Cross-vendor multiparametric mapping of the human brain using 3D-QALAS: A multicenter and multivendor study

PURPOSE

To evaluate a vendor-agnostic multiparametric mapping scheme based on 3D quantification using an interleaved Look-Locker acquisition sequence with a T2 preparation pulse (3D-QALAS) for whole-brain T1, T2, and proton density (PD) mapping.

METHODS

This prospective, multi-institutional study was conducted between September 2021 and February 2022 using five different 3T systems from four prominent MRI vendors. The accuracy of this technique was evaluated using a standardized MRI system phantom. Intra-scanner repeatability and inter-vendor reproducibility of T1, T2, and PD values were evaluated in 10 healthy volunteers (6 men; mean age ± SD, 28.0 ± 5.6 y) who underwent scan-rescan sessions on each scanner (total scans = 100). To evaluate the feasibility of 3D-QALAS, nine patients with multiple sclerosis (nine women; mean age ± SD, 48.2 ± 11.5 y) underwent imaging examination on two 3T MRI systems from different manufacturers.

RESULTS

Quantitative maps obtained with 3D-QALAS showed high linearity (R2  = 0.998 and 0.998 for T1 and T2, respectively) with respect to reference measurements. The mean intra-scanner coefficients of variation for each scanner and structure ranged from 0.4% to 2.6%. The mean structure-wise test-retest repeatabilities were 1.6%, 1.1%, and 0.7% for T1, T2, and PD, respectively. Overall, high inter-vendor reproducibility was observed for all parameter maps and all structure measurements, including white matter lesions in patients with multiple sclerosis.

CONCLUSION

The vendor-agnostic multiparametric mapping technique 3D-QALAS provided reproducible measurements of T1, T2, and PD for human tissues within a typical physiological range using 3T scanners from four different MRI manufacturers.

The glymphatic system as a potential biomarker and therapeutic target in secondary progressive multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is a refractory immune-mediated inflammatory disease of the central nervous system, and some cases of the major subtype, relapsing-remitting (RR), transition to secondary progressive (SP). However, the detailed pathogenesis, biomarkers, and effective treatment strategies for secondary progressive multiple sclerosis have not been established. The glymphatic system, which is responsible for waste clearance in the brain, is an intriguing avenue for investigation and is primarily studied through diffusion tensor image analysis along the perivascular space (DTI-ALPS). This study aimed to compare DTI-ALPS indices between patients with RRMS and SPMS to uncover potential differences in their pathologies and evaluate the utility of the glymphatic system as a possible biomarker.

METHODS

A cohort of 26 patients with MS (13 RRMS and 13 SPMS) who met specific criteria were enrolled in this prospective study. Magnetic resonance imaging (MRI), including diffusion MRI, 3D T1-weighted imaging, and relaxation time quantification, was conducted. The ALPS index, a measure of glymphatic function, was calculated using diffusion-weighted imaging data. Demographic variables, MRI metrics, and ALPS indices were compared between patients with RRMS and those with SPMS.

RESULTS

The ALPS index was significantly lower in the SPMS group. Patients with SPMS exhibited longer disease duration and higher Expanded Disability Status Scale (EDSS) scores than those with RRMS. Despite these differences, the correlations between the EDSS score, disease duration, and ALPS index were minimal, suggesting that the impact of these clinical variables on ALPS index variations was negligible.

DISCUSSION

Our study revealed the potential microstructural and functional differences between RRMS and SPMS related to glymphatic system impairment. Although disease severity and duration vary among subtypes, their influence on ALPS index differences appears to be limited. This highlights the stronger association between SP conversion and changes in the ALPS index. These findings align with those of previous research, indicating the involvement of the glymphatic system in the progression of MS.

CONCLUSION

Although the causality remains uncertain, our study suggests that a reduced ALPS index, reflecting glymphatic system dysfunction, may contribute to MS progression, particularly in SPMS. This suggests the potential of the ALPS index as a diagnostic biomarker for SPMS and underscores the potential of the glymphatic system as a therapeutic target to mitigate MS progression. Future studies with larger cohorts and pathological validation are necessary to confirm these findings. This study provides new insights into the pathogenesis of SPMS and the potential for innovative therapeutic strategies.

Glymphatic System Dysfunction in Myelin Oligodendrocyte Glycoprotein Immunoglobulin G Antibody-Associated Disorders: Association with Clinical Disability

BACKGROUND AND PURPOSE

Impaired glymphatic function has been suggested to be implicated in the pathophysiology of MS and aquaporin-4 immunoglobulin G-positive neuromyelitis optica spectrum disorder. This study aimed to investigate the interstitial fluid dynamics in the brain in patients with myelin oligodendrocyte glycoprotein antibody disorders (MOGAD), another demyelinating disorder, using a noninvasive imaging technique called the diffusivity along the perivascular space (ALPS) index.

MATERIALS AND METHODS

A prospective study was conducted on 16 patients with MOGAD in remission and 22 age- and sex-matched healthy control subjects. MR imaging was performed using a 3T scanner, and the ALPS index was calculated using diffusion MR imaging data with a b-value of 1000 s/mm2. The ALPS index and gray matter volumes were compared between the 2 groups, and these parameters were correlated with the Expanded Disability Status Scale.

RESULTS

The mean ALPS index of patients with MOGAD was significantly lower than that of healthy controls (Cohen d = 0.93, false discovery rate-corrected P = .02). The lower mean ALPS index was significantly associated with a worse Expanded Disability Status Scale score (Spearman ρ = -0.51; 95% CI, -0.85 to -0.02; P = .03). However, cortical volume and deep gray matter volume were not significantly different between the 2 groups, and they were not correlated with the Expanded Disability Status Scale.

CONCLUSIONS

This study suggests that patients with MOGAD may have impaired glymphatic function, as measured by the ALPS index, which is associated with patient disability. Further study is warranted with a larger sample size.

Sbp2l contributes to oligodendrocyte maturation through translational control in Tcf7l2 signaling

Oligodendrocytes (OLs) are the myelin-forming cells in the CNS that support neurons through the insulating sheath of axons. This unique feature and developmental processes are achieved by extrinsic and intrinsic gene expression programs, where RNA-binding proteins can contribute to dynamic and fine-tuned post-transcriptional regulation. Here, we identified SECIS-binding protein 2-like (Sbp2l), which is specifically expressed in OLs by integrated transcriptomics. Histological analysis revealed that Sbp2l is a molecular marker of OL maturation. Sbp2l knockdown (KD) led to suppression of matured OL markers, but not a typical selenoprotein, Gpx4. Transcriptome analysis demonstrated that Sbp2l KD decreased cholesterol-biosynthesis-related genes regulated by Tcf7l2 transcription factor. Indeed, we confirmed the downregulation of Tcf7l2 protein without changing its mRNA in Sbp2l KD OPCs. Furthermore, Sbp2l KO mice showed the decrease of Tcf7l2 protein and deficiency of OL maturation. These results suggest that Sbp2l contributes to OL maturation by translational control of Tcf7l2.

