CNS-intrinsic and not mediated by peripheral immune cells. Therefore, LAQ downregulation of the astrocytic pro-inflammatory response may be an important mechanism underlying its protective effects on myelin, oligodendrocytes and axons. Modulation of astrocyte activation may be an attractive therapeutic target to prevent tissue damage in MS.

Investigating structural brain changes of dehydration using voxel-based morphometry

Dehydration can affect the volume of brain structures, which might imply a confound in volumetric and morphometric studies of normal or diseased brain. Six young, healthy volunteers were repeatedly investigated using three-dimensional T₁-weighted magnetic resonance imaging during states of normal hydration, hyperhydration, and dehydration to assess volume changes in gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF). The datasets were analyzed using voxel-based morphometry (VBM), a widely used voxel-wise statistical analysis tool, FreeSurfer, a fully automated volumetric segmentation measure, and SIENAr a longitudinal brain-change detection algorithm. A significant decrease of GM and WM volume associated with dehydration was found in various brain regions, most prominently, in temporal and sub-gyral parietal areas, in the left inferior orbito-frontal region, and in the extra-nuclear region. Moreover, we found consistent increases in CSF, that is, an expansion of the ventricular system affecting both lateral ventricles, the third, and the fourth ventricle. Similar degrees of shrinkage in WM volume and increase of the ventricular system have been reported in studies of mild cognitive impairment or Alzheime s disease during disease progression. Based on these findings, a potential confound in GM and WM or ventricular volume studies due to the subjects’ hydration state cannot be excluded and should be appropriately addressed in morphometric studies of the brain.

Retinal axonal loss begins early in the course of multiple sclerosis and is similar between progressive phenotypes

BACKGROUND

To determine whether retinal axonal loss is detectable in patients with a clinically isolated syndrome (CIS), a first clinical demyelinating attack suggestive of multiple sclerosis (MS), and examine patterns of retinal axonal loss across MS disease subtypes.

METHODOLOGY/PRINCIPAL FINDINGS

Spectral-domain Optical Coherence Tomography was performed in 541 patients with MS, including 45 with high-risk CIS, 403 with relapsing-remitting (RR)MS, 60 with secondary-progressive (SP)MS and 33 with primary-progressive (PP)MS, and 53 unaffected controls. Differences in retinal nerve fiber layer (RNFL) thickness and macular volume were analyzed using multiple linear regression and associations with age and disease duration were examined in a cross-sectional analysis. In eyes without a clinical history of optic neuritis (designated as "eyes without optic neuritis"), the total and temporal peripapillary RNFL was thinner in CIS patients compared to controls (temporal RNFL by -5.4 µm [95% CI -0.9 to--9.9 µm, p = 0.02] adjusting for age and sex). The total (p = 0.01) and temporal (p = 0.03) RNFL was also thinner in CIS patients with clinical disease for less than 1 year compared to controls. In eyes without optic neuritis, total and temporal RNFL thickness was nearly identical between primary and secondary progressive MS, but total macular volume was slightly lower in the primary progressive group (p<0.05).

CONCLUSIONS/SIGNIFICANCE

Retinal axonal loss is increasingly prominent in more advanced stages of disease--progressive MS>RRMS>CIS--with proportionally greater thinning in eyes previously affected by clinically evident optic neuritis. Retinal axonal loss begins early in the course of MS. In the absence of clinically evident optic neuritis, RNFL thinning is nearly identical between progressive MS subtypes.

Revisiting brain atrophy and its relationship to disability in multiple sclerosis

Background

Brain atrophy is a well-accepted imaging biomarker of multiple sclerosis (MS) that partially correlates with both physical disability and cognitive impairment.

