Sex Differences under Vitamin D Supplementation in an Animal Model of Progressive Multiple Sclerosis.

A central role for vitamin D (VD) in immune modulation has recently been recognized linking VD insufficiency to autoimmune disorders that commonly exhibit sex-associated differences. Similar to other autoimmune diseases, there is a higher incidence of multiple sclerosis (MS) in women, but a poorer prognosis in men, often characterized by a more rapid progression. Although sex hormones are most likely involved, this phenomenon is still poorly understood. Oxidative stress, modulated by VD serum levels as well as sex hormones, may act as a contributing factor to demyelination and axonal damage in both MS and the corresponding preclinical models. In this study, we analyzed sex-associated differences and VD effects utilizing an animal model that recapitulates histopathological features of the progressive MS phase (PMS). In contrast to relapsing-remitting MS (RRMS), PMS has been poorly investigated in this context. Male (n = 50) and female (n = 46) Dark Agouti rats received either VD (400 IU per week; VD+) or standard rodent food without extra VD (VD-) from weaning onwards. Myelination, microglial activation, apoptotic cell death and neuronal viability were assessed using immunohistochemical markers in brain tissue. Additionally, we also used two different histological markers against oxidized lipids along with colorimetric methods to measure protective polyphenols (PP) and total antioxidative capacity (TAC) in serum. Neurofilament light chain serum levels (sNfL) were analyzed using single-molecule array (SIMOA) analysis. We found significant differences between female and male animals. Female rats exhibited a better TAC and higher amounts of PP. Additionally, females showed higher myelin preservation, lower microglial activation and better neuronal survival while showing more apoptotic cells than male rats. We even found a delay in reaching the peak of the disease in females. Overall, both sexes benefitted from VD supplementation, represented by significantly less cortical, neuroaxonal and oxidative damage. Unexpectedly, male rats had an even higher overall benefit, most likely due to differences in oxidative capacity and defense systems.

Vitamin D-An Effective Antioxidant in an Animal Model of Progressive Multiple Sclerosis.

Vitamin D (VD) is the most discussed antioxidant supplement for multiple sclerosis (MS) patients and many studies suggest correlations between a low VD serum level and onset and progression of the disease. While many studies in animals as well as clinical studies focused on the role of VD in the relapsing-remitting MS, knowledge is rather sparse for the progressive phase of the disease and the development of cortical pathology. In this study, we used our established rat model of cortical inflammatory demyelination, resembling features seen in late progressive MS, to address the question about whether VD could have positive effects on reducing cortical pathology, oxidative stress, and neurofilament light chain (NfL) serum levels. For this purpose, we used male Dark Agouti (DA) rats, with one group being supplemented with VD (400 IE per week; VD+) from the weaning on at age three weeks; the other group received standard rodent food. The rat brains were assessed using immunohistochemical markers against demyelination, microglial activation, apoptosis, neurons, neurofilament, and reactive astrocytes. To evaluate the effect of VD on oxidative stress and the antioxidant capacity, we used two different oxidized lipid markers (anti- Cu++ and HOCl oxidized LDL antibodies) along with colorimetric methods for protective polyphenols (PP) and total antioxidative capacity (TAC). NfL serum levels of VD+ and VD- animals were analyzed by fourth generation single-molecule array (SIMOA) analysis. We found significant differences between the VD+ and VD- animals both in histopathology as well as in all serum markers. Myelin loss and microglial activation is lower in VD+ animals and the number of apoptotic cells is significantly reduced with a higher neuronal survival. VD+ animals show significantly lower NfL serum levels, a higher TAC, and more PP. Additionally, there is a significant reduction of oxidized lipid markers in animals under VD supplementation. Our data thus show a positive effect of VD on cellular features of cortical pathology in our animal model, presumably due to protection against reactive oxygen species. In this study, VD enhanced remyelination and prevented neuroaxonal and oxidative damage, such as demyelination and neurodegeneration. However, more studies on VD dose relations are required to establish an optimal response while avoiding overdosing.

