Evidence of axonal damage in the early stages of multiple sclerosis and its relevance to disability

Brain Metabolite Changes in Patients with Relapsing-Remitting and Secondary Progressive Multiple Sclerosis: A Two-Year Follow-Up Study

Magnetic resonance spectroscopy (MRS) provides the unique ability to monitor several disease-related pathological processes via their characteristic metabolic markers in vivo. In the present study metabolic compositions were assessed every six months over the period of two years in 36 patients with Multiple Sclerosis (MS) including 21 relapsing-remitting (RR), 15 secondary progressive (SP) patients and 12 normal subjects. The concentrations of the main MRS-detectable metabolites N-acetylaspartate and N-acetylaspartylglutamate (tNAA), creatine and phosphocreatine (tCr), choline containing compounds (Cho), myo-Inositol (Ins), glutamine and glutamate (Glx) and their ratios were calculated in the normal appearing white matter (NAWM) and in selected non-enhancing white matter (WM) lesions. Association between metabolic concentrations in the NAWM and disability were investigated. Concentration of tNAA, a marker for neuroaxonal integrity, did not show any difference between the investigated groups. However, the patients with SPMS showed significant reduction of tNAA in the NAWM over the investigation period of two years indicating diffuse neuroaxonal loss during the disease course. Furthermore, we found a significant increase of Ins, Ins/tCr and Ins/tNAA in WM lesions independently from the course of the disease suggesting ongoing astrogliosis in silent-appearing WM lesions. Analyzing correlations between MRS metabolites in the NAWM and patients clinical status we found the positive correlation of Ins/tNAA with disability in patients with RRMS. In SPMS positive correlation of Cho with disability was found.

Brain health: time matters in multiple sclerosis

INTRODUCTION

We present international consensus recommendations for improving diagnosis, management and treatment access in multiple sclerosis (MS). Our vision is that these will be used widely among those committed to creating a better future for people with MS and their families.

METHODS

Structured discussions and literature searches conducted in 2015 examined the personal and economic impact of MS, current practice in diagnosis, treatment and management, definitions of disease activity and barriers to accessing disease-modifying therapies (DMTs).

RESULTS

Delays often occur before a person with symptoms suggestive of MS sees a neurologist. Campaigns to raise awareness of MS are needed, as are initiatives to improve access to MS healthcare professionals and services. We recommend a clear treatment goal: to maximize neurological reserve, cognitive function and physical function by reducing disease activity. Treatment should start early, with DMT and lifestyle measures. All parameters that predict relapses and disability progression should be included in the definition of disease activity and monitored regularly when practical. On suboptimal control of disease activity, switching to a DMT with a different mechanism of action should be considered. A shared decision-making process that embodies dialogue and considers all appropriate DMTs should be implemented. Monitoring data should be recorded formally in registries to generate real-world evidence. In many jurisdictions, access to DMTs is limited. To improve treatment access the relevant bodies should consider all costs to all parties when conducting economic evaluations and encourage the continuing investigation, development and use of cost-effective therapeutic strategies and alternative financing models.

CONCLUSIONS

The consensus findings of an international author group recommend a therapeutic strategy based on proactive monitoring and shared decision-making in MS. Early diagnosis and improved treatment access are also key components.

MRI/MRS of corpus callosum in patients with clinically isolated syndrome suggestive of multiple sclerosis

A trophy of corpus callosum (C C) related to axonal loss has previously been observed in patients at the early stage of clinically definite multiple sclerosis (CDMS). Atrophy increases with the progression of the disease. Nevertheless, no data concerning the onset of atrophy of C C are currently available. The purpose of this study is to determine if damage in callosal tissue was present at the earliest stage of MS, in a subgroup of patients presenting with a clinically isolated syndrome suggestive of MS (C ISSMS), fulfilling the dissemination in space criteria according to McDonald. Magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) techniques were applied to measure C C volume, magnetization transfer ratio (MTR), mean diffusivity (MD), N-acetyl aspartate/choline-containing compounds (NAA/C ho) ratio, N-acetyl aspartate/total creatine (NA A/C r) ratio and C ho/C r ratio inside the C C of 46 C ISSMS patients and 24 sexand age-matched controls. No atrophy of C C was observed in the C ISSMS group. C C of patients was character ized by decreased MTR and increased MD. No change in the NA A/C r ratio was observed while the NA A/C ho ratio decreased and C ho/C r ratio increased in the splenium and the central anterio r part of C C. These abnormalities were present in patients with, but also without, macroscopic lesions inside the C C. O ur results indicate that diffuse structural and metabolic changes, which may be interpreted as representing predominantly myelin patho logy, occur in the C C at the earliest stage of MS before any atrophy is detected.

Relationship between Proton Magnetic Resonance Spectroscopy of Frontoinsular Gray Matter and Neurodevelopmental Outcomes in Very Low Birth Weight Children at the Age of 4

Very low birth weight is associated with long term neurodevelopmental complications. Macroscopic brain abnormalities in prematurity survivors have been investigated in several studies. However, there is limited data regarding local cerebral metabolic status and neurodevelopmental outcomes. The purpose of this study was to characterize the relationship between proton magnetic resonance spectra in basal ganglia, frontal white matter and frontoinsular gray matter, neurodevelopmental outcomes assessed with the Leiter scale and the Developmental Test of Visual Perception and selected socioeconomic variables in a cohort of very low birth weight children at the age of four. Children were divided in three groups based on the severity of neurodevelopmental impairment. There were no differences in spectroscopy in basal ganglia and frontal white matter between the groups. Lower concentrations of N-acetylaspartate (NAA), choline (Cho) and myoinositol (mI) were observed in the frontoinsular cortex of the left hemisphere in children with neurodevelopmental impairment compared to children with normal neurodevelopmental outcomes. Higher parental education, daycare attendance and breastfeeding after birth were associated with more favorable neurodevelopmental prognosis, whereas rural residence was more prevalent in children with moderate and severe impairment. Our study demonstrates the role of long term neurometabolic disruption in the left frontoinsular cortex and selected socioeconomic variables in determination of neurodevelopmental prognosis in prematurity survivors.

Imaging Axonal Degeneration and Repair in Preclinical Animal Models of Multiple Sclerosis

Multiple sclerosis (MS) is a central nervous system (CNS) disease characterized by chronic neuroinflammation, demyelination, and axonal damage. Infiltration of activated lymphocytes and myeloid cells are thought to be primarily responsible for white matter damage and axonopathy. Over time, this neurologic damage manifests clinically as debilitating motor and cognitive symptoms. Existing MS therapies focus on symptom relief and delay of disease progression through reduction of neuroinflammation. However, long-term strategies to remyelinate, protect, or regenerate axons have remained elusive, posing a challenge to treating progressive forms of MS. Preclinical mouse models and techniques, such as immunohistochemistry, flow cytometry, and genomic and proteomic analysis have provided advances in our understanding of discrete time-points of pathology following disease induction. More recently, in vivo and in situ two-photon (2P) microscopy has made it possible to visualize continuous real-time cellular behavior and structural changes occurring within the CNS during neuropathology. Research utilizing 2P imaging to study axonopathy in neuroinflammatory demyelinating disease has focused on five areas: (1) axonal morphologic changes, (2) organelle transport and health, (3) relationship to inflammation, (4) neuronal excitotoxicity, and (5) regenerative therapies. 2P imaging may also be used to identify novel therapeutic targets via identification and clarification of dynamic cellular and molecular mechanisms of axonal regeneration and remyelination. Here, we review tools that have made 2P accessible for imaging neuropathologies and advances in our understanding of axonal degeneration and repair in preclinical models of demyelinating diseases.