Methodology/Principal Findings

Based on MRI scans of 60 MS cases and 37 healthy volunteers, we measured the volumes of white matter (WM) lesions, cortical gray matter (GM), cerebral WM, caudate nucleus, putamen, thalamus, ventricles, and brainstem using a validated and completely automated segmentation method. We correlated these volumes with the Expanded Disability Status Scale (EDSS), MS Severity Scale (MSSS), MS Functional Composite (MSFC), and quantitative measures of ankle strength and toe sensation. Normalized volumes of both cortical and subcortical GM structures were abnormally low in the MS group, whereas no abnormality was found in the volume of the cerebral WM. High physical disability was associated with low cerebral WM, thalamus, and brainstem volumes (partial correlation coefficients ∼0.3–0.4) but not with low cortical GM volume. Thalamus volumes were inversely correlated with lesion load (r = −0.36, p<0.005).

Conclusion

The GM is atrophic in MS. Although lower WM volume is associated with greater disability, as might be expected, WM volume was on average in the normal range. This paradoxical result might be explained by the presence of coexisting pathological processes, such as tissue damage and repair, that cause both atrophy and hypertrophy and that underlie the observed disability.

Clinical correlates of grey matter pathology in multiple sclerosis

Traditionally, multiple sclerosis has been viewed as a disease predominantly affecting white matter. However, this view has lately been subject to numerous changes, as new evidence of anatomical and histological changes as well as of molecular targets within the grey matter has arisen. This advance was driven mainly by novel imaging techniques, however, these have not yet been implemented in routine clinical practice. The changes in the grey matter are related to physical and cognitive disability seen in individuals with multiple sclerosis. Furthermore, damage to several grey matter structures can be associated with impairment of specific functions. Therefore, we conclude that grey matter damage - global and regional - has the potential to become a marker of disease activity, complementary to the currently used magnetic resonance markers (global brain atrophy and T2 hyperintense lesions). Furthermore, it may improve the prediction of the future disease course and response to therapy in individual patients and may also become a reliable additional surrogate marker of treatment effect.

New magnetic resonance imaging biomarkers for the diagnosis of multiple sclerosis

INTRODUCTION

Magnetic resonance imaging (MRI) is sensitive in revealing focal white matter (WM) lesions in patients suspected of having multiple sclerosis (MS). As a consequence, MRI has become an established tool in addition to clinical evaluation in the diagnostic work-up of these patients.

AREAS COVERED

This review discusses the role of MRI biomarkers in patients at presentation with clinically isolated syndromes (CIS) suggestive of MS. Conventional MRI has been formally included in the diagnostic work-up of these patients, and imaging criteria have been proposed and are updated on a regular basis. Since in patients with established MS, pathologic and MRI studies have demonstrated that the disease affects the normal-appearing WM and gray matter of the brain and spinal cord in a distributed fashion, significant efforts have been devoted to the development of quantitative MR measures, sensitive to damage to these central nervous system compartments, to better characterize lesion burden at disease onset, to differentiate MS from other neurological conditions and to identify objective markers of an unfavorable clinical evolution in the subsequent years.

EXPERT OPINION

In addition to clinical measures, conventional MR sequences are the 'reference standard' for diagnosis and monitoring disease progression in patients who present with CIS suggestive of MS. The potential and utility of novel advanced MRI techniques in these patients still need to be fully evaluated.

Radiolabeled annexin V imaging: a useful technique for determining apoptosis in multiple sclerosis

Multiple sclerosis (MS) is an inflammatory disease of the central nervous system (CNS) that involves myelin, oligodendrocytes and axons and culminates in consecutive neuronal death and progressive neurologic disability. Based on magnetic resonance imaging (MRI), neuroaxonal loss in MS results in brain atrophy and has a strong correlation with neurological disability. The newer MR imaging tools seem to be sensitive biomarkers for measuring the pathogenetic processes associated with disease activity and progression. However, they are unable to detect apoptosis in neurodegenerative diseases. Annexin V has a high affinity for phosphatidylserine (PS) that presents on the outer surface of the plasma membrane early on during the onset of apoptosis. Radiolabeled annexin V imaging may reveal the initiation and degree of neuronal apoptosis. We propose that radiolabeled annexin V imaging is a useful modality in determining apoptosis in MS and can assess and monitor the effectiveness of neuroprotective and immunomodulatory therapies on the clinical course of MS.