Two Elderly Men with Myasthenia Gravis during Androgen Deprivation Therapy for Prostate Cancer

Myasthenia gravis (MG) development is female-dominant in younger patients and male-dominant in older patients. The reason for the sex-ratio inversion in elderly MG patients remains unclear. One possible explanation is the decrease in androgen secretion that occurs with aging, as androgen has an immunosuppressive function. We experienced two elderly men who developed MG after initiating androgen deprivation therapy (ADT) for treatment of prostate cancer and whose symptoms were ameliorated after ADT cessation. Our cases indicate that MG in older male patients can be caused by an androgen effect.

Comparing clinical and imaging features of patients with MOG antibody-positivity and with and without oligoclonal bands

Introduction

Myelin-oligodendrocyte glycoprotein antibody (MOG)-associated disorder (MOGAD) is a recently identified immune-mediated inflammatory disorder of the central nervous system (CNS). The significance of oligoclonal bands (OCBs) is not fully elucidated. This study investigated the clinical differences between patients with MOGAD who tested positive or negative for OCBs.

Methods

The study was conducted on 23 patients with MOG-IgG-seropositivity who presented with central nervous system (CNS) symptoms. The patients were screened and divided into OCB-positive (n=10) and OCB-negative (n=13) groups, and their demographic, clinical, and magnetic resonance imaging (MRI) features were compared.

Results

The results revealed that patients with OCB-positivity had a significantly higher frequency of relapse, and their IgG index was significantly higher.

Discussion

OCBs were common in MOGAD met the consensus criteria. The study concluded that careful treatment decision-making is necessary in MOG antibody-positive cases with OCB-positivity.

Mycobacterium avium subsp. paratuberculosis Antigens Elicit a Strong IgG4 Response in Patients with Multiple Sclerosis and Exacerbate Experimental Autoimmune Encephalomyelitis

Neuroinflammation can be triggered by microbial products disrupting immune regulation. In this study, we investigated the levels of IgG1, IgG2, IgG3, and IgG4 subclasses against the heat shock protein (HSP)70_533-545 peptide and lipopentapeptide (MAP_Lp5) derived from Mycobacterium avium subsp. paratuberculosis (MAP) in the blood samples of Japanese and Italian individuals with relapsing remitting multiple sclerosis (MS). Additionally, we examined the impact of this peptide on MOG-induced experimental autoimmune encephalomyelitis (EAE). A total of 130 Japanese and 130 Italian subjects were retrospectively analyzed using the indirect ELISA method. Furthermore, a group of C57BL/6J mice received immunization with the MAP_HSP70_533-545 peptide two weeks prior to the active induction of MOG_35-55 EAE. The results revealed a significantly robust antibody response against MAP_HSP70_533-545 in serum of both Japanese and Italian MS patients compared to their respective control groups. Moreover, heightened levels of serum IgG4 antibodies specific to MAP antigens were correlated with the severity of the disease. Additionally, EAE mice that were immunized with MAP_HSP70_533-545 peptide exhibited more severe disease symptoms and increased reactivity of MOG_35-55-specific T-cell compared to untreated mice. These findings provide evidence suggesting a potential link between MAP and the development or exacerbation of MS, particularly in a subgroup of MS patients with elevated serum IgG4 levels.

Metric fixed point theory and partial impredicativity

We show that the Priess-Crampe & Ribenboim fixed point theorem is provable in [Formula: see text]. Furthermore, we show that Caristi's fixed point theorem for both Baire and Borel functions is equivalent to the transfinite leftmost path principle, which falls strictly between [Formula: see text] and [Formula: see text]. We also exhibit several weakenings of Caristi's theorem that are equivalent to [Formula: see text] and to [Formula: see text]. This article is part of the theme issue 'Modern perspectives in Proof Theory'.

Adjuvant Activity of Mycobacterium paratuberculosis in Enhancing the Immunogenicity of Autoantigens During Experimental Autoimmune Encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE) induced by myelin oligodendrocyte glycoprotein (MOG) requires immunization by a MOG peptide emulsified in complete Freund's adjuvant (CFA) containing inactivated Mycobacterium tuberculosis. The antigenic components of the mycobacterium activate dendritic cells to stimulate T-cells to produce cytokines that promote the Th1 response via toll-like receptors. Therefore, the amount and species of mycobacteria present during the antigenic challenge are directly related to the development of EAE. This methods paper presents an alternative protocol to induce EAE in C57BL/6 mice using a modified incomplete Freund's adjuvant containing the heat-killed Mycobacterium avium subspecies paratuberculosis strain K-10. M. paratuberculosis, a member of the Mycobacterium avium complex, is the causative agent of Johne's disease in ruminants and has been identified as a risk factor for several human T-cell-mediated disorders, including multiple sclerosis. Overall, mice immunized with Mycobacterium paratuberculosis showed earlier onset and greater disease severity than mice immunized with CFA containing the strain of M. tuberculosis H37Ra at the same doses of 4 mg/mL. The antigenic determinants of Mycobacterium avium subspecies paratuberculosis (MAP) strain K-10 were able to induce a strong Th1 cellular response during the effector phase, characterized by significantly higher numbers of T-lymphocytes (CD4⁺ CD27⁺), dendritic cells (CD11c⁺ I-A/I-E⁺), and monocytes (CD11b⁺ CD115⁺) in the spleen compared to mice immunized with CFA. Furthermore, the proliferative T-cell response to the MOG peptide appeared to be highest in M. paratuberculosis-immunized mice. The use of an encephalitogen (e.g., MOG35-55) emulsified in an adjuvant containing M. paratuberculosis in the formulation may be an alternative and validated method to activate dendritic cells for priming myelin epitope-specific CD4⁺ T-cells during the induction phase of EAE.

Bacillus Calmette-Guérin Tokyo-172 vaccine provides age-related neuroprotection in actively induced and spontaneous experimental autoimmune encephalomyelitis models

Multiple sclerosis is the most common immune-mediated disorder affecting the central nervous system in young adults but still has no cure. Bacillus Calmette-Guérin (BCG) vaccine is reported to have non-specific anti-inflammatory effects and therapeutic benefits in autoimmune disorders including multiple sclerosis. However, the precise mechanism of action of BCG and the host immune response to it remain unclear. In this study, we aimed to investigate the efficacy of the BCG Tokyo-172 vaccine in suppressing experimental autoimmune encephalomyelitis (EAE). Groups of young and mature adult female C57BL/6J mice were BCG-vaccinated 1 month prior or 6 days after active EAE induction using myelin oligodendrocyte glycoprotein (MOG)35-55 peptide. Another group of 2D2 TCRMOG transgenic female mice was BCG-vaccinated before and after the onset of spontaneous EAE. BCG had an age-associated protective effect against active EAE only in wild-type mice vaccinated 1 month before EAE induction. Furthermore, the incidence of spontaneous EAE was significantly lower in BCG vaccinated 2D2 mice than in non-vaccinated controls. Protection against EAE was associated with reduced splenic T-cell proliferation in response to MOG35-55 peptide together with high frequency of CD8+ interleukin-10-secreting T cells in the spleen. In addition, microglia and astrocytes isolated from BCG-vaccinated mice showed polarization to anti-inflammatory M2 and A2 phenotypes, respectively. Our data provide new insights into the cell-mediated and humoral immune mechanisms underlying BCG vaccine-induced neuroprotection, potentially useful for developing better strategies for the treatment of MS.