Neuronal expression of pathological tau accelerates oligodendrocyte progenitor cell differentiation

Oligodendrocyte progenitor cell (OPC) differentiation is an important therapeutic target to promote remyelination in multiple sclerosis (MS). We previously reported hyperphosphorylated and aggregated microtubule-associated protein tau in MS lesions, suggesting its involvement in axonal degeneration. However, the influence of pathological tau-induced axonal damage on the potential for remyelination is unknown. Therefore, we investigated OPC differentiation in human P301S tau (P301S-htau) transgenic mice, both in vitro and in vivo following focal demyelination. In 2-month-old P301S-htau mice, which show hyperphosphorylated tau in neurons, we found atrophic axons in the spinal cord in the absence of prominent axonal degeneration. These signs of early axonal damage were associated with microgliosis and an upregulation of IL-1β and TNFα. Following in vivo focal white matter demyelination we found that OPCs differentiated more efficiently in P301S-htau mice than wild type (Wt) mice. We also found an increased level of myelin basic protein within the lesions, which however did not translate into increased remyelination due to higher susceptibility of P301S-htau axons to demyelination-induced degeneration compared to Wt axons. In vitro experiments confirmed higher differentiation capacity of OPCs from P301S-htau mice compared with Wt mice-derived OPCs. Because the OPCs from P301S-htau mice do not ectopically express the transgene, and when isolated from newborn mice behave like Wt mice-derived OPCs, we infer that their enhanced differentiation capacity must have been acquired through microenvironmental priming. Our data suggest the intriguing concept that damaged axons may signal to OPCs and promote their differentiation in the attempt at rescue by remyelination.

Treatment Optimization in Multiple Sclerosis

The treatment of multiple sclerosis has finally become possible with the advent of the current disease-modifying therapies (DMTs) that have had a significant impact on those living with this disease. Though demonstrating clear efficacy on a number of short-term outcome measures, unfortunately, these agents are not “cures” and many patients with multiple sclerosis continue to experience disease activity in spite of treatment. Clinicians are becoming more comfortable initiating therapy with DMTs, but it is now important to focus attention on monitoring the results of the chosen therapy and deciding whether or not a patient is responding well to treatment. At present, however, clinicians lack criteria for defining optimal versus suboptimal responses to DMTs as well as evidence-based guidelines on how to improve treatment outcomes. Using a recently published model as a framework, The Canadian Multiple Sclerosis Working Group developed practical recommendations on how neurologists can assess the status of patients on DMTs and decide when it may be necessary to modify treatment in order to optimize outcomes. The Canadian Multiple Sclerosis Working Group's recommendations are based on monitoring relapses, neurological progression and MRI activity. Other possible causes of suboptimal treatment responses or treatment failure are also considered.

Neuronal Hemoglobin Expression and Its Relevance to Multiple Sclerosis Neuropathology

Multiple sclerosis (MS) is characterized by demyelination and progressive neurological disability. Previous studies have reported defects to mitochondria in MS including decreased expression of nuclear encoded electron transport chain subunit genes and inhibition of respiratory complexes. We previously reported increased levels of the hemoglobin β subunit (Hbb) in mitochondrial fractions isolated from postmortem MS cortex compared to controls. In the present study, we performed immunohistochemistry to determine the distribution of Hbb in postmortem MS cortex and identified proteins which interact with Hbb by liquid chromatography tandem mass spectrometry (LC-MS/MS). We found that Hbb was enriched in pyramidal neurons in internal layers of the cortex and interacts with subunits of ATP synthase, histones, and a histone lysine demethylase. We also found that Hbb is present in the nucleus and that expression of Hbb in SH-SY5Y neuroblastoma cells increased trimethylation of histone H3 on lysine 4 (H3K4me3), a histone mark that regulates cellular metabolism. These data suggest that Hbb may be a part of a mechanism linking neuronal energetics with epigenetic changes to histones in the nucleus and may provide neuroprotection in MS by supporting neuronal metabolism.

Optimizing the initial choice and timing of therapy in relapsing-remitting multiple sclerosis

With 12 available US Food and Drug Administration approved medications for the treatment of relapsing multiple sclerosis (MS), choosing an initial therapy is no longer a straightforward task. Each disease-modifying therapy (DMT) has a distinct risk-benefit profile and each patient is an individual. Therefore, the development of a simple algorithm to apply in selecting initial therapy is not feasible. Instead, the prescribing physician must consider many factors related to the treatments themselves, such as efficacy, safety, and tolerability, while also taking into account a particular patient's disease characteristics, personal preferences, comorbid illnesses and reproductive plans. The efficacy of each drug may be assessed through clinical trial data, although these data are limited by scarcity of direct comparisons among the different agents and lack of availability of biomarkers to predict an individual patient's response. Differences in safety profiles help to distinguish the various DMTs and influence selection of agent; both the known safety concerns, which can be addressed with risk mitigation and monitoring strategies, and the potential for yet undiscovered safety issues must be assessed, and an individual patient's comfort level with the risks and ability to comply with monitoring must be determined. Potential issues related to tolerability, which largely relate to matters of patient personal preference and lifestyle, should also be factored into the decision-making process. With regard to the timing of therapy initiation, it must be acknowledged that long-term benefits of early DMT have not yet been definitively demonstrated. Nonetheless, starting DMT early in the MS disease course has been shown to have a beneficial effect on relapse prevention, and appears to curtail the atrophy and neurodegenerative changes that are now known to begin at disease onset. Although under certain circumstances there are acceptable reasons for deferring treatment, it is generally recommended that DMT is initiated early in the disease course.

Amiloride Clinical Trial In Optic Neuritis (ACTION) protocol: a randomised, double blind, placebo controlled trial

INTRODUCTION

Neurodegeneration is a widely accepted contributor to the development of long-term disability in multiple sclerosis (MS). While current therapies in MS predominantly target inflammation and reduce relapse rate they have been less effective at preventing long-term disability. The identification and evaluation of effective neuroprotective therapies within a trial paradigm are key unmet needs. Emerging evidence supports amiloride, a licenced diuretic, as a neuroprotective agent in MS through acid sensing ion channel blockade. Optic neuritis (ON) is a common manifestation of MS with correlates of inflammation and neurodegeneration measurable within the visual pathways. Amiloride Clinical Trial In Optic Neuritis (ACTION) will utilise a multimodal approach to assess the neuroprotective efficacy of amiloride in acute ON.