Sex differences in autoimmune diseases

Women are more susceptible to a variety of autoimmune diseases including systemic lupus erythematosus (SLE), multiple sclerosis (MS), primary biliary cirrhosis, rheumatoid arthritis and Hashimoto's thyroiditis. This increased susceptibility in females compared to males is also present in animal models of autoimmune diseases such as spontaneous SLE in (NZBxNZW)F1 and NZM.2328 mice, experimental autoimmune encephalomyelitis (EAE) in SJL mice, thyroiditis, Sjogren's syndrome in MRL/Mp-lpr/lpr mice and diabetes in non-obese diabetic mice. Indeed, being female confers a greater risk of developing these diseases than any single genetic or environmental risk factor discovered to date. Understanding how the state of being female so profoundly affects autoimmune disease susceptibility would accomplish two major goals. First, it would lead to an insight into the major pathways of disease pathogenesis and, secondly, it would likely lead to novel treatments which would disrupt such pathways.

Review of neurologic diseases for the urologist

This article reviews the neurologic conditions associated with a high prevalence of bladder dysfunction and about which significant advances in understanding have occurred in recent years. The importance of the frontal lobes for bladder control has been confirmed through functional brain imaging, and recent findings in the elderly with incontinence suggest the problem may result from disconnection of important frontal areas caused by white matter disease. The very different urologic profile of the two sometimes-confused conditions, multiple system atrophy and Parkinson's disease, is clarified. The advances in treatments for multiple sclerosis in recent years have been remarkable and are briefly described.

Imaging biomarkers in multiple sclerosis

Recent years have witnessed impressive advances in the use of magnetic resonance imaging (MRI) for the assessment of patients with multiple sclerosis (MS). Complementary to the clinical evaluation, conventional MRI provides crucial pieces of information for the diagnosis of MS. However, the correlation between the burden of lesions observed on conventional MRI scans and the clinical manifestations of the disease remains weak. The discrepancy between clinical and conventional MRI findings in MS is explained, at least partially, by the limited ability of conventional MRI to characterize and quantify the heterogeneous features of MS pathology. Other quantitative MR-based techniques, however, have the potential to overcome such a limitation of conventional MRI. Indeed, magnetization transfer MRI, diffusion tensor MRI, proton MR spectroscopy, and functional MRI are contributing to elucidate the mechanisms that underlie injury, repair, and functional adaptation in patients with MS. Such techniques are likely to benefit from the use of high-field MR systems and thus allow in the near future providing additional insight into all these aspects of the disease. This review summarizes how MRI is dramatically changing our understanding of the factors associated with the accumulation of irreversible disability in MS and highlights the reasons why they should be used more extensively in studies of disease evolution and clinical trials.

Neither retinal nor brain atrophy can be shown in patients with isolated unilateral optic neuritis at the time of presentation

Background:Acute monosymptomatic optic neuritis (ON) may be the earliest manifestation of multiple sclerosis (MS). Atrophy has been shown to be a prominent feature of MS with great impact on disability.

Objectives:The objectives of this study were to evaluate retinal and brain atrophy and possible associations at the earliest possible stages of MS.

Methods:In a prospective observational cohort study we included 60 untreated patients with monosymptomatic ON and 19 healthy volunteers. Unaffected fellow eyes were examined with optical coherence tomography (OCT) and normalized brain volumes were calculated based on MRI. Additionally, visual evoked potentials (VEPs) were recorded.

Results:Neither OCT measurements nor brain volume measures revealed signs of localized or generalized atrophy in patients compared with healthy volunteers. Stratification of patients into high risk based on the presence of white matter lesions did not reveal differences. The association between OCT measures and brain volumes previously found could not be confirmed at the time of the first clinical event. VEP latency was significantly prolonged in patients with white matter lesions compared to those without lesions. A trend towards a relationship between VEP amplitude of fellow eyes and brain volumes was noted.

