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Background: The mechanism of action of oral cladribine, recently licensed for relapsing multiple sclerosis, is unknown., Objective: To determine whether cladribine depletes memory B cells consistent with our recent hypothesis that effective, disease-modifying treatments act by physical/functional depletion of memory B cells., Methods: A cross-sectional study examined 40 people with multiple sclerosis at the end of the first cycle of alemtuzumab or injectable cladribine. The relative proportions and absolute numbers of peripheral blood B lymphocyte subsets were measured using flow cytometry. Cell-subtype expression of genes involved in cladribine metabolism was examined from data in public repositories., Results: Cladribine markedly depleted class-switched and unswitched memory B cells to levels comparable with alemtuzumab, but without the associated initial lymphopenia. CD3 + T cell depletion was modest. The mRNA expression of metabolism genes varied between lymphocyte subsets. A high ratio of deoxycytidine kinase to group I cytosolic 5' nucleotidase expression was present in B cells and was particularly high in mature, memory and notably germinal centre B cells, but not plasma cells., Conclusions: Selective B cell cytotoxicity coupled with slow repopulation kinetics results in long-term, memory B cell depletion by cladribine. These may offer a new target, possibly with potential biomarker activity, for future drug development.

Purpose: Current MRI techniques cannot reliably assess iron content in white matter due to the confounding diamagnetic effect of myelin. The purpose of this study was to validate with histology a novel iron mapping technique that uses the temperature dependency of the paramagnetic susceptibility in multiple sclerosis (MS) brains, where white matter has been reported to show significant variations in iron content., Methods: We investigated post mortem brain tissue from three MS patients and one control subject. Temperature-dependent R2* relaxometry was performed between 4°C and 37°C. The resulting temperature coefficient ( TcR2*) maps were compared with immunohistochemical stains for ferritin light chain., Results: Good agreement between TcR2* maps and ferritin staining was found by way of visual comparison and quantitative analysis. The highest iron concentrations were detected at the edge of MS lesions and in the basal ganglia. For all regions, except the subcortical U-fibers, there was a significant negative correlation between the TcR2* values and the ferritin count., Conclusion: This study provides further evidence that TcR2* may be a reliable measure of white matter iron content due to the elimination of myelin-induced susceptibility changes and is well suited for further research into neurological diseases with distortions of the iron homeostasis. Magn Reson Med 79:1609-1615, 2018. © 2017 International Society for Magnetic Resonance in Medicine., (© 2017 International Society for Magnetic Resonance in Medicine.)

Background: Alemtuzumab is a CD52-specific monoclonal antibody that markedly depletes T and B lymphocytes and inhibits relapsing multiple sclerosis (MS). However, polymorphonuclear neutrophils also express CD52 and can be depleted by alemtuzumab, thereby potentially contributing to the infections that develop post-alemtuzumab treatment. Surprisingly, however, the degree of neutrophil depletion in MS was not included in the pivotal trial reports., Methods: The regulatory submission of the Comparison of Alemtuzumab and Rebif® Efficacy in MS 1 and 2 trials was obtained from the European Medicines Agency through Freedom of Information. The data relating to neutrophils was extracted., Results: Data extraction from the submission was straightforward. In year one 72/811 (8.9%) and in year two 116/808 (14.4%) people with MS (pwMS) developed neutropenia. The degree of neutropenia was generally mild, and only 5/811 (0.6%) in year 1 and 12/808 (1.5%) in year 2 developed grade 3-4 toxicity (< 1.0 × 10 9 /L). Two pwMS developed severe neutropenia-related adverse events., Conclusions: Treatment with alemtuzumab induces neutropenia, which is mild in the large majority of pwMS treated. Leucocyte levels following alemtuzumab should be monitored as a marker of efficacy and safety; persistent neutropenia may require treatment., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: In multiple sclerosis (MS) upper limb neurological impairments, are an important driver of disability and handicap. The gold standard for assessing upper limb function is the 9-hole peg test (9HPT). One disadvantage of the current plastic version is its price, which prevents its widespread use as a self-monitoring tool by the MS community., Objective: To develop and validate an affordable cardboard version of 9HPT for patients to self-monitor upper limb function at home. The aim is not to replace the plastic version, which would stay the gold standard in MS centers., Methods: We enrolled 177 volunteers, 68 healthy controls and 109 people with MS (pwMS) at varying stages of their disease. Volunteers performed two trials of the 9HPT with their dominant hand and two with their non-dominant hand using both plastic 9HPT and cardboard 9HPT. The primary comparison parameter was the time needed to perform the task., Results: The mean score for the cardboard 9HPT was 24.58 (SEM 1.54s) seconds compared to 26.03 (SEM 1.44s) seconds for the plastic 9HPT (p = 0.007). However, the two versions of the tests correlated very strongly, r = 0.96 (p < 0.001). The coefficient of variation, repeat-repeat testing, showed less variability with the cardboard version than in the plastic one with 10% and 14%, respectively. Two-thirds of pwMS preferred using the cardboard version., Conclusion: This study demonstrates that the cardboard version is at least equivalent to the plastic version of the test with arguably better design attributes making it the preferred option for self-monitoring., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Importance: Alemtuzumab, a CD52-depleting monoclonal antibody, effectively inhibits relapsing multiple sclerosis (MS) but is associated with a high incidence of secondary B-cell autoimmunities that limit use. These effects may be avoided through control of B-cell hyperproliferation., Objective: To investigate whether the data describing the effect of alemtuzumab on lymphocyte subsets collected during the phase 3 trial program reveal mechanisms explaining efficacy and the risk for secondary autoimmunity with treatment of MS., Design, Setting, and Participants: Lymphocyte reconstitution data from regulatory submissions of the pivotal Comparison of Alemtuzumab and Rebif Efficacy in Multiple Sclerosis I and II (CARE-MS I and II) trials were obtained from the European Medicines Agency via Freedom of Information requests. Data used in this study were reported from June 22 to October 12, 2016., Main Outcomes and Measures: Tabulated data from T- and B-lymphocyte subset analysis and antidrug antibody responses were extracted from the supplied documents., Results: Alemtuzumab depleted CD4+ T cells by more than 95%, including regulatory cells (-80%) and CD8+ T cells (>80% depletion), which remained well below reference levels throughout the trials. However, although CD19+ B cells were initially also depleted (>85%), marked (180% increase) hyperrepopulation of immature B cells occurred with conversion to mature B cells over time. These lymphocyte kinetics were associated with rapid development of alemtuzumab-binding and -neutralizing antibodies and subsequent occurrence of secondary B-cell autoimmunity. Hyperrepopulation of B cells masked a marked, long-term depletion of CD19+ memory B cells that may underpin efficacy in MS., Conclusions and Relevance: Although blockade of memory T and B cells may limit MS, rapid CD19+ B-cell subset repopulation in the absence of effective T-cell regulation has implications for the safety and efficacy of alemtuzumab. Controlling B-cell proliferation until T-cell regulation recovers may limit secondary autoimmunity, which does not occur with other B-cell-depleting agents.