METHODS AND ANALYSIS

46 patients will be recruited within 28 days from onset of ON visual symptoms and randomised on a 1:1 basis to placebo or amiloride 10 mg daily. Double-blinded treatment groups will be balanced for age, sex and visual loss severity by a random-deterministic minimisation algorithm. The primary objective is to demonstrate that amiloride is neuroprotective in ON as assessed by scanning laser polarimetry of the peripapillary retinal nerve fibre layer (RNFL) thickness at 6 months in the affected eye compared to the unaffected eye at baseline. RNFL in combination with further retinal measures will also be assessed by optical coherence tomography. Secondary outcome measures on brain MRI will include cortical volume, diffusion-weighted imaging, resting state functional MRI, MR spectroscopy and magnetisation transfer ratio. In addition, high and low contrast visual acuity, visual fields, colour vision and electrophysiology will be assessed alongside quality of life measures.

ETHICS AND DISSEMINATION

Ethical approval was given by the south central Oxford B research ethics committee (REC reference: 13/SC/0022). The findings from ACTION will be disseminated through peer-reviewed publications and at scientific conferences.

TRIAL REGISTRATION NUMBER

EudraCT2012-004980-39, ClinicalTrials.gov Identifier: NCT01802489.

Sub-analysis of geographical variations in the 2-year observational COPTIMIZE trial of patients with relapsing-remitting multiple sclerosis converting to glatiramer acetate

BACKGROUND

Studies suggest that patients with relapsing-remitting multiple sclerosis (RRMS) who fail to benefit from a disease-modifying treatment (DMT) may benefit from converting to another DMT class. COPTIMIZE was a 24-month observational study designed to assess the disease course of patients converting to glatiramer acetate (GA) 20 mg daily from another DMT and the association of disease characteristics and reasons for converting. This sub-analysis was to determine if any findings varied by three geographic locations: Latin America (LA), Canada and Western Europe (CWE), and Eastern Europe (EE).

METHODS

A total of 668 patients were included (263 LA, 248 CWE, 157 EE) in an analysis of annualized relapse rate (ARR) and annualized rate of deterioration (ARD), as well as secondary endpoints including reason for DMT switch and changes in disability and fatigue scores. Repeated-measures analysis of variance and log transformation were used to analyze ARR and ARD, whereas the Wilcoxon signed rank test was used for secondary endpoints.

RESULTS

The sub-analysis of treatment outcomes stratified by region showed that Latin American patients had higher ARR before conversion to GA compared with patients from the other two areas and subsequently experienced the largest reduction in ARR. Latin American patients also had higher baseline rates of comorbidities and relapses with incomplete remissions and improved more than those in the other two regions based on measures of fatigue, quality of life, depression, and cognition scores. Latin American patients also generally had a better perception of the benefits associated with their conversion to GA in terms of efficacy and adverse events.

CONCLUSIONS

These findings indicate that, in RRMS patients, converting to GA is associated with positive treatment outcomes regardless of geographic location. However, the reasons for converting and the type and degree of any associated benefits appear to vary depending on various factors, including patients' geographical location.

Brain and cord myelin water imaging: a progressive multiple sclerosis biomarker

OBJECTIVES

Conventional magnetic resonance imaging (MRI) is used to diagnose and monitor inflammatory disease in relapsing remitting (RR) multiple sclerosis (MS). In the less common primary progressive (PP) form of MS, in which focal inflammation is less evident, biomarkers are still needed to enable evaluation of novel therapies in clinical trials. Our objective was to characterize the association - across the brain and cervical spinal cord - between clinical disability measures in PPMS and two potential biomarkers (one for myelin, and one for atrophy, both resulting from the same imaging technique).

METHODS

Multi-component driven equilibrium single pulse observation of T1 and T2 (mcDESPOT) MRI of the brain and cervical spinal cord were obtained for 15 PPMS patients and 11 matched controls. Data were analysed to estimate the signal related to myelin water (VFM), as well as volume measurements. MS disability was assessed using the Multiple Sclerosis Functional Composite score, which includes measures of cognitive processing (Paced Auditory Serial Addition Test), manual dexterity (9-Hole Peg Test) and ambulatory function (Timed 25-Foot Walk); and the Expanded Disability Status Scale.

RESULTS

Brain and spinal cord volumes were different in PPMS compared to controls, particularly ventricular (+ 46%, p = 0.0006) and cervical spinal cord volume (- 16%, p = 0.0001). Brain and spinal cord myelin (VFM) were also reduced in PPMS (brain: - 11%, p = 0.01; spine: - 19%, p = 0.000004). Cognitive processing correlated with brain ventricular volume (p = 0.009). Manual dexterity correlated with brain ventricular volume (p = 0.007), and both brain and spinal cord VFM (p = 0.01 and 0.06, respectively). Ambulation correlated with spinal cord volume (p = 0.04) and spinal cord VFM (p = 0.04).

INTERPRETATION

In this study we demonstrated that mcDESPOT can be used to measure myelin and atrophy in the brain and spinal cord. Results correlate well with clinical disability scores in PPMS representing cognitive, fine motor and ambulatory disability.

Optical coherence tomography reflects brain atrophy in multiple sclerosis: A four-year study

OBJECTIVE

The aim of this work was to determine whether atrophy of specific retinal layers and brain substructures are associated over time, in order to further validate the utility of optical coherence tomography (OCT) as an indicator of neuronal tissue damage in patients with multiple sclerosis (MS).

METHODS

Cirrus high-definition OCT (including automated macular segmentation) was performed in 107 MS patients biannually (median follow-up: 46 months). Three-Tesla magnetic resonance imaging brain scans (including brain-substructure volumetrics) were performed annually. Individual-specific rates of change in retinal and brain measures (estimated with linear regression) were correlated, adjusting for age, sex, disease duration, and optic neuritis (ON) history.

RESULTS

Rates of ganglion cell + inner plexiform layer (GCIP) and whole-brain (r = 0.45; p < 0.001), gray matter (GM; r = 0.37; p < 0.001), white matter (WM; r = 0.28; p = 0.007), and thalamic (r = 0.38; p < 0.001) atrophy were associated. GCIP and whole-brain (as well as GM and WM) atrophy rates were more strongly associated in progressive MS (r = 0.67; p < 0.001) than relapsing-remitting MS (RRMS; r = 0.33; p = 0.007). However, correlation between rates of GCIP and whole-brain (and additionally GM and WM) atrophy in RRMS increased incrementally with step-wise refinement to exclude ON effects; excluding eyes and then patients (to account for a phenotype effect), the correlation increased to 0.45 and 0.60, respectively, consistent with effect modification. In RRMS, lesion accumulation rate was associated with GCIP (r = -0.30; p = 0.02) and inner nuclear layer (r = -0.25; p = 0.04) atrophy rates.

INTERPRETATION

Over time GCIP atrophy appears to mirror whole-brain, and particularly GM, atrophy, especially in progressive MS, thereby reflecting underlying disease progression. Our findings support OCT for clinical monitoring and as an outcome in investigative trials.

Therapeutic effect of Avonex, Rebif and Betaferon on quality of life in multiple sclerosis

AIMS

The aim of this study was to evaluate the effect of various disease-modifying therapies (DMT) on quality of life in multiple sclerosis (MS).