Conclusions:In this cohort we were not able to show atrophic features in the retina or the brain, and the association between structural measures of the retina and the brain as indicated in the later stages of MS could not be reproduced. These findings suggest that atrophy does require time to evolve and indicate the complexity of the relationship between local and general structural measures.

Brain atrophy correlates with functional outcome in a murine model of multiple sclerosis

White matter (WM) lesions are the classic pathological hallmarks of multiple sclerosis (MS). However, MRI-based WM lesion load shows relatively poor correlation with functional outcome, resulting in the "clinico-radiological paradox" of MS. Unlike lesion based measures, volumetric MRI assessment of brain atrophy shows a strong correlation with functional outcome, and the presence of early atrophy predicts a worse disease course. While extensive literature exists describing MRI characteristics of atrophy in MS, the exact pathogenesis and the substrate of atrophy-gray vs. WM loss, axonal/neuronal damage vs. demyelination, or a combination of the above-remain unclear. Animal models of atrophy would allow for detailed investigations of the pathomechanism, and would contribute to an enhanced understanding of structural-functional connections in this complex disease. We now report that in the Theiler's Murine Encephalitis Virus (TMEV) model of MS in SJL/J mice, significant brain atrophy accompanies the development of the progressive MS-like disease. We conducted volumetric MRI studies in 8 cases and 4 age, gender- and strain-matched control mice. While in controls we did not detect any brain atrophy, significant atrophy developed as early as 3 months into the disease course, and reached its peak by 6 months, resulting in ventricular enlargement by 118% (p=0.00003). A strong correlation (r=-0.88) between atrophy and disability, as assessed by rotarod assay, was also demonstrated. We earlier reported another neurodegenerative feature in this model, the presence of deep gray matter T2 hypointensity in thalamic nuclei. Future studies utilizing this model will allow us to investigate key components of MRI detectable neurodegenerative feature development, their tissue correlations and associations with functional outcome measures. These studies are expected to pave the way to a better understanding of the substrate of disability in MS models.

Shifting the paradigm toward earlier treatment of multiple sclerosis with interferon beta

BACKGROUND

Axonal damage occurs early in the course of multiple sclerosis (MS). Among untreated patients, 85% to 94% with a first clinically isolated syndrome (CIS) suggestive of MS and positive findings on magnetic resonance imaging (MRI) are at risk for developing MS.

OBJECTIVES

This article reviews the current literature concerning early diagnosis of MS, the rationale for early immunomodulatory treatment of patients with a CIS and MRI evidence of central nervous system lesions, and the efficacy of early treatment with interferon beta (IFN-beta).

METHODS

MEDLINE was searched from 1990 through the end of 2008 for papers published in English concerning the treatment of MS. Search terms included IFN-beta, early treatment, CIS, and multiple sclerosis, and limits were set to return results related to human clinical trials in adults.

RESULTS

Three pivotal randomized controlled trials were identified, 2 involving IFN-beta-1a (30 microg IM once weekly and 22 microg SC once weekly) and 1 involving IFN-beta-1b (250 microg SC qod). In these trials, treatment with IFN-beta effectively reduced the risk of developing MS by up to 50% in patients with a CIS. Furthermore, compared with delayed treatment, early treatment was associated with a reduced risk of disease progression: a 40% reduction in risk for confirmed disability progression at 3 years and a 41% reduction in risk of MS at 3 years.

CONCLUSIONS

The evidence that axonal damage begins in the early stages of MS, before symptoms are evident, provides a rationale for early intervention with immunomodulatory agents. In 3 pivotal clinical trials, IFN-beta effectively reduced the risk of developing clinically definite MS in CIS patients with a first demyelinating event and positive brain MRI.