Objective: To understand the efficacy of cladribine (CLAD) treatment in MS through analysis of lymphocyte subsets collected, but not reported, in the pivotal phase III trials of cladribine and alemtuzumab induction therapies., Methods: The regulatory submissions of the CLAD Tablets Treating Multiple Sclerosis Orally (CLARITY) (NCT00213135) cladribine and Comparison of Alemtuzumab and Rebif Efficacy in Multiple Sclerosis, study one (CARE-MS I) (NCT00530348) alemtuzumab trials were obtained from the European Medicine Agency through Freedom of Information requests. Data were extracted and statistically analyzed., Results: Either dose of cladribine (3.5 mg/kg; 5.25 mg/kg) tested in CLARITY reduced the annualized relapse rate to 0.16-0.18 over 96 weeks, and both doses were similarly effective in reducing the risk of MRI lesions and disability. Surprisingly, however, T-cell depletion was rather modest. Cladribine 3.5 mg/kg depleted CD4 + cells by 40%-45% and CD8 + cells by 15%-30%, whereas alemtuzumab suppressed CD4 + cells by 70%-95% and CD8 + cells by 47%-55%. However, either dose of cladribine induced 70%-90% CD19 + B-cell depletion, similar to alemtuzumab (90%). CD19 + cells slowly repopulated to 15%-25% of baseline before cladribine redosing. However, alemtuzumab induced hyperrepopulation of CD19 + B cells 6-12 months after infusion, which probably forms the substrate for B-cell autoimmunities associated with alemtuzumab., Conclusions: Cladribine induced only modest depletion of T cells, which may not be consistent with a marked influence on MS, based on previous CD4 + T-cell depletion studies. The therapeutic drug-response relationship with cladribine is more consistent with lasting B-cell depletion and, coupled with the success seen with monoclonal CD20 + depletion, suggests that B-cell suppression could be the major direct mechanism of action.

Rebound disease following cessation of disease modifying treatment (DMT) has been reported in people with both relapsing and progressive multiple sclerosis (pwRMS, pwPMS) questioning strict separation between these two phenotypes. While licensed DMT is available for pwRMS to counter rebound disease, no such option exists for pwPMS. We report on a pwPMS who developed rebound disease, with 45 Gadolinium-enhancing lesions on T 1 weighted MRI brain, within 6 months after fingolimod 0.5 mg/day was stopped. Treatment with a short course of subcutaneous cladribine 60 mg led to effective suppression of inflammatory activity and partial recovery with no short-term safety issues or adverse events.

Trials of anti-inflammatory therapies in non-relapsing progressive multiple sclerosis (MS) have been stubbornly negative except recently for an anti-CD20 therapy in primary progressive MS and a S1P modulator siponimod in secondary progressive MS. We argue that this might be because trials have been too short and have focused on assessing neuronal pathways, with insufficient reserve capacity, as the core component of the primary outcome. Delayed neuroaxonal degeneration primed by prior inflammation is not expected to respond to disease-modifying therapies targeting MS-specific mechanisms. However, anti-inflammatory therapies may modify these damaged pathways, but with a therapeutic lag that may take years to manifest. Based on these observations we propose that clinically apparent neurodegenerative components of progressive MS may occur in a length-dependent manner and asynchronously. If this hypothesis is confirmed it may have major implications for the future design of progressive MS trials., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Although multiple sclerosis (MS) is considered to be a CD4, Th17-mediated autoimmune disease, supportive evidence is perhaps circumstantial, often based on animal studies, and is questioned by the perceived failure of CD4-depleting antibodies to control relapsing MS. Therefore, it was interestingly to find that current MS-treatments, believed to act via T cell inhibition, including: beta-interferons, glatiramer acetate, cytostatic agents, dimethyl fumarate, fingolimod, cladribine, daclizumab, rituximab/ocrelizumab physically, or functionally in the case of natalizumab, also depleted CD19+, CD27+ memory B cells. This depletion was substantial and long-term following CD52 and CD20-depletion, and both also induced long-term inhibition of MS with few treatment cycles, indicating induction-therapy activity. Importantly, memory B cells were augmented by B cell activating factor (atacicept) and tumor necrosis factor (infliximab) blockade that are known to worsen MS. This creates a unifying concept centered on memory B cells that is consistent with therapeutic, histopathological and etiological aspects of MS., (Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Incidence and prevalence rates of multiple sclerosis (MS) are generally higher in White populations than in other ethnic groups. Relevant studies in the United Kingdom were conducted over 30 years ago., Objectives: To provide updated ethnicity-specific MS prevalence rates in the United Kingdom., Methods: Electronic records from general practices (GPs) in four east London boroughs were queried for the number of people diagnosed with MS, grouped by ethnicity, into 5-year age bands. Compared against total registered GP patients in the area (c. 900,000), the age-standardised MS prevalence was calculated by ethnic group., Results: The overall age-standardised prevalence of MS was 111 per 100,000 (152 for women and 70 for men), and 180, 74 and 29 for the White, Black and South Asian populations, respectively. The sex ratios (female:male) were 2.2:1, 2.1:1 and 2.8:1, respectively., Conclusion: MS prevalence was considerably lower among Black and South Asian populations, compared to the White population, by 59% and 84%, respectively. However, compared to available data in Africa and South Asia, MS is several times more prevalent among Black people and South Asians living in the United Kingdom than their territorial ancestry.

Objective: Multiple sclerosis (MS) develops as a result of environmental influences on the genetically susceptible. Siblings of people with MS have an increased risk of both MS and demonstrating asymptomatic changes in keeping with MS. We set out to develop an MS risk score integrating both genetic and environmental risk factors. We used this score to identify siblings at extremes of MS risk and attempted to validate the score using brain MRI., Methods: 78 probands with MS, 121 of their unaffected siblings and 103 healthy controls were studied. Personal history was taken, and serological and genetic analysis using the illumina immunochip was performed. Odds ratios for MS associated with each risk factor were derived from existing literature, and the log values of the odds ratios from each of the risk factors were combined in an additive model to provide an overall score. Scores were initially calculated using log odds ratio from the HLA-DRB1*1501 allele only, secondly using data from all MS-associated SNPs identified in the 2011 GWAS. Subjects with extreme risk scores underwent validation studies. MRI was performed on selected individuals., Results: There was a significant difference in the both risk scores between people with MS, their unaffected siblings and healthy controls (p<0.0005). Unaffected siblings had a risk score intermediate to people with MS and controls (p<0.0005). The best performing risk score generated an AUC of 0.82 (95%CI 0.75-0.88)., Interpretations: The risk score demonstrates an AUC on the threshold for clinical utility. Our score enables the identification of a high-risk sibling group to inform pre-symptomatic longitudinal studies., Competing Interests: RD, SR, JT, and BS have no conflicts of interest to declare. KS is PI of trials sponsored by Novartis & Roche. He is involved in trials sponsored by Biogen, Genzyme, Teva, Merck Inc. and BIAL. Speaking honoraria from, and/or in an advisory role for, Novartis, Sanofi-Aventis, Merck-Serono and Merck Inc. DC has received research support from the MS Society of Great Britain and Northern Ireland, and the National Institute for Health Research University College London Hospitals Biomedical Research Centre. He has received honoraria (paid to his employer) from Ismar Healthcare NV, Swiss MS Society, Excemed (previously Serono Symposia International Foundation), Merck, Bayer and Teva for faculty-led education work; Teva for advisory board work; meeting expenses from Merck, Teva, Novartis, the MS Trust and National MS Society; and has previously held stock in GlaxoSmithKline. He is a member of the MS Society of Great Britain and Northern Ireland's Biomedical Grant Review Panel. He is a member of the Data Safety Monitoring Committee for the PROXIMUS study, which is funded by National Multiple Sclerosis Society and Novartis. Both of these roles are unpaid. GG has received research grant support from Bayer-Schering Healthcare, Biogen-Idec, GW Pharma, Merck Serono, Merz, Novartis, Teva and Sanofi-Aventis. He has received personal compensation for participating on Advisory Boards in relation to clinical trial design, trial steering committees and data and safety monitoring committees from: Bayer-Schering Healthcare, Biogen-Idec, Eisai, Elan, Fiveprime, Genzyme, Genentech, GSK, GW Pharma, Ironwood, Merck-Serono, Novartis, Pfizer, Roche, Sanofi-Aventis, Synthon BV, Teva, UCB Pharma and Vertex Pharmaceuticals. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Background: An altered balance of gonadal hormones in males with gender identity disorders (GIDs) may increase multiple sclerosis (MS) risk both inherently and secondary to treatment in undergoing male-to-female conversion., Objective: We investigated any association between GIDs and MS through analysis of record-linked hospital statistics., Method: Analysis of English Hospital Episode Statistics, 1999-2012., Results: The adjusted rate ratio (RR) of MS following GIDs in males was 6.63 (95% confidence interval (95% CI) = 1.81-17.01, p = 0.0002). The RR of MS following GIDs in females was 1.44 (95% CI = 0.47-3.37, p = 0.58)., Conclusion: We report a strong association between GIDs and MS in male-to-females, supporting a potential role for low testosterone and/or feminising hormones on MS risk in males., (© The Author(s), 2016.)