Effects of actual and imagined music-cued gait training on motor functioning and brain activity in people with multiple sclerosis: protocol of a randomised parallel multicentre trial.

INTRODUCTION: Motor imagery (MI) refers to the mental rehearsal of a physical action without muscular activity. Our previous studies showed that MI combined with rhythmic-auditory cues improved walking, fatigue and quality of life (QoL) in people with multiple sclerosis (pwMS). Largest improvements were seen after music and verbally cued MI. It is unclear whether actual cued gait training achieves similar effects on walking as cued MI in pwMS. Furthermore, in pwMS it is unknown whether any of these interventions leads to changes in brain activation. The purpose of this study is therefore to compare the effects of imagined and actual cued gait training and a combination thereof on walking, brain activation patterns, fatigue, cognitive and emotional functioning in pwMS. METHODS AND ANALYSIS: A prospective double-blind randomised parallel multicentre trial will be conducted in 132 pwMS with mild to moderate disability. Randomised into three groups, participants will receive music, metronome and verbal cueing, plus MI of walking (1), MI combined with actual gait training (2) or actual gait training (3) for 30 min, 4× per week for 4 weeks. Supported by weekly phone calls, participants will practise at home, guided by recorded instructions. Primary endpoints will be walking speed (Timed 25-Foot Walk) and distance (2 min Walk Test). Secondary endpoints will be brain activation patterns, fatigue, QoL, MI ability, anxiety, depression, cognitive functioning, music-induced motivation-to-move, pleasure, arousal and self-efficacy. Data will be collected at baseline, postintervention and 3-month follow-up. MRI reference values will be generated using 15 matched healthy controls. ETHICS AND DISSEMINATION: This study follows the Standard Protocol Items: Recommendations for Interventional Trials-PRO Extension. Ethical approval was received from the Ethics Committees of the Medical Universities of Innsbruck (1347/2020) and Graz (33-056 ex 20/21), Austria. Results will be disseminated via national and international conferences and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: DRKS00023978.

Disability in multiple sclerosis is related to thalamic connectivity and cortical network atrophy.

BACKGROUND: Thalamic atrophy is proposed to be a major predictor of disability progression in multiple sclerosis (MS), while thalamic function remains understudied. OBJECTIVES: To study how thalamic functional connectivity (FC) is related to disability and thalamic or cortical network atrophy in two large MS cohorts. METHODS: Structural and resting-state functional magnetic resonance imaging (fMRI) was obtained in 673 subjects from Amsterdam (MS: N = 332, healthy controls (HC): N = 96) and Graz (MS: N = 180, HC: N = 65) with comparable protocols, including disability measurements in MS (Expanded Disability Status Scale, EDSS). Atrophy was measured for the thalamus and seven well-recognized resting-state networks. Static and dynamic thalamic FC with these networks was correlated with disability. Significant correlates were included in a backward multivariate regression model. RESULTS: Disability was most strongly related (adjusted R2 = 0.57, p < 0.001) to higher age, a progressive phenotype, thalamic atrophy and increased static thalamic FC with the sensorimotor network (SMN). Static thalamus-SMN FC was significantly higher in patients with high disability (EDSS ⩾ 4) and related to network atrophy but not thalamic atrophy or lesion volumes. CONCLUSION: The severity of disability in MS was related to increased static thalamic FC with the SMN. Thalamic FC changes were only related to cortical network atrophy, but not to thalamic atrophy.

Development and evaluation of a manual segmentation protocol for deep grey matter in multiple sclerosis: Towards accelerated semi-automated references.