Estrogen treatment in multiple sclerosis

Currently available treatments for multiple sclerosis (MS) reduce inflammatory lesions on MRI and decrease clinical relapses but have limited effects on disability. Novel treatment options that target both the inflammatory as well as the neurodegenerative component of the disease are therefore needed. A growing body of evidence from basic science and clinical studies supports the therapeutic potential of estrogens in MS. Mechanisms of action include both immunomodulatory and directly neuroprotective pathways. A first pilot trial of oral estriol treatment showed encouraging results. There are now several phase II trials underway to further determine the efficacy of estrogen treatment in MS.

The use of MR imaging as an outcome measure in multiple sclerosis clinical trials

MR imaging is an integral part of multiple sclerosis (MS) clinical trials. It provides the primary efficacy outcome of preliminary proof-of-concept studies and important corroborating data as secondary and exploratory outcomes in pivotal trials. At all stages of drug development, MR imaging provides important information on the kinetics and magnitude of treatment effect and insight into potential mechanisms of action. Attention to issues in scan acquisition, quantitative image processing, and statistical analysis is critical to generate high-quality data. Although it is unlikely that one single outcome measure can capture all aspects of the MS disease process, there is potential for MR imaging outcomes to evaluate inflammatory and degenerative components within clinical trials.

Extent of cerebellum, subcortical and cortical atrophy in patients with MS: a case-control study

Cortical and subcortical atrophy occurs in multiple sclerosis (MS) and relates to clinical outcomes. FreeSurfer, a voxel-based automated software for brain reconstruction was used to investigate the extent of subcortical and cortical atrophy in 71 MS and 17 clinically isolated syndrome (CIS) patients, and 38 normal controls (NC), and to relate group differences to disease type and severity. Segmentation was performed on 3D SPGR T1-weighted MRI 1.5T images. Region-specific subcortical tissue volumes were calculated in mm(3) and cortical thickness in mm. Logistic regression and general linear model analyses, adjusted for age and intracranial volume, examined differences between NC, MS and CIS patients and disease subtypes. The MS group was characterized by significantly lower volumes of thalamus (left and right p<0.0001), left inferior lateral ventricle, third ventricle (p<0.0001), ventral diencephalon, pallidum and putamen bilaterally, as well as of right accumbens and brainstem with corresponding bilateral increase in volumes of lateral ventricles (p<0.01). Focal cortical atrophy areas in the thalamus, inferior parietal lobule of left hemisphere and in right precuneus were also significant in the MS sample. Versus CIS patients, RR or progressive MS patients showed significantly lower volumes of subcortical regions and cortical thinning. Hippocampal atrophy appeared only in advanced disease stages. Cerebellum WM volumes were significantly lower in MS and CIS patients vs. NC. Subcortical and cortical atrophy correlated with higher disability as measured by EDSS. This study confirmed selective deep gray matter atrophy (mostly thalamic), revealed cerebellum WM atrophy from the earliest clinical stages, and showed that cortical thinning advances with disease progression.

Estrogen and testosterone therapies in multiple sclerosis

It has been known for decades that females are more susceptible than men to inflammatory autoimmune diseases, including multiple sclerosis (MS), rheumatoid arthritis, and psoriasis. In addition, female patients with these diseases experience clinical improvements during pregnancy with a temporary "rebound" exacerbation postpartum. These clinical observations indicate an effect of sex hormones on disease and suggest the potential use of the male hormone testosterone and the pregnancy hormone estriol, respectively, for the treatment of MS. A growing number of studies using the MS animal model experimental autoimmune encephalomyelitis (EAE) support a therapeutic effect of these hormones. Both testosterone and estriol have been found to induce anti-inflammatory as well as neuroprotective effects. Findings from two recent pilot studies of transdermal testosterone in male MS patients and oral estriol in female MS patients are encouraging. In this paper, we review the preclinical and clinical evidence for sex hormone treatments in MS and discuss potential mechanisms of action.