Age related immune modulation of experimental autoimmune encephalomyelitis in PINK1 knockout mice

OBJECTIVE

Recent research has shown that Parkin, an E3 ubiquitin ligase, modulates peripheral immune cells-mediated immunity during experimental autoimmune encephalomyelitis (EAE). Because the PTEN-induced putative kinase 1 (PINK1) protein acts upstream of Parkin in a common mitochondrial quality control pathway, we hypothesized that the systemic deletion of PINK1 could also modify the clinical course of EAE, altering the peripheral and central nervous systems' immune responses.

METHODS

EAE was induced in female PINK1^-/- mice of different age groups by immunization with myelin oligodendrocyte glycoprotein peptide.

RESULTS

Compared to young wild-type controls, PINK1^-/- mice showed earlier disease onset, albeit with a slightly less severe disease, while adult PINK1^-/- mice displayed early onset and more severe acute symptoms than controls, showing persistent disease during the recovery phase. In adult mice, EAE severity was associated with significant increases in frequency of dendritic cells (CD11C⁺, IAIE⁺), lymphocytes (CD8⁺), neutrophils (Ly6G⁺, CD11b⁺), and a dysregulated cytokine profile in spleen. Furthermore, a massive macrophage (CD68⁺) infiltration and microglia (TMEM119⁺) and astrocyte (GFAP⁺) activation were detected in the spinal cord of adult PINK1^-/- mice.

CONCLUSIONS

PINK1 plays an age-related role in modulating the peripheral inflammatory response during EAE, potentially contributing to the pathogenesis of neuroinflammatory and other associated conditions.

Molecular brain (micro report) oxytocin ameliorates impaired social behavior in a mouse model of 3q29 deletion syndrome

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by specific social symptoms, restricted interests, stereotyped repetitive behaviors, and delayed language development. The 3q29 microdeletion (3q29del), a recurrent copy number variant, confers a high risk for ASD and schizophrenia, and serves as an important pathological model for investigating the molecular pathogenesis of a large number of neurodevelopmental and psychiatric conditions. Recently, mouse models carrying a deletion of the chromosomal region corresponding to the human 3q29 region (Df/+ mice) were generated and demonstrated neurodevelopmental and psychiatric conditions associated behavioral abnormalities, pointing to the relevance of Df/+ mice as a model for these conditions with high construct and face validity. Currently, the molecular pathogenesis of these behavioral phenotypes in Df/+ mice remains unclear. The oxytocin (OXT) system plays a central role in social behavior across species and has a potential role in ASD. In this study, to elucidate the molecular mechanisms behind impaired social behavior in Df/+ mice, we investigated the possible involvement of OXT signaling in impaired social behavior in Df/+ mice. We demonstrated that OXT administration restored the impaired social behavior in Df/+ mice. We also demonstrated that the number of OXT-positive cells in the paraventricular nucleus (PVN) was significantly lower in Df/+ mice than in wild-type (WT) littermates. Consistent with this, the level of OXT peptide in the cerebral cortex of Df/+ mice was lower than in WT littermates. Our study may provide important insights into the molecular pathophysiological basis of neurodevelopmental and psychiatric conditions, including ASD.

Multimodal magnetic resonance imaging quantification of gray matter alterations in relapsing-remitting multiple sclerosis and neuromyelitis optica spectrum disorder

Herein, we combined neurite orientation dispersion and density imaging (NODDI) and synthetic magnetic resonance imaging (SyMRI) to evaluate the spatial distribution and extent of gray matter (GM) microstructural alterations in patients with relapsing-remitting multiple sclerosis (RRMS) and neuromyelitis optica spectrum disorder (NMOSD). The NODDI (neurite density index [NDI], orientation dispersion index [ODI], and isotropic volume fraction [ISOVF]) and SyMRI (myelin volume fraction [MVF]) measures were compared between age- and sex-matched groups of 30 patients with RRMS (6 males and 24 females; mean age, 51.43 ± 8.02 years), 18 patients with anti-aquaporin-4 antibody-positive NMOSD (2 males and 16 females; mean age, 52.67 ± 16.07 years), and 19 healthy controls (6 males and 13 females; mean age, 51.47 ± 9.25 years) using GM-based spatial statistical analysis. Patients with RRMS showed reduced NDI and MVF and increased ODI and ISOVF, predominantly in the limbic and paralimbic regions, when compared with healthy controls, while only increases in ODI and ISOVF were observed when compared with NMOSD. Compared to NDI and MVF, the changes in ODI and ISOVF were observed more widely, including in the cerebellar cortex. These abnormalities were associated with disease progression and disability. In contrast, patients with NMOSD only showed reduced NDI mainly in the cerebellar, limbic, and paralimbic cortices when compared with healthy controls and patients with RRMS. Taken together, our study supports the notion that GM pathologies in RRMS are distinct from those of NMOSD. However, owing to the limitations of the study, the results should be cautiously interpreted.

Dysregulated B cell differentiation towards antibody-secreting cells in neuromyelitis optica spectrum disorder

Background

Anti-aquaporin 4 (AQP4) antibody (AQP4-Ab) is involved in the pathogenesis of neuromyelitis optica spectrum disorder (NMOSD). However, the mechanism involved in AQP4-Ab production remains unclear.

Methods

We analyzed the immunophenotypes of patients with NMOSD and other neuroinflammatory diseases as well as healthy controls (HC) using flow cytometry. Transcriptome analysis of B cell subsets obtained from NMOSD patients and HCs was performed. The differentiation capacity of B cell subsets into antibody-secreting cells was analyzed.

Results

The frequencies of switched memory B (SMB) cells and plasmablasts were increased and that of naïve B cells was decreased in NMOSD patients compared with relapsing–remitting multiple sclerosis patients and HC. SMB cells from NMOSD patients had an enhanced potential to differentiate into antibody-secreting cells when cocultured with T peripheral helper cells. Transcriptome analysis revealed that the profiles of B cell lineage transcription factors in NMOSD were skewed towards antibody-secreting cells and that IL-2 signaling was upregulated, particularly in naïve B cells. Naïve B cells expressing CD25, a receptor of IL-2, were increased in NMOSD patients and had a higher potential to differentiate into antibody-secreting cells, suggesting CD25⁺ naïve B cells are committed to differentiate into antibody-secreting cells.

Conclusions

To the best of our knowledge, this is the first study to demonstrate that B cells in NMOSD patients are abnormally skewed towards antibody-secreting cells at the transcriptome level during the early differentiation phase, and that IL-2 might participate in this pathogenic process. Our study indicates that CD25⁺ naïve B cells are a novel candidate precursor of antibody-secreting cells in autoimmune diseases.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-021-02375-w.

Efficacy of BCG vaccine in animal models of neurological disorders

The Bacillus Calmette-Guerin (BCG) vaccine can modulate the immune response via antigen-specific immune response, but also it can confer nonspecific protection and therapeutic benefits in several neurological conditions through different heterologous effects of vaccination. However, the precise mechanism of action of BCG remains unclear. In this review, different mechanisms underlying BCG-mediated immunity will be explained in animal models that reflects characteristic feature of neuroinflammatory and neurodegenerative disorders such as multiple sclerosis, Alzheimer's and Parkinson's diseases. Furthermore, evidence for a beneficial effect of the BCG on neuropsychiatric disorders, will be also discussed.