BACKGROUND: Deep grey matter (dGM) structures, particularly the thalamus, are clinically relevant in multiple sclerosis (MS). However, segmentation of dGM in MS is challenging; labeled MS-specific reference sets are needed for objective evaluation and training of new methods. OBJECTIVES: This study aimed to (i) create a standardized protocol for manual delineations of dGM; (ii) evaluate the reliability of the protocol with multiple raters; and (iii) evaluate the accuracy of a fast-semi-automated segmentation approach (FASTSURF). METHODS: A standardized manual segmentation protocol for caudate nucleus, putamen, and thalamus was created, and applied by three raters on multi-center 3D T1-weighted MRI scans of 23 MS patients and 12 controls. Intra- and inter-rater agreement was assessed through intra-class correlation coefficient (ICC); spatial overlap through Jaccard Index (JI) and generalized conformity index (CIgen). From sparse delineations, FASTSURF reconstructed full segmentations; accuracy was assessed both volumetrically and spatially. RESULTS: All structures showed excellent agreement on expert manual outlines: intra-rater JI > 0.83; inter-rater ICC ≥ 0.76 and CIgen ≥ 0.74. FASTSURF reproduced manual references excellently, with ICC ≥ 0.97 and JI ≥ 0.92. CONCLUSIONS: The manual dGM segmentation protocol showed excellent reproducibility within and between raters. Moreover, combined with FASTSURF a reliable reference set of dGM segmentations can be produced with lower workload.

MRI correlates of cognitive improvement after home-based EEG neurofeedback training in patients with multiple sclerosis: a pilot study.

OBJECTIVE: Neurofeedback training may improve cognitive function in patients with neurological disorders. However, the underlying cerebral mechanisms of such improvements are poorly understood. Therefore, we aimed to investigate MRI correlates of cognitive improvement after EEG-based neurofeedback training in patients with MS (pwMS). METHODS: Fourteen pwMS underwent ten neurofeedback training sessions within 3-4 weeks at home using a tele-rehabilitation system. Half of the pwMS (N = 7, responders) learned to self-regulate sensorimotor rhythm (SMR, 12-15 Hz) by visual feedback and improved cognitively after training, whereas the remainder (non-responders, n = 7) did not. Diffusion-tensor imaging and resting-state fMRI of the brain was performed before and after training. We analyzed fractional anisotropy (FA) and functional connectivity (FC) of the default-mode, sensorimotor (SMN) and salience network (SAL). RESULTS: At baseline, responders and non-responders were comparable regarding sex, age, education, disease duration, physical and cognitive impairment, and MRI parameters. After training, compared to non-responders, responders showed increased FA and FC within the SAL and SMN. Cognitive improvement correlated with increased FC in SAL and a correlation trend with increased FA was observed. CONCLUSIONS: This exploratory study suggests that successful neurofeedback training may not only lead to cognitive improvement, but also to increases in brain microstructure and functional connectivity.

Manual and automated tissue segmentation confirm the impact of thalamus atrophy on cognition in multiple sclerosis: A multicenter study.

BACKGROUND AND RATIONALE: Thalamus atrophy has been linked to cognitive decline in multiple sclerosis (MS) using various segmentation methods. We investigated the consistency of the association between thalamus volume and cognition in MS for two common automated segmentation approaches, as well as fully manual outlining. METHODS: Standardized neuropsychological assessment and 3-Tesla 3D-T1-weighted brain MRI were collected (multi-center) from 57 MS patients and 17 healthy controls. Thalamus segmentations were generated manually and using five automated methods. Agreement between the algorithms and manual outlines was assessed with Bland-Altman plots; linear regression assessed the presence of proportional bias. The effect of segmentation method on the separation of cognitively impaired (CI) and preserved (CP) patients was investigated through Generalized Estimating Equations; associations with cognitive measures were investigated using linear mixed models, for each method and vendor. RESULTS: In smaller thalami, automated methods systematically overestimated volumes compared to manual segmentations [ρ=(-0.42)-(-0.76); p-values < 0.001). All methods significantly distinguished CI from CP MS patients, except manual outlines of the left thalamus (p = 0.23). Poorer global neuropsychological test performance was significantly associated with smaller thalamus volumes bilaterally using all methods. Vendor significantly affected the findings. CONCLUSION: Automated and manual thalamus segmentation consistently demonstrated an association between thalamus atrophy and cognitive impairment in MS. However, a proportional bias in smaller thalami and choice of MRI acquisition system might impact the effect size of these findings.

