Cortical lesions in radiologically isolated syndrome

Radiologically isolated syndromes: to treat or not to treat?

The widespread use of magnetic resonance imaging (MRI) has led to increased detection of individuals exhibiting asymptomatic brain and spinal cord lesions suggestive of multiple sclerosis (MS), defined as "radiologically isolated syndrome" (RIS). Specific criteria have been proposed and updated over time to identify individuals with RIS. Moreover, a younger age, the presence of infratentorial, spinal cord or gadolinium-enhancing lesions, as well as of cerebrospinal fluid-specific oligoclonal bands have been recognized as relevant risk factors for the occurrence of a first clinical event. Recent randomized controlled trials conducted in individuals with RIS have shown that dimethyl fumarate and teriflunomide significantly reduce the occurrence of clinical events in this population. These findings support the notion that early treatment initiation may positively influence the prognosis of these patients. However, several aspects should be taken into account before treating individuals with RIS in the real-world clinical setting, including an accurate identification of individuals with RIS to avoid misdiagnosis, a precise stratification of their risk of experiencing a first clinical event and further data supporting favorable balance between benefits and risks, even in the long term. This commentary provides an overview of the latest updates in RIS diagnosis, prognosis, and emerging treatment evidence.

Emerging imaging markers in radiologically isolated syndrome: implications for earlier treatment initiation

The presence of central nervous system lesions fulfilling the criteria of dissemination in space and time on MRI leads to the diagnosis of a radiologically isolated syndrome (RIS), which may be an early sign of multiple sclerosis (MS). However, some patients who do not fulfill the necessary criteria for RIS still evolve to MS, and some T2 hyperintensities that resemble demyelinating lesions may originate from mimics. In light of the recent recognition of the efficacy of disease-modifying therapy (DMT) in RIS, it is relevant to consider additional imaging features that are more specific of MS. We performed a narrative review on cortical lesions (CL), the central vein sign (CVS), and paramagnetic rim lesions (PRL) in patients with RIS. In previous RIS studies, the reported prevalence of CLs ranges between 20.0 and 40.0%, CVS + white matter lesions (WMLs) between 87.0 and 93.0% and PRLs between 26.7 and 63.0%. Overall, these imaging findings appear to be frequent in RIS cohorts, although not consistently taken into account in previous studies. The search for CLs, CVS + WML and PRLs in RIS patients could lead to earlier identification of patients who will evolve to MS and benefit from DMTs.

Cortical lesions, central vein sign, and paramagnetic rim lesions in multiple sclerosis: Emerging machine learning techniques and future avenues

The current diagnostic criteria for multiple sclerosis (MS) lack specificity, and this may lead to misdiagnosis, which remains an issue in present-day clinical practice. In addition, conventional biomarkers only moderately correlate with MS disease progression. Recently, some MS lesional imaging biomarkers such as cortical lesions (CL), the central vein sign (CVS), and paramagnetic rim lesions (PRL), visible in specialized magnetic resonance imaging (MRI) sequences, have shown higher specificity in differential diagnosis. Moreover, studies have shown that CL and PRL are potential prognostic biomarkers, the former correlating with cognitive impairments and the latter with early disability progression. As machine learning-based methods have achieved extraordinary performance in the assessment of conventional imaging biomarkers, such as white matter lesion segmentation, several automated or semi-automated methods have been proposed as well for CL, PRL, and CVS. In the present review, we first introduce these MS biomarkers and their imaging methods. Subsequently, we describe the corresponding machine learning-based methods that were proposed to tackle these clinical questions, putting them into context with respect to the challenges they are facing, including non-standardized MRI protocols, limited datasets, and moderate inter-rater variability. We conclude by presenting the current limitations that prevent their broader deployment and suggesting future research directions.

The Multiple Sclerosis Prodrome: Evidence to Action

A growing body of work points toward the existence of a clinically symptomatic prodromal phase in multiple sclerosis (MS) that might span 5–10 years or more. A prodrome is an early set of signs or symptoms predating the onset of classical disease, which in turn predates a definitive diagnosis. Evidence for a prodromal phase in MS could have major implications for prevention, earlier recognition and treatment, as well as an improved disease course or prognosis. This Perspective provides a succinct overview of the recent advances in our understanding of the MS prodrome and current key challenges. Many of the MS prodromal features characterized thus far are non-specific and are common in the general population; no single feature alone is sufficient to identify an individual with prodromal MS. Biomarkers may increase specificity and accuracy for detecting individuals in the MS prodromal phase, but are yet to be discovered or formally validated. Progress made in the elucidation of prodromal phases in other neurological and immune-mediated diseases suggests that these barriers can be overcome. Therefore, while knowledge of a prodromal phase in MS remains nascent, how best to move from the rapidly growing evidence to research-related action is critical. Immediate implications include refining the concept of the MS continuum to include a prodromal phase. This will help inform the true “at risk” period when considering exposures that might cause MS. Major long-term implications include the earlier recognition of MS, improved prognosis, through earlier disease management, and the future possibility of MS disease prevention.

The multiple sclerosis prodrome

A prodrome is an early set of signs, symptoms or other findings that occur before the onset of typical symptoms of a disease. Prodromal phases are well recognized in several neurological and inflammatory diseases, but the possibility of a prodrome in multiple sclerosis (MS) has received relatively little attention until the past few years. In this Perspective, we summarize what is currently known about the MS prodrome, including its possible duration, clinical features and potential biomarkers. We also consider what insights and lessons can be learned from knowledge of and research into the prodromal phases of other diseases. A better understanding of the MS prodrome could have profound clinical implications as it could enable earlier recognition of MS and earlier initiation of treatments that reduce relapse rates and long-term disability. Knowledge of the MS prodrome could also affect research into the causes of MS, and putative risk factors must be re-evaluated in light of the MS prodrome. We conclude by outlining the major knowledge gaps and propose future initiatives.