Gray matter atrophy correlates with MS disability progression measured with MSFC but not EDSS

BACKGROUND

Gray matter (GM) pathology is an important component of the multiple sclerosis (MS) disease process. Accelerated gray matter atrophy has been observed in MS patients, but its relationship to neurological disability is not defined. This study was done to determine the relationship between whole brain, GM, and white matter (WM) atrophy and MS disability progression.

METHODS

Patients with MS and Clinically Isolated Syndromes (CIS), and age- and gender-matched healthy controls were entered into an observational protocol. Baseline brain parenchymal fraction (BPF), GM fraction, and WM fraction, and change over 4 years were correlated with sustained disability progression over the entire study duration. Disability progression was measured using the Multiple Sclerosis Functional Composite (MSFC) and the Expanded Disability Status Scale (EDSS).

RESULTS

Seventy MS and CIS patients and 17 HCs were studied for an average of 6.6 years (range, 3.6-7.8 years). At the final visit, 7 patients were classified as CIS, 36 as relapsing-remitting MS (RRMS), and 27 as secondary progressive MS (SPMS). Baseline whole brain, GM, and WM atrophy predicted EDSS >6.0 at the last study visit. Twenty-one (33%) patients worsened using the EDSS to define disability progression; 29 (46%) worsened using MSFC to define disability progression. Patients with MSFC progression had significantly higher GM atrophy rates compared with patients who were stable on MSFC. White matter atrophy was similar in patients with and without disability progression. Atrophy rates were not different in patients with or without disability progression defined using EDSS.

CONCLUSIONS

Whole brain, GM, and WM atrophy predicted MS disability progression observed over the next 6.6 years. Gray matter atrophy rates over 4 years correlated with disability progression measured with the MSFC, but not EDSS. This indicates that MSFC defined disability progression is more closely linked to brain atrophy than EDSS defined disability progression, and provides important new insight into the poor correlation between MRI and clinical disability in MS. The findings confirm the clinical relevance of gray matter atrophy in MS.

Gray matter atrophy in multiple sclerosis: a longitudinal study

OBJECTIVE

To determine gray matter (GM) atrophy rates in multiple sclerosis (MS) patients at all stages of disease, and to identify predictors and clinical correlates of GM atrophy.

METHODS

MS patients and healthy control subjects were observed over 4 years with standardized magnetic resonance imaging (MRI) and neurological examinations. Whole-brain, GM, and white matter atrophy rates were calculated. Subjects were categorized by disease status and disability progression to determine the clinical significance of atrophy. MRI predictors of atrophy were determined through multiple regression.

RESULTS

Subjects included 17 healthy control subjects, 7 patients with clinically isolated syndromes, 36 patients with relapsing-remitting MS (RRMS), and 27 patients with secondary progressive MS (SPMS). Expressed as fold increase from control subjects, GM atrophy rate increased with disease stage, from 3.4-fold normal in clinically isolated syndromes patients converting to RRMS to 14-fold normal in SPMS. In contrast, white matter atrophy rates were constant across all MS disease stages at approximately 3-fold normal. GM atrophy correlated with disability. MRI measures of focal and diffuse tissue damage accounted for 62% of the variance in GM atrophy in RRMS, but there were no significant predictors of GM atrophy in SPMS.

INTERPRETATION

Gray matter tissue damage dominates the pathological process as MS progresses, and underlies neurological disabillity. Imaging correlates of gray matter atrophy indicate that mechanisms differ in RRMS and SPMS. These findings demonstrate the clinical relevance of gray matter atrophy in MS, and underscore the need to understand its causes.

Gray matter atrophy is related to long-term disability in multiple sclerosis

OBJECTIVE

To determine the relation of gray matter (GM) and white matter (WM) brain volumes, and WM lesion load, with clinical outcomes 20 years after first presentation with clinically isolated syndrome suggestive of multiple sclerosis (MS).