There are several options for switching people with multiple sclerosis (MS) who are at high risk of developing progressive multifocal leukoencephalopathy (PML) from natalizumab to alemtuzumab. However, some of these have risks that need to be managed, for example, the risks of carrying over asymptomatic PML from natalizumab on to the new therapy, and the risk of rebound disease activity associated with a prolonged washout after starting natalizumab. We propose a pragmatic bridging strategy, using another disease-modifying therapy (DMT), to reduce the risk of switching from natalizumab to alemtuzumab. We also discuss the caveats and subtleties associated with sequencing DMTs in MS and the complex decision making involved., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Background: Acute demyelinating optic neuritis, a common feature of multiple sclerosis, can damage vision through neurodegeneration in the optic nerve and in its fibres in the retina. Inhibition of voltage-gated sodium channels is neuroprotective in preclinical models. In this study we aimed to establish whether sodium-channel inhibition with phenytoin is neuroprotective in patient with acute optic neuritis., Methods: We did a randomised, placebo-controlled, double-blind phase 2 trial at two UK academic hospitals in London and Sheffield. Patients with acute optic neuritis aged 18-60 years, presenting within 2 weeks of onset, with visual acuity of 6/9 or worse, were randomly assigned (1:1) by minimisation via a web-based service to oral phenytoin (maintenance dose 4 mg/kg per day if randomised before or on July 16, 2013, and 6 mg/kg per day if randomised on or after July 17, 2013) or placebo for 3 months, stratified by time from onset, centre, previous multiple sclerosis diagnosis, use of disease-modifying treatment, and use of corticosteroids for acute optic neuritis. Participants and treating and assessing physicians were masked to group assignment. The primary outcome was retinal nerve fibre layer (RNFL) thickness in the affected eye at 6 months, adjusted for fellow-eye RNFL thickness at baseline, analysed in a modified intention-to-treat population of all randomised participants who were followed up at 6 months. Safety was analysed in the entire population, including those who were lost to follow-up. The trial is registered with ClinicalTrials.gov, number NCT 01451593., Findings: We recruited 86 participants between Feb 3, 2012, and May 22, 2014 (42 assigned to phenytoin and 44 to placebo). 29 were assigned to phenytoin 4 mg/kg and 13 to phenytoin 6 mg/kg. Five participants were lost to follow-up, so the primary analysis included 81 participants (39 assigned to phenytoin and 42 to placebo). Mean 6-month RNFL thickness in the affected eye at 6 months was 81.46 μm (SD 16.27) in the phenytoin group (a mean decrease of 16.69 μm [SD 13.73] from baseline) versus 74.29 μm (15.14) in the placebo group (a mean decrease of 23.79 μm [13.97] since baseline; adjusted 6-month difference of 7.15 μm [95% CI 1.08-13.22]; p=0.021), corresponding to a 30% reduction in the extent of RNFL loss with phenytoin compared with placebo. Treatment was well tolerated, with five (12%) of 42 patients having a serious adverse event in the phenytoin group (only one, severe rash, was attributable to phenytoin) compared with two (5%) of 44 in the placebo group., Interpretation: These findings support the concept of neuroprotection with phenytoin in patients with acute optic neuritis at concentrations at which it blocks voltage-gated sodium channels selectively. Further investigation in larger clinical trials in optic neuritis and in relapsing multiple sclerosis is warranted., Funding: US National Multiple Sclerosis Society, Multiple Sclerosis Society of Great Britain and Northern Ireland, Novartis, UK National Institute for Health Research (NIHR), and NIHR UCLH/UCL Biomedical Research Centre., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Objective: To compare the cancer risk of cladribine and other disease-modifying drugs (DMDs) in trials of people with relapsing multiple sclerosis (pwRMS)., Methods: Meta-analysis of phase III trials of licensed DMDs for pwRMS and a phase III trial of cladribine (CLARITY). Cancer rates were compared using Fisher exact test., Results: Eleven trials were included. Investigated treatments included cladribine, dimethyl fumarate, fingolimod, teriflunomide, natalizumab, alemtuzumab, and glatiramer acetate. The cancer rate in the CLARITY treatment group (0.34%) was not increased compared to all other treatment groups, whether including placebo-controlled trials only (0.6%, p = 0.4631) or all trials, i.e., including those with an active comparator arm (0.67%, p = 0.3669). No cancer was reported in the CLARITY placebo group, whereas the combined cancer rate of all other placebo groups was 1.19% (p = 0.0159). The cancer rate of zero in the CLARITY placebo group was also lower than that in the phase III trial of cladribine in people with clinically isolated syndrome (ORACLE MS, 2.91%, p = 0.0012). In fact, no difference was detected between cancer rates in the treatment groups of CLARITY (0.34%) and ORACLE MS (0.49%) (p = 0.6546)., Conclusions: Our study does not support an increased cancer risk from cladribine in the doses used in CLARITY and ORACLE MS, which previously contributed to refusal of market authorization of cladribine in Europe. Longer-term follow-up is required to assess the safety profile of cladribine, as well as currently licensed DMDs, to definitively assess cancer risk.