Radiologically isolated syndrome: from biological bases to practical management

BACKGROUND

Technological advances and greater availability of magnetic resonance imaging have prompted an increment on incidental and unexpected findings within the central nervous system. The concept of radiologically isolated syndrome characterizes a group of subjects with images suggestive of demyelinating disease in the absence of a clinical episode compatible with multiple sclerosis. Since the description of this entity, many questions have arisen; some have received responses but others remain unanswered. A panel of experts met with the objective of performing a critical review of the currently available evidence. Definition, prevalence, biological bases, published evidence, and implications on patient management were reviewed. Thirty to 50% of subjects with radiologically isolated syndrome will progress to multiple sclerosis in 5 years. Male sex, age < 37 years old, and spinal lesions increase the risk. These subjects should be evaluated by a multiple sclerosis specialist, carefully excluding alternative diagnosis. An initial evaluation should include a brain and complete spine magnetic resonance, visual evoked potentials, and identification of oligoclonal bands in cerebrospinal fluid. Disease-modifying therapies could be considered when oligoclonal bands or radiological progression is present.

CONCLUSION

At present time, radiologically isolated syndrome cannot be considered a part of the multiple sclerosis spectrum. However, a proportion of patients may evolve to multiple sclerosis, meaning it represents much more than just a radiological finding.

[Radiologically isolated syndrome: prognosis and predictors of conversion to multiple sclerosis]

Increased sensitivity and availability of magnetic resonance imaging (MRI) in neurological routine practice led to the fact that more and more experts began to encounter changes typical for multiple sclerosis (MS) according to MRI in the absence of anamnestic and clinical indications of damage to the central nervous system (CNS). This nosological form has been defined as a radiologically isolated syndrome (RIS). More and more RIS cases convert to MS (up to 30% in the first 5 years after RIS diagnosis). At the moment, there are no biological markers that allow combining RIS and MS into one pathological process and early treatment with disease-modifying drugs (DMT). Prospective studies are actively being conducted to identify demographic, clinical, neuroimaging and biochemical conversion predictors. The identification of the molecular biological RIS features, combining these changes with MS, is an urgent scientific task and will allow timely initiation of therapy of the pathological process already at the subclinical stage.

Radiologically Isolated Syndrome: A Review for Neuroradiologists

Radiologically isolated syndrome refers to an entity in which white matter lesions fulfilling the criteria for multiple sclerosis occur in individuals without a history of a clinical demyelinating attack or alternative etiology. Since its introduction in 2009, the diagnostic criteria of radiologically isolated syndrome and its clinical relevance have been widely debated by neurologists and radiologists. The aim of the present study was to review the following: 1) historical evolution of radiologically isolated syndrome criteria, 2) clinical and imaging findings in adults and children with radiologically isolated syndrome, 3) imaging features of patients with radiologically isolated syndrome at high risk for conversion to MS, and 4) challenges and controversies for work-up, management, and therapeutic interventions of patients with radiologically isolated syndrome.

Treatment Considerations in the Radiologically Isolated Syndrome

PURPOSE OF REVIEW

This review provides the reader with updated information needed to make an accurate diagnosis of radiologically isolated syndrome (RIS), discusses controversies and considerations related to therapeutic intervention in RIS, and summarizes ongoing clinical intervention trials.

RECENT FINDINGS

Individuals with RIS lack clinical neurological symptoms but are at risk for the subsequent development of a first clinical neurological event consistent with a diagnosis of multiple sclerosis. There are two ongoing clinical intervention trials to determine whether disease-modifying treatments for multiple sclerosis can delay or prevent a first clinical event in individuals with RIS. If clinical trials demonstrate a beneficial effect of disease-modifying therapy, such interventions should be considered in individuals with RIS.

MRI features associated with high likelihood of conversion of radiologically isolated syndrome to multiple sclerosis

Radiologically isolated syndrome (RIS) is the asymptomatic precursor to clinically isolated syndrome, relapsing-remitting multiple sclerosis (MS) or primary progressive MS. RIS is frequently diagnosed when an individual gets an MRI for an unrelated medical issue, such as headache or trauma. Treating RIS patients is controversial, but physicians may be inclined to offer prophylactic treatment for high-risk RIS patients. Identifying imaging and clinical features associated with high likelihood of early clinical conversion may prove helpful to identify a high-risk subset for potential MS therapy. The goal of this paper is to review current literatures to identify imaging and clinical features that predict early (within 5 years) conversion from RIS to MS.

Dynamic gray matter volume changes in pediatric multiple sclerosis

Objectives

To assess, using MRI, the spatial patterns of gray matter (GM) atrophy in pediatric patients with multiple sclerosis (MS), their dynamic changes over time, and their clinical relevance.

Methods

Sixty-eight pediatric patients with MS (30 with a clinical and MRI follow-up after 3.5 years) and 26 healthy controls (HC) underwent clinical and MRI evaluation. To overcome difficulties in obtaining longitudinal scans in pediatric HC, a group of 317 pediatric HC from an NIH-funded MRI Study of Normal Brain Development was used to estimate GM developmental trajectories. In pediatric patients with MS, deviations from normative GM volume values at the voxel level were assessed at baseline and during the follow-up, using linear mixed-effects models. Correlations between GM volume deviations and disability, IQ, and white matter (WM) lesion volumes (LV) were estimated.

Results

Pediatric patients with MS showed failures in GM development in several cortical and subcortical regions, as well as GM atrophy progression in most of these regions, which were only partially related to focal WM LV. Significant correlations were found between regional GM atrophy (particularly of deep GM regions) and disability, whereas higher IQ was associated with reduced deviations from age-expected GM volumes of specific GM regions at baseline and during the follow-up.

Conclusions

Impaired GM maturation occurs in pediatric patients with MS, which is only partially driven by WM inflammation, suggesting that early neurodegenerative phenomena contribute to disability. High IQ, a measure of reserve, may offer protection by promoting remodeling of GM pruning in this young age.