METHODS

This was a three-arm parallel study with balanced randomization in which 90 newly diagnosed, definite MS subjects referred to Ghaem Medical Center, Mashhad, Iran were enrolled between 2006 and 2009. Patients were randomly allocated into three DMT groups: Avonex, Rebif and Betaferon. Health-related quality of life was assessed in MS patients at baseline and 12 months after treatment with DMT using the MS Quality of Life-54 questionnaire.

RESULTS

Both mental and physical health scores improved within all three treatment groups after 12 months of treatment; however, this increase was only significant in the mental health composite in the Betaferon group (P = 0.024). Betaferon had the highest mental health score change (14.04) while this change was 7.26 for Avonex (P = 0.031) and 5.08 for Rebif (P = 0.017). A physical health composite score comparison among the three treatment groups revealed no significant results.

CONCLUSIONS

With a positive impact of DMT on mental and physical dimensions of QOL in MS patients, initiation of treatment soon after diagnosis is recommended. In MS patients with more mental issues and fewer physical disabilities, Betaferon might be considered as a better choice of treatment.

Targeting demyelination and virtual hypoxia with high-dose biotin as a treatment for progressive multiple sclerosis

Progressive multiple sclerosis (MS) is a severely disabling neurological condition, and an effective treatment is urgently needed. Recently, high-dose biotin has emerged as a promising therapy for affected individuals. Initial clinical data have shown that daily doses of biotin of up to 300 mg can improve objective measures of MS-related disability. In this article, we review the biology of biotin and explore the properties of this ubiquitous coenzyme that may explain the encouraging responses seen in patients with progressive MS. The gradual worsening of neurological disability in patients with progressive MS is caused by progressive axonal loss or damage. The triggers for axonal loss in MS likely include both inflammatory demyelination of the myelin sheath and primary neurodegeneration caused by a state of virtual hypoxia within the neuron. Accordingly, targeting both these pathological processes could be effective in the treatment of progressive MS. Biotin is an essential co-factor for five carboxylases involved in fatty acid synthesis and energy production. We hypothesize that high-dose biotin is exerting a therapeutic effect in patients with progressive MS through two different and complementary mechanisms: by promoting axonal remyelination by enhancing myelin production and by reducing axonal hypoxia through enhanced energy production. This article is part of the Special Issue entitled 'Oligodendrocytes in Health and Disease'.

Poor early relapse recovery affects onset of progressive disease course in multiple sclerosis

OBJECTIVE

To evaluate the relationship between early relapse recovery and onset of progressive multiple sclerosis (MS).

METHODS

We studied a population-based cohort (105 patients with relapsing-remitting MS, 86 with bout-onset progressive MS) and a clinic-based cohort (415 patients with bout-onset progressive MS), excluding patients with primary progressive MS. Bout-onset progressive MS includes patients with single-attack progressive and secondary progressive MS. "Good recovery" (as opposed to "poor recovery") was assigned if the peak deficit of the relapse improved completely or almost completely (patient-reported and examination-confirmed outcome measured ≥6 months post relapse). Impact of initial relapse recovery and first 5-year average relapse recovery on cumulative incidence of progressive MS was studied accounting for patients yet to develop progressive MS in the population-based cohort (Kaplan-Meier analyses). Impact of initial relapse recovery on time to progressive MS onset was also studied in the clinic-based cohort with already-established progressive MS (t test).

RESULTS

In the population-based cohort, 153 patients (80.1%) had on average good recovery from first 5-year relapses, whereas 30 patients (15.7%) had on average poor recovery. Half of the good recoverers developed progressive MS by 30.2 years after MS onset, whereas half of the poor recoverers developed progressive MS by 8.3 years after MS onset (p = 0.001). In the clinic-based cohort, good recovery from the first relapse alone was also associated with a delay in progressive disease onset (p < 0.001). A brainstem, cerebellar, or spinal cord syndrome (p = 0.001) or a fulminant relapse (p < 0.0001) was associated with a poor recovery from the initial relapse.

CONCLUSIONS

Patients with MS with poor recovery from early relapses will develop progressive disease course earlier than those with good recovery.

Neurophysiological Correlates of Central Fatigue in Healthy Subjects and Multiple Sclerosis Patients before and after Treatment with Amantadine

In ten healthy subjects and in ten patients suffering from Multiple Sclerosis (MS), we investigated the cortical functional changes induced by a standard fatiguing repetitive tapping task. The Cortical Silent Period (CSP), an intracortical, mainly GABA_B-mediated inhibitory phenomenon, was recorded by two different hand muscles, one acting as prime mover of the fatiguing index-thumb tapping task (First Dorsal Interosseous, FDI) and the other one not involved in the task but sharing largely overlapping central, spinal, and peripheral innervation (Abductor Digiti Minimi, ADM). At baseline, the CSP was shorter in patients than in controls. As fatigue developed, CSP changes involved both the “fatigued” FDI and the “unfatigued” ADM muscles, suggesting a cortical spread of central fatigue mechanisms. Chronic therapy with amantadine annulled differences in CSP duration between controls and patients, possibly through restoration of more physiological levels of intracortical inhibition in the motor cortex. These inhibitory changes correlated with the improvement of fatigue scales. The CSP may represent a suitable marker of neurophysiological mechanisms accounting for central fatigue generation either in controls or in MS patients, involving corticospinal neural pools supplying not only the fatigued muscle but also adjacent muscles sharing an overlapping cortical representation.

Metabolic changes in de novo Parkinson's disease after dopaminergic therapy: A proton magnetic resonance spectroscopy study

The aim of this study was to assess metabolic changes in the motor cortex in de novo Parkinson's disease (PD) patients before and after therapy with ropinirole. Twenty de novo drug-naïve PD patients and 15 healthy controls underwent conventional magnetic resonance imaging and proton magnetic resonance spectroscopy imaging ((1)H-MRSI). The resonance intensities of N-acetylaspartate (NAA) and choline (Cho) were normalized for the resonance intensities of creatine (Cr). At baseline, lower NAA/Cr and NAA/Cho ratios and higher Cho/Cr ratios were found in the motor cortex of PD patients compared with controls (p<0.001). Ten months after ropinirole treatment, PD patients showed a significant clinical improvement in the UPDRS motor sub-scores (p<0.001) and an increase of NAA/Cr and NAA/Cho ratios (p<0.006 and p=0.01, respectively). A highly significant correlation between NAA/Cr and NAA/Cho ratios and UPDRS motor sub-scores was observed (r=-0.981 and r=-0.983, respectively). We could argue that the ropinirole efficacy to improve the motor performances is the result of partial restoration of neuronal functions, due to the increase of NAA in motor cortex.

