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We agree with Dr. Domingue's observation that the trajectory of recovery after spinal cord injury (SCI) is complex and difficult to predict. We should clarify that in the present study, we investigated the effects of traumatic SCI on neurodegeneration across the neuroaxis.1 However, we and others have shown that in cervical spondolytic myelopathy (i.e., nontraumatic SCI) remote tissue specific cord pathology is also evident.2,3 Surprisingly, the extent of neurodegeneration is similar to traumatic SCI, although these patients with nontraumatic SCI had only mild clinical symptoms.2 This suggests that, in a slow progressive disease (e.g., cervical spondolytic myelopathy), the CNS can compensate for neurodegenerative processes for much longer; however, with time, the competition between processes of reorganization and neurodegeneration is lost in favor of the latter. Nevertheless, the clinical viability of MRI-based structural measures for monitoring and predicting recovery after nontraumatic and traumatic SCI is feasible and will provide a tool to improve our understanding of the disease mechanism, which affects not only the spinal cord but also the brain after SCI.3–5 These new insights will enable us to better predict individual recovery trajectories and identify patients who could profit from further interventions to delay, or even prevent, further clinical deterioration.

[Excerpt] Introduction The management of multiple sclerosis (MS) has been a neurology success story for the past 25 years. Advances in understanding of the disease mechanisms and the dynamic nature of the disease have brought around 12 disease-modifying therapies (DMTs) to market in many countries.[...], This study was funded by F Hoffmann-La Roche., info:eu-repo/semantics/publishedVersion

The analysis of clinical trials is limited to pre-specified outcomes, thereby precluding a mechanistic understanding of the treatment response. Multivariate mechanistic models can elucidate the causal chain of events by simultaneous analysis of multi-modal data that link intermediate variables to outcomes of interest. A double-blind, randomised, controlled, phase 2 clinical trial in secondary progressive multiple sclerosis (MS-STAT, NCT00647348) demonstrated that simvastatin (80mg/day) over two years reduced the brain atrophy rate and was associated with beneficial effects on cognitive and disability outcomes. Therefore, this trial offers an opportunity to apply mechanistic models to investigate the hypothesised pathways that link simvastatin to clinical outcome measures, either directly or indirectly via changes in serum total cholesterol levels and to determine which is the more likely. We re-analysed the MS-STAT trial in which 140 patients with secondary progressive multiple sclerosis were randomised (1:1) to receive placebo or simvastatin (80 mg/day). At baseline and after one and two years patients underwent brain magnetic resonance imaging; their cognitive and physical disability were assessed on the block design test and Expanded Disability Status Scale (EDSS). Serum total cholesterol levels were measured at each visit. We calculated the annual percentage change of brain volume loss using mixed-effects models. With multivariate mechanistic models and Bayesian mediation analyses, a cholesterol-dependent model was compared to a cholesterol-independent model. As described previously, the simvastatin group showed a slower rate of brain atrophy and clinical deterioration (as reflected by both the EDSS and the block design test) and a faster decline in serum cholesterol levels (all p

Objective To evaluate whether structural brain network metrics correlate better with clinical impairment and information processing speed in multiple sclerosis (MS) beyond atrophy measures and white matter lesions. Methods This cross-sectional study included 51 healthy controls and 122 patients comprising 58 relapsing–remitting, 28 primary progressive and 36 secondary progressive. Structural brain networks were reconstructed from diffusion-weighted MRIs and standard metrics reflecting network density, efficiency and clustering coefficient were derived and compared between subjects’ groups. Stepwise linear regression analyses were used to investigate the contribution of network measures that explain clinical disability (Expanded Disability Status Scale (EDSS)) and information processing speed (Symbol Digit Modalities Test (SDMT)) compared with conventional MRI metrics alone and to determine the best statistical model that explains better EDSS and SDMT. Results Compared with controls, network efficiency and clustering coefficient were reduced in MS while these measures were also reduced in secondary progressive relative to relapsing–remitting patients. Structural network metrics increase the variance explained by the statistical models for clinical and information processing dysfunction. The best model for EDSS showed that reduced network density and global efficiency and increased age were associated with increased clinical disability. The best model for SDMT showed that lower deep grey matter volume, reduced efficiency and male gender were associated with worse information processing speed. Conclusions Structural topological changes exist between subjects’ groups. Network density and global efficiency explained disability above non-network measures, highlighting that network metrics can provide clinically relevant information about MS pathology.

Increasing numbers of drugs are being developed for the treatment of multiple sclerosis (MS). Measurement of relevant outcomes is key for assessing the efficacy of new drugs in clinical trials and for monitoring responses to disease-modifying drugs in individual patients. Most outcomes used in trial and clinical settings reflect either clinical or neuroimaging aspects of MS (such as relapse and accrual of disability or the presence of visible inflammation and brain tissue loss, respectively). However, most measures employed in clinical trials to assess treatment effects are not used in routine practice. In clinical trials, the appropriate choice of outcome measures is crucial because the results determine whether a drug is considered effective and therefore worthy of further development; in the clinic, outcome measures can guide treatment decisions, such as choosing a first-line disease-modifying drug or escalating to second-line treatment. This Review discusses clinical, neuroimaging and composite outcome measures for MS, including patient-reported outcome measures, used in both trials and the clinical setting. Its aim is to help clinicians and researchers navigate through the multiple options encountered when choosing an outcome measure. Barriers and limitations that need to be overcome to translate trial outcome measures into the clinical setting are also discussed.