Multiple sclerosis

Multiple sclerosis (MS) is the most common chronic inflammatory, demyelinating and neurodegenerative disease of the central nervous system in young adults. This disorder is a heterogeneous, multifactorial, immune-mediated disease that is influenced by both genetic and environmental factors. In most patients, reversible episodes of neurological dysfunction lasting several days or weeks characterize the initial stages of the disease (that is, clinically isolated syndrome and relapsing-remitting MS). Over time, irreversible clinical and cognitive deficits develop. A minority of patients have a progressive disease course from the onset. The pathological hallmark of MS is the formation of demyelinating lesions in the brain and spinal cord, which can be associated with neuro-axonal damage. Focal lesions are thought to be caused by the infiltration of immune cells, including T cells, B cells and myeloid cells, into the central nervous system parenchyma, with associated injury. MS is associated with a substantial burden on society owing to the high cost of the available treatments and poorer employment prospects and job retention for patients and their caregivers.

Anomalies Characteristic of Central Nervous System Demyelination: Radiologically Isolated Syndrome

Radiologically isolated syndrome (RIS) was defined in 2009 for asymptomatic patients who presented incidentally identified white matter anomalies within the central nervous system suggestive of multiple sclerosis (MS). Approximately one-third of RIS subjects will have a seminal clinical demyelinating event within 5 years of the identification of their abnormal MRI. Clinical evolution mirrors relapsing remitting or progressive forms of MS. Pejorative factors for clinical conversion are male gender, age younger than 35 years, and spinal cord lesions.

Correlation between cortical lesions and cognitive impairment in multiple sclerosis

OBJECTIVES

Gray matter (GM) damage is well known as a fundamental aspect of multiple sclerosis (MS). Above all, cortical lesions (CLs) burden, detectable at MRI with double inversion recovery (DIR) sequences, has been demonstrated to correlate with cognitive impairment (CI). The aim of this study was to investigate the role of CLs number in predicting CI in a cohort of patients with MS in a clinical practice setting.

MATERIALS AND METHODS

Thirty consecutive patients with MS presenting CLs (CL+) at high-field (3.0 T) MRI 3D-DIR sequences and an even group of MS patients without CLs (CL-) as a control, were investigated with the Rao Brief Repeatable Battery of Neuropsychological Tests (BRB), Version A. Total and lobar CLs number were computed in CL+ patients.

RESULTS

Among the sixty patients with MS enrolled, forty-seven (78.3%) had a relapsing-remitting course, while thirteen (21.7%) a progressive one, eleven secondary progressive, and two primary progressive. Compared to CL-, CL+ patients had a greater proportion of progressive forms (p = .03). The most affected region was the frontal lobe (73.3% of patients), followed by temporal and parietal ones (both 60.0%). Multivariate (logistic regression) analysis revealed a significant correlation between total CLs number and the presence of mild cognitive impairment defined as pathologic score in at least one BRB test (p = .04); it was also correlated with deficit at PASAT 3 (p = .05) and Stroop Test (p = .02).

CONCLUSIONS

We confirmed CLs number, evaluated with a technique quite commonly available in clinical practice, as a predictive factor of CI in patients with MS, in order to improve the diagnosis and management of CI and monitor potential neuroprotective effects of therapies.

In vivo characterization of cortical and white matter neuroaxonal pathology in early multiple sclerosis

Neuroaxonal pathology is a main determinant of disease progression in multiple sclerosis; however, its underlying pathophysiological mechanisms, including its link to inflammatory demyelination and temporal occurrence in the disease course are still unknown. We used ultra-high field (7 T), ultra-high gradient strength diffusion and T1/T2-weighted myelin-sensitive magnetic resonance imaging to characterize microstructural changes in myelin and neuroaxonal integrity in the cortex and white matter in early stage multiple sclerosis, their distribution in lesional and normal-appearing tissue, and their correlations with neurological disability. Twenty-six early stage multiple sclerosis subjects (disease duration ≤5 years) and 24 age-matched healthy controls underwent 7 T T2*-weighted imaging for cortical lesion segmentation and 3 T T1/T2-weighted myelin-sensitive imaging and neurite orientation dispersion and density imaging for assessing microstructural myelin, axonal and dendrite integrity in lesional and normal-appearing tissue of the cortex and the white matter. Conventional mean diffusivity and fractional anisotropy metrics were also assessed for comparison. Cortical lesions were identified in 92% of early multiple sclerosis subjects and they were characterized by lower intracellular volume fraction (P = 0.015 by paired t-test), lower myelin-sensitive contrast (P = 0.030 by related-samples Wilcoxon signed-rank test) and higher mean diffusivity (P = 0.022 by related-samples Wilcoxon signed-rank test) relative to the contralateral normal-appearing cortex. Similar findings were observed in white matter lesions relative to normal-appearing white matter (all P < 0.001), accompanied by an increased orientation dispersion (P < 0.001 by paired t-test) and lower fractional anisotropy (P < 0.001 by related-samples Wilcoxon signed-rank test) suggestive of less coherent underlying fibre orientation. Additionally, the normal-appearing white matter in multiple sclerosis subjects had diffusely lower intracellular volume fractions than the white matter in controls (P = 0.029 by unpaired t-test). Cortical thickness did not differ significantly between multiple sclerosis subjects and controls. Higher orientation dispersion in the left primary motor-somatosensory cortex was associated with increased Expanded Disability Status Scale scores in surface-based general linear modelling (P < 0.05). Microstructural pathology was frequent in early multiple sclerosis, and present mainly focally in cortical lesions, whereas more diffusely in white matter. These results suggest early demyelination with loss of cells and/or cell volumes in cortical and white matter lesions, with additional axonal dispersion in white matter lesions. In the cortex, focal lesion changes might precede diffuse atrophy with cortical thinning. Findings in the normal-appearing white matter reveal early axonal pathology outside inflammatory demyelinating lesions.