METHODS

Seventy-three patients were studied a mean of 20 years from first presentation with a clinically isolated syndrome (33 of whom developed relapsing-remitting MS and 11 secondary-progressive MS, with the rest experiencing no further definite neurological events), together with 25 healthy control subjects. GM and WM volumetric measures were obtained from three-dimensional T1-weighted brain magnetic resonance images using Statistical Parametric Mapping 2.

RESULTS

Significant GM (p < 0.001) and WM atrophy (p = 0.001) was seen in MS patients compared with control subjects. There was significantly more GM, but not WM atrophy, in secondary-progressive MS versus relapsing-remitting MS (p = 0.003), and relapsing-remitting MS versus clinically isolated syndrome (p < 0.001). GM, but not WM, fraction correlated with expanded disability status scale (r(s) = -0.48; p < 0.001) and MS Functional Composite scores (r(s) = 0.59; p < 0.001). WM lesion load correlated with GM (r(s) = -0.63; p < 0.001), but not with WM fraction. Regression modeling indicated that the GM fraction explained more of the variability in clinical measures than did WM lesion load.

INTERPRETATION

In MS patients with a relatively long and homogeneous disease duration, GM atrophy is more marked than WM atrophy, and reflects disease subtype and disability to a greater extent than WM atrophy or lesions.

Diameter assessment of the third ventricle with transcranial sonography in patients with multiple sclerosis

BACKGROUND AND PURPOSE

Diameter measurement of the third ventricle with magnetic resonance imaging (MRI) and recently also with transcranial sonography (TCS) has emerged as a surrogate marker for brain atrophy and disease progression in multiple sclerosis (MS). This study aims to evaluate TCS measurements of the third ventricle diameter in a clinical routine setting against MRI.

METHODS

Transverse diameters of the third ventricle were determined in 27 MS patients using both, TCS and MRI. In TCS, the distance between the leading edges of the brain-ventricle interfaces was assessed in axial image planes. In MRI, the transverse diameter of the mid-portion of the third ventricle was measured on axial T1-weighted images.

RESULTS

The mean diameter of the third ventricle was 4.0 mm (SD 1.7 mm), when measured with MRI, and 4.4 mm (SD 1.7 mm), when measured with TCS. The 95% limits of agreement of the Bland-Altman Plot were 2.93 mm (95% CI 2.08 to 3.78 mm) and -2.23 mm (95%CI -3.08 to -1.38 mm). Pearson correlation coefficient was .71 (P < .0001).

CONCLUSIONS

TCS may appear suitable as screening examination for the extent of brain atrophy at a single-point study, but at least in the early stages of the disease, TCS is not useful to monitor disease progression.

A three-year, multi-parametric MRI study in patients at presentation with CIS

OBJECTIVES

To define the extent of overall brain damage in patients with clinically isolated syndromes (CIS) suggestive of multiple sclerosis (MS) and to identify non-conventional magnetic resonance (MR) metrics predictive of evolution to definite MS.

METHODS

Brain conventional and magnetization transfer (MT) MRI scans were obtained from 208 CIS patients and 55 matched healthy controls, recruited in four centres. Patients were assessed clinically at the time of MRI acquisition and after a median period of 3.1 years from disease onset. The following measures were derived: T2, T1 and gadolinium (Gd)- enhancing lesion volumes (LV), normalized brain volume (NBV), MTR histogram-derived quantities of the normal-appearing white matter (NAWM) and grey matter (GM).

RESULTS

During the follow-up, 43 % of the patients converted to definite MS. At baseline, a significant inter-centre heterogeneity was detected for T2 LV (p = 0.003), T1 LV (p = 0.006), NBV (p < 0.001) and MTR histogram-derived metrics (p < 0.001). Pooled average MTR values differed between CIS patients and controls for NAWM (p = 0.003) and GM (p = 0.01). Gdactivity and positivity of International Panel (IP) criteria for disease dissemination in space (DIS), but not NAWM and GM MTR and NBV, were associated with evolution to definite MS. The final multivariable model retained only MRI IP criteria for DIS (p = 0.05; HR = 1.66, 95 % CI = 1.00-2.77) as an independent predictor of evolution to definite MS.