The management of multiple sclerosis is becoming increasingly complex with the emergence of new and more effective disease-modifying therapies (DMT). We propose a new treatment paradigm that individualises treatment based on a choice between two interchangeable therapeutic strategies of maintenance-escalation or induction therapy. We propose treating- to-target of no evident disease activity (NEDA) as defined using clinical and MRI criteria. This algorithm requires active monitoring with a rebaselining MRI, at a point in time after the specific DMT concerned has had sufficient time to work, and at least annual MRI studies to monitor for subclinical relapses. Disease activity on the maintenance-escalation therapy arm of the algorithm indicates a sub-optimal treatment response and should trigger a discussion about switching, or escalating, therapy or the consideration of switching to the induction therapy arm of the algorithm. In comparison, disease activity on an induction therapy arm would be an indication for retreatment or a switch to the maintenance-escalation therapy arm. We envisage the definition of NEDA evolving with time as new technological innovations are adopted into clinical practice, for example the normalisation of whole, or regional, brain atrophy rates and cerebrospinal fluid neurofilament levels., (Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.)

If it is not feasible to develop licensed drugs to the stage that they can actually be prescribed for a new indication, can we justify, either ethically or economically, the undertaking of proof-of-concept studies using off-patent medications? Without a financial incentive it is very difficult to repurpose off patent drugs for a new indication. Therefore, we need a political solution to allow the repurposing of off-patent drugs by other stakeholders or Big Pharma., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Background: Tumefactive demyelinating lesions are a rare manifestation of multiple sclerosis (MS). Differential diagnosis of such space occupying lesions may not be straightforward and sometimes necessitate brain biopsy. Impaired cognition is the second most common clinical manifestation of tumefactive MS; however complex cognitive syndromes are unusual., Case Presentation: We report the case of a 30 year old woman who presented with Gerstmann's syndrome. MRI revealed a large heterogeneous contrast enhancing lesion in the left cerebral hemisphere. Intravenous corticosteroids did not stop disease progression. A tumour or cerebral lymphoma was suspected, however brain biopsy confirmed inflammatory demyelination. Following diagnosis of tumefactive MS treatment with natalizumab effectively suppressed disease activity., Conclusions: The case highlights the need for clinicians, radiologists and surgeons to appreciate the heterogeneous presentation of tumefactive MS. Early brain biopsy facilitates rapid diagnosis and management. Treatment with natalizumab may be useful in cases of tumefactive demyelination where additional evidence supports a diagnosis of relapsing MS.

Background: Enhancing remyelination in MS might improve function and protect axons from future damage. Lesion magnetisation transfer ratio (MTR) is sensitive to myelin content, and may be a useful measure for trials evaluating potential remyelinating agents., Objective: Estimating sample sizes required for a parallel group, placebo-controlled trial in MS using change in mean MTR of all T2lesions as a primary outcome measure., Methods: The primary sample size calculation was derived from data from a natural history study of relapsing remitting MS (n=18). The MTR values observed in demyelinated and remyelinated lesions in an ex vivo study were used to estimate the effect of remyelination on lesion MTR. The ex vivo data were also used to independently calculate sample sizes in order to inform the robustness of the in vivo estimates., Results: Calculations suggest that 30% remyelination of T2 lesions could be detected with 80% power in 38 (95% confidence interval 12-96) patients per arm based on the in vivo data, and in 66 per arm based on the ex vivo data., Conclusion: The sample sizes derived are in a range that makes MTR a feasible outcome measure for proof-of-concept trials of putative therapies achieving remyelination in MS lesions., (© 2013 The Authors. Published by Elsevier B.V. All rights reserved.)

Background and Purpose: Lumbar puncture (LP) is a key diagnostic procedure in medicine. Post lumbar puncture headache (PLPHA) is a well recognized complication of LP. Evidence suggests that using atraumatic needles for diagnostic LP (ATNLP) reduces risk of PLPHA. However, clinicians in Europe and the USA routinely use traumatic needles for diagnostic LP (TNLP). The occurrence of PLPHA following ATNLP and TNLP was compared in a clinical setting. Further, a survey was performed exploring use of ATNLP amongst UK neurologists., Methods: Service development study. Patients were followed up 2 and 7 days after LP using blinded telephone assessment. A questionnaire was developed to assess use of ATNLP amongst UK neurologists. Frequency, onset, duration and severity of PLPHA were recorded as were use of analgesia, general practitioner consultations, hospital readmissions, days off work due to PLPHA and cost. Neurologists were asked about their familiarity with, and use of, ATNLP., Results: One hundred and nine participants attending the Royal London Hospital were included, and 74 attendees of the Association of British Neurologists 2012 conference completed an on-site questionnaire. ATNLP reduced the rate of PLPHA (27.1% vs. 60.4%; P < 0.01). In those participants who developed PLPHA symptoms were short lived (mean 50 h vs. 94 h, P = 0.02) and less severe after ATNLP. Use of ATNLP led to significant cost savings. Only one in five UK neurologists regularly use ATNLP stating lack of training and availability of atraumatic needles as main reasons., Conclusions: ATNLP significantly reduces the risk of PLPHA. Training is required 3 to facilitate a change from TNLP to ATNLP amongst clinicians., (© 2013 The Author(s) European Journal of Neurology © 2013 EFNS.)

Objective: Interferon-β (IFN-β) has been shown to reduce relapse rates in multiple sclerosis; however, the clinical response appears to vary among individuals. Can early MRI be used to identify those patients who have a poor response to treatment?, Methods: A systematic review of studies examining differential treatment response and clinical endpoints in groups defined as responders or nonresponders to IFN-β was performed. Meta-analytic techniques were used to combine study results where appropriate., Results: Patients with MRI evidence of poor response to IFN-β treatment as defined by either ≥2 new hyperintense T2 lesions or new gadolinium-enhancing lesions had significantly increased risk of both future relapses and progression as defined by the Expanded Disability Status Scale. There appeared to be an increased risk of poor outcomes 16 years after treatment initiation in those with an initial poor response to treatment. Previous evidence has shown this not to be the case in placebo arms of clinical trials., Conclusions: For those patients starting IFN-β, early MRI, within 6 to 24 months after starting treatment, has the potential to provide important information when counseling patients about the likelihood of future treatment failure. This can inform treatment decisions before clinical relapses or disease progression.

Atypical lesions of a presumably idiopathic inflammatory demyelinating origin present quite variably and may pose diagnostic problems. The subsequent clinical course is also uncertain. We, therefore, wanted to clarify if atypical idiopathic inflammatory demyelinating lesions (AIIDLs) can be classified according to previously suggested radiologic characteristics and how this classification relates to prognosis. Searching the databases of eight tertiary referral centres we identified 90 adult patients (61 women, 29 men; mean age 34 years) with ≥ 1 AIIDL. We collected their demographic, clinical and magnetic resonance imaging data and obtained follow-up (FU) information on 77 of these patients over a mean duration of 4 years. The AIIDLs presented as a single lesion in 72 (80 %) patients and exhibited an infiltrative (n = 35), megacystic (n = 16), Baló (n = 10) or ring-like (n = 16) lesion appearance in 77 (86 %) patients. Additional multiple sclerosis (MS)-typical lesions existed in 48 (53 %) patients. During FU, a further clinical attack occurred rarely (23-35 % of patients) except for patients with ring-like AIIDLs (62 %). Further attacks were also significantly more often in patients with coexisting MS-typical lesions (41 vs. 10 %, p < 0.005). New AIIDLs developed in six (7 %), and new MS-typical lesions in 29 (42 %) patients. Our findings confirm the previously reported subtypes of AIIDLs. Most types confer a relatively low risk of further clinical attacks, except for ring-like lesions and the combination with MS-typical lesions.