Radiologically isolated syndrome and multiple sclerosis

BACKGROUND

Incidental white matter lesions (WML) are increasingly seen on brain magnetic resonance imaging (MRI) in clinical practice. Demyelination consistent with MS is seen in 0.1-0.7% of the population as evident by autopsy and MRI studies. The term radiologically isolated syndrome (RIS) was coined to define a subgroup of patients with demyelinating lesions highly suggestive of multiple sclerosis (MS). The Okuda criteria for diagnosing RIS help in stratifying the risk of conversion to MS but RIS is still not considered a distinct MS phenotype.

METHODS

The authors reviewed the current literature on diagnostic criteria, natural history and treatment indications in RIS, to assess the challenges faced in diagnosing and treating such patients in clinical practice.

RESULTS

Typically, one-third of patients convert to clinically definite MS within 5 years, with some progressing directly into primary progressive MS (PPMS). The main risk factors for conversion are: age < 37 years, male gender and presence of spinal cord lesions. Patients with RIS have evidence of early axonal loss, brain atrophy, cognitive deficits, increased anxiety and depression, and subclinical inflammatory disease.

CONCLUSION

Patients with RIS at high risk of clinical conversion might be considered for treatment, although this is still a controversial issue. Prospective follow-up of RIS patients by an MS specialist is recommended.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

CLINICALTRIALSGOV IDENTIFIER

NCT00176592.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

CLINICALTRIALSGOV IDENTIFIER

NCT00176592.

Pharmacological Approaches to the Management of Secondary Progressive Multiple Sclerosis

It is well recognised that the majority of the impact of multiple sclerosis (MS), both personal and societal, arises in the progressive phase where disability accumulates inexorably. As such, progressive MS (PMS) has been the target of pharmacological therapies for many years. However, there are no current licensed treatments for PMS. This stands in marked contrast to relapsing remitting MS (RRMS) where trials have resulted in numerous licensed therapies. PMS has proven to be a more difficult challenge compared to RRMS and this review focuses on secondary progressive MS (SPMS), where relapses occur before the onset of gradual, irreversible disability, and not primary progressive MS where disability accumulation occurs without prior relapses. Although there are similarities between the two forms, in both cases pinpointing when PMS starts is difficult in a condition in which disability can vary from day to day. There is also an overlap between the pathology of relapsing and progressive MS and this has contributed to the lack of well-defined outcomes, both surrogates and clinically relevant outcomes in PMS. In this review, we used the search term 'randomised controlled clinical drug trials in secondary progressive MS' in publications since 1988 together with recently completed trials where results were available. We found 34 trials involving 21 different molecules, of which 38% were successful in reaching their primary outcome. In general, the trials were well designed (e.g. double blind) with sample sizes ranging from 35 to 1949 subjects. The majority were parallel group, but there were also multi-arm and multidose trials as well as the more recent use of adaptive designs. The disability outcome most commonly used was the Expanded Disability Status Scale (EDSS) in all phases, but also magnetic resonance imaging (MRI)-measured brain atrophy has been utilised as a surrogate endpoint in phase II studies. The majority of the treatments tested in SPMS over the years were initially successful in RRMS. This has a number of implications in terms of targeting SPMS, but principally implies that the optimal strategy to target SPMS is to utilise the prodrome of relapses to initiate a therapy that will aim to both prevent progression and slow its accumulation. This approach is in agreement with the early targeting of MS but requires treatments that are both effective and safe if it is to be used before disability is a major problem. Recent successes will hopefully result in the first licensed therapy for PMS and enable us to test this approach.

Diagnosis of multiple sclerosis: progress and challenges

The diagnosis of multiple sclerosis is based on neurological symptoms and signs, alongside evidence of dissemination of CNS lesions in space and time. MRI is often sufficient to confirm the diagnosis when characteristic lesions accompany a typical clinical syndrome, but in some patients, further supportive information is obtained from cerebrospinal fluid examination and neurophysiological testing. Differentiation is important from other diseases in which demyelination is a feature (eg, neuromyelitis optica spectrum disorder and acute disseminated encephalomyelitis) and from non-demyelinating disorders such as chronic small vessel disease and other inflammatory, granulomatous, infective, metabolic, and genetic causes that can mimic multiple sclerosis. Advances in MRI and serological and genetic testing have greatly increased accuracy in distinguishing multiple sclerosis from these disorders, but misdiagnosis can occur. In this Series paper we explore the progress and challenges in the diagnosis of multiple sclerosis with reference to diagnostic criteria, important differential diagnoses, controversies and uncertainties, and future prospects.

Optimization and stratification of multiple sclerosis treatment in fast developing economic countries: a perspective from Qatar

OBJECTIVE

The introduction of disease-modifying therapies (DMTs) - with varying degrees of efficacy for reducing annual relapse rate and disability progression - has considerably transformed the therapeutic landscape of relapsing-remitting multiple sclerosis (RRMS). We aim to develop rational evidence-based treatment recommendations and algorithms for the management of clinically isolated syndrome (CIS) and RRMS that conform to the healthcare system in a fast-developing economic country such as Qatar.

RESEARCH DESIGN AND METHODS

We conducted a systematic review using a comprehensive search of MEDLINE, PubMed, and Cochrane Database of Systematic Reviews (1 January 1990 through 30 September 2016). Additional searches of the American Academy of Neurology and European Committee for Treatment and Research in Multiple Sclerosis abstracts from 2012 through 2016 were performed, in addition to searches of the Food and Drug Administration and European Medicines Agency websites to obtain relevant safety information on these DMTs.