Elevated mycobacterium avium subsp. paratuberculosis (MAP) antibody titer in Japanese multiple sclerosis

To investigate whether antibody production against mycobacterium avium subsp. paratuberculosis (MAP) is related to clinical characteristics of multiple sclerosis (MS) and human leukocyte antigen (HLA) alleles, IgG antibody against three MAP peptides and two human peptides homologous to MAP were measured in sera from 103 MS patients and 50 healthy controls (HCs). MS patients had higher IgG levels against MAP2694_295-303 (MAP2694-IgG) than HCs, while the other antibodies were comparable. Multivariate analysis demonstrated that higher MAP2694-IgG titers were associated with higher EDSS scores, but not with HLA alleles or dairy product consumption. Immune response against MAP may worsen MS disability.

Electron-phonon superconductivity in C-doped topological nodal-line semimetal Zr5Pt3: a muon spin rotation and relaxation (μSR) study

In the present work, we demonstrate that C-doped Zr₅Pt₃is an electron-phonon superconductor (with critical temperatureT_C= 3.8 K) with a nonsymmorphic topological Dirac nodal-line semimetal state, which we report here for the first time. The superconducting properties of Zr₅Pt₃C_0.5have been investigated by means of magnetization, resistivity, specific heat, and muon spin rotation and relaxation (μSR) measurements. We find that at low temperatures, the depolarization rate is almost constant and it can be well described by a single-bands-wave model with a superconducting gap of 2Δ(0)/k_BT_C= 3.84, somewhat higher than the value of BCS theory. From the transverse field μSR analysis, we estimate the London penetration depthλ_L= 469 nm, superconducting carrier densityn_s= 1.83 × 10²⁶ m^-3, and effective massm* = 1.428m_e. The zero field μSR confirms the absence of any spontaneous magnetic field in the superconducting ground state. In order to gain additional insights into the electronic ground state of C-doped Zr₅Pt₃, we also performed first-principles calculations within the framework of density functional theory (DFT). The observed homogenous electronic character of the Fermi surface as well as the mutual decrease ofT_Cand density of states at the Fermi level are consistent with the experimental findings of this study. However, the band structure reveals the presence of robust, gapless fourfold-degenerate nodal lines protected by 6₃screw rotations and glide mirror planes. Therefore, Zr₅Pt₃represents a novel, unprecedented condensed matter system to investigate the intricate interplay between superconductivity and topology.

PARKIN modifies peripheral immune response and increases neuroinflammation in active experimental autoimmune encephalomyelitis (EAE)

Neuroinflammation plays an important role in the pathogenesis of several neurodegenerative disorders. To elucidate the effects of the mitophagy-related gene Parkin on neuroinflammation, we used a mouse model of experimental autoimmune encephalomyelitis (EAE). Female Parkin^-/- and female wild type control mice were immunized with myelin oligodendrocyte glycoprotein to develop active EAE. Compared to the wild type controls, the Parkin^-/- mice showed an earlier onset and greater severity of EAE with a greatly increased number of CD8αβ⁺TCRαβ⁺ T cells in the spleen and brain as well as a stronger T-cell proliferative response and an altered cytokine secretion in splenocytes. Furthermore, the Parkin^-/- mice showed massive recruitment of monocytes/macrophages and activated microglia in the spinal cord during the acute phase of the disease. They also showed accumulation of microglia co-expressing M1 and M2 markers in the brain and a strong over-expression of A1 reactive astrocytes in the spinal cord. Furthermore, the Parkin^-/- mice that developed persistent disease exhibited reduced glial cell numbers and abnormalities in mitochondrial morphology. Our study sheds light on the role of PARKIN protein in modulating peripheral immune cells-mediated immunity during EAE, highlighting its importance in neuroinflammation, and thus elucidating its potential in the development of novel neuroprotective therapies.

Potential of PINK1 and PARKIN Proteins as Biomarkers for Active Multiple Sclerosis: A Japanese Cohort Study

Background

Mitochondrial dysfunction has been suggested to play an important role in all stages of multiple sclerosis (MS).

Objective

To determine the expression of two mitophagy-related proteins, PTEN-induced kinase 1 (PINK1) and PARKIN, in a cohort of Japanese patients with different neuroinflammatory disorders.

Methods

Protein concentrations were measured using commercial ELISA in paired cerebrospinal fluid (CSF) and serum samples from patients with multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD), and myelin oligodendrocyte glycoprotein antibody disorders (MOGAD), and from age- and sex-matched controls.

Results

CSF and serum concentrations of PINK1 were higher in patients with MS than in patients with NMOSD (p = 0.004 and p < 0.001, respectively), MOGAD (p = 0.008 and p = 0.011, respectively), and controls (p = 0.021 and p = 0.002, respectively). CSF and concentrations of PARKIN were elevated in patients with MS in comparison with those in controls (p = 0.016 and p = 0.05, respectively).

Conclusions

Our study highlighted the importance of mitophagy in MS and suggested the potential application of PINK1 and PARKIN as biomarkers to predict disease activity.

Multiple sclerosis plaques may undergo continuous myelin degradation: a cross-sectional study with myelin and axon-related quantitative magnetic resonance imaging metrics

PURPOSE

We hypothesize that myelin is more susceptible to damage over time than axons. We investigated the association between the estimated duration from the onset of multiple sclerosis (MS) plaques and myelin- and axon-related quantitative synthetic magnetic resonance imaging (SyMRI) and neurite orientation dispersion and density imaging (NODDI) metrics.

METHODS

We analyzed 31 patients with MS with 73 newly appeared plaques. Simple linear regression analysis was performed to assess the association between the estimated duration from the onset of plaques and quantitative MRI metrics. These metrics included the myelin volume fraction (MVF), axon volume fraction, and g-ratio in plaque and normal-appearing white matter.

RESULTS

MS plaques with a longer estimated duration from onset were significantly correlated with a lower MVF (slope =  - 0.0070, R² = 0.0970), higher g-ratio (slope = 0.0078, R² = 0.0842) (all P values < 0.05).

CONCLUSION

These results suggested that myelin in plaques undergoes continuous damage, more so than axons. Myelin imaging with SyMRI and NODDI may be useful for the quantitative assessment of temporal changes in MS plaques.

Accelerated Isotropic Multiparametric Imaging by High Spatial Resolution 3D-QALAS With Compressed Sensing: A Phantom, Volunteer, and Patient Study

OBJECTIVES

The aims of this study were to develop an accelerated multiparametric magnetic resonance imaging method based on 3D-quantification using an interleaved Look-Locker acquisition sequence with a T2 preparation pulse (3D-QALAS) combined with compressed sensing (CS) and to evaluate the effect of CS on the quantitative mapping, tissue segmentation, and quality of synthetic images.

MATERIALS AND METHODS

A magnetic resonance imaging system phantom, containing multiple compartments with standardized T1, T2, and proton density (PD) values; 10 healthy volunteers; and 12 patients with multiple sclerosis were scanned using the 3D-QALAS sequence with and without CS and conventional contrast-weighted imaging. The scan times of 3D-QALAS with and without CS were 5:56 and 11:11, respectively. For healthy volunteers, brain volumetry and myelin estimation were performed based on the measured T1, T2, and PD. For patients with multiple sclerosis, the mean T1, T2, PD, and the amount of myelin in plaques and contralateral normal-appearing white matter (NAWM) were measured. Simple linear regression analysis and Bland-Altman analysis were performed for each metric obtained from the datasets with and without CS. To compare overall image quality and structural delineations on synthetic and conventional contrast-weighted images, case-control randomized reading sessions were performed by 2 neuroradiologists in a blinded manner.