We consider the problem of reconstructing brain networks in a longitudinal study, where diffusion-weighted and T1-weighted magnetic resonance images have been acquired at multiple time-points for the same subject. We introduce a method for registering diffusion-weighted and structural scans in a subject-specific half-way space and we demonstrate that half-way network metrics are strongly correlated with native network metrics. We also report sufficient agreement between the two techniques in a cohort comprising of healthy controls (n = 12) and multiple sclerosis patients (n = 12). The results remained unaffected when the analyses were evaluated in controls and patients separately. These study findings might be of particular interest in longitudinal structural network studies assessing network changes over time in normal and disease conditions.

Objectives: To measure the development of spinal cord (SC) atrophy over 1 year in patients with progressive multiple sclerosis (PMS) and determine the sample sizes required to demonstrate a reduction in spinal cord cross-sectional area (SC-CSA) as an outcome measure in clinical trials. Methods: In total, 44 PMS patients (26 primary progressive multiple sclerosis (PPMS), 18 secondary progressive multiple sclerosis (SPMS)) and 29 healthy controls (HCs) were studied at baseline and 12 months. SC-CSA was measured using the three-dimensional (3D) fast field echo sequences acquired at 3T and the active surface model. Multiple linear regressions were used to investigate changes in imaging measurements. Results: PPMS patients had shorter disease duration, lower Expanded Disability Status Scale (EDSS) and larger SC-CSA than SPMS patients. All patients together showed a significantly greater decrease in percentage SC-CSA change than HCs, which was driven by the PPMS. All patients deteriorated over 1 year, but no association was found between percentage SC-CSA change and clinical changes. The sample size per arm required to detect a 50% treatment effect over 1 year, at 80% power, was 57 for PPMS and 546 for SPMS. Conclusion: SC-CSA may become an outcome measure in trials of PPMS patients, when they are at an early stage of the disease, have moderate disability and modest SC atrophy.

Progressive multiple sclerosis (MS) will be a major area of research interest for years to come. No treatments exist and success in the field will generalise to other neurological conditions where neurodegeneration coexists with neuroinflammation. The issue is complex, and interdisciplinary approaches – uniting scientists with different competences (neurobiology, immunogenetics, etc.) and ‘mindsets’ (academia and industry) – will be decisive. The International Progressive MS Alliance is catalysing this process through various initiatives, the most recent of which was a meeting where scientists from academia (also outside the MS field) and from industry reviewed data and strategies to determine the next steps towards the translation of current knowledge into effective therapies. Key findings are: (i). Concerted efforts are essential to prioritise pathogenetic mechanisms according to impact on the disease and druggability. (ii). Combination therapies will probably be needed, possibly early in the disease, along with new trial designs and treatment schedules. (iii). Drug screenings are a pragmatic approach hopefully enriched by the use of neural and oligodendrocyte progenitors differentiated from induced pluripotent stem cells (iPSCs). (iv). The field of network biology will increase our ability to predict therapeutic targets. (v). Genome-wide association studies (GWAS) must try to identify variants associated with disease progression.

Neurodegeneration is thought to be the major cause of ongoing, irreversible disability in progressive stages of multiple sclerosis. Gamma-aminobutyric acid is the principle inhibitory neurotransmitter in the brain. The aims of this study were to investigate if gamma-aminobutyric acid levels (i) are abnormal in patients with secondary progressive multiple sclerosis compared with healthy controls; and (ii) correlate with physical and cognitive performance in this patient population. Thirty patients with secondary progressive multiple sclerosis and 17 healthy control subjects underwent single-voxel MEGA-PRESS (MEscher-GArwood Point RESolved Spectroscopy) magnetic resonance spectroscopy at 3 T, to quantify gamma-aminobutyric acid levels in the prefrontal cortex, right hippocampus and left sensorimotor cortex. All subjects were assessed clinically and underwent a cognitive assessment. Multiple linear regression models were used to compare differences in gamma-aminobutyric acid concentrations between patients and controls adjusting for age, gender and tissue fractions within each spectroscopic voxel. Regression was used to examine the relationships between the cognitive function and physical disability scores specific for these regions with gamma-aminobuytric acid levels, adjusting for age, gender, and total N-acetyl-aspartate and glutamine-glutamate complex levels. When compared with controls, patients performed significantly worse on all motor and sensory tests, and were cognitively impaired in processing speed and verbal memory. Patients had significantly lower gamma-aminobutyric acid levels in the hippocampus (adjusted difference = -0.403 mM, 95% confidence intervals -0.792, -0.014, P = 0.043) and sensorimotor cortex (adjusted difference = -0.385 mM, 95% confidence intervals -0.667, -0.104, P = 0.009) compared with controls. In patients, reduced motor function in the right upper and lower limb was associated with lower gamma-aminobutyric acid concentration in the sensorimotor cortex. Specifically for each unit decrease in gamma-aminobutyric acid levels (in mM), there was a predicted -10.86 (95% confidence intervals -16.786 to -4.482) decrease in grip strength (kg force) (P < 0.001) and -8.74 (95% confidence intervals -13.943 to -3.015) decrease in muscle strength (P < 0.006). This study suggests that reduced gamma-aminobutyric acid levels reflect pathological abnormalities that may play a role in determining physical disability. These abnormalities may include decreases in the pre- and postsynaptic components of gamma-aminobutyric acid neurotransmission and in the density of inhibitory neurons. Additionally, the reduced gamma-aminobutyric acid concentration may contribute to the neurodegenerative process, resulting in increased firing of axons, with consequent increased energy demands, which may lead to neuroaxonal degeneration and loss of the compensatory mechanisms that maintain motor function. This study supports the idea that modulation of gamma-aminobutyric acid neurotransmission may be an important target for neuroprotection in multiple sclerosis.See De Stefano and Giorgio (doi:10.1093/brain/awv213) for a scientific commentary on this article.