RESULTS

For each of the DMTs, the mode of action, efficacy, safety and tolerability are briefly discussed. To facilitate the interpretation, the efficacy data of the pivotal phase III trials are expressed by their most clinically useful measure of therapeutic efficacy, the number needed to treat (NNT). In addition, an overview of head-to-head trials in RRMS is provided as well as a summary of the several different RRMS management strategies (lateral switching, escalation, induction, maintenance and combination therapy) and the potential role of each DMT. Finally, algorithms were developed for CIS, active and highly active or rapidly evolving RRMS and subsequent breakthrough disease or suboptimal treatment response while on DMTs. The benefit-to-risk profiles of the DMTs, taking into account patient preference, allowed the provision of rational and safe patient-tailored treatment algorithms.

CONCLUSIONS

Recommendations and algorithms for the management of CIS and RRMS have been developed relevant to the healthcare system of this fast-developing economic country.

Radiologically Isolated Syndrome: MR Imaging Features Suggestive of Multiple Sclerosis Prior to First Symptom Onset

Remarkable advances in the understanding of the biology of multiple sclerosis have been achieved through the use of conventional and novel MR imaging techniques of the central nervous system. With improvements in access by patients and utilization of MR imaging technology in health care, an increasing number of unanticipated structural anomalies are being appreciated. In certain instances, white matter abnormalities within the brain and spinal cord are discovered in subjects with no prior history of neurologic symptoms supportive of inflammatory demyelinating events.

Reducing costs while enhancing quality of care in MS

The rapid escalation in prices of disease-modifying therapies (DMTs) for multiple sclerosis (MS) over the past decade has resulted in a dramatic overall increase in the costs of MS-related care. In this article, we outline various approaches whereby neurologists can contribute to responsible cost containment while maintaining, and even enhancing, the quality of MS care. The premise of the article is that clinicians are uniquely positioned to introduce innovative management strategies that are both medically sound and cost-efficient. We describe our "top 5" recommendations, including strategies for customizing relapse treatment; developing alternative dosing schedules for Food and Drug Administration-approved MS DMTs; using off-label therapies for relapse suppression; and limiting the use of DMTs to those who clearly fulfill diagnostic criteria, and who might benefit from continued use over time. These suggestions are well-grounded in the literature and our personal experience, but are not always supported with rigorous Class I evidence as yet. We advocate for neurologists to take a greater role in shaping clinical research agendas and helping to establish cost-effective approaches on a firm empiric basis.

Epilepsy in multiple sclerosis: The role of temporal lobe damage

Background:

Although temporal lobe pathology may explain some of the symptoms of multiple sclerosis (MS), its role in the pathogenesis of seizures has not been clarified yet.

Objectives:

To investigate the role of temporal lobe damage in MS patients suffering from epilepsy, by the application of advanced multimodal 3T magnetic resonance imaging (MRI) analysis.

Methods:

A total of 23 relapsing remitting MS patients who had epileptic seizures (RRMS/E) and 23 disease duration matched RRMS patients without any history of seizures were enrolled. Each patient underwent advanced 3T MRI protocol specifically conceived to evaluate grey matter (GM) damage. This includes grey matter lesions (GMLs) identification, evaluation of regional cortical thickness and indices derived from the Neurite Orientation Dispersion and Density Imaging model.

Results:

Regional analysis revealed that in RRMS/E, the regions most affected by GMLs were the hippocampus (14.2%), the lateral temporal lobe (13.5%), the cingulate (10.0%) and the insula (8.4%). Cortical thinning and alteration of diffusion metrics were observed in several regions of temporal lobe, in insular cortex and in cingulate gyrus of RRMS/E compared to RRMS ( p< 0.05 for all comparisons).

Conclusions:

Compared to RRMS, RRMS/E showed more severe damage of temporal lobe, which exceeds what would be expected on the basis of the global GM damage observed.

Radiologically isolated syndrome: An update on a rare entity

Our understanding of radiologically isolated syndrome (RIS) is evolving, as new data emerge on the clinical characterization and the pathophysiological nature of this rare entity. This topical review aims to (1) outline state-of-the-art clinical and magnetic resonance imaging findings of RIS research; (2) raise the main obstacles to RIS research; (3) discuss the most controversial issues of current RIS findings; and (4) highlight potential strategies for upcoming research studies.

Normal-appearing brain tissue analysis in radiologically isolated syndrome using 3 T MRI

To date, it remains largely unknown whether there is in radiologically isolated syndrome (RIS) brain damage beyond visible T2 white matter lesions. We used single- voxel proton magnetic resonance spectroscopy and diffusion tensor imaging (3 T MRI) to analyze normal-appearing brain tissue regions in 18 RIS patients and 18 matched healthy controls. T2-hyperintense lesion volumes and structural brain volumes were also measured. The absolute metabolite concentrations and ratios of total N-acetylaspartate+N-acetylaspartyl glutamate (NAA), choline-containing compounds, myoinositol, and glutamine-glutamate complex to creatine were calculated. Spectral analysis was performed by LCModel. Voxelwise morphometry analysis was performed to localize regions of brain tissue showing significant changes of fractional anisotropy or mean diffusivity. Compared with healthy controls, RIS patients did not show any significant differences in either the absolute concentration of NAA or NAA/Cr ratio in mid-parietal gray matter. A trend toward lower NAA concentrations (-3.35%) was observed among RIS patients with high risk for conversion to multiple sclerosis. No differences in the other metabolites or their ratios were observed. RIS patients showed lower fractional anisotropy only in clusters overlapping lesional areas, namely in the cingulate gyrus bilaterally and the frontal lobe subgyral bilaterally (P < 0.001). Normalized brain and cortical volumes were significantly lower in RIS patients than in controls (P = 0.01 and P = 0.03, respectively). Our results suggest that in RIS, global brain and cortical atrophy are not primarily driven by significant occult microstructural normal appearing brain damage. Longitudinal MRI studies are needed to better understand the pathological processes underlying this novel entity.

Incidental Lesions Suggesting Multiple Sclerosis

PURPOSE OF REVIEW

Neurologists are frequently asked to consult on patients with incidentally observed anomalies on brain MRI that may be suggestive of multiple sclerosis (MS). The identification of such findings has important clinical management implications. This review provides an overview and practical clinical approach options for clinicians.