Systemic inflammation and the brain: novel roles of genetic, molecular, and environmental cues as drivers of neurodegeneration

The nervous and immune systems have evolved in parallel from the early bilaterians, in which innate immunity and a central nervous system (CNS) coexisted for the first time, to jawed vertebrates and the appearance of adaptive immunity. The CNS feeds from, and integrates efferent signals in response to, somatic and autonomic sensory information. The CNS receives input also from the periphery about inflammation and infection. Cytokines, chemokines, and damage-associated soluble mediators of systemic inflammation can also gain access to the CNS via blood flow. In response to systemic inflammation, those soluble mediators can access directly through the circumventricular organs, as well as open the blood–brain barrier. The resulting translocation of inflammatory mediators can interfere with neuronal and glial well-being, leading to a break of balance in brain homeostasis. This in turn results in cognitive and behavioral manifestations commonly present during acute infections – including anorexia, malaise, depression, and decreased physical activity – collectively known as the sickness behavior (SB). While SB manifestations are transient and self-limited, under states of persistent systemic inflammatory response the cognitive and behavioral changes can become permanent. For example, cognitive decline is almost universal in sepsis survivors, and a common finding in patients with systemic lupus erythematosus. Here, we review recent genetic evidence suggesting an association between neurodegenerative disorders and persistent immune activation; clinical and experimental evidence indicating previously unidentified immune-mediated pathways of neurodegeneration; and novel immunomodulatory targets and their potential relevance for neurodegenerative disorders.

Oxidative Stress and Neurobiology of Demyelination

Despite a large amount of research which aims at defining the pathophysiology of human demyelination (i.e., multiple sclerosis), etiological bases of disease have been unknown so far. The point of intersection of all assumed etiological factors, which are mainly based upon immunological cascades, is neuroinflammation. The precise definition of the place and role of all pathogenetic factors in the occurrence and development of the disease is of crucial importance for understanding the clinical nature and for finding more effective therapeutic options. There are few studies whose results give more precise data about the role and the importance of other factors in neuroinflammation, besides immunological ones, with regard to clinical and paraclinical correlates of the disease. The review integrates results found in previously performed studies which have evaluated oxidative stress participation in early and late neuroinflammation. The largest number of studies indicates that the use of antioxidants affects the change of neuroinflammation course under experimental conditions, which is reflected in the reduction of the severity and the total reversibility in clinical presentation of the disease, the faster achieving of remission, and the delayed and slow course of neuroinflammation. Therapies based on the knowledge of redox biology targeting free radical generation hold great promise in modulation of the neuroinflammation and its clinical presentations.

A unified cell biological perspective on axon-myelin injury

Demyelination and axon loss are pathological hallmarks of the neuroinflammatory disorder multiple sclerosis (MS). Although we have an increasingly detailed understanding of how immune cells can damage axons and myelin individually, we lack a unified view of how the axon-myelin unit as a whole is affected by immune-mediated attack. In this review, we propose that as a result of the tight cell biological interconnection of axons and myelin, damage to either can spread, which might convert a local inflammatory disease process early in MS into the global progressive disorder seen during later stages. This mode of spreading could also apply to other neurological disorders.

Short-term cuprizone feeding verifies N-acetylaspartate quantification as a marker of neurodegeneration

Proton magnetic resonance spectroscopy (1H-MRS) is a quantitative MR imaging technique often used to complement conventional MR imaging with specific metabolic information. A key metabolite is the amino acid derivative N-Acetylaspartate (NAA) which is an accepted marker to measure the extent of neurodegeneration in multiple sclerosis (MS) patients. NAA is catabolized by the enzyme aspartoacylase (ASPA) which is predominantly expressed in oligodendrocytes. Since the formation of MS lesions is paralleled by oligodendrocyte loss, NAA might accumulate in the brain, and therefore, the extent of neurodegeneration might be underestimated. In the present study, we used the well-characterized cuprizone model. There, the loss of oligodendrocytes is paralleled by a reduction in ASPA expression and activity as demonstrated by genome-wide gene expression analysis and enzymatic activity assays. Notably, brain levels of NAA were not increased as determined by gas chromatography-mass spectrometry and 1H-MRS. These important findings underpin the reliability of NAA quantification as a valid marker for the paraclinical determination of the extent of neurodegeneration, even under conditions of oligodendrocyte loss in which impaired metabolization of NAA is expected. Future studies have to reveal whether other enzymes are able to metabolize NAA or whether an excess of NAA is cleared by other mechanisms rather than enzymatic metabolism.

Placebo-controlled trial of oral laquinimod in multiple sclerosis: MRI evidence of an effect on brain tissue damage

OBJECTIVE

In Assessment of OraL Laquinimod in PrEventing ProGRession in Multiple SclerOsis (ALLEGRO), a phase III study in relapsing-remitting multiple sclerosis (RRMS), oral laquinimod slowed disability and brain atrophy progression, suggesting laquinimod may reduce tissue damage in MS. MRI techniques sensitive to the most destructive aspects of the disease were used to further investigate laquinimod's potential effects on inflammation and neurodegeneration.

METHODS

1106 RRMS patients were randomised 1:1 to receive once-daily oral laquinimod (0.6 mg) or placebo for 24 months. White matter (WM), grey matter (GM) and thalamic fractions were derived at months 0, 12 and 24. Also assessed were evolution of gadolinium-enhancing and/or new T2 lesions into permanent black holes (PBH); magnetisation transfer ratio (MTR) of normal-appearing brain tissue (NABT), WM, GM and T2 lesions; and N-acetylaspartate/creatine (NAA/Cr) levels in WM.

RESULTS

Compared with placebo, laquinimod-treated patients showed lower rates of WM at months 12 and 24 (p=0.004 and p=0.035) and GM (p=0.004) atrophy at month 12 and a trend for less GM atrophy at month 24 (p=0.078). Laquinimod also slowed thalamic atrophy at month 12 (p=0.005) and month 24 (p=0.003) and reduced the number of PBH at 12 and 24 months evolving from active lesions (all p<0.05). By month 24, MTR decreased significantly in NABT (p=0.015), WM (p=0.011) and GM (p=0.034) in placebo-treated patients, but not in laquinimod-treated patients. WM NAA/Cr tended to increase with laquinimod and decrease with placebo at 24 months (p=0.179).

CONCLUSIONS

Oral laquinimod may reduce (at least in the initial phase of treatment) some of the more destructive pathological processes in RRMS patients.

TRIAL REGISTRATION

The ALLEGRO trial identifier number with clinicaltrials.gov is NCT00509145.

Decreased NAA in gray matter is correlated with decreased availability of acetate in white matter in postmortem multiple sclerosis cortex

Multiple sclerosis (MS) is an inflammatory neurodegenerative disease of the central nervous system (CNS) which leads to progressive neurological disability. Our previous studies have demonstrated mitochondrial involvement in MS cortical pathology and others have documented decreased levels of the neuronal mitochondrial metabolite N-acetyl aspartate (NAA) in the MS brain. While NAA is synthesized in neurons, it is broken down in oligodendrocytes into aspartate and acetate. The resulting acetate is incorporated into myelin lipids, linking neuronal mitochondrial function to oligodendrocyte-mediated elaboration of myelin lipids in the CNS. In the present study we show that treating human SH-SY5Y neuroblastoma cells with the electron transport chain inhibitor antimycin A decreased levels of NAA as measured by HPLC. To better understand the significance of the relationship between mitochondrial function and levels of NAA and its breakdown product acetate on MS pathology we then quantitated the levels of NAA and acetate in MS and control postmortem tissue blocks. Regardless of lesion status, we observed that levels of NAA were decreased 25 and 32 % in gray matter from parietal and motor cortex in MS, respectively, compared to controls. Acetate levels in adjacent white matter mirrored these decreases as evidenced by the 36 and 45 % reduction in acetate obtained from parietal and motor cortices. These data suggest a novel mechanism whereby mitochondrial dysfunction and reduced NAA levels in neurons may result in compromised myelination by oligodendrocytes due to decreased availability of acetate necessary for the synthesis of myelin lipids.