The Progressive MS Alliance Industry Forum describes a new approach to address barriers to developing treatments for progressive multiple sclerosis (MS). This innovative model promises to facilitate robust collaboration between industry, academia, and patient organizations and accelerate research towards the overarching goal of developing safe and effective treatments for progressive MS.

The application of imaging biomarkers has provided new insights into the mechanisms of damage in multiple sclerosis (MS) and the risk of MS development and progression. The goal of eliminating all disease activity requires a timely escalation of treatment. This increasing complexity is compounded by the need to treat comorbidities.

Background and purpose: Multiple sclerosis (MS) is a complex disease of the central nervous system. As new drugs are becoming available, knowledge on diagnosis and treatment must continuously evolve. There is therefore a need for a reference tool compiling current data on benefit and safety, to aid professionals in treatment decisions and use of resources across Europe. The European Committee of Treatment and Research in Multiple Sclerosis (ECTRIMS) and the European Academy of Neurology (EAN) have joined forces to meet this need. The objective was to develop an evidence-based clinical practice guideline for the pharmacological treatment of people with MS to guide healthcare professionals in the decision-making process. Methods: This guideline has been developed using the GRADE methodology and following the recently updated EAN recommendations for guideline development. Clinical questions were formulated in PICO format (patient, intervention, comparator, outcome) and outcomes were prioritized according to their relevance to clinical practice. An exhaustive literature search up to December 2016 was performed for each question and the evidence is presented narratively and, when possible, combined in a meta-analysis using a random-effects model. The quality of evidence for each outcome was rated into four categories – very high, high, low and very low − according to the risk of bias. GRADE evidence profiles were created using GRADEprofiler (GRADEpro) software (Version 3.6). The recommendations with assigned strength (strong, weak) were formulated based on the quality of evidence and the risk−benefit balance. Consensus between the panellists was reached by use of the modified nominal group technique. Results: A total of 10 questions have been agreed, encompassing treatment efficacy, response criteria, strategies to address suboptimal response and safety concerns and treatment strategies in MS and pregnancy. The guideline takes into account all disease-modifying drugs approved by the European Medicine Agency at the time of publication. A total of 20 recommendations were agreed by the guideline working group members after three rounds of consensus.

ObjectiveGrey matter (GM) atrophy occurs in all multiple sclerosis (MS) phenotypes. We investigated whether there is a spatiotemporal pattern of GM atrophy that is associated with faster disability accumulation in MS.MethodsWe analysed 3,604 brain high-resolution T1-weighted MRI scans from 1,417 participants: 1,214 MS patients (253 clinically-isolated syndrome[CIS], 708 relapsingremitting[RRMS], 128 secondary-progressive[SPMS], 125 primary-progressive[PPMS]), over an average follow-up of 2.41 years (standard deviation[SD]=1.97), and 203 healthy controls (HCs) [average follow-up=1.83 year, SD=1.77], attending 7 European centres. Disability was assessed with the Expanded-Disability Status Scale (EDSS). We obtained volumes of the deep GM (DGM), temporal, frontal, parietal, occipital and cerebellar GM, brainstem and cerebral white matter. Hierarchical mixed-models assessed annual percentage rate of regional tissue loss and identified regional volumes associated with time-to-EDSS progression.ResultsSPMS showed the lowest baseline volumes of cortical GM and DGM. Of all baseline regional volumes, only that of the DGM predicted time-to-EDSS progression (hazard ratio=0.73, 95% CIs 0.65, 0.82; pppInterpretationThis large multi-centre and longitudinal study shows that DGM volume loss drives disability accumulation in MS, and that temporal cortical GM shows accelerated atrophy in SPMS than RRMS. The difference in regional GM atrophy development between phenotypes needs to be taken into account when evaluating treatment effect of therapeutic interventions.

The demand and growth for published research in the field of multiple sclerosis (MS) has increased exponentially over the last few years. The primary aim of the Multiple Sclerosis Journal (MSJ) has always been to reflect the excellent work of the ever-expanding and diverse clinical and research field of MS, and this role will now be shared by MSJ’s companion journal MSJ Experimental, Translational, and Clinical, an open access journal.

Understanding the mechanisms underlying progression in multiple sclerosis (MS) and identifying appropriate therapeutic targets is a key challenge facing the MS community. This challenge has been championed internationally by organizations such as the Progressive MS Alliance, which has raised the profile of progressive MS and identified the key obstacles to treatment. This review will outline the considerable progress against these challenges.New insights into mechanisms underlying progression have opened up potential therapeutic opportunities. This has been complemented by ongoing validation of clinical and imaging outcomes for Phase II trials of progression, coupled with the development of innovative trial designs. The field has been greatly encouraged by recent positive Phase III trials in both primary and secondary progressive MS, albeit with modest benefit. Early trials of neuroprotection and repair have provided important new data with which to drive the field. Improving symptom management and advancing rehabilitation approaches, critical for this patient population which, taken together with identifying and managing comorbidities and risk factors, has an appreciable impact on health-related quality of life.Raising the profile of progressive MS has resulted in the first effective treatments with the promise of more to come.