CONCLUSIONS

Although irreversible tissue injury is present from the earliest clinical stages of MS, macroscopic focal lesions but not "diffuse" brain damage measured by MTR are associated to an increased risk of subsequent development of definite MS in CIS patients.

Regional brain atrophy development is related to specific aspects of clinical dysfunction in multiple sclerosis

Brain atrophy in multiple sclerosis (MS) is thought to reflect irreversible tissue damage leading to persistent clinical deficit. Little is known about the rate of atrophy in specific brain regions in relation to specific clinical deficits. We determined the displacement of the brain surface between two T1-weighted MRI images obtained at baseline and after a median follow-up time of 2.2 years for 79 recently diagnosed, mildly disabled MS patients. Voxel- and cluster-wise permutation-based statistics were used to identify brain regions in which atrophy development was significantly related to Expanded Disability Status Scale (EDSS), Timed Walk Test (TWT), Paced Auditory Serial Addition Test (PASAT) and 9-Hole Peg Test (HPT). Clusters were considered significant at a corrected cluster-wise p-value of 0.05. Worse EDSS change-score and worse follow-up EDSS were related to atrophy development of periventricular and brainstem regions and right-sided parietal, occipital and temporal regions. Worse PASAT at follow-up was significantly related to atrophy of the ventricles. A worse TWT change-score and worse follow-up TWT were exclusively related to atrophy around the ventricles and of the brainstem. Worse HPT change-score and worse follow-up HPT of either arm were significantly related to the atrophy of widely distributed peripheral regions, as well as atrophy of periventricular and brainstem regions. Our findings suggest that decline in ambulatory function is related to atrophy of central brain regions exclusively, whereas decline in neurologically more complex tasks for coordinated hand function is related to atrophy of both central and peripheral brain regions.

Measuring brain atrophy in multiple sclerosis

The last decade has seen the development of methods that use conventional magnetic resonance imaging (MRI) to provide sensitive and reproducible assessments of brain volumes. This has increased the interest in brain atrophy measurement as a reliable indicator of disease progression in many neurological disorders, including multiple sclerosis (MS). After a brief introduction in which we discuss the most commonly used methods for assessing brain atrophy, we will review the most relevant MS studies that have used MRI-based quantitative measures of brain atrophy, the clinical importance of these results, and the potential for future application of these measures to understand MS pathology and progression. Despite the number of issues that still need to be solved, the measurement of brain atrophy by MRI is sufficiently precise and accurate. It represents one of most promising in vivo measures of neuroaxonal degeneration in MS, and it should be used extensively in the future to assess and monitor pathological evolution and treatment efficacy in this disease.

Transcranial brain sonography findings related to neuropsychological impairment in multiple sclerosis

Cognitive dysfunction, fatigue and mood disorder contribute to the neuropsychological impairment that is common in multiple sclerosis (MS). The present paper reviews application of transcranial brain sonography (TCS) in MS patients and TCS findings related to neuropsychological dysfunction. TCS is a new neuroimaging method displaying tissue echogenicity of the brain through the intact skull. Whereas the cortex can not be discriminated from the subcortical white matter with TCS, subcortical brain structures such as ventricles and basal ganglia can be adequately displayed. Even though TCS proved sensitive and reliable in measuring widths of third and lateral ventricles in a number of neurodegenerative diseases, relatively few TCS studies on MS patients have been reported. Data of these studies suggest a good correlation of cognitive dysfunction and width of third ventricle which can be measured reliably with TCS. Moreover, abnormal TCS findings of basal ganglia were associated with cognitive impairment. However, TCS findings of midbrain structures, basal ganglia and ventricles did not correlate with fatigue or depression in MS patients. TCS has the advantages of low costs, short investigation times and unlimited repeatability. The use of third-ventricle and basalganglia TCS for predicting and monitoring neuropsychological impairment in MS patients, however, needs to be elucidated in further studies.