Cross-sectional and Longitudinal Assessment of Brain Iron Level in Alzheimer Disease Using 3-T MRI.

Background Deep gray matter structures in patients with Alzheimer disease (AD) contain higher brain iron concentrations. However, few studies have included neocortical areas, which are challenging to assess with MRI. Purpose To investigate baseline and change in brain iron levels using MRI at 3 T with R2* relaxation rate mapping in individuals with AD compared with healthy control (HC) participants. Materials and Methods In this prospective study, participants with AD recruited between 2010 and 2016 and age-matched HC participants selected from 2010 to 2014 were evaluated. Of 100 participants with AD, 56 underwent subsequent neuropsychological testing and brain MRI at a mean follow-up of 17 months. All participants underwent 3-T MRI, including R2* mapping corrected for macroscopic B0 field inhomogeneities. Anatomic structures were segmented, and median R2* values were calculated in the neocortex and cortical lobes, basal ganglia (BG), hippocampi, and thalami. Multivariable linear regression analysis was applied to study the difference in R2* levels between groups and the association between longitudinal changes in R2* values and cognition in the AD group. Results A total of 100 participants with AD (mean age, 73 years ± 9 [standard deviation]; 58 women) and 100 age-matched HC participants (mean age, 73 years ± 9; 60 women) were evaluated. Median R2* levels were higher in the AD group than in the HC group in the BG (HC, 29.0 sec-1; AD, 30.2 sec-1; P = .01) and total neocortex (HC, 17.0 sec-1; AD, 17.4 sec-1; P < .001) and regionally in the occipital (HC, 19.6 sec-1; AD, 20.2 sec-1; P = .007) and temporal (HC, 16.4 sec-1; AD, 18.1 sec-1; P < .001) lobes. R2* values in the temporal lobe were associated with longitudinal changes in Consortium to Establish a Registry for Alzheimer's Disease total score (ß = -3.23 score/sec-1, P = .003) in participants with AD independent of longitudinal changes in brain volume. Conclusion Iron concentration in the deep gray matter and neocortical regions was higher in patients with Alzheimer disease than in healthy control participants. Change in iron levels over time in the temporal lobe was associated with cognitive decline in individuals with Alzheimer disease. © RSNA, 2020 Online supplemental material is available for this article.

Self-regulation of brain activity and its effect on cognitive function in patients with multiple sclerosis - First insights from an interventional study using neurofeedback.

OBJECTIVE: To investigate the effects of EEG-based neurofeedback training, in which one can learn to self-regulate one's own brain activity, on cognitive function in patients with multiple sclerosis (pwMS). METHODS: Fourteen pwMS performed ten neurofeedback training sessions within 3-4 weeks at home using a tele-rehabilitation system. The aim of the neurofeedback training was to increase voluntarily the sensorimotor rhythm (SMR, 12-15 Hz) in the EEG over central brain areas by receiving visual real-time feedback thereof. Cognitive function was assessed before and after all neurofeedback training sessions using a comprehensive standardized neuropsychological test battery. RESULTS: Half of the pwMS (N = 7) showed cognitive improvements in long-term memory and executive functions after neurofeedback training. These patients successfully learned to self-regulate their own brain activity by means of neurofeedback training. The other half of pwMS (N = 7) did neither show any cognitive changes when comparing the pre- and post-assessment nor were they able to modulate their own brain activity in the desired direction during neurofeedback training. CONCLUSIONS: Data from this interventional study provide first preliminary evidence that successful self-regulation of one's own brain activity may be associated with cognitive improvements in pwMS. SIGNIFICANCE: These promising results should stimulate further studies. Neurofeedback might be a promising and alternative tool for future cognitive rehabilitation.