In 2006, Zamboni reintroduced the concept that chronic impaired venous outflow of the central nervous system is associated with multiple sclerosis (MS), coining the term of chronic cerebrospinal venous insufficiency ('CCSVI'). The diagnosis of 'CCSVI' is based on sonographic criteria, which he found exclusively fulfilled in MS. The concept proposes that chronic venous outflow failure is associated with venous reflux and congestion and leads to iron deposition, thereby inducing neuroinflammation and degeneration. The revival of this concept has generated major interest in media and patient groups, mainly driven by the hope that endovascular treatment of 'CCSVI' could alleviate MS. Many investigators tried to replicate Zamboni's results with duplex sonography, magnetic resonance imaging, and catheter angiography. The data obtained here do generally not support the 'CCSVI' concept. Moreover, there are no methodologically adequate studies to prove or disprove beneficial effects of endovascular treatment in MS. This review not only gives a comprehensive overview of the methodological flaws and pathophysiologic implausibility of the 'CCSVI' concept, but also summarizes the multimodality diagnostic validation studies and open-label trials of endovascular treatment. In our view, there is currently no basis to diagnose or treat 'CCSVI' in the care of MS patients, outside of the setting of scientific research.

Background: There are modest correlations between multiple sclerosis (MS) disability and white matter lesion (WML) volumes, as measured by T2-weighted (T2w) magnetic resonance imaging (MRI) scans (T2-WML). This may partly reflect pathological heterogeneity in WMLs, which is not apparent on T2w scans., Objective: To determine if ADvanced IMage Algebra (ADIMA), a novel MRI post-processing method, can reveal WML heterogeneity from proton-density weighted (PDw) and T2w images., Methods: We obtained conventional PDw and T2w images from 10 patients with relapsing-remitting MS (RRMS) and ADIMA images were calculated from these. We classified all WML into bright (ADIMA-b) and dark (ADIMA-d) sub-regions, which were segmented. We obtained conventional T2-WML and T1-WML volumes for comparison, as well as the following quantitative magnetic resonance parameters: magnetisation transfer ratio (MTR), T1 and T2. Also, we assessed the reproducibility of the segmentation for ADIMA-b, ADIMA-d and T2-WML., Results: Our study's ADIMA-derived volumes correlated with conventional lesion volumes (p < 0.05). ADIMA-b exhibited higher T1 and T2, and lower MTR than the T2-WML (p < 0.001). Despite the similarity in T1 values between ADIMA-b and T1-WML, these regions were only partly overlapping with each other. ADIMA-d exhibited quantitative characteristics similar to T2-WML; however, they were only partly overlapping. Mean intra- and inter-observer coefficients of variation for ADIMA-b, ADIMA-d and T2-WML volumes were all < 6 % and < 10 %, respectively., Conclusion: ADIMA enabled the simple classification of WML into two groups having different quantitative magnetic resonance properties, which can be reproducibly distinguished.

Background: In a phase 2b study in patients with relapsing-remitting MS (RRMS), BG-12 240 mg three times daily significantly reduced the number of new gadolinium-enhanced (Gd+) lesions from weeks 12 to 24 (primary end point) by 69% compared with placebo., Objective: In this analysis, the effect of BG-12 240 mg three times daily on the number of Gd+ lesions from weeks 12 to 24 was evaluated in subgroups based on baseline disease characteristics and demographics., Methods: Two hundred and fifty-seven patients were randomized equally to receive BG-12 (120 mg once daily or three times daily or 240 mg three times daily) or placebo., Results: BG-12 240 mg three times daily significantly reduced the number of new Gd+ lesions compared with placebo in the following subgroups: Expanded Disability Status Scale (EDSS) score ≤ 2.5 (74%), EDSS score > 2.5 (63%), no Gd+ lesions (80%), ≥ 1 Gd+ lesion (55%), age < 40 years (49%), age ≥ 40 years (89%), female patients (81%), disease duration ≤ 6 years (81%) and disease duration > 6 years (54%) (all comparisons p < 0.05)., Conclusion: BG-12 demonstrated efficacy in patients with RRMS by decreasing new Gd+ lesion development across a range of subgroups defined by baseline disease characteristics or demographics.

Aims: Multiple sclerosis (MS) leaves a signature on the phosphorylation and thus proton binding capacity of axonal neurofilament (Nf) proteins. The proton binding capacity in a tissue is the major determinant for exchange between bound and free protons and thus the magnetisation transfer ratio (MTR). This study investigated whether the MTR of non-lesional white matter (NLWM) was related to the brain tissue concentration of neurofilament phosphoforms., Methods: Unfixed post-mortem brain slices of 12 MS patients were analysed using MTR, T1 at 1.5 T. Blocks containing NLWM were processed for embedding in paraffin and inspected microscopically. Adjacent tissue was microdissected, homogenised and specific protein levels were quantified by ELISA for the Nf heavy chain (NfH) phosphoforms, glial fibrillary acidic protein (GFAP), S100B and ferritin., Results: Averaged hyperphosphorylated NfH (SMI34) but not phosphorylated NfH (SMI35) levels were different between individual patients NLWM. The concentration of hyperphosphorylated NfH-SMI34 correlated with T1 (R=0.70, p=0.0114) and - inversely - with MTR (R=-0.73, p=0.0065). NfH-SMI35 was not correlated to any of the MR indices., Conclusions: Post-translational modifications of axonal proteins such as phosphorylation of neurofilaments occur in NLWM and may precede demyelination. The resulting change of proton mobility influences MTR and T1. This permits the in vivo detection of these subtle tissue changes on a proteomic level in patients with MS., (Copyright © 2011 Elsevier Inc. All rights reserved.)

BG-12, an immunomodulatory agent, reduces frequency of new gadolinium-enhancing (Gd+) lesions in relapsing multiple sclerosis (MS). This study reports the effect of 240 mg BG-12 orally three times daily (tid) for 24 weeks on the evolution of new Gd+ lesions to T1-hypointense lesions. Brain magnetic resonance imaging (MRI) scans from patients in placebo and 240 mg BG-12 tid arms of a phase 2b study were examined retrospectively. Included patients had at least one new Gd+ lesion from weeks 4 to 12. Week 24 scans were analyzed for number and proportion of new Gd+ lesions that evolved to T1-hypointense lesions. Eighteen patients receiving BG-12 and 38 patients receiving placebo were included in the analysis. The analysis tracked 147 new Gd+ lesions in patients from the BG-12 group and 221 Gd+ lesions in patients from the placebo group. The percentage of Gd+ lesions that evolved to T1-hypointense lesions was 34% lower with BG-12 treatment versus placebo (29%, BG-12; 44%, placebo; odds ratio 0.51; 95% confidence interval 0.43, 0.61; p < 0.0001). In addition to reducing frequency of new Gd+ lesions, BG-12 significantly reduced probability of their evolution to T1-hypointense lesions in patients with MS compared with placebo.