A first-ever spinal cord imaging meeting was sponsored by the International Spinal Research Trust and the Wings for Life Foundation with the aim of identifying the current state-of-the-art of spinal cord imaging, the current greatest challenges, and greatest needs for future development. This meeting was attended by a small group of invited experts spanning all aspects of spinal cord imaging from basic research to clinical practice. The greatest current challenges for spinal cord imaging were identified as arising from the imaging environment itself; difficult imaging environment created by the bone surrounding the spinal canal, physiological motion of the cord and adjacent tissues, and small crosssectional dimensions of the spinal cord, exacerbated by metallic implants often present in injured patients. Challenges were also identified as a result of a lack of "critical mass" of researchers taking on the development of spinal cord imaging, affecting both the rate of progress in the field, and the demand for equipment and software to manufacturers to produce the necessary tools. Here we define the current state-of-the-art of spinal cord imaging, discuss the underlying theory and challenges, and present the evidence for the current and potential power of these methods. In two review papers (part I and part II), we propose that the challenges can be overcome with advances in methods, improving availability and effectiveness of methods, and linking existing researchers to create the necessary scientific and clinical network to advance the rate of progress and impact of the research. © 2013 Elsevier Inc.

Presently, the only commercially available power generating thermoelectric (TE) modules are based on bismuth telluride (Bi2Te3) alloys and are limited to a hot side temperature of 250 °C due to the melting point of the solder interconnects and/or generally poor power generation performance above this point. For the purposes of demonstrating a TE generator or TEG with higher temperature capability, we selected skutterudite based materials to carry forward with module fabrication because these materials have adequate TE performance and are mechanically robust. We have previously reported the electrical power output for a 32 couple skutterudite TE module, a module that is type identical to ones used in a high temperature capable TEG prototype. The purpose of this previous work was to establish the expected power output of the modules as a function of varying hot and cold side temperatures. Recent upgrades to the TE module measurement system built at the Fraunhofer Institute for Physical Measurement Techniques allow for the assessment of not only the power output, as previously described, but also the thermal to electrical energy conversion efficiency. Here we report the power output and conversion efficiency of a 32 couple, high temperature skutterudite module at varying applied loading pressures and with different interface materials between the module and the heat source and sink of the test system. We demonstrate a 7% conversion efficiency at the module level when a temperature difference of 460 °C is established. Extrapolated values indicate that 7.5% is achievable when proper thermal interfaces and loading pressures are used.

The treatment of multiple sclerosis (MS) has evolved remarkably over the past 25 years. This progress has been enabled by advances in research, drug development and active engagement of the scientific community with regulatory authorities. However, an inconsistent approach to MS disease courses could have a negative impact on the drug development process.

We combined tract-based spatial statistics (TBSS) and magnetization transfer (MT) imaging to assess white matter (WM) tract-specific short-term changes in early primary-progressive multiple sclerosis (PPMS) and their relationships with clinical progression. Twenty-one PPMS patients within 5 years from onset underwent MT and diffusion tensor imaging (DTI) at baseline and after 12 months. Patients' disability was assessed. DTI data were processed to compute fractional anisotropy (FA) and to generate a common WM "skeleton," which represents the tracts that are "common" to all subjects using TBSS. The MT ratio (MTR) was computed from MT data and co-registered with the DTI. The skeletonization procedure derived for FA was applied to each subject's MTR image to obtain a "skeletonised" MTR map for every subject. Permutation tests were used to assess (i) changes in FA, principal diffusivities, and MTR over the follow-up, and (ii) associations between changes in imaging parameters and changes in disability. Patients showed significant decreases in MTR over one year in the corpus callosum (CC), bilateral corticospinal tract (CST), thalamic radiations, and superior and inferior longitudinal fasciculi. These changes were located both within lesions and the normal-appearing WM. No significant longitudinal change in skeletonised FA was found, but radial diffusivity (RD) significantly increased in several regions, including the CST bilaterally and the right inferior longitudinal fasciculus. MTR decreases, RD increases, and axial diffusivity decreases in the CC and CST correlated with a deterioration in the upper limb function. We detected tract-specific multimodal imaging changes that reflect the accrual of microstructural damage and possibly contribute to clinical impairment in PPMS. We propose a novel methodology that can be extended to other diseases to map cross-subject and tract-specific changes in MTR. Hum Brain Mapp, 2013. © 2013 Wiley Periodicals, Inc.

Ionizing radiation is a potent carcinogen, inducing cancer through DNA damage. The signatures of mutations arising in human tissues following in vivo exposure to ionizing radiation have not been documented. Here, we searched for signatures of ionizing radiation in 12 radiation-associated second malignancies of different tumour types. Two signatures of somatic mutation characterize ionizing radiation exposure irrespective of tumour type. Compared with 319 radiation-naive tumours, radiation-associated tumours carry a median extra 201 deletions genome-wide, sized 1–100 base pairs often with microhomology at the junction. Unlike deletions of radiation-naive tumours, these show no variation in density across the genome or correlation with sequence context, replication timing or chromatin structure. Furthermore, we observe a significant increase in balanced inversions in radiation-associated tumours. Both small deletions and inversions generate driver mutations. Thus, ionizing radiation generates distinctive mutational signatures that explain its carcinogenic potential., Ionizing radiation may induce irreparable DNA damage leading to cancer. Here, the authors identify a specific signature of mutations arising in patients exposed to ionizing radiation and suggest that radiation-induced tumorigenesis is associated with higher rates of genome-wide deletions and balanced inversions.