RESULTS

The linearity of both phantom and volunteer measurements in T1, T2, and PD values obtained with and without CS was very strong (R2 = 0.9901-1.000). The tissue segmentation obtained with and without CS also had high linearity (R2 = 0.987-0.999). The quantitative tissue values of the plaques and NAWM obtained with CS showed high linearity with those without CS (R2 = 0.967-1.000). There were no significant differences in overall image quality between synthetic contrast-weighted images obtained with and without CS (P = 0.17-0.99).

CONCLUSIONS

Multiparametric imaging of the whole brain based on 3D-QALAS can be accelerated using CS while preserving tissue quantitative values, tissue segmentation, and quality of synthetic images.

[Burnout in Japanese neurologists: comparison of male and female physicians]

A questionnaire survey was conducted on 8,402 members of the Japanese Neurological Society to examine the current status and countermeasures for physician burnout, and 1,261 respondents (15.0%) responded. In this paper, we report the results of a comparison between male and female physicians. There was a significant difference in working and living conditions only for married people. It was confirmed that men work under stricter conditions in terms of working hours, and that the burden on women is heavier in the division of housework. Analysis using the Japanese Burnout Scale revealed no gender differences in overall scores, but as for factors related to burnout, in addition to factors common to both men and women, factors specific to men or women were clarified.

Differentiation between multiple sclerosis and neuromyelitis optica spectrum disorders by multiparametric quantitative MRI using convolutional neural network

Multiple sclerosis and neuromyelitis optica spectrum disorders are both neuroinflammatory diseases and have overlapping clinical manifestations. We developed a convolutional neural network model that differentiates between the two based on magnetic resonance imaging data. Thirty-five patients with relapsing-remitting multiple sclerosis and eighteen age-, sex-, disease duration-, and Expanded Disease Status Scale-matched patients with anti-aquaporin-4 antibody-positive neuromyelitis optica spectrum disorders were included in this study. All patients were scanned on a 3-T scanner using a multi-dynamic multi-echo sequence that simultaneously measures R1 and R2 relaxation rates and proton density. R1, R2, and proton density maps were analyzed using our convolutional neural network model. To avoid overfitting on a small dataset, we aimed to separate features of images into those specific to an image and those common to the group, based on SqueezeNet. We used only common features for classification. Leave-one-out cross validation was performed to evaluate the performance of the model. The area under the receiver operating characteristic curve of the developed convolutional neural network model for differentiating between the two disorders was 0.859. The sensitivity to multiple sclerosis and neuromyelitis optica spectrum disorders, and accuracy were 80.0%, 83.3%, and 81.1%, respectively. In conclusion, we developed a convolutional neural network model that differentiates between multiple sclerosis and neuromyelitis optica spectrum disorders, and which is designed to avoid overfitting on small training datasets. Our proposed algorithm may facilitate a differential diagnosis of these diseases in clinical practice.

Distinctive regional asymmetry in dopaminergic and serotoninergic dysfunction in degenerative Parkinsonisms

PURPOSE

This study aimed to identify regional asymmetry in dopaminergic and serotoninergic dysfunction in degenerative parkinsonisms, using dopamine transporter single-photon emission computed tomography images.

MATERIAL AND METHODS

This study included 213 consecutive participants (Parkinson's disease [n = 111], dementia with Lewy bodies [n = 64], progressive supranuclear palsy with Richardson's syndrome [n = 18], and healthy participants [n = 20]) who underwent both magnetic resonance imaging and ¹²³I-labelled 2β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl) nortropane single-photon emission computed tomography/computed tomography. Using normalized specific binding ratio images, we created voxel-wise regional asymmetry index images to identify the regional specific pattern of regional asymmetries in degenerative parkinsonisms.

RESULTS

Compared with healthy controls, patients with Parkinson's disease showed a regional asymmetry index increase in the nigrostriatal dopaminergic pathway, and those with dementia with Lewy bodies showed a regional asymmetry index increase confined to the bilateral caudate. Individuals with progressive supranuclear palsy exhibited a distinct regional asymmetry index increase in the pallido-subthalamic pathway. Notably, the regional asymmetry index increase in the subthalamic nucleus was significantly greater in progressive supranuclear palsy than in Parkinson's disease.

CONCLUSION

The current study revealed distinctive regional asymmetry in dopaminergic and serotoninergic dysfunction in degenerative parkinsonisms. The present findings highlight the potential application of visual diagnosis in degenerative parkinsonisms.

[Current and future strategies for burnout in Japanese neurologists]

To identify factors associated with burnout among Japanese physician and to use them in future measures, the Japanese Society of Neurology conducted a survey of neurologists on burnout using a web-based questionnaire in October 2019. A total of 1,261 respondents, 15.0% of the 8,402 members, responded to the survey. The mean of the subscales of the Japanese Burnout Scale was 2.86/5 points for emotional exhaustion, 2.21/5 points for depersonalization, and 3.17/5 points for lack of personal accomplishment. In addition, the burnout of our country's neurologists is not related to workloads such as working hours and the number of patients in charge, but also to a decreased meaningfulness and professional accomplishment. Therefore, it is necessary to take comprehensive measures to improve these issues at the individual, hospital, academic and national levels.

A mucosal immune response induced by oral administration of heat-killed Mycobacterium avium subsp. paratuberculosis exacerbates EAE

Findings in humans and animals have demonstrated a potential role for Mycobacterium avium subsp. paratuberculosis (MAP) antigenic components in encephalitogenic T cell activation. Here we reported that oral administration of MAP activates the mucosal immunity and exacerbates active experimental autoimmune encephalomyelitis (EAE) in C57BL/6J mice, modulating the immune cell traffic from secondary lymphoid organs to central nervous system. The detection of antigenic mycobacterial components by intestinal antigen-presenting cells may modulate the immune system and the subsequent inflammatory status through various signaling mechanisms, including the synthesis of pro-inflammatory cytokines involved in EAE pathogenesis.

3D Quantitative Synthetic MRI in the Evaluation of Multiple Sclerosis Lesions

BACKGROUND AND PURPOSE

Synthetic MR imaging creates multiple contrast-weighted images based on a single time-efficient quantitative scan, which has been mostly performed for 2D acquisition. We assessed the utility of 3D synthetic MR imaging in patients with MS by comparing its diagnostic image quality and lesion volumetry with conventional MR imaging.

MATERIALS AND METHODS

Twenty-four patients with MS prospectively underwent 3D quantitative synthetic MR imaging and conventional T1-weighted, T2-weighted, FLAIR, and double inversion recovery imaging, with acquisition times of 9 minutes 3 seconds and 18 minutes 27 seconds for the synthetic MR imaging and conventional MR imaging sequences, respectively. Synthetic phase-sensitive inversion recovery images and those corresponding to conventional MR imaging contrasts were created for synthetic MR imaging. Two neuroradiologists independently assessed the image quality on a 5-point Likert scale. The numbers of cortical lesions and lesion volumes were quantified using both synthetic and conventional image sets.