RECENT FINDINGS

An increase in the number of brain MRI studies performed annually is expected to result in detection of a corresponding greater number of unanticipated anomalies. A disproportionate number of patients referred to neurologists for this reason have punctate subcortical T2 hyperintensities that appear nonspecific in origin rather than having imaging features concerning for MS. However, in some instances, the MRI characteristics appear to be typical for demyelination. When these features are observed, efforts should be pursued to identify an accurate explanation for the preclinical findings through rigorous clinical evaluation, paraclinical testing, and utilization of longitudinal imaging.

SUMMARY

The identification of subjects with incidental T2 hyperintensities highly suggestive of MS is important for patient counseling and management. Continued neurologic evaluations and reassessment of the original clinical impression are recommended to ensure accurate interpretation of the available data.

Incidence of Radiologically Isolated Syndrome: A Population-Based Study

BACKGROUND AND PURPOSE

Incidental MR imaging findings resembling MS in asymptomatic individuals, fulfilling the Okuda criteria, are termed "radiologically isolated syndrome." Those with radiologically isolated syndrome are at high risk of their condition converting to MS. The epidemiology of radiologically isolated syndrome remains largely unknown, and there are no population-based studies, to our knowledge. Our aim was to study the population-based incidence of radiologically isolated syndrome in a high-incidence region for MS and to evaluate the effect on radiologically isolated syndrome incidence when revising the original radiologically isolated syndrome criteria by using the latest radiologic classification for dissemination in space.

MATERIALS AND METHODS

All 2272 brain MR imaging scans in 1907 persons obtained during 2013 in the Swedish county of Västmanland, with a population of 259,000 inhabitants, were blindly evaluated by a senior radiologist and a senior neuroradiologist. The Okuda criteria for radiologically isolated syndrome were applied by using both the Barkhof and Swanton classifications for dissemination in space. Assessments of clinical data were performed by a radiology resident and a senior neurologist.

RESULTS

The cumulative incidence of radiologically isolated syndrome was 2 patients (0.1%), equaling an incidence rate of 0.8 cases per 100,000 person-years, in a region with an incidence rate of MS of 10.2 cases per 100,000 person-years. There was no difference in the radiologically isolated syndrome incidence rate when applying a modified version of the Okuda criteria by using the newer Swanton classification for dissemination in space.

CONCLUSIONS

Radiologically isolated syndrome is uncommon in a high-incidence region for MS. Adapting the Okuda criteria to use the dissemination in space-Swanton classification may be feasible. Future studies on radiologically isolated syndrome may benefit from a collaborative approach to ensure adequate numbers of participants.

Cortical Perfusion Alteration in Normal-Appearing Gray Matter Is Most Sensitive to Disease Progression in Relapsing-Remitting Multiple Sclerosis

BACKGROUND AND PURPOSE

The role of gray matter in multiple sclerosis is increasingly evident; however, conventional images demonstrate limitations in cortical lesion identification. Perfusion imaging appears sensitive to changes in tissue type and disease severity in MS. We sought to use bookend perfusion to quantify parameters in healthy controls and normal-appearing and lesional tissue at different relapsing-remitting MS stages.

MATERIALS AND METHODS

Thirty-nine patients with relapsing-remitting MS and 19 age-matched healthy controls were prospectively recruited. The Minimal Assessment of Cognitive Function in MS battery was used to assess cognitive performance. Perfusion parameters, including cerebral blood flow and volume and mean transit time, were compared for healthy controls and normal-appearing and lesional tissue for all study groups. Dispersion of perfusion measures for white matter lesions and cortical lesions was assessed.

RESULTS

Twenty of the 39 patients with relapsing-remitting MS were cognitively impaired. Significant differences were displayed between all relapsing-remitting MS subgroups and healthy controls in all comparisons except for normal-appearing gray matter CBV between healthy controls and unimpaired patients with relapsing-remitting MS and for all normal-appearing white matter perfusion parameters between healthy controls and unimpaired patients with relapsing-remitting MS. White matter lesion but not cortical lesion perfusion was significantly reduced in cognitively impaired patients with relapsing-remitting MS versus unimpaired patients with relapsing-remitting MS. Perfusion reduction with disease progression was greater in normal-appearing gray matter and normal-appearing white matter compared with cortical lesions and white matter lesions. Smaller dispersion was observed for cortical lesions compared with white matter lesions for each perfusion parameter.

CONCLUSIONS

Quantitative GM and WM analysis demonstrated significant but disproportionate white matter lesion, cortical lesion, normal-appearing white matter, and normal-appearing gray matter changes present between healthy controls and patients with relapsing-remitting MS with and without cognitive impairment, necessitating absolute rather than relative lesion perfusion measurement.

Gray Matter Involvement in Radiologically Isolated Syndrome

The unanticipated magnetic resonance imaging (MRI) detection in the brain of asymptomatic subjects of white matter lesions suggestive of multiple sclerosis has recently been named as radiologically isolated syndrome (RIS). The pathophysiological processes of RIS remain largely unknown and questions as to whether gray matter alterations actually occur in this entity are yet to be investigated in more detail. By means of a 3 T multimodal MRI approach, we searched for cortical and deep gray matter changes in a cohort of RIS patients. Seventeen RIS patients, 17 clinically isolated syndrome (CIS) patients (median disease duration from symptom onset = 12 months), and 17 healthy controls underwent MRI and neuropsychological testing. Normalized deep gray matter volumes and regional cortical thickness were assessed using FreeSurfer. SIENAX was used to obtain normalized global and cortical brain volumes. Voxelwise morphometry analysis was performed by using SPM8 software to localize regions of brain tissue showing significant changes of fractional anisotropy or mean diffusivity. Although no differences were observed between CIS and healthy controls groups, RIS patients showed significantly lower normalized cortical volume (673 ± 27.07 vs 641 ± 35.88 [cm³ × 10³, Tukey P test = 0.009) and mean thalamic volume (0.0051 ± 0.4 vs 0.0046 ± 0.4 mm, P = 0.014) compared with healthy controls. RIS patients also showed significant thinning in a number of cortical areas, that were primarily distributed in frontal and temporal lobes (P < 0.05, uncorrected). Strong correlations were observed between T2-white matter lesion volume and regional cortical thickness (rho spearman ranging from 0.60 to 0.80). Our data suggest that white matter lesions on T2-weighted images are not the only hallmark of RIS. Future longitudinal studies with larger samples are warranted to better clarify the effect of RIS-related white matter lesions on gray matter tissue.