Twelve-year monitoring of a patient with megalencephalic leukoencephalopathy with subcortical cysts

Megalencephalic leukoencephalopathy (MLC) with subcortical cysts is an infantile-onset inherited disease of the brain white matter with a defect in brain ion and water homoeostasis, which leads to an abnormal brain volume regulation. Clinical features of the disease can be variable, but patients typically show early-onset macrocephaly, motor abnormalities, seizures, and almost constant late-onset mild mental deterioration. Brain magnetic resonance imaging (MRI) reveals diffusely abnormal and mildly swollen white matter as well as subcortical cysts in the anterior temporal and frontoparietal regions. We describe here clinical findings and volumetric MRI and (1)H-MR spectroscopic imaging ((1)H-MRSI) data of a 12-year follow-up on a patient with MLC. The patient had only slight clinical worsening during the long follow-up. Volumetric findings showed substantially unchanged cystic volumes and mild brain atrophy rate. In addition, there was no over time increase in the volume of white matter hypointense lesions seen on FLAIR images at baseline, but the degree of hypointensity of these white matter voxels increased over 12 years. Longitudinal (1)H-MRSI examination showed long-term undetectable metabolite signals in the white matter, whereas the metabolic pattern of gray matter voxels remained unchanged over time. Results show that, in MLC, the chronic brain white matter changes resulting from the brain ion, and water homeostasis can be monitored by quantitative MRI modalities. This might be important for assessing treatment effects.

Clinical proton MR spectroscopy in central nervous system disorders

A large body of published work shows that proton (hydrogen 1 [(1)H]) magnetic resonance (MR) spectroscopy has evolved from a research tool into a clinical neuroimaging modality. Herein, the authors present a summary of brain disorders in which MR spectroscopy has an impact on patient management, together with a critical consideration of common data acquisition and processing procedures. The article documents the impact of (1)H MR spectroscopy in the clinical evaluation of disorders of the central nervous system. The clinical usefulness of (1)H MR spectroscopy has been established for brain neoplasms, neonatal and pediatric disorders (hypoxia-ischemia, inherited metabolic diseases, and traumatic brain injury), demyelinating disorders, and infectious brain lesions. The growing list of disorders for which (1)H MR spectroscopy may contribute to patient management extends to neurodegenerative diseases, epilepsy, and stroke. To facilitate expanded clinical acceptance and standardization of MR spectroscopy methodology, guidelines are provided for data acquisition and analysis, quality assessment, and interpretation. Finally, the authors offer recommendations to expedite the use of robust MR spectroscopy methodology in the clinical setting, including incorporation of technical advances on clinical units.

Relationship between Structural and Functional Assessment of the Visual System in Mildly Disabled Relapsing-Remitting Multiple Sclerosis Patients

Studies that explored the anterior visual pathway in the patients with multiple sclerosis (MS) have demonstrated contradictory results about the correlation between structural and functional status of optic nerve and retina. We aimed to investigate the functional and structural findings in our cohort of mildly disabled relapsing-remitting MS patients. A total of 134 eyes (80 eyes of the patients with MS and 54 eyes of the control group) were investigated. Eyes of MS patients were divided into two groups-as eyes with history of optic neuritis (ON group) and without history of optic neuritis (NON group). Ophthalmological investigation including visual evoked potentials, standard automated perimetry, and optical coherence tomography were performed for all participants. Retinal and macular thicknesses were significantly decreased in ON and NON groups compared with controls. Also, visual evoked potential latencies and visual field loss were worse in the both MS groups compared with control group. We did not find any correlation between visual evoked potentials and retinal or macular thickness values but visual field parameters were correlated between retinal and macular layer loss in the NON group. According to our results and some previous studies, although both functional and structural changes were detected in patients with MS, functional status markers do not always show parallelism (or synchrony) with structural changes, especially in eyes with history of optic neuritis.

Disease-modifying agents in multiple sclerosis

Over the past two decades, major advances have been made in the development of disease-modifying agents (DMAs) for multiple sclerosis (MS), and nine agents are now licensed for use in the treatment of MS in the United States. Clinical trials have demonstrated that a number of investigational agents have beneficial effects on clinical and radiographic measures of disease activity, thus the repertoire of available DMAs in MS will likely continue to expand moving forward. Although many of the first-line DMAs have the benefits of established long-term safety and tolerability, in some patients, treatment with one of the more potent novel agents may be appropriate. However, the use of novel agents must be approached with caution, since short-term clinical trials give little information on the long-term efficacy and safety of novel DMAs in MS patients. This chapter will consider the efficacy and safety of both established and investigational agents for the treatment of MS.

Insights from magnetic resonance imaging

Recent years have witnessed impressive advancements in the use of magnetic resonance imaging (MRI) for the assessment of patients with multiple sclerosis (MS). Complementary to the clinical evaluation, conventional MRI (cMRI) provides crucial pieces of information for the diagnosis of MS, the understanding of its natural history, and monitoring the efficacy of experimental treatments. Measures derived from cMRI present clear advantages over the clinical assessment, including their more objective nature and an increased sensitivity to MS-related changes. However, the correlation between these measures and the clinical manifestations of the disease remains weak, and this can be explained, at least partially, by the limited ability of cMRI to characterize and quantify the heterogeneous features of MS pathology. Quantitative MR-based techniques have the potential to overcome the limitations of cMRI. Magnetization transfer MRI, diffusion-weighted and diffusion tensor MRI with fiber tractography, proton magnetic resonance spectroscopy, T1 and T2 relaxation time measurement, and functional MRI are contributing to elucidate the mechanisms that underlie injury, repair, and functional adaptation in patients with MS. All conventional and nonconventional MR techniques will benefit from the use of high-field MR systems (3.0T or more).

Pertussis toxin attenuates experimental autoimmune encephalomyelitis by upregulating neuronal vascular endothelial growth factor

We have reported earlier that pertussis toxin (PTx) attenuates the motor deficits in experimental autoimmune encephalomyelitis (EAE), an animal model for human multiple sclerosis. PTx protects neurons from inflammatory insults. Vascular endothelial growth factor (VEGF) is also neuroprotective. However, the effect of PTx on VEGF has never been studied. We investigated whether PTx modulates neuronal VEGF expression and how it affects the pathogenesis of EAE. EAE was induced by injecting myelin oligodendrocyte glycoprotein 35-55 peptides with adjuvants into C57BL/6 mice. Clinical scores of EAE were evaluated daily for 19 days. Brain and spinal cord samples were collected and assessed for inflammation and demyelination. VEGF, NeuN for neurons, and Caspase-3 for apoptosis were stained for localization using immunohistochemistry techniques, followed by western blot analysis for quantification. Primary neurons were cultured to assess the direct effect of PTx on neuronal VEGF expression. PTx treatment increases neuronal VEGF expression by up to ∼75% in vitro and ∼60% in vivo, preventing neurons from apoptosis. This leads to resolution in inflammation and remyelination and amendment in motor deficits. Our findings suggest that upregulation of endogenous neuronal VEGF by PTx protects motor deficits in EAE and it is a potential therapeutic option for multiple sclerosis.