RESULTS

The overall diagnostic image quality of synthetic T1WI and double inversion recovery images was noninferior to that of conventional images (P = .23 and .20, respectively), whereas that of synthetic T2WI and FLAIR was inferior to that of conventional images (both Ps < .001). There were no significant differences in the number of cortical lesions (P = .17 and .53 for each rater) or segmented lesion volumes (P = .61) between the synthetic and conventional image sets.

CONCLUSIONS

Three-dimensional synthetic MR imaging could serve as an alternative to conventional MR imaging in evaluating MS with a reduced scan time.

Improvement in the Symptoms and VEGF Levels after Resection of an Extrame Dullary Spinal Tumor and Additional Chemotherapy in a Patient with Multiple Myeloma Complicated with POEMS Syndrome

We herein report a case of multiple myeloma and polyneuropathy, organomegaly, endocrinopathy, myeloma protein, and skin changes (POEMS) syndrome. The patient experienced exacerbated gait disturbance due to weakness and numbness in the lower limbs. Thoracic magnetic resonance imaging revealed an extramedullary tumor with spinal compression that required surgical resection. Plasmacytoma was diagnosed based on a biopsy. Radiation, betamethasone, and chemotherapy were therefore administered. Surgical removal of extramedullary tumors improved his symptoms, motor conduction velocity, and amplitude of the muscle action potential in the peroneal and tibial nerves, as shown by the nerve conduction study. Surgery also decreased the serum vascular endothelial growth factor levels. The patient required additional chemotherapy due to multiple myeloma and showed better outcomes nine months after discharge. The benefits of some treatments remain controversial due to the small number of patients. However, our findings reveal that an early diagnosis and comprehensive treatment may result in better outcomes in such patients.

The Utility of a Convolutional Neural Network for Generating a Myelin Volume Index Map from Rapid Simultaneous Relaxometry Imaging

Purpose:

A current algorithm to obtain a synthetic myelin volume fraction map (SyMVF) from rapid simultaneous relaxometry imaging (RSRI) has a potential problem, that it does not incorporate information from surrounding pixels. The purpose of this study was to develop a method that utilizes a convolutional neural network (CNN) to overcome this problem.

Methods:

RSRI and magnetization transfer images from 20 healthy volunteers were included. A CNN was trained to reconstruct RSRI-related metric maps into a myelin volume-related index (generated myelin volume index: GenMVI) map using the MVI map calculated from magnetization transfer images (MTMVI) as reference. The SyMVF and GenMVI maps were statistically compared by testing how well they correlated with the MTMVI map. The correlations were evaluated based on: (i) averaged values obtained from 164 atlas-based ROIs, and (ii) pixel-based comparison for ROIs defined in four different tissue types (cortical and subcortical gray matter, white matter, and whole brain).

Results:

For atlas-based ROIs, the overall correlation with the MTMVI map was higher for the GenMVI map than for the SyMVF map. In the pixel-based comparison, correlation with the MTMVI map was stronger for the GenMVI map than for the SyMVF map, and the difference in the distribution for the volunteers was significant (Wilcoxon sign-rank test, P < 0.001) in all tissue types.

Conclusion:

The proposed method is useful, as it can incorporate more specific information about local tissue properties than the existing method. However, clinical validation is necessary.

HPRL – International cooperation to identify and monitor priority nuclear data needs for nuclear applications

The OECD-NEA High Priority Request List (HPRL) is a point of reference to guide and stimulate the improvement of nuclear data for nuclear energy and other applications, and a tool to bridge the gap between data users and producers. The HPRL is application-driven and the requests are submitted by nuclear data users or representatives of the user’s communities. A panel of international experts reviews and monitors the requests in the framework of an Expert Group mandated by the NEA Nuclear Science Committee Working Party on International Nuclear Data Evaluation Cooperation (WPEC). After approval, individual requests are classified to three categories: high priority requests, general requests, and special purpose requests (e.g., dosimetry, standards). The HPRL is hosted by the NEA in the form of a relational database publicly available on the web. This paper provides an overview of HPRL entries, status and outlook. Examples of requests successfully completed are given and new requests are described with emphasis on updated nuclear data needs in the fields of nuclear energy, neutron standards and dosimetry.

CD8+ T-cell encephalitis mimicking PRES in AIDS: a case report

Background

Diverse mechanisms including infections, autoimmune inflammatory reactions, neoplasms, and degeneration are involved in the central nervous system in cases of acquired immune deficiency syndrome. In such cases, it is difficult to determine the precise pathogenesis by radiological examination and laboratory testing.

Case presentation

We report a 37-year-old Japanese woman who had untreated hypertension and gender identity disorder and had been taking testosterone injections since she was 19 years old. She developed a headache and visual field deficits together with elevated blood pressure. According to radiological findings, she was initially suspected as having posterior reversible encephalopathy syndrome in the right parieto-occipital lobe with reversible cerebral vasoconstriction syndrome. Human immunodeficiency virus antibody was positive and the CD4⁺ T-lymphocyte count was 140 cells/μl. Therefore, antiretroviral therapy was started. Antiretroviral therapy suppressed the activity of acquired immune deficiency syndrome but worsened her visual symptoms and expanding radiological lesions. Brain biopsy led to the diagnosis of CD8⁺ encephalitis, and she also fulfilled the diagnosis of paradoxical immune reconstitution inflammatory syndrome. Corticosteroid therapy alleviated her symptoms.

Conclusions

This is a rare case of CD8⁺ encephalitis, with an exacerbation owing to paradoxical immune reconstitution inflammatory syndrome after antiretroviral therapy, which radiologically mimicked posterior reversible encephalopathy syndrome. Corticosteroid therapy was effective; thus, it is important to provide a pathological diagnosis in such cases.

Suitable indications of eculizumab for patients with refractory generalized myasthenia gravis

Background:

Eculizumab is a humanized monoclonal antibody that targets complement protein C5 and inhibits terminal complement-mediated damage at the neuromuscular junction. Recently, the REGAIN study showed that eculizumab was effective and well tolerated in patients with anti-acetylcholine receptor antibody-positive refractory generalized myasthenia gravis (gMG). However, there is no consensus regarding which kind of patients with gMG are selected to preferentially receive eculizumab.

Methods:

Between January and December 2018, we followed 1388 patients with MG at seven hospitals located in Tokyo and Chiba. We evaluated the clinical features of MG and the patients’ quality of life. Clinical status and severity were determined by the recommendations of the Myasthenia Gravis Foundation of America.

Results:

Of 1388 patients with MG, 12 (0.9%) patients received eculizumab. A total of 11 patients who were anti-acetylcholine receptor antibody-positive with refractory gMG (M:F = 3:8) completed the 26-week treatment with eculizumab. The disease subtypes represented included five cases of early onset MG, one of late-onset MG, and five of thymoma-associated MG. Overall, seven patients had experienced myasthenic crisis. The mean quantitative MG score ranged from 18.6 at baseline to 9.1 at week 26 (p = 0.008). Similarly, the mean MG activities of daily living score ranged from 10.8 at baseline to 4.2 at week 26 (p = 0.002). There were marked improvements in all patients’ quality of life status. Overall, seven patients were able to reduce the dose of prednisolone at week 26. All but one patient did not require additional rescue treatment. Overall, one patient with early onset MG could not continue the eculizumab treatment due to nausea and vertigo.

