Multimodal imaging in systemic lupus erythematosus patients with diffuse neuropsychiatric involvement

Differences in Brain Atrophy Pattern between People with Multiple Sclerosis and Systemic Diseases with Central Nervous System Involvement Based on Two-Dimensional Linear Measures

Conventional brain magnetic resonance imaging (MRI) in systemic diseases with central nervous system involvement (SDCNS) may imitate MRI findings of multiple sclerosis (MS). In order to better describe the MRI characteristics of these conditions, in our study we assessed brain volume parameters in MS (n = 58) and SDCNS (n = 41) patients using two-dimensional linear measurements (2DLMs): bicaudate ratio (BCR), corpus callosum index (CCI) and width of third ventricle (W3V). In SDCNS patients, all 2DLMs were affected by age (CCI p = 0.005, BCR p < 0.001, W3V p < 0.001, respectively), whereas in MS patients only BCR and W3V were (p = 0.001 and p = 0.015, respectively). Contrary to SDCNS, in the MS cohort BCR and W3V were associated with T1 lesion volume (T1LV) (p = 0.020, p = 0.009, respectively) and T2 lesion volume (T2LV) (p = 0.015, p = 0.009, respectively). CCI was associated with T1LV in the MS cohort only (p = 0.015). Moreover, BCR was significantly higher in the SDCNS group (p = 0.01) and CCI was significantly lower in MS patients (p = 0.01). The best predictive model to distinguish MS and SDCNS encompassed gender, BCR and T2LV as the explanatory variables (sensitivity 0.91; specificity 0.68; AUC 0.86). Implementation of 2DLMs in the brain MRI analysis of MS and SDCNS patients allowed for the identification of diverse patterns of local brain atrophy in these clinical conditions.

A meta-analysis of structural MRI studies of the brain in systemic lupus erythematosus (SLE)

A comprehensive search of published literature in brain volumetry was conducted in three autoimmune diseases - systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and ulcerative colitis (UC) - with the intention of performing a meta-analysis of published data. Due to the lack of data in RA and UC, the reported meta-analysis was limited to SLE. The MEDLINE database was searched for studies from 1988 to March 2022. A total of 175 papers met the initial inclusion criteria, and 16 were included in a random-effects meta-analysis. The reduction in the number of papers included in the final analysis is primarily due to the lack of overlap in measured and reported brain regions. A significantly lower volume was seen in patients with SLE in the hippocampus, corpus callosum, and total gray matter volume measurements as compared to age- and sex-matched controls. There were not enough studies to perform a meta-analysis for RA and UC; instead, we include a summary of published volumetric studies. The meta-analyses revealed structural brain abnormalities in patients with SLE, suggesting that lower global brain volumes are associated with disease status. This volumetric difference was seen in both the hippocampus and corpus callosum and total gray matter volume measurements. These results indicate both gray and white matter involvements in SLE and suggest there may be both localized and global reductions in brain volume.

The conundrum of neuropsychiatric systemic lupus erythematosus: Current and novel approaches to diagnosis

Recognising neuropsychiatric involvement by systemic lupus erythematosus (SLE) is of growing importance, however many barriers to this exist at multiple levels of our currently available diagnostic algorithms that may ultimately delay its diagnosis and subsequent treatment. The heterogeneous and non-specific clinical syndromes, serological and cerebrospinal fluid (CSF) markers and neuroimaging findings that often do not mirror disease activity, highlight important research gaps in the diagnosis of neuropsychiatric SLE (NPSLE). Formal neuropsychological assessments or the more accessible screening metrics may also help improve objective recognition of cognitive or mood disorders. Novel serum and CSF markers, including autoantibodies, cytokines and chemokines have also shown increasing utility as part of diagnosis and monitoring, as well as in distinguishing NPSLE from SLE patients without SLE-related neuropsychiatric manifestations. Novel neuroimaging studies also expand upon our existing strategy by quantifying parameters that indicate microarchitectural integrity or provide an assessment of neuronal function. Some of these novel markers have shown associations with specific neuropsychiatric syndromes, suggesting that future research move away from considering NPSLE as a single entity but rather into its individually recognized neuropsychiatric manifestations. Nevertheless, it is likely that a composite panel of these investigations will be needed to better address the gaps impeding recognition of neuropsychiatric involvement by SLE.