OBJECTIVE: To determine whether concentrations of soluble E-selectin (sE-selectin), an immunological marker of endothelial activation, were correlated with gadolinium-DPTA enhancement on MRI in patients with multiple sclerosis. METHODS: Serial sE-selectin concentrations were measured in 28 patients with multiple sclerosis undergoing monthly gadolinium (Gd) enhanced MRI of the brain and spinal cord, and in 10 control subjects. C reactive protein (CRP), von Willebrand factor (vWF), and tumour necrosis factor-alpha (TNF alpha) were also determined. RESULTS: Primary progressive patients had significantly increased sE-selectin concentrations compared with the relapsing remitting and secondary progressive patients who had normal sE-selectin concentrations (22.2 (SD1 6.1) ng/ml v 9.8 (SD2.1) ng/ml and 7.7 (SD2.7) ng/ml, respectively, P = 0.03). This difference was attributable to five of the 10 primary progressive patients who had persistently raised sE-selectin concentrations, with relatively inactive MRI studies. No correlation could be found between sE-selectin concentrations and Gd enhancement on MRI, but a close correlation existed between mean concentrations of sE-selectin and TNF alpha (r = 0.71, P < 0.001). Despite raised sE-selectin and TNF alpha concentrations, primary progressive patients had normal CRP concentrations (1.03 (SD1.14) mg/l), which were significantly lower than the relapsing remitting (3.16 (SD2.54) mg/l) and secondary progressive patients (2.28 (SD2.1) mg/l, P = 0.03). Raised CRP concentrations did correlate with infectious episodes, clinical relapse, and Gd enhancement, and were significantly raised when no MRI activity was found. Concentrations of vWF were normal in all patient groups. CONCLUSIONS: The results further high-light the differences between patients with primary progressive and those with relapsing remitting/secondary progressive multiple sclerosis.

We compared the responsiveness of the Cervical Dystonia Impact Profile (CDIP-58), Medical Outcome Study Short Form-Health Survey (SF-36), Functional Disability Questionnaire (FDQ), and Pain and Activities of Daily Living subscales of the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) in participants with cervical dystonia treated with botulinum toxin A. Subscales of CDIP-58 were more sensitive in detecting statistical and clinical change than comparable subscales of the SF-36, FDQ, and TWSTRS.

In recent years, criteria for the diagnosis of multiple sclerosis (MS) have changed, mainly due to the incorporation of new MRI criteria. While the new criteria are a logical step forward, they are complex and-not surprisingly-a good working knowledge of them is not always evident among neurologists and neuroradiologists. In some circumstances, several MRI examinations are needed to achieve an accurate and prompt diagnosis. This provides an incentive for continued efforts to refine the incorporation of MRI-derived information into the diagnostic workup of patients presenting with a clinically isolated syndrome. Within the European multicenter collaborative research network that studies MRI in MS (MAGNIMS), a workshop was held in London in November 2007 to review information that may simplify the existing MS diagnostic criteria, while maintaining a high specificity that is essential to minimize false positive diagnoses. New data that are now published were reviewed and discussed and together with a new proposal are integrated in this position paper.

We aimed to provide evidence-based guidelines for using the Short Form 36 (SF-36) as an outcome measure in cervical dystonia (CD). To do this, we tested the hypothesized relationships between items, scales, and summary measures of the SF-36 using psychometric analyses in data from a postal survey of 235 people with CD. Although the majority of subscales performed adequately, the Role Physical and Role Emotional subscales had substantial floor and/or ceiling effects. Evidence did not support computing SF-36 Physical and Mental Component Summary scores. We propose guidelines that include the recommendation that these subscale and summary scores should be reported with caution.

Objective: The temporal relationship between white matter (WM) and gray matter (GM) damage in vivo in early primary progressive multiple sclerosis (PPMS) was investigated testing 2 hypotheses: (1) WM tract abnormalities predict subsequent changes in the connected cortex (“primary WM damage model”); and (2) cortical abnormalities predict later changes in connected WM tracts (“primary GM damage model”). Methods: Forty-seven patients with early PPMS and 18 healthy controls had conventional and magnetization transfer imaging at baseline; a subgroup of 35 patients repeated the protocol after 2 years. Masks of the corticospinal tracts, genu of the corpus callosum and optic radiations, and of connected cortical regions, were used for extracting the mean magnetization transfer ratio (MTR). Multiple regressions within each of 5 tract-cortex pairs were performed, adjusting for the dependent variable9s baseline MTR; tract lesion load and MTR, spinal cord area, age, and sex were examined for potential confounding. Results: The baseline MTR of most regions was lower in patients than in healthy controls. The tract-cortex pair relationships in the primary WM damage model were significant for the bilateral motor pair and right visual pair, while those in the primary GM damage model were only significant for the right motor pair. Lower lesion MTR at baseline was associated with lower MTR in the same tract normal-appearing WM at 2 years in 3 tracts. Conclusion: These results are consistent with the hypothesis that in early PPMS, cortical damage is for the most part a sequela of normal-appearing WM pathology, which, in turn, is predicted by abnormalities within WM lesions.