Purpose: To investigate changes in magnetic resonance imaging (MRI) indices following formalin fixation of postmortem multiple sclerosis (MS) cortical gray matter (CGM). Postmortem MS brain is being used to establish pathological correlates of changes detected using MRI, with recent emphasis on CGM. Fixation induces tissue alterations that may confound inference of in vivo observations from MRI/histology correlation studies., Materials and Methods: T(2)-weighted scans were obtained alongside quantitative T(1), magnetization transfer ratio (MTR), and macromolecular proton fraction (f(B)) measurements before and after formalin fixation of 15 postmortem brain samples. Type and size of CGM lesions (CGML) was identified on sections immunostained for myelin basic protein., Results: MRI indices obtained in unfixed MS CGM were similar to values obtained in subjects with MS in vivo. Fixation led to reduction in T(1) (617 msec [standard deviation = 114] vs. 1156 msec [216]) and MTR (24.1 [3.3] percent units [pu] vs. 29.1 [2.5] pu) and increase in f(B) (5.4 [0.7] pu vs. 3.2 [2.3] pu) (all P < 0.01). The proportion of CGM affected by demyelination did not alter the MRI data., Conclusion: MRI indices in the CGM are significantly altered following tissue fixation., (© 2010 Wiley-Liss, Inc.)

Objective: Multiple sclerosis (MS) is characterized by demyelination centered around cerebral veins. Recent studies suggested this topographic pattern may be caused by venous congestion, a condition termed chronic cerebrospinal venous insufficiency (CCSVI). Published sonographic criteria of CCSVI include reflux in the deep cerebral veins and/or the internal jugular and vertebral veins (IJVs and VVs), stenosis of the IJVs, missing flow in IJVs and VVs, and inverse postural response of the cerebral venous drainage., Methods: We performed an extended extra- and transcranial color-coded sonography study including analysis of extracranial venous blood volume flow (BVF), cross-sectional areas, IJV flow analysis during Valsalva maneuver (VM), and CCSVI criteria. Fifty-six MS patients and 20 controls were studied., Results: Except for 1 patient, blood flow direction in the IJVs and VVs was normal in all subjects. In none of the subjects was IJV stenosis detected. IJV and VV BVF in both groups was equal in the supine body position. The decrease of total jugular BVF on turning into the upright position was less pronounced in patients (173 +/- 235 vs 362 +/- 150 ml/min, p < 0.001), leading to higher BVF in the latter position (318 ml/min +/- 242 vs 123 +/- 109 ml/min; p < 0.001). No differences between groups were seen in intracranial veins and during VM. None of the subjects investigated in this study fulfilled >1 criterion for CCSVI., Interpretation: Our results challenge the hypothesis that cerebral venous congestion plays a significant role in the pathogenesis of MS. Future studies should elucidate the difference between patients and healthy subjects in BVF regulation.

Multiple sclerosis is an inflammatory, degenerative disease of the central nervous system. The most obvious pathological change in multiple sclerosis is multifocal demyelination of the white matter, but grey matter demyelination may be of equal or even greater importance for its clinical manifestations. In order to assess the pathogenetic role of lesions in the grey and white matter, and to explore the association between demyelinated and non-lesional brain tissue, tools are needed to depict each of these tissue components accurately in vivo. Due to its sensitivity in detecting white matter lesions, T(2)-weighted magnetic resonance imaging at 1.5 T is important in the diagnosis of multiple sclerosis. However, magnetic resonance imaging at 1.5 T largely fails to detect grey matter lesions. In this study, we used T(2)-weighted magnetic resonance imaging at 9.4 T to detect grey matter lesions in fixed post-mortem multiple sclerosis motor cortex. Furthermore, we produced T(1), T(2) and magnetization transfer ratio maps, and correlated these indices with quantitative histology [neuronal density, intensity of immunostaining for myelin basic protein (reflecting myelin content) and phosphorylated neurofilament (reflecting axonal area)] using t-tests and multivariate regression. In 21 tissue samples, 28 cortical grey matter lesions were visible on both T(2)-weighted magnetic resonance imaging and sections immunostained for myelin basic protein, 15/28 being mixed white and grey matter and 11/28 subpial cortical grey matter lesions; 2/28 cortical grey matter lesions involved all layers of the cortex. Compared with non-lesional cortex, cortical grey matter lesions showed reduction of neuronal density (98/mm(2), SD = 34/mm(2;) versus 129/mm(2), SD = 44; P < 0.01), phosphorylated neurofilament (1/transmittance = 1.16; SD = 0.09 versus 1.24; SD = 0.1; P < 0.01) and magnetization transfer ratio (31.1 pu; SD = 11.9 versus 37.5 pu; SD = 8.7; P = 0.01), and an increase of T(2) (25.9; SD = 5 versus 22.6 ms; SD = 4.7; P < 0.01). Associations were detected between phosphorylated neurofilament and myelin basic protein (r = 0.58, P < 0.01), myelin basic protein and T(2) (r = -0.59, P < 0.01), and neuronal density and T(1) (r = -0.57, P < 0.01). All indices correlated with duration of tissue fixation, however, including the latter in the analysis did not fundamentally affect the associations described. Our data show that T(2)-weighted magnetic resonance imaging at 9.4 T enables detection of cortical grey matter lesion in post-mortem multiple sclerosis brain. The quantitative associations suggest that in cortical grey matter T(1) may be a predictor of neuronal density, and T(2) of myelin content (and-secondarily-axons). Successful translation of these results into in vivo studies using high field magnetic resonance imaging (e.g. 3 T and 7 T) will improve the assessment of cortical pathology and thereby have an impact on the diagnosis and natural history studies of patients with multiple sclerosis, as well as clinical trial designs for putative treatments to prevent cortical demyelination and neuronal loss.

Background: Evidence suggests that Epstein-Barr virus (EBV) plays a role in triggering or perpetuating disease activity in multiple sclerosis (MS)., Methods: We investigated 100 subjects (50 clinically isolated syndrome [CIS], 25 relapsing-remitting [RR] MS, 25 primary progressive [PP] MS) for 1) evidence of EBV reactivation and 2) disease activity as indicated by serial gadolinium (Gd)-enhanced MRIs over a 5-year period. EBV DNA in blood was quantified by real-time quantitative PCR and EBV serology for anti-Epstein-Barr virus nuclear antigen 1 (EBNA-1) immunoglobulin G (IgG), anti-viral capsid antigen (VCA) IgG, and anti-EBV IgM. Data were analyzed using repeated measures analysis, analysis of variance, and logistic regression analysis., Results: All subjects had serologic evidence of previous EBV infection, but no lytic reactivation was detected. Significant differences in EBNA-1 IgG titers were found between subgroups, highest in the RRMS cohort compared with PPMS (p < 0.001) and CIS (p < 0.001). Gd-enhancing lesions on MRI correlated with EBNA-1 IgG (r = 0.33, p < 0.001) and EBNA-1:VCA IgG ratio (r = 0.36, p < 0.001). EBNA-1 IgG also correlated with change in T2 lesion volume (r = 0.27, p = 0.044) and Expanded Disability Status Scale score (r = 0.3, p = 0.035)., Conclusions: The correlation between elevated Epstein-Barr virus nuclear antigen 1 (EBNA-1) immunoglobulin G (IgG) and gadolinium-enhancing lesions suggests an association between Epstein-Barr virus (EBV) infection and multiple sclerosis (MS) disease activity. The heightened immune response to EBV in MS is specifically related to EBNA-1 IgG, a marker of the latent phase of the virus. The lack of association between acute viral reactivation in the peripheral blood and Gd(+) lesions suggests a limited role of the former in driving disease activity.