Blood pressure normalization post-jugular venous balloon angioplasty

Objective

This study is the first in a series investigating the relationship between autonomic nervous system dysfunction and chronic cerebrospinal venous insufficiency in multiple sclerosis patients. We screened patients for the combined presence of the narrowing of the internal jugular veins and symptoms of autonomic nervous system dysfunction (fatigue, cognitive dysfunction, sleeping disorders, headache, thermal intolerance, bowel/bladder dysfunction) and determined systolic and diastolic blood pressure responses to balloon angioplasty.

Methods

The criteria for eligibility for balloon angioplasty intervention included ≥50% narrowing in one or both internal jugular veins, as determined by the magnetic resonance venography, and ≥3 clinical symptoms of autonomic nervous system dysfunction. Blood pressure was measured at baseline and post-balloon angioplasty.

Results

Among patients who were screened, 91% were identified as having internal jugular veins narrowing (with obstructing lesions) combined with the presence of three or more symptoms of autonomic nervous system dysfunction. Balloon angioplasty reduced the average systolic and diastolic blood pressure. However, blood pressure categorization showed a biphasic response to balloon angioplasty. The procedure increased blood pressure in multiple sclerosis patients who presented with baseline blood pressure within lower limits of normal ranges (systolic ≤105 mmHg, diastolic ≤70 mmHg) but decreased blood pressure in patients with baseline blood pressure above normal ranges (systolic ≥130 mmHg, diastolic ≥ 80 mmHg). In addition, gender differences in baseline blood pressure subcategories were observed.

Discussion

The coexistence of internal jugular veins narrowing and symptoms of autonomic nervous system dysfunction suggests that the two phenomena may be related. Balloon angioplasty corrects blood pressure deviation in multiple sclerosis patients undergoing internal jugular vein dilation. Further studies should investigate the association between blood pressure deviation and internal jugular veins narrowing, and whether blood pressure normalization affects Patient's clinical outcomes.

Biomarkers for the diagnosis and prognosis of mild traumatic brain injury/concussion

Mild traumatic brain injury (mTBI) results from a transfer of mechanical energy into the brain from traumatic events such as rapid acceleration/deceleration, a direct impact to the head, or an explosive blast. Transfer of energy into the brain can cause structural, physiological, and/or functional changes in the brain that may yield neurological, cognitive, and behavioral symptoms that can be long-lasting. Because mTBI can cause these symptoms in the absence of positive neuroimaging findings, its diagnosis can be subjective and often is based on self-reported neurological symptoms. Further, proper diagnosis can be influenced by the motivation to conceal or embellish signs and/or an inability of the patient to notice subtle dysfunctions or alterations of consciousness. Therefore, appropriate diagnosis of mTBI would benefit from objective indicators of injury. Concussion and mTBI are often used interchangeably, with concussion being primarily used in sport medicine, whereas mTBI is used in reference to traumatic injury. This review provides a critical assessment of the status of current biomarkers for the diagnosis of human mTBI. We review the status of biomarkers that have been tested in TBI patients with injuries classified as mild, and introduce a new concept for the discovery of biomarkers (termed symptophenotypes) to predict common and unique symptoms of concussion. Finally, we discuss the need for biomarker/biomarker signatures that can detect mTBI in the context of polytrauma, and to assess the consequences of repeated injury on the development of secondary injury syndrome, prolongation of post-concussion symptoms, and chronic traumatic encephalopathy.

Moving toward earlier treatment of multiple sclerosis: Findings from a decade of clinical trials and implications for clinical practice

The first clinical presentation of multiple sclerosis (MS) is usually a single episode of typical symptoms and signs and is designated a "first clinical demyelinating event" (FCDE) or a "clinically isolated syndrome". Patients with an FCDE who show 'silent' magnetic resonance imaging lesions are at high risk of further clinical events and therefore of meeting the criteria for the diagnosis of clinically definite MS (CDMS). Here we review five Phase III trials, in which treatment with the following disease-modifying drugs (DMDs) was initiated at this early stage: interferon beta (ETOMS, CHAMPS, BENEFIT, and REFLEX) and glatiramer acetate (PreCISe). Differences in the design of the trials and their patient inclusion criteria limit comparisons. However, the proportion of placebo-treated patients who developed CDMS within 2 years was 38-45% across studies, and this rate was significantly reduced by DMD treatment. Conversion to McDonald MS was reported by only two of the trials: BENEFIT (2001 criteria) and REFLEX (2005 criteria). Around 85% of placebo-treated patients developed McDonald MS by 2 years in each, and again a beneficial effect of DMD treatment was seen. Overall, these studies support early use of DMDs to treat patients with an FCDE who are at high risk of conversion to CDMS.

Metabolomic approach to human brain spectroscopy identifies associations between clinical features and the frontal lobe metabolome in multiple sclerosis

Proton magnetic resonance spectroscopy ((1)H-MRS) is capable of noninvasively detecting metabolic changes that occur in the brain tissue in vivo. Its clinical utility has been limited so far, however, by analytic methods that focus on independently evaluated metabolites and require prior knowledge about which metabolites to examine. Here, we applied advanced computational methodologies from the field of metabolomics, specifically partial least squares discriminant analysis and orthogonal partial least squares, to in vivo (1)H-MRS from frontal lobe white matter of 27 patients with relapsing-remitting multiple sclerosis (RRMS) and 14 healthy controls. We chose RRMS, a chronic demyelinating disorder of the central nervous system, because its complex pathology and variable disease course make the need for reliable biomarkers of disease progression more pressing. We show that in vivo MRS data, when analyzed by multivariate statistical methods, can provide reliable, distinct profiles of MRS-detectable metabolites in different patient populations. Specifically, we find that brain tissue in RRMS patients deviates significantly in its metabolic profile from that of healthy controls, even though it appears normal by standard MRI techniques. We also identify, using statistical means, the metabolic signatures of certain clinical features common in RRMS, such as disability score, cognitive impairments, and response to stress. This approach to human in vivo MRS data should promote understanding of the specific metabolic changes accompanying disease pathogenesis, and could provide biomarkers of disease progression that would be useful in clinical trials.

Viruses and neurodegeneration

Neurodegenerative diseases (NDs) are chronic degenerative diseases of the central nervous system (CNS), which affect 37 million people worldwide. As the lifespan increases, the NDs are the fourth leading cause of death in the developed countries and becoming increasingly prevalent in developing countries. Despite considerable research, the underlying mechanisms remain poorly understood. Although the large majority of studies do not show support for the involvement of pathogenic aetiology in classical NDs, a number of emerging studies show support for possible association of viruses with classical neurodegenerative diseases in humans. Space does not permit for extensive details to be discussed here on non-viral-induced neurodegenerative diseases in humans, as they are well described in literature.Viruses induce alterations and degenerations of neurons both directly and indirectly. Their ability to attack the host immune system, regions of nervous tissue implies that they can interfere with the same pathways involved in classical NDs in humans. Supporting this, many similarities between classical NDs and virus-mediated neurodegeneration (non-classical) have been shown at the anatomic, sub-cellular, genomic and proteomic levels suggesting that viruses can explain neurodegenerative disorders mechanistically. The main objective of this review is to provide readers a detailed snapshot of similarities viral and non-viral neurodegenerative diseases share, so that mechanistic pathways of neurodegeneration in human NDs can be clearly understood. Viruses can guide us to unveil these pathways in human NDs. This will further stimulate the birth of new concepts in the biological research, which is needed for gaining deeper insights into the treatment of human NDs and delineate mechanisms underlying neurodegeneration.