MRI criteria for the diagnosis of multiple sclerosis: MAGNIMS consensus guidelines

In patients presenting with a clinically isolated syndrome, MRI can support and substitute clinical information in the diagnosis of multiple sclerosis by showing disease dissemination in space and time and by helping to exclude disorders that can mimic multiple sclerosis. MRI criteria were first included in the diagnostic work-up for multiple sclerosis in 2001, and since then several modifications to the criteria have been proposed in an attempt to simplify lesion-count models for showing disease dissemination in space, change the timing of MRI scanning to show dissemination in time, and increase the value of spinal cord imaging. Since the last update of these criteria, new data on the use of MRI to establish dissemination in space and time have become available, and MRI technology has improved. State-of-the-art MRI findings in these patients were discussed in a MAGNIMS workshop, the goal of which was to provide an evidence-based and expert-opinion consensus on proposed modifications to MRI criteria for the diagnosis of multiple sclerosis.

Humoral response to EBV is associated with cortical atrophy and lesion burden in patients with MS

Objective:

Because dysregulated Epstein-Barr virus (EBV)-infected B cells may induce meningeal inflammation, which contributes to cortical pathology in multiple sclerosis (MS), we investigated associations between antibody responses to EBV and development of cortical pathology in MS.

Methods:

We included 539 patients with MS (369 with relapsing-remitting MS, 135 with secondary progressive MS, and 35 with primary progressive MS), 66 patients with clinically isolated syndrome (CIS), 63 patients with other neurologic diseases (OND), and 178 age- and sex-matched healthy controls (HC). All participants were scanned on 3T MRI. Serum samples were analyzed for IgG antibodies against EBV viral capsid antigen (VCA) and EBV nuclear antigen-1 (EBNA-1), and their quartiles were determined on the whole study sample. Differences between the study groups were assessed using analysis of covariance adjusted for multiple comparisons.

Results:

More than 30% of patients with MS and CIS presented with the highest quartile of anti-EBV-VCA and -EBNA-1 status compared to ≤10% of HC (p < 0.001). The figures were 9 (14.3%) and 7 (12.3%) for patients with OND. Patients with MS with the highest quartile of anti-EBV-VCA showed significantly increased T2 lesion volume (p = 0.001), T1 lesion number (p = 0.002), and T1 lesion volume (p = 0.04) and decreased gray matter (p = 0.041) and cortical (p = 0.043) volumes compared to patients with MS with lower quartiles. No significant differences of MRI outcomes in patients with CIS, patients with OND, and HC with lower or highest quartiles of anti-EBV-VCA and -EBNA-1 were detected.

Conclusions:

Humoral response to anti-EBV-VCA and -EBNA-1 is associated with more advanced cortical atrophy, accumulation of chronic T1 black holes, and focal white matter lesions in patients with MS.

The radiologically isolated syndrome

Even prior to the introduction of criteria defining the radiologically isolated syndrome (RIS), longitudinal clinical data from individuals with incidentally identified T2 lesions suggestive of multiple sclerosis (MS) were described. Healthy individuals who do not exhibit signs of neurological dysfunction may have a brain MRI performed for a reason other than suspicion of MS that reveals unexpected anomalies highly suggestive of demyelinating plaques given their size, location, and morphology. These healthy subjects lack a history or symptomatology suggestive of MS and fulfill formal criteria for RIS, a recently described MS subtype that shares the phenotype of at-risk individuals for future demyelinating events. A formal description of RIS was first introduced in 2009 by Okuda et al., and defines a cohort of individuals who are at risk for future demyelinating events. European or North American observational studies have found that up to 30-45% of patients presenting with RIS will present with neurological symptoms, either acute or progressive. The median time to clinical conversion differs between studies. It was 2.3 years for a series of French patients and 5.4 years for an American cohort. Most patients who developed clinical symptoms had prior radiological progression. The presence of asymptomatic lesions in the cervical cord indicated an increased risk of progression, either to relapsing or to progressive MS. The consortium studying the epidemiology of RIS worldwide (RISC) presented their first retrospective cohort last year. Data were available for 451 RIS subjects (F: 354 [78.5%]). The mean age at RIS diagnosis was 37.2 years with a mean clinical follow-up time of 4.4 years. The observed 5-year conversion rate to the first clinical event was 34%. Of the converters within this time period, 9.6% fulfilled criteria for primary progressive MS. In the multivariate model, age, sex (male), and lesions within the cervical or thoracic spinal cord were identified as significant predictors for the development of a first clinical event. Cognitive impairment is observed in RIS patients, and two studies demonstrated a significant proportion of patients with cognitive decline compared with healthy controls. Despite progress into the characterization of RIS subjects and into our understanding of risk factors for initial symptom development, the natural course of such cases and risk-profiles for a seminal neurological event, from prospectively acquired data, remain unclear. A prospective study is mandatory to increase our knowledge about these asymptomatic patients and individual therapeutic initiatives cannot be undertaken until a prospective clinical study demonstrates the benefit of introducing a disease modifying treatment for this very early stage of a chronic demyelinating disease.