Objective:We tested whether brain gray matter (GM) imaging measures can differentiate between multiple sclerosis (MS) and neuromyelitis optica (NMO) using random-forest classification.Methods:Ninety participants (25 patients with MS, 30 patients with NMO, and 35 healthy controls [HCs]) were studied in Tehran, Iran, and 54 (24 patients with MS, 20 patients with NMO, and 10 HCs) in Padua, Italy. Participants underwent brain T1 and T2/fluid-attenuated inversion recovery MRI. Volume, thickness, and surface of 50 cortical GM regions and volumes of the deep GM nuclei were calculated and used to construct 3 random-forest models to classify patients as either NMO or MS, and separate each patient group from HCs. Clinical diagnosis was the gold standard against which the accuracy was calculated.Results:The classifier distinguished patients with MS, who showed greater atrophy especially in deep GM, from those with NMO with an average accuracy of 74% (sensitivity/specificity: 77/72; p < 0.01). When we used thalamic volume (the most discriminating GM measure) together with the white matter lesion volume, the accuracy of the classification of MS vs NMO was 80%. The classifications of MS vs HCs and NMO vs HCs achieved higher accuracies (92% and 88%).Conclusions:GM imaging biomarkers, automatically obtained from clinical scans, can be used to distinguish NMO from MS, even in a 2-center setting, and may facilitate the differential diagnosis in clinical practice.Classification of evidence:This study provides Class II evidence that GM imaging biomarkers can distinguish patients with NMO from those with MS.

Cognitive impairment in multiple sclerosis (MS) is common, debilitating and burdensome. Key evidence from trials was reviewed to enable recommendations to be made to guide clinical practice and research. Behavioural and pharmacological interventions on cognition reported in published studies were reviewed. Most studies evaluating behavioural treatment for impairment in learning and memory, deficits of attention and executive function have demonstrated some improvement. Controlled studies in relapsing remitting MS indicate interferon (IFN) β-1b and IFN β-1a were associated with modest cognitive improvement. The effects of symptomatic therapies such as modafinil and donepezil are inconsistent. Most studies yielding positive findings have significant methodological difficulties limiting the confidence in making any broad treatment recommendations. There are no published reports of glatiramer acetate, natalizumab and fingolimod being effective in improving cognition in controlled trials. The effects of disease modifying therapies in other forms of MS and clinically isolated syndrome have not yielded positive results. Data linking behavioural therapy, symptomatic treatment or disease modifying treatment, to either reducing cognitive decline or improving impaired cognition are limited and inconsistent. The treatment and prevention of cognitive impairment needs to remain a key research focus, identifying new interventions and improving clinical trial methodology.

The performance of thermoelectric (TE) materials has improved tremendously over the past decade. The intrinsic thermal and electrical properties of state-of-the-art TE materials demonstrate that the potential for widespread practical TE applications is very large and includes TE generators (TEGs) for automotive waste heat recovery. TE materials for automotive TEG applications must have good intrinsic performance, be thermomechanically compatible, and be chemically stable in the 400 K to 850 K temperature range. Both n-type and p-type varieties must be available at low cost, easily fabricated, and durable. They must also form robust junctions and develop good interfaces with other materials to permit efficient flows of electrical and thermal energy. Among the TE materials of interest for automotive waste heat recovery systems are the skutterudite compounds, which are the antimony-based transition-metal compounds RTE4Sb12, where R can be an alkali metal (e.g., Na, K), alkaline earth (e.g., Ba), or rare earth (e.g., La, Ce, Yb), and TE can be a transition metal (e.g., Co, Fe). We synthesized a considerable quantity of n-type and p-type skutterudites, fabricated TE modules, incorporated these modules into a prototype TEG, and tested the TEG on a production General Motors (GM) vehicle. We discuss our progress on skutterudite TE module fabrication and present module performance data for electrical power output under simulated operating conditions for automotive waste heat recovery systems. We also present preliminary durability results on our skutterudite modules.

Despite significant progress in the development of therapies for relapsing MS, progressive MS remains comparatively disappointing. Our objective, in this paper, is to review the current challenges in developing therapies for progressive MS and identify key priority areas for research. A collaborative was convened by volunteer and staff leaders from several MS societies with the mission to expedite the development of effective disease-modifying and symptom management therapies for progressive forms of multiple sclerosis. Through a series of scientific and strategic planning meetings, the collaborative identified and developed new perspectives on five key priority areas for research: experimental models, identification and validation of targets and repurposing opportunities, proof-of-concept clinical trial strategies, clinical outcome measures, and symptom management and rehabilitation. Our conclusions, tackling the impediments in developing therapies for progressive MS will require an integrated, multi-disciplinary approach to enable effective translation of research into therapies for progressive MS. Engagement of the MS research community through an international effort is needed to address and fund these research priorities with the ultimate goal of expediting the development of disease-modifying and symptom-relief treatments for progressive MS.

Background People with Hereditary and Sporadic Spastic Parapresis (SP) walk with a stiff legged gait characterised by a lack of knee flexion. Objective We investigated the relationship between lower limb strength and stiffness and knee flexion during swing phase while walking in 20 people with SP and 18 matched controls. Methods Maximal isometric strength was measured using a dynamometer. Passive stiffness and spasticity was assessed during motor-driven slow (5°/s) and fast (60°/s) stretches at the ankle and knee while the subject was relaxed or preactivating the muscle. Walking was assessed using 3D motion analysis. Results Isometric muscle strength was decreased in people with SP with over a 50% reduction in strength being found in the ankle dorsiflexors. Passive stiffness, assessed during slow stretches, was 35% higher in the plantarflexors in people with SP (P 0.05). Lower knee flexion during swing phase was associated with reduced knee flexion velocity at the end of stance phase which in turn was associated with reduced plantarflexor strength and increased passive stiffness in the knee extensors. Conclusions The relative importance of muscle paresis and passive stiffness in limiting walking in SP suggests that these impairments should be the target of future therapies.