Optical Coherence Tomography in Patients with Relapsing-Remitting Multiple Sclerosis without Optic Neuritis: A 20-Month Longitudinal Study

Optical coherence tomography is supported and used as a technique for visualisation of neuro-axonal loss in multiple sclerosis, but there are also a few studies expressing the opposite view. The aim of our study was to investigate retinal nerve fibre layer and optic nerve head parameters in patients with multiple sclerosis without a history of prior optic neuritis and symptoms of a new clinical attack during the follow-up for a total of 20-month period. Full ophthalmic evaluation was performed for all of the participants. The baseline retinal nerve fibre layer and macular thicknesses and focal and global loss of macular volume values were significantly lower in the eyes of the patients with multiple sclerosis compared with the healthy controls. No significant change between baseline and follow-up scans were found in all optical coherence tomography parameters in the multiple sclerosis group. Statistical analyses revealed significant retinal nerve fibre layer and macular thickness differences between baseline and second measurements in the controls. No significant difference in percent change between baseline and second measurements was observed between the patient and control groups. We conclude that whereas healthy subjects have an age-related tendency toward a decrease in retinal nerve fibre layer thickness, patients with multiple sclerosis patients are likely to pass through different stages of retinal thinning and thickening due to subclinical optic neuritis and, as a result, we could not detect any statistically significant change between baseline and second measurements in our multiple sclerosis patients.

1H magnetic resonance spectroscopy in multiple sclerosis and related disorders

Proton magnetic resonance spectroscopy ((1)H-MRS) is an unconventional technique that allows noninvasive characterization of metabolic abnormalities in the central nervous system. (1)H-MRS provides important insights into the chemical-pathologic changes that occur in patients with multiple sclerosis (MS). In this review article we present the main brain and spinal cord (1)H-MRS features in MS, their diagnostic value in differentiating pseudotumoral demyelinating lesions from primary brain tumors, and their relationship with clinical variables. Last, some data related to the use of (1)H-MRS in therapeutic trials is presented.

Intense inflammation and nerve damage in early multiple sclerosis subsides at older age: a reflection by cerebrospinal fluid biomarkers

Inflammatory mediators have crucial roles in leukocyte recruitment and subsequent central nervous system (CNS) neuroinflammation. The extent of neuronal injury and axonal loss are associated with the degree of CNS inflammation and determine physical disability in multiple sclerosis (MS). The aim of this study was to explore possible associations between a panel of selected cerebrospinal fluid biomarkers and robust clinical and demographic parameters in a large cohort of patients with MS and controls (n = 1066) using data-driven multivariate analysis. Levels of matrix metalloproteinase 9 (MMP9), chemokine (C-X-C motif) ligand 13 (CXCL13), osteopontin (OPN) and neurofilament-light chain (NFL) were measured by ELISA in 548 subjects comprising different MS subtypes (relapsing-remitting, secondary progressive and primary progressive), clinically isolated syndrome and persons with other neurological diseases with or without signs of inflammation/infection. Principal component analyses and orthogonal partial least squares methods were used for unsupervised and supervised interrogation of the data. Models were validated using data from a further 518 subjects in which one or more of the four selected markers were measured. There was a significant association between increased patient age and lower levels of CXCL13, MMP9 and NFL. CXCL13 levels correlated well with MMP9 in the younger age groups, but less so in older patients, and after approximately 54 years of age the levels of CXCL13 and MMP9 were consistently low. CXCL13 and MMP9 levels also correlated well with both NFL and OPN in younger patients. We demonstrate a strong effect of age on both inflammatory and neurodegenerative biomarkers in a large cohort of MS patients. The findings support an early use of adequate immunomodulatory disease modifying drugs, especially in younger patients, and may provide a biological explanation for the relative inefficacy of such treatments in older patients at later disease stages.

Neuroprotection with glatiramer acetate: evidence from the PreCISe trial

The phase III, multicenter, randomized, placebo-controlled PreCISe trial assessed glatiramer acetate (GA) effects in patients with clinically isolated syndromes (CIS) suggestive of multiple sclerosis (MS). To assess the neuroprotective effect of GA in a subset of patients in the PreCISe trial, we used proton magnetic resonance spectroscopy (MRS) to measure N-acetylaspartate (NAA), a marker of neuronal integrity, in a large central volume of brain. Thirty-four CIS patients randomized to GA 20 mg/day (n = 19) SC or placebo (n = 15) were included. Patients who relapsed (developed clinically definite MS [CDMS]) were removed from the substudy. NAA/creatine (NAA/Cr) ratios were compared between GA-treated and placebo-treated patients. Twenty patients with CIS had not converted to CDMS and were still in the double-blind phase of the trial at 12 months of follow-up. Paired changes in NAA/Cr differed significantly in patients treated with GA (+0.14, n = 11) compared with patients receiving placebo (-0.33, n = 9, p = 0.03) at 12 months, consistent with a neuroprotective effect of GA in vivo. Patients with CIS who received GA showed improvement in brain neuroaxonal integrity, as indicated by increased NAA/Cr, relative to comparable patients treated with placebo, who showed a decline in NAA/Cr consistent with findings from natural history studies.

The effect of daclizumab on brain atrophy in relapsing-remitting multiple sclerosis

Daclizumab is a monoclonal antibody that reduces inflammation in multiple sclerosis (MS). Through a retrospective analysis, our objective was to determine whether daclizumab treatment reduces the rate of brain structure atrophy in comparison to a mixture of other disease-modifying therapies (mainly different interferon β preparations). We analyzed MRI examinations (1332 scans from 70 MS cases) obtained between 2000 and 2011 in a single center and processed with an automated brain segmentation method. We used mixed-effects multivariable linear regression models to determine whether a median of 4.3 years of daclizumab therapy in 26 patients altered rates of brain-volume change, controlling for variations in MRI protocol. The control group consisted of 44 patients not treated with daclizumab. We found that supratentorial brain volume declined by 5.17 ml per year (95% confidence limits: 3.58-6.77) off daclizumab therapy. On daclizumab, the annual rate of volume loss decreased to 3.72 ml (p=0.01). The rate of ventricular enlargement decreased from 1.26 to 0.42 ml per year (p<0.001). Focused analysis suggests that reduction in gray matter atrophy rate most likely underlies these results. In summary, in this retrospective analysis, daclizumab therapy substantially decreased the rate of brain atrophy in relapsing-remitting MS in comparison to other disease-modifying therapies, predominantly interferon β.