Evidence-based guidelines: MAGNIMS consensus guidelines on the use of MRI in multiple sclerosis-clinical implementation in the diagnostic process

The clinical use of MRI in patients with multiple sclerosis (MS) has advanced markedly over the past few years. Technical improvements and continuously emerging data from clinical trials and observational studies have contributed to the enhanced performance of this tool for achieving a prompt diagnosis in patients with MS. The aim of this article is to provide guidelines for the implementation of MRI of the brain and spinal cord in the diagnosis of patients who are suspected of having MS. These guidelines are based on an extensive review of the recent literature, as well as on the personal experience of the members of the MAGNIMS (Magnetic Resonance Imaging in MS) network. We address the indications, timing, coverage, reporting and interpretation of MRI studies in patients with suspected MS. Our recommendations are intended to help radiologists and neurologists standardize and optimize the use of MRI in clinical practice for the diagnosis of MS.

Exploring the origins of grey matter damage in multiple sclerosis

Multiple sclerosis is characterized at the gross pathological level by the presence of widespread focal demyelinating lesions of the myelin-rich white matter. However, it is becoming clear that grey matter is not spared, even during the earliest phases of the disease. Furthermore, grey matter damage may have an important role both in physical and cognitive disability. Grey matter pathology involves both inflammatory and neurodegenerative mechanisms, but the relationship between the two is unclear. Histological, immunological and neuroimaging studies have provided new insight in this rapidly expanding field, and form the basis of the most recent hypotheses on the pathogenesis of grey matter damage.

Appraisal of brain connectivity in radiologically isolated syndrome by modeling imaging measures

We hypothesized that appraisal of brain connectivity may shed light on the substrate of the radiologically isolated syndrome (RIS), a term applied to asymptomatic subjects with brain MRI abnormalities highly suggestive of multiple sclerosis. We thus used a multimodal MRI approach on the human brain by modeling measures of microstructural integrity of white matter (WM) tracts with those of functional connectivity (FC) at the level of resting state networks in RIS subjects, demographically matched normal controls (NC), and relapsing-remitting (RR) MS patients, also matched with RIS for brain macrostructural damage (i.e., lesions and atrophy). Compared with NC, in both RIS subjects and MS patients altered integrity of WM tracts was present. However, RIS subjects showed, at a less conservative threshold, lower diffusivities than RRMS patients in distinct cerebral associative, commissural, projection, and cerebellar WM tracts, suggesting a relatively better anatomical connectivity. FC was similar in NC and RIS subjects, even in the presence of important risk factors for MS (spinal cord lesions, oligoclonal bands, and dissemination in time on MRI) and increased in RRMS patients in two clinically relevant networks subserving "processing" (sensorimotor) and "control" (working memory) functions. In RIS, the lack of functional reorganization in key brain networks may represent a model of "functional reserve," which may become upregulated, with an adaptive or maladaptive role, only at a later stage in case of occurrence of clinical deficit.

Genetic associations with brain cortical thickness in multiple sclerosis

Multiple sclerosis (MS) is characterized by temporal and spatial dissemination of demyelinating lesions in the central nervous system. Associated neurodegenerative changes contributing to disability have been recognized even at early disease stages. Recent studies show the importance of gray matter damage for the accrual of clinical disability rather than white matter where demyelination is easily visualized by magnetic resonance imaging (MRI). The susceptibility to MS is influenced by genetic risk, but genetic factors associated with the disability are not known. We used MRI data to determine cortical thickness in 557 MS cases and 75 controls and in another cohort of 219 cases. We identified nine areas showing different thickness between cases and controls (regions of interest, ROI) (eight of them were negatively correlated with Kurtzke's expanded disability status scale, EDSS) and conducted genome-wide association studies (GWAS) in 464 and 211 cases available from the two data sets. No marker exceeded genome-wide significance in the discovery cohort. We next combined nominal statistical evidence of association with physical evidence of interaction from a curated human protein interaction network, and searched for subnetworks enriched with nominally associated genes and for commonalities between the two data sets. This network-based pathway analysis of GWAS detected gene sets involved in glutamate signaling, neural development and an adjustment of intracellular calcium concentration. We report here for the first time gene sets associated with cortical thinning of MS. These genes are potentially correlated with disability of MS.

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.

Longitudinal Follow-up of a Cohort of Patients with Incidental Abnormal Magnetic Resonance Imaging Findings at Presentation and Their Risk of Developing Multiple Sclerosis

BACKGROUND

Magnetic resonance imaging (MRI) is widely used in clinical practice, and "abnormal brain MRI" findings often prompt assessment for multiple sclerosis (MS), even when there are no symptoms suggestive of the disease. Despite several studies involving individuals with "radiologically isolated syndrome" (RIS), little is known about what factors might predict future development of MS. The objective of this study was to longitudinally evaluate clinical and MRI characteristics of people who presented to an MS clinic because of incidental abnormal MRI findings but did not have typical symptoms of MS, in order to assess risk factors for developing MS.

METHODS

Thirty consecutive patients presenting to an MS clinic for evaluation of abnormal MRI findings were enrolled in the study. Clinical and paraclinical data, including MRI results, were reviewed. Magnetic resonance imaging findings of T2 hyperintensities measuring more than 3 mm in diameter and fulfilling at least three out of four Barkhof criteria, with or without gadolinium-enhancing lesions, were considered to be suggestive of MS.

RESULTS

The median follow-up time was 5.5 years. No participants without MRI findings suggestive of MS were diagnosed with MS (P = .005). Fifteen participants had MRI findings suggestive of MS. Seven of the 15 (47%) were diagnosed with MS on follow-up. Cerebrospinal fluid (CSF) testing results were available for 15 participants. Abnormal results were found in six participants, of whom five (83%) also had MRI findings suggestive of MS. Only two of the nine (22%) participants with normal CSF results (P = .04) had MRI findings suggestive of MS.

CONCLUSIONS

In our cohort, none of the participants without MRI findings suggestive of MS developed MS. The participants with MRI findings suggestive of MS were more likely to develop symptoms and MRI changes typical of MS on follow-up.