Conclusion:

We demonstrate that eculizumab provided remarkable benefits for refractory gMG in practical real-world experience as well as in the REGAIN study. Patients with refractory gMG with myasthenia crisis and thymoma-associated MG are suitable for eculizumab administration.

Somnolence Preceded the Development of a Subthalamic Lesion in Neuromyelitis Optica Spectrum Disorder

A 67-year-old woman with neuromyelitis optica spectrum disorder (NMOSD) developed severe somnolence. Ten days after admission, fluid-attenuated inversion-recovery magnetic resonance imaging (MRI) revealed hyperintense areas around the bilateral hypothalamus, which were not present on MRI at admission. The orexin level, which is decreased in idiopathic narcolepsy, was slightly decreased in her cerebrospinal fluid. Immunosuppressive treatment and methylphenidate markedly improved her somnolence. This case shows that NMOSD in the acute phase can cause somnolence in a patient without apparent lesions in the hypothalamus.

New-onset Refractory Status Epilepticus Involving the Limbic System, Spinal Cord, and Peripheral Nerves

A healthy 28-year-old woman presented suddenly with intractable status epilepticus: a focal seizure evolved into a generalized seizure preceded by a high fever. Brain magnetic resonance imaging indicated bilateral hyperintensities in the hippocampus on T2-weighted imaging. Electroencephalograms continuously demonstrated diffuse sharp waves and poly-spikes. Comprehensive immunomodulation therapies and anti-epileptic drugs did not lead to any improvements. We therefore diagnosed her with cryptogenic limbic encephalitis and new-onset refractory status epilepticus (NORSE). We detected positive anti-ganglioside antibodies, IgG-GQ1b, GD1a, and GT1b, which were negative at six months after the onset. We emphasize the heterogeneous pathogenesis and intractable conditions of NORSE.

Overview of the OECD-NEA Working Party on International Nuclear Data Evaluation Cooperation (WPEC)

The OECD Nuclear Energy Agency (NEA) Working Party on International Nuclear Data Evaluation Cooperation (WPEC) was established in 1989 to facilitate collaboration in nuclear data activities. Over its thirty year history, different Subgroups have been created to address topics in nearly every aspect of nuclear data, including: experimental measurements, evaluation, validation, model development, quality assurance of databases and the development of software tools.

WPEC has recently completed activities on fission yield evaluation, the general nuclear database structure (GNDS) to replace the ENDF-6 format, methods to provide feedback to evaluation, studies of specific capture cross sections, new methods in thermal scattering kernel evaluation and the Collaborative International Evaluated Library Organisation (CIELO) Pilot Project. Ongoing activities in GNDS application programming interface (API) development, methods for covariance evaluation and quality assurance in nuclear data validation using the International Criticality Safety Benchmark Evaluation Project (ICSBEP) database are complemented by the work of two Expert Groups that oversee the High-Priority Request List (HPRL) for Nuclear Data and the continuous development of the GNDS. New activities on the use of integral experiments for nuclear data validation and adjustment, as well as the use of the Shielding Integral Benchmark Archive and Database (SINBAD) for validation have begun and will be coordinated alongside future Subgroups.

After three decades we will review the status of WPEC, how it integrates other collections and activities organised by the NEA and how it dovetails with the initiatives of the IAEA and other bodies to effectively coordinate international activities in nuclear data.

Clinical Characterization of Definite Autoimmune Limbic Encephalitis: A 30-case Series

Objective Limbic encephalitis (LE) is an inflammatory condition of the limbic system that has an acute or subacute onset. Several types of antibodies are related to the onset of LE, including anti-N-methyl D-aspartate receptor (NMDAR) antibodies and voltage-gated potassium channel (VGKC)-complex antibodies. However, the characteristics and prevalence of LE remain unclear, especially in Asian cohorts, due to the rarity. We aimed to survey their characteristics. Materials and Methods Data of 30 cases clinically defined as "definite autoimmune LE" (based on the standard criteria) were retrospectively collected. These patients were categorized into four subtypes: NMDAR (+) (n=8), VGKC (+) (n=2), antibodies related to paraneoplastic syndrome (n=2), and an antibody-negative group (uncategorized) (n=18). Results LE is rare in Japan, and affected only 30 of 16,759 hospital patients (0.2%) over a ten-year period. The NMDAR (+) group showed distinctive symptoms, while the other three groups had similar indications. Brain MRI indicated significant medial temporal lobe atrophy at one year follow up after discharge. The prevalence of cognitive dysfunction as a complication was 64% (9/14). First-line immunotherapy resulted in a good outcome. A drastic improvement was seen from 4.0±1.1 to 1.1+ on the modified Rankin Scale. A good treatment outcome was observed in all groups (NMDAR, VGKC, and uncategorized), suggesting the importance of an early clinical diagnosis and the early initiation of treatment. Furthermore, we reviewed 26 cases that were clinically diagnosed as definitive autoimmune LE in previous case reports. Conclusion Our findings show that the establishment of a clinical diagnosis based on the clinical criteria of definitive autoimmune LE is important for the initiation of immunotherapy.

Psychiatric-disorder-related behavioral phenotypes and cortical hyperactivity in a mouse model of 3q29 deletion syndrome

3q29 microdeletion, a rare recurrent copy number variant (CNV), greatly confers an increased risk of psychiatric disorders, such as schizophrenia and autism spectrum disorder (ASD), as well as intellectual disability. However, disease-relevant cellular phenotypes of 3q29 deletion syndrome remain to be identified. To reveal the molecular and cellular etiology of 3q29 deletion syndrome, we generated a mouse model of human 3q29 deletion syndrome by chromosome engineering, which achieved construct validity. 3q29 deletion (Df/+) mice showed reduced body weight and brain volume and, more importantly, impaired social interaction and prepulse inhibition. Importantly, the schizophrenia-related impaired prepulse inhibition was reversed by administration of antipsychotics. These findings are reminiscent of the growth defects and neuropsychiatric behavioral phenotypes in patients with 3q29 deletion syndrome and exemplify that the mouse model achieves some part of face validity and predictive validity. Unbiased whole-brain imaging revealed that neuronal hyperactivation after a behavioral task was strikingly exaggerated in a restricted region of the cortex of Df/+ mice. We further elucidated the cellular phenotypes of neuronal hyperactivation and the reduction of parvalbumin expression in the cortex of Df/+ mice. Thus, the 3q29 mouse model provides invaluable insight into the disease-causative molecular and cellular pathology of psychiatric disorders.

White Matter Abnormalities in Multiple Sclerosis Evaluated by Quantitative Synthetic MRI, Diffusion Tensor Imaging, and Neurite Orientation Dispersion and Density Imaging

BACKGROUND AND PURPOSE

A number of MR-derived quantitative metrics have been suggested to assess the pathophysiology of MS, but the reports about combined analyses of these metrics are scarce. Our aim was to assess the spatial distribution of parameters for white matter myelin and axon integrity in patients with relapsing-remitting MS by multiparametric MR imaging.

MATERIALS AND METHODS

Twenty-four patients with relapsing-remitting MS and 24 age- and sex-matched controls were prospectively scanned by quantitative synthetic and 2-shell diffusion MR imaging. Synthetic MR imaging data were used to retrieve relaxometry parameters (R1 and R2 relaxation rates and proton density) and myelin volume fraction. Diffusion tensor metrics (fractional anisotropy and mean, axial, and radial diffusivity) and neurite orientation and dispersion index metrics (intracellular volume fraction, isotropic volume fraction, and orientation dispersion index) were retrieved from diffusion MR imaging data. These data were analyzed using Tract-Based Spatial Statistics.