Correlates of Executive Functions in Multiple Sclerosis Based on Structural and Functional MR Imaging: Insights from a Multicenter Study.

Purpose To study the concomitant use of structural and functional magnetic resonance (MR) imaging correlates to explain information processing speed (IPS) and executive function (EF) in multiple sclerosis (MS). Materials and Methods Local ethics committee approval was obtained at all sites for this prospective, multicenter study. All subjects provided written informed consent. Twenty-six patients with relapsing-remitting MS and 32 healthy control subjects from four centers underwent structural and functional MR imaging, including a go/no-go task and neuropsychological assessment. Subtests of the Brief Repeatable Battery of Neuropsychological Tests, the Wisconsin Card Sorting Test, and the performance with the functional MR imaging paradigm were used as estimates of IPS and EF. Activation of the thalamus and the inferior frontal gyrus (pars triangularis), thalamic volume, T2 lesion load, and age were used to explain IPS and EF in regression models. Results Compared with control subjects, patients showed increased activation in a frontoparietal network, including both thalami, during the execution of the go/no-go task. Patients had decreased thalamic volume (P < .001). Among tested variables, thalamic volume (ß = 0.606, P = .001), together with thalamic activation (ß = -0.410, P = .022), were the best predictors of IPS and EF and helped explain 52.7% of the variance in IPS and EF. Conclusion This study highlights the potential of the combined use of functional and morphologic parameters to explain IPS and EF in patients with relapsing-remitting MS and confirms the central role of the thalamus as a relay station in executive functioning. (©) RSNA, 2016.

Connectivity-based parcellation of the thalamus in multiple sclerosis and its implications for cognitive impairment: A multicenter study.

In this multicenter study, we performed a tractography-based parcellation of the thalamus and its white matter connections to investigate the relationship between thalamic connectivity abnormalities and cognitive impairment in multiple sclerosis (MS). Dual-echo, morphological and diffusion tensor (DT) magnetic resonance imaging (MRI) scans were collected from 52 relapsing-remitting MS patients and 57 healthy controls from six European centers. Patients underwent an extensive neuropsychological assessment. Thalamic connectivity defined regions (CDRs) were segmented based on their cortical connectivity using diffusion tractography-based parcellation. Between-group differences of CDRs and cortico-thalamic tracts DT MRI indices were assessed. A vertex analysis of thalamic shape was also performed. A random forest analysis was run to identify the best imaging predictor of global cognitive impairment and deficits of specific cognitive domains. Twenty-two (43%) MS patients were cognitively impaired (CI). Compared to cognitively preserved, CI MS patients had increased fractional anisotropy of frontal, motor, postcentral and occipital connected CDRs (0.002

Levodopa changes brain motor network function during ankle movements in Parkinson's disease.

Bradykinesia-the cardinal symptom in Parkinson's disease (PD)-affects both upper and lower limbs. While several functional imaging studies investigated the impact of levodopa on movement-related neural activity in Parkinson's disease during upper limb movements, analogue studies on lower limb movements are rare. We studied 20 patients with PD (mean age 66.8 ± 7.2 years) after at least 12 h drug withdrawal (OFF-state) and a second time approximately 40 min after oral administration of 200 mg levodopa (ON-state) behaviourally and by functional magnetic resonance imaging (fMRI) at 3 T during externally cued active ankle movements of the more affected foot at fixed rate. Results were compared with that obtained in ten healthy controls (HC) to separate pure pharmacological from disease-related levodopa-induced effects and to allow for interaction analyses. Behaviourally, all patients improved by at least 20 % regarding the motor score of the Unified Parkinson's disease rating scale after levodopa-challenge (mean scores OFF-state: 38.4 ± 10.1; ON-state: 25.5 ± 8.1). On fMRI, levodopa application elicited increased activity in subcortical structures (contralateral putamen and thalamus) in the patients. In contrast, no significant levodopa-induced activation changes were found in HC. The interaction between "PD/HC group factor" and "levodopa OFF/ON" did not show significant results. Given the levodopa-induced activation increases in the putamen and thalamus with unilateral ankle movements in patients with PD but not in HC, we speculate that these regions show the most prominent response to levodopa within the cortico-subcortical motor-circuit in the context of nigrostriatal dysfunction.