Background: In multiple sclerosis, grey matter (GM) damage appears more clinically relevant than either white matter damage or lesion load., Objective: We investigated if normal-appearing white matter (NAWM) and grey matter tissue changes assessed by magnetization transfer ratio were associated with long-term disability., Methods: Sixty-nine people were assessed 20 years after presentation with a clinically isolated syndrome (CIS) [28 still CIS, 31 relapsing-remitting multiple sclerosis, 10 secondary progressive multiple sclerosis], along with 19 healthy subjects. Mean magnetization transfer ratio, peak height (PH) and peak location of the normalized magnetization transfer ratio histograms were determined in NAWM and grey matter, as well as, white matter and GM Fraction (GMF) and T(2)-weighted lesion load., Results: Median expanded disability status scale for multiple sclerosis patients was 2.5 (range 1-8). GM-PH, and less so, NAWM mean and peak location, were lower in multiple sclerosis patients (P = 0.009) versus controls, relapsing-remitting multiple sclerosis versus CIS (P = 0.008) and secondary progressive multiple sclerosis versus relapsing-remitting multiple sclerosis (P = 0.002). GM-PH (as well as GMF) correlated with expanded disability status scale (r(s) = -0.49; P = 0.001) and multiple sclerosis functional score (r(s) = 0.51; P = 0.001). GM-PH independently predicted disability with similar strength to the associations of GMF with clinical measures., Conclusion: Grey matter damage was related to long-term disability in multiple sclerosis cohort with a relatively low median expanded disability status scale. Markers of intrinsic grey matter damage (magnetization transfer ratio) and tissue loss offer clinically relevant information in multiple sclerosis.

Objective: To evaluate the safety and tolerability of natalizumab when added to glatiramer acetate (GA) in patients with relapsing multiple sclerosis. The primary outcome assessed whether this combination would increase the rate of development of new active lesions on cranial MRI scans vs GA alone., Methods: This phase 2, randomized, double-blind, placebo-controlled study included patients aged 19 to 55 years who were treated with GA for at least 1 year before randomization and experienced at least one relapse during the previous year. Patients received IV natalizumab 300 mg (n = 55) or placebo (n = 55) once every 4 weeks plus GA 20 mg subcutaneously once daily for < or = 20 weeks., Results: The mean rate of development of new active lesions was 0.03 with combination therapy vs 0.11 with GA alone (p = 0.031). Combination therapy resulted in lower mean numbers of new gadolinium-enhancing lesions (0.6 vs 2.3 for GA alone, p = 0.020) and new/newly enlarging T2-hyperintense lesions (0.5 vs 1.3, p = 0.029). The incidence of infection and infusion reactions was similar in both groups; no hypersensitivity reactions were observed. One serious adverse event occurred with combination therapy (elective hip surgery). With the exception of an increase in anti-natalizumab antibodies with combination therapy, laboratory data were consistent with previous clinical studies of natalizumab alone., Conclusion: The combination of natalizumab and glatiramer acetate seemed safe and well tolerated during 6 months of therapy.

Background: Oral fumarate (BG00012) might have dual anti-inflammatory and neuroprotective effects. Our aim was to assess the efficacy and safety of BG00012 in patients with relapsing-remitting multiple sclerosis., Methods: 257 patients, aged 18-55 years, with relapsing-remitting multiple sclerosis were randomly assigned to receive 120 mg once daily (n=64), 120 mg three times daily (n=64), or 240 mg three times daily (n=64) BG00012, or placebo (n=65) for 24 weeks. During an extension period of 24 weeks for safety assessment, patients treated with placebo received BG00012 240 mg three times daily. The primary endpoint was total number of new gadolinium enhancing (GdE) lesions on brain MRI scans at weeks 12, 16, 20, and 24. Additional endpoints included cumulative number of new GdE lesions (weeks 4-24), new or enlarging T2-hyperintense lesions, new T1-hypointense lesions at week 24, and annualised relapse rate. Analysis was done on the efficacy-evaluable population. Safety and tolerability were also assessed. This study is registered with ClinicalTrials.gov, number NCT00168701., Findings: Treatment with BG00012 240 mg three times daily reduced by 69% the mean total number of new GdE lesions from week 12 to 24 compared with placebo (1.4 vs 4.5, p<0.0001). It also reduced number of new or enlarging T2-hyperintense (p=0.0006) and new T1-hypointense (p=0.014) lesions compared with placebo. BG00012 reduced annualised relapse rate by 32% (0.44 vs 0.65 for placebo; p=0.272). Adverse events more common in patients given BG00012 than in those given placebo included abdominal pain, flushing, and hot flush. Dose-related adverse events in patients on BG00012 were headache, fatigue, and feeling hot., Interpretation: The anti-inflammatory effects and favourable safety profile of BG00012 warrant further long-term phase III studies in large patient groups.

Aims: Axonal pathology extends to the axonal cytoarchitecture leaving its signature on axoskeletal proteins. This study investigated whether neurofilament (NfH) phosphorylation would relate to the dynamics of axonal pathology in multiple sclerosis (MS)., Methods: NfH phosphoforms (SMI32, SMI34, SMI35) were quantified by ELISA from microdissected samples of control and MS brain and spinal cord. Individual axons were analysed by electron microscopy, densitometrically and morphologically in adjacent tissue sections. Experiments were carried out pre- and post enzymatic dephosphorylation., Results: In control tissue a rostro-caudal gradient of NfH indicated an increase in axonal density from the brain gray matter towards the spinal cord. The highest levels of phosphorylated and hyperphosphorylated NfH were found in acute lesions of brain and spinal cord, in contrast to chronic lesions where levels were lower than in white matter, consistent with axonal loss. Dephosphorylated NfH was higher, but less densly packed in MS white matter axons compared to control tissue., Conclusions: The findings suggest that a less organised/compact axoskeleton or impaired axonal transport may represent an early sign of axonal pathology within the normal appearing white matter in MS. Subsequently a proportional increase of dephosphorylated NfH, aberrant phosphorylation and/or aggregation may occur whilst the protein is transported through the white matter towards the MS plaque, where hyperphosphorylated NfH dominates.

Unfixed and fixed postmortem multiple sclerosis (MS) brain is being used to probe pathology underlying quantitative MR (qMR) changes. Effects of fixation on qMR indices in MS brain are unknown. In 15 postmortem MS brain slices T(1), T(2), MT ratio (MTR), macromolecular proton fraction (f(B)), fractional anisotropy (FA), and mean, axial, and radial diffusivity (MD, D(ax), and D(rad)) were assessed in white matter (WM) lesions (WML) and normal appearing WM (NAWM) before and after fixation in formalin. Myelin content, axonal count, and gliosis were quantified histologically. Student's t-test and regression were used for analysis. T(1), T(2), MTR, and f(B) obtained in unfixed MS brain were similar to published values obtained in patients with MS in vivo. Following fixation T(1), T(2) (NAWM, WML) and MTR (NAWM) dropped, whereas f(B) (NAWM, WML) increased. Compared to published in vivo data all diffusivity measures were lower in unfixed MS brain, and dropped further following fixation (except for FA). MTR was the best predictor of T(myelin) (inversely related to myelin) in unfixed MS brain (r = -0.83; P < 0.01) whereas postfixation T(2) (r = 0.92; P < 0.01), T(1) (r = 0.89; P < 0.01), and f(B) (r = -0.86; P < 0.01) were superior. All diffusivity measures (except for D(ax) in unfixed tissue) were predictors of myelin content., ((c) 2008 Wiley-Liss, Inc.)