Quantitative diffusion analysis of white matter (WM) tracts has been utilised in many diseases for determining damage to, and changes in, WM tracts throughout the brain. However, there are limited studies investigating associations between quantitative measures in WM tracts and anatomically linked grey matter (GM), due to the difficulty in determining GM regions connected with a given WM tract. This work describes a straightforward method for extending a WM tract through GM based on geometry. The tract is extended by following a straight line from each point on the tract boundary to the outer boundary of the cortex. A comparison between a multiplanar 2D approach and a 3D method was made. This study also tested an analysis pipeline from tracking WM tracts to quantifying magnetisation transfer ratios (MTR) in the associated cortical GM, and assessed the applicability of the method to healthy control subjects. Tract and associated cortical volumes and MTR values for the cortico-spinal tracts, genu and body of the corpus callosum were extracted; the between-subjects standard deviation was calculated. It was found that a multiplanar 2D approach produced a more anatomically plausible volume of GM than a 3D approach, at the expense of possible overestimation of the GM volume. The between-subjects standard deviation of the tract specific quantitative measurements (from both the WM and GM masks) ranged between 1.2 and 7.3% for the MTR measures, and between 10 and 45% for the absolute volume measures. The results show that the method can be used to produce anatomically plausible extensions of the WM tracts through the GM, and regions defined in this way yield reliable estimates of the MTR from the regions.

BackgroundMore than half of patients with multiple sclerosis have progressive disease characterised by accumulating disability. The absence of treatments for progressive multiple sclerosis represents a major unmet clinical need. On the basis of evidence that mesenchymal stem cells have a beneficial effect in acute and chronic animal models of multiple sclerosis, we aimed to assess the safety and efficacy of these cells as a potential neuroprotective treatment for secondary progressive multiple sclerosis. MethodsPatients with secondary progressive multiple sclerosis involving the visual pathways (expanded disability status score 5·5–6·5) were recruited from the East Anglia and north London regions of the UK. Participants received intravenous infusion of autologous bone-marrow-derived mesenchymal stem cells in this open-label study. Our primary objective was to assess feasibility and safety; we compared adverse events from up to 20 months before treatment until up to 10 months after the infusion. As a secondary objective, we chose efficacy outcomes to assess the anterior visual pathway as a model of wider disease. Masked endpoint analyses was used for electrophysiological and selected imaging outcomes. We used piecewise linear mixed models to assess the change in gradients over time at the point of intervention. This trial is registered with ClinicalTrials.gov, number NCT00395200. FindingsWe isolated, expanded, characterised, and administered mesenchymal stem cells in ten patients. The mean dose was 1·6×106 cells per kg bodyweight (range 1·1–2·0). One patient developed a transient rash shortly after treatment; two patients had self-limiting bacterial infections 3–4 weeks after treatment. We did not identify any serious adverse events. We noted improvement after treatment in visual acuity (difference in monthly rates of change −0·02 logMAR units, 95% CI −0·03 to −0·01; p=0·003) and visual evoked response latency (−1·33 ms, −2·44 to −0·21; p=0·020), with an increase in optic nerve area (difference in monthly rates of change 0·13 mm2, 0·04 to 0·22; p=0·006). We did not identify any significant effects on colour vision, visual fields, macular volume, retinal nerve fibre layer thickness, or optic nerve magnetisation transfer ratio. InterpretationAutologous mesenchymal stem cells were safely given to patients with secondary progressive multiple sclerosis in our study. The evidence of structural, functional, and physiological improvement after treatment in some visual endpoints is suggestive of neuroprotection.

A high-temperature Harman technique for measuring material ZT, or thermo- electric figure of merit, with increased measurement accuracy is presented. Traditional Harman tests are sensitive to radiation heat losses at elevated temperature, and measurement errors are minimized by applying current in positive and negative polarities while thermally sinking the sample base to a constant temperature for both polarities (referred to here as bottom temperature match, BTM). Since the sample top temperature differs between polarities in BTM, the heat losses are not equivalent and still add error to the ZT measurement. A modification is presented in which the sample base temperature is adjusted until the sample top temperature is the same in both polarities (referred to as top temperature match, TTM). This ensures that heat losses from the top of the sample are nearly identical and cancel out of the ZT calculation. A temperature-controlled radiation guard maintained at the sample top temperature is employed to minimize radiation loss and increase ZT calculation accuracy. Finite-element analysis (FEA) models suggest that ZT errors less than 5% for Bi2Te3 alloys tested at 250°C are achievable, a 30% improvement over the conventional BTM approach. Experimental results support these trends.