B vitamins and magnetic resonance imaging-detected ischemic brain lesions in patients with recent transient ischemic attack or stroke: the VITAmins TO Prevent Stroke (VITATOPS) MRI-substudy.

BACKGROUND AND PURPOSE: Elevated concentrations of homocysteine are associated with cerebral small vessel disease (CSVD). B-vitamin supplementation with folate and vitamins B12 and B6 reduces homocysteine concentrations. In a substudy of the VITAmins TO Prevent Stroke (VITATOPS) trial, we assessed the hypothesis that the addition of once-daily supplements of B vitamins would reduce the progression of CSVD-related brain lesions. METHODS: A total of 359 patients with recent stroke or transient ischemic attack, who were randomly allocated to double-blind treatment with placebo or b vitamins, underwent brain MRI at randomization and after 2 years of B-vitamin supplementation. MR images were analyzed blinded to treatment allocation. Outcomes related to the prespecified hypothesis were progression of white matter hyperintensities and incident lacunes. We also explored the effect of B-vitamin supplementation on the incidence of other ischemic abnormalities. RESULTS: After 2 years of treatment with b vitamins or placebo, there was no significant difference in white matter hyperintensities volume change (0.08 vs 0.13 cm3; P=0.419) and incidence of lacunes (8.0% vs 5.9%, P=0.434; odds ratio=1.38). In a subanalysis of patients with MRI evidence of severe CSVD at baseline, b-vitamin supplementation was associated with a significant reduction in white matter hyperintensities volume change (0.3 vs 1.7 cm3; P=0.039). CONCLUSIONS: Daily B-vitamin supplementation for 2 years did not significantly reduce the progression of brain lesions resulting from presumed CSVD in all patients with recent stroke or transient ischemic attack but may do so in the subgroup of patients with recent stroke or transient ischemic attack and severe CSVD. CLINICAL TRIAL REGISTRATION: http://vitatops.highway1.com.au/. Unique identifier: NCT00097669 and ISRCTN74743444.

Brain motor system function in a patient with complete spinal cord injury following extensive brain-computer interface training.

Although several features of brain motor function appear to be preserved even in chronic complete SCI, previous functional MRI (fMRI) studies have also identified significant derangements such as a strongly reduced volume of activation, a poor modulation of function and abnormal activation patterns. It might be speculated that extensive motor imagery training may serve to prevent such abnormalities. We here report on a unique patient with a complete traumatic SCI below C5 who learned to elicit electroencephalographic signals beta-bursts in the midline region upon imagination of foot movements. This enabled him to use a neuroprosthesis and to "walk from thought" in a virtual environment via a brain-computer interface (BCI). We here used fMRI at 3T during imagined hand and foot movements to investigate the effects of motor imagery via persistent BCI training over 8 years on brain motor function and compared these findings to a group of five untrained healthy age-matched volunteers during executed and imagined movements. We observed robust primary sensorimotor cortex (SMC) activity in expected somatotopy in the tetraplegic patient upon movement imagination while such activation was absent in healthy untrained controls. Sensorimotor network activation with motor imagery in the patient (including SMC contralateral to and the cerebellum ipsilateral to the imagined side of movement as well as supplementary motor areas) was very similar to the pattern observed with actual movement in the controls. We interpret our findings as evidence that BCI training as a conduit of motor imagery training may assist in maintaining access to SMC in largely preserved somatopy despite complete deafferentation.