There is increasing interest in imaging cadavers for noninvasive autopsies for research purposes. However, the temperature is well below that of in vivo imaging, and a variety of interesting 'cold brain' effects are observed. At lower temperatures conventional FLAIR sequences no longer produce dark cerebrospinal fluid (CSF); T(1) is reduced from about 4.0 sec in vivo to 1.7 sec at 1 degrees C. The diffusion coefficient (DC) of CSF is much reduced (from 3.1 10(-9) m(2)s(-1) in vivo to 1.1 at 1 degrees C). DC values therefore provide a noninvasive thermometer to measure brain core temperature to within 1.0 degrees C. In three cadavers DC values were 1.1-1.5 10(-9) m(2)s(-1), indicating brain core temperatures of 1-10 degrees C, consistent with external thermocouple measurements. An improved inversion time (TI(0)) can then be found for FLAIR. At 10 degrees C this Cold FLAIR sequence (TI(0) = 1.5 sec) gave black CSF. Expressions for CSF DC and T(1) as a function of temperature were produced. A measurement of CSF DC could be converted directly to temperature and the required TI(0) found. In vitro values of CSF DC were about 1% lower than that of water. Thus, FLAIR imaging can be optimized for cadaveric brains at low and unknown temperatures, thereby improving value for autopsy purposes and facilitating comparisons with in vivo imaging., (2007 Wiley-Liss, Inc)

Purpose: To investigate the relationship of myelin content, axonal density, and gliosis with the fraction of macromolecular protons (fB) and T2 relaxation of the macromolecular pool (T2B) acquired using quantitative magnetization transfer (qMT) MRI in postmortem brains of subjects with multiple sclerosis (MS)., Materials and Methods: fB and T2B were acquired in unfixed postmortem brain slices of 20 subjects with MS. The myelin content, axonal count, and severity of gliosis were all quantified histologically. t-Tests and multiple regression were used for analysis., Results: MR indices obtained in unfixed postmortem MS brains were consistent with in vivo values reported in the literature. A significant correlation was detected between Tr(myelin) (inversely proportional to myelin content) and 1) fB (r = -0.80, P < 0.001) and 2) axonal count (r = -0.79, P < 0.001). fB differed between 1) normal-appearing white matter (NAWM) and remyelinated WM lesions (rWMLs) (mean: fB 6.9 [SD 2] vs. 4.0 [1.8], P = 0.01), and 2) rWMLs and demyelinated WMLs (mean: 4.2 [2.2] vs. 2.5 [1.3], P = 0.016). No association was detected between T2B and any of the histological measures., Conclusion: fB in MS WM is dependent on myelin content and may be a tool to monitor patients with this condition., (Copyright 2007 Wiley-Liss, Inc.)

Magnetic resonance imaging (MRI) is being used to probe the central nervous system (CNS) of patients with multiple sclerosis (MS), a chronic demyelinating disease. Conventional T(2)-weighted MRI (cMRI) largely fails to predict the degree of patients' disability. This shortcoming may be due to poor specificity of cMRI for clinically relevant pathology. Diffusion tensor imaging (DTI) has shown promise to be more specific for MS pathology. In this study we investigated the association between histological indices of myelin content, axonal count and gliosis, and two measures of DTI (mean diffusivity [MD] and fractional anisotropy [FA]), in unfixed post mortem MS brain using a 1.5-T MR system. Both MD and FA were significantly lower in post mortem MS brain compared to published data acquired in vivo. However, the differences of MD and FA described in vivo between white matter lesions (WMLs) and normal-appearing white matter (NAWM) were retained in this study of post mortem brain: average MD in WMLs was 0.35x10(-3) mm(2)/s (SD, 0.09) versus 0.22 (0.04) in NAWM; FA was 0.22 (0.06) in WMLs versus 0.38 (0.13) in NAWM. Correlations were detected between myelin content (Tr(myelin)) and (i) FA (r=-0.79, p<0.001), (ii) MD (r=0.68, p<0.001), and (iii) axonal count (r=-0.81, p<0.001). Multiple regression suggested that these correlations largely explain the apparent association of axonal count with (i) FA (r=0.70, p<0.001) and (ii) MD (r=-0.66, p<0.001). In conclusion, this study suggests that FA and MD are affected by myelin content and - to a lesser degree - axonal count in post mortem MS brain.

Quantitative magnetisation transfer (MT) analysis is based on a two-pool model of magnetisation transfer and allows important physical properties of the two proton pools to be assessed. A good signal-to-noise ratio (SNR) for the measured signal is essential in order to estimate reliably the parameters from a small number of samples, thus prompting the use of a sequence with high SNR, such as a three-dimensional spoiled gradient acquisition. Here, we show how full brain coverage can be accomplished efficiently, using a three-dimensional acquisition, in a clinically acceptable time, and without the use of large numbers of slice-selective radio-frequency pulses which could otherwise confound analysis. This acquisition was first compared in post mortem human brain tissue to established two-dimensional acquisition protocols with differing SNR levels and then used to collect data from six healthy subjects. Image data were fitted using the two pool model and showed negligible residual deviations. Quantitative results were assessed in several brain locations. Results were consistent with previous single-slice data, and parametric maps were of good quality. Further investigations are needed to interpret the regional variation of quantitative MT quantities.

Several quantitative magnetic resonance (MR) measures are used to investigate multiple sclerosis (MS) in vivo. Precise quantitative investigation of the histopathological correlates of such measures has, to date, been limited. This study investigates the relationship of quantitative measures of myelin content, axonal density, and gliosis with quantitative MR measures in postmortem (PM) MS tissue. MR imaging (MRI) was performed on a 1.5T scanner and T1-relaxation time (T1-RT) and magnetization transfer ratio (MTR) maps were acquired in fresh PM brain of 20 MS subjects. Myelin content, axonal counts, and the extent of gliosis all were quantified using morphometric and digital imaging techniques. MRI and pathological data were in most cases coregistered using stereotactic navigation. Using multiple regression analysis, we detected significant correlations between myelin content (Tr(myelin)) and MTR (r = -0.84, p < 0.001) and myelin content and axonal count (-0.80, p < 0.001); MTR correlated with T1-RT (r = -0.79, p < 0.001). No association was detected between the extent of gliosis and either MR measure. MTR was significantly higher in remyelinated than demyelinated lesions (means: 30.0 [standard deviation, 2.9] vs 23.8 [standard deviation, 4.3], p = 0.008). In conclusion, MTR is affected by myelin content in MS white matter.

Magnetic resonance imaging (MRI) is often divided into structural MRI and functional MRI (fMRI). The former is a widely used imaging technique in research as well as in clinical practice. This review describes the more important developments in structural MRI in recent years, including high resolution imaging, T2 relaxation measurement, T2*-weighted imaging, T1 relaxation measurement, magnetisation transfer imaging, and diffusion imaging. The principles underlying these techniques, as well as their use in research and in clinical practice, will be discussed.