Functional imaging studies, using blood oxygen level-dependent signals, have demonstrated cortical reorganization of forearm muscle maps towards the denervated leg area following spinal cord injury (SCI). The extent of cortical reorganization was predicted by spinal atrophy. We therefore expected to see a similar shift in the motor output of corticospinal projections of the forearm towards more denervated lower body parts in volunteers with cervical injury. Therefore, we used magnetic resonance imaging-navigated transcranial magnetic stimulation (TMS) to non-invasively measure changes in cortical map reorganization of a forearm muscle in the primary motor cortex (M1) following human SCI. We recruited volunteers with chronic cervical injuries resulting in bilateral upper and lower motor impairment and severe cervical atrophy and healthy control participants. All participants underwent a T1-weighted anatomical scan prior to the TMS experiment. The motor thresholds of the extensor digitorum communis muscle (EDC) were defined, and its cortical muscle representation was mapped. The centre of gravity (CoG), the cortical silent period (CSP) and active motor thresholds (AMTs) were measured. Regression analysis was used to investigate relationships between trauma-related anatomical changes and TMS parameters. SCI participants had increased AMTs (P = 0.01) and increased CSP duration (P = 0.01). The CoG of the EDC motor-evoked potential map was located more posteriorly towards the anatomical hand representation of M1 in SCI participants than in controls (P = 0.03). Crucially, cord atrophy was negatively associated with AMT and CSP duration (r 2 ‡ 0.26, P < 0.05). In conclusion, greater spinal cord atrophy predicts changes at the cortical level that lead to reduced excitability and increased inhibition. Therefore, cortical forearm motor representations may reorganize towards the intrinsic hand motor representation to maximize output to muscles of the impaired forearm following SCI.

Asymmetric cortical representation of cardiac function is a matter of debate and large inter-individual variability of cortical autonomic networks and different study designs may contribute to this controversy. Lateralised seizure activity in individual patients may provide valuable insights into cortical regulation of cardiac function. We report two patients with focal epilepsy who had seizures arising from both hemispheres. In Patient 1, heart rate increased over two-fold with seizures arising from the right hemisphere, whereas heart rate increased invariably less with seizures arising from the left hemisphere. In Patient 2, heart rate increased 1.3 fold or less with seizures arising from the left hemisphere, whereas a seizure with right-sided onset was followed by bradycardia and asystole. Our findings support the notion that effects on autonomic function are lateralised, although lateralisation varies from patient to patient. This may partially explain the difficulty in determining cortical representation of cardiac autonomic function.

Background Non-arteritic anterior ischaemic optic neuropathy (NA-AION) can cause disabling visual loss and traditionally, visual prognosis has been considered poor, although recent studies have demonstrated improvements in visual acuity in about 30% of patients over time. The aim of the study was to determine whether there was significant cortical reorganisation with functional MRI (fMRI) after acute NA-AION by comparing affected individuals with healthy controls. Methods 9 patients with NA-AION were studied acutely and then after 1, 2, 3 and 6 months. 23 healthy volunteers underwent scanning at least twice. At each time point, patients were assessed clinically and with fMRI. For the fMRI experiments, subjects underwent monocular visual stimulation (wearing goggles with flashing LED displays). Results When stimulating the affected eye, occipital activation was reduced in patients compared with controls. Also, within the NA-AION group, activation in the right Brodmann areas (BA) 44 and 45 was seen during the early phase of the condition. The same areas were activated within the NA-AION group several months later for fellow eye stimulation. When the NA-AION and healthy control groups were formally compared however, these areas (BA 44/45) were not significantly different. NA-AION subjects did show greater activation in visual related areas compared with controls when stimulating the fellow eye. Visual acuity was correlated with more occipital cortex activation when stimulating the affected eye. Conclusions There is cortical re-organisation of the fMRI response in extra-visual areas, seen when both affected and fellow eyes are stimulated after NA-AION.

New evidence and consensus has led to further revision of the McDonald Criteria for diagnosis of multiple sclerosis. The use of imaging for demonstration of dissemination of central nervous system lesions in space and time has been simplified, and in some circumstances dissemination in space and time can be established by a single scan. These revisions simplify the Criteria, preserve their diagnostic sensitivity and specificity, address their applicability across populations, and may allow earlier diagnosis and more uniform and widespread use. Ann Neurol 2011

Background: White matter (WM) and grey matter (GM) brain damage in multiple sclerosis (MS) is widespread, but the extent of cerebellar involvement and impact on disability needs to be clarified. Objective: This study aimed to assess cerebellar WM and GM atrophy and the degree of fibre coherence in the main cerebellar connections, and their contribution to disability in relapsing–remitting MS (RRMS) and primary progressive MS (PPMS). Methods: Fourteen patients with RRMS, 12 patients with PPMS and 16 healthy controls were recruited. Cerebellar WM and GM volumes and tractography-derived measures from the middle and superior cerebellar peduncles, including fractional anisotropy (FA), mean diffusivity (MD), and directional diffusivities, were quantified from magnetic resonance imaging (MRI). Patients were assessed on clinical scores, including the MS Functional Composite score subtests. Linear regression models were used to compare imaging measures between 12 RRMS, 11 PPMS and 16 controls, and investigate their association with clinical scores. Results: Patients with PPMS showed reduced FA and increased radial diffusivity in the middle cerebellar peduncle compared with controls and patients with RRMS. In PPMS, lower cerebellar WM volume was associated with worse performance on the upper limb test. In the same patient group, we found significant relationships between superior cerebellar peduncle FA and upper limb function, and between superior cerebellar peduncle FA, MD and radial diffusivity and speed of walking. Conclusion: These findings indicate reduced fibre coherence in the main cerebellar connections, and link damage in the whole cerebellar WM, and, in particular, in the superior cerebellar peduncle, to motor deficit in PPMS.