RESULTS

Patients with MS showed significantly lower fractional anisotropy and myelin volume fraction and higher isotropic volume fraction in widespread white matter areas. Areas with different isotropic volume fractions were included within areas with lower fractional anisotropy. Myelin volume fraction showed no significant difference in some areas with significantly decreased fractional anisotropy in MS, including in the genu of the corpus callosum and bilateral anterior corona radiata, whereas myelin volume fraction was significantly decreased in some areas where fractional anisotropy showed no significant difference, including the bilateral posterior limb of the internal capsule, external capsule, sagittal striatum, fornix, and uncinate fasciculus.

CONCLUSIONS

We found differences in spatial distribution of abnormality in fractional anisotropy, isotropic volume fraction, and myelin volume fraction distribution in MS, which might be useful for characterizing white matter in patients with MS.

P14.01 Differential diagnosis of IDH mutant/IDH wildtype of glioma by using 11C-methionine, 11C-choline, and18F-fluorodeoxyglucose positron emission tomography

BACKGROUND

Positron emission tomography (PET) is important in noninvasive diagnostic imaging of gliomas. There are many PET studies on glioma diagnosis based on the 2007 World Health Organization (WHO) classification; however, there are no studies on glioma diagnosis using the new classification (the 2016 WHO classification).Here we investigated the relationship between PET imaging using 11C-methionine (MET), 11C-choline (CHO), and 18F-fluorodeoxyglucose (FDG) and wildtype isocitrate dehydrogenase (IDH) (IDH-wt)/mutant IDH (IDH-mut) in astrocytic and oligodendroglial tumors according to the 2016 WHO classification.

MATERIAL AND METHODS

In total, 105 patients with newly diagnosed cerebral gliomas (six diffuse astrocytomas [DAs] with IDH-wt, six DAs with IDH-mut, seven anaplastic astrocytomas [AAs] with IDH-wt, 24 AAs with IDH-mut, 26 glioblastomas [GBMs] with IDH-wt, five GBMs with IDH-mut, 19 oligodendrogliomas [ODs], and 12 anaplastic oligodendrogliomas [AOs]) were included. All OD and AO patients had both IDH-mut and 1p/19q codeletion. The maximum standardized uptake values (SUVs) of the tumor/normal cortex mean SUV ratios (T/N ratios) for MET, CHO, and FDG were calculated; the mean T/N ratios of DA, AA, and GBM with IDH-wt/IDH-mut were compared. The diagnostic accuracy for distinguishing gliomas with IDH-wt from those with IDH-mut was assessed using receiver operating characteristic (ROC) curve analysis of the mean T/N ratios for the three PET tracers.

RESULTS

There were significant differences in the mean T/N ratios for all three PET tracers between the IDH-wt and IDH-mut groups including all histological classifications (p<0.001). Among the 27 gliomas with mean T/N ratios higher than the cutoff values for all three PET tracers, 23 (85.2%) were classified into the IDH-wt group using ROC analysis. In DA, there were no significant differences in the T/N ratios for MET, CHO, and FDG between the IDH-wt and IDH-mut groups. In AA, the mean T/N ratios of all three PET tracers in the IDH-wt group were significantly higher than those in the IDH-mut group (p<0.001). In GBM, the mean T/N ratio in the IDH-wt group was significantly higher than that of the IDH-mut group for both MET (p=0.034) and CHO (p=0.01). However, there was no significant difference in the ratio for FDG.

CONCLUSIONS

PET imaging using MET, CHO, and FDG was confirmed to be informative for preoperatively differentiating gliomas according to the 2016 WHO classification, particularly for differentiating IDH-wt and IDH-mut tumors.

P14.08 Bevacizumab treatment for the lesion emerging after the radiotherapy for malignant glioma

BACKGROUND

Because blocking vascular endothelial growth factor from reaching leaky capillaries is a logical strategy for the treatment, we reasoned that bevacizumab might be an effective treatment on recurrent malignant glioma and radiation necrosis (RN). In this study, the authors examined to differentiate RN from recurrent malignant glioma, and evaluated the results of bevacizumab treatment in each diagnosis.

MATERIAL AND METHODS

Four patients of malignant glioma (2 glioblastomas and 2 anaplastic astrocytomas), which demonstrated symptomatic lesion after radiotherapy, were involved in this study. All four patients were treated with bevacizumab on a 10 mg/kg biweekly (one cycle), for a total dose of 30 mg/kg (3 cycles) or furthermore. RN was differentiated from local recurrence in all four patients on the basis of 11C-methionine positron emission tomography and/or clinical course. Clinical evaluation and MRI studies were obtained after bevacizumab treatment in all cases repeatedly as possible.

RESULTS

Two patients were diagnosed as RN, and another two patients as tumor recurrence. Of the two patients with RN, neurological dysfunction was distinctly alleviated after bevacizumab treatment. Other two patients with tumor recurrence demonstrated no remarkable improvement in neurological dysfunction after bevacizumab treatment. Of all the two patients with RN, post-treatment MRI performed after the bevacizumab therapy showed a significant reduction of the massive lesion.

CONCLUSION

We concluded that bevacizumab could control the symptomatic massive lesion occurring after radiotherapy, and it might be more effective with the patients of RN, than with those of recurrent tumor.

Safety of tapering tacrolimus dose in patients with well-controlled anti-acetylcholine receptor antibody-positive myasthenia gravis

BACKGROUND AND PURPOSE

Tapering immunosuppressants is desirable in patients with well-controlled myasthenia gravis (MG). However, the association between tapering of calcineurin inhibitor dosage and reduction-associated exacerbation is not known. The aim of this study was to clarify the frequency of reduction-associated exacerbation when tacrolimus is tapered in stable patients with anti-acetylcholine receptor antibody-positive MG, and to determine the factors that predict exacerbations.

METHODS

We retrospectively analyzed 115 patients in whom tacrolimus dosage was tapered. The reduction-associated exacerbation was defined as the appearance or worsening of one or more MG symptoms <3 months after the reduction.

RESULTS

Tacrolimus dosage was successfully tapered in 110 patients (96%) without any exacerbation. Five patients (4%) experienced an exacerbation, but symptoms were reversed in all patients when the tacrolimus dose was increased to the previous maintenance level. No patient developed an MG crisis. The age at onset was significantly earlier (30 vs. 56 years, P = 0.025) and the reduction in dosage was significantly larger (2.0 vs. 1.0 mg/day, P = 0.002) in patients with reduction-associated exacerbation than in those without exacerbation. The cut-off values determined in a receiver-operating characteristic curve analysis were 52 years (sensitivity, 57%; specificity, 100%) for the age at onset and 1.5 mg (sensitivity, 80%; specificity, 100%) for the dose reduction.

CONCLUSION

Tapering of tacrolimus was possible in most patients with well-controlled anti-acetylcholine receptor antibody-positive MG. Early age at onset and a large reduction from maintenance dosage were associated with exacerbation. Reductions ≤1.5 mg/day from the maintenance dosage should be considered for patients with late-onset disease.