Diffusion tensor imaging analysis of rheumatoid arthritis patients with neuropsychiatric features to determine the alteration of white matter integrity due to vascular events

INTRODUCTION

The pathophysiology of neuropsychiatric manifestations in rheumatoid arthritis is not well known. The magnetic resonance imaging of the brain in rheumatoid arthritis demonstrates non-specific findings, and in the majority of cases, magnetic resonance imaging fails to detect an abnormality, even in rheumatoid arthritis patients with neuropsychiatric manifestations. Therefore, we aimed to assess microstructural integrity changes of white matter in patients with rheumatoid arthritis by using different diffusion tensor imaging parameters.

METHODS

Eighteen rheumatoid arthritis patients (10 with neuropsychiatric symptoms and 8 without any neuropsychiatric symptoms) and 14 controls were included. The volume of the T2 hyperintense lesions was assessed. Different diffusion tensor imaging parameters such as fractional anisotropy, apparent diffusion coefficient, trace, axial diffusivity, and radial diffusivity were obtained from six different regions of white matter. Inter group significant difference was determined by one-way analysis of variance followed by Tukey's post hoc test. The accuracy of diffusion tensor imaging matrices was evaluated from the receiver operating characteristic curve.

RESULTS

No significant difference in lesions' volume was detected between rheumatoid arthritis patients with or without neuropsychiatric symptoms. There was an increased apparent diffusion coefficient and radial diffusivity (p < 0.05) as well as decreased fractional anisotropy and axial diffusivity (p < 0.5) in rheumatoid arthritis patients with neuropsychiatric symptoms compared to controls. Moreover, the apparent diffusion coefficient (p < .05) was increased in both positive and negative MRI of patients with neuropsychiatric features compared to the control group. The sensitivity and specificity of the apparent diffusion coefficient parameters was 73% and 72%, respectively.

CONCLUSIONS

The various anisotropic metrics were altered in rheumatoid arthritis patients with neuropsychiatric symptoms by using diffusion tensor imaging analysis, representing that central nervous system vasculitis leads to tissue hypoxia resulting in vasogenic edema. This may lead to axonal and myelin degeneration of white matter fibers and neuronal cell disruption. Key Points • Our study confirms that neurovascular events are not uncommon in RA patients with NP features. Diffusion tensor imaging (DTI) is superior to conventional MRI scan for RA patients with NP features because it distinguishes between gray and white matter structures. • RA patients with NP features are more likely to have microstructural changes detected by DTI than by DWI, and it can provide comprehensive anatomical layouts describing regional disparities in neurodegeneration. • DTI's quantitative association of NP symptoms in a large patient cohort is an important study scope.

Sensitivity of Diffusion MRI to White Matter Pathology: Influence of Diffusion Protocol, Magnetic Field Strength, and Processing Pipeline in Systemic Lupus Erythematosus

There are many ways to acquire and process diffusion MRI (dMRI) data for group studies, but it is unknown which maximizes the sensitivity to white matter (WM) pathology. Inspired by this question, we analyzed data acquired for diffusion tensor imaging (DTI) and diffusion kurtosis imaging (DKI) at 3T (3T-DTI and 3T-DKI) and DTI at 7T in patients with systemic lupus erythematosus (SLE) and healthy controls (HC). Parameter estimates in 72 WM tracts were obtained using TractSeg. The impact on the sensitivity to WM pathology was evaluated for the diffusion protocol, the magnetic field strength, and the processing pipeline. Sensitivity was quantified in terms of Cohen's d for group comparison. Results showed that the choice of diffusion protocol had the largest impact on the effect size. The effect size in fractional anisotropy (FA) across all WM tracts was 0.26 higher when derived by DTI than by DKI and 0.20 higher in 3T compared with 7T. The difference due to the diffusion protocol was larger than the difference due to magnetic field strength for the majority of diffusion parameters. In contrast, the difference between including or excluding different processing steps was near negligible, except for the correction of distortions from eddy currents and motion which had a clearly positive impact. For example, effect sizes increased on average by 0.07 by including motion and eddy correction for FA derived from 3T-DTI. Effect sizes were slightly reduced by the incorporation of denoising and Gibbs-ringing removal (on average by 0.011 and 0.005, respectively). Smoothing prior to diffusion model fitting generally reduced effect sizes. In summary, 3T-DTI in combination with eddy current and motion correction yielded the highest sensitivity to WM pathology in patients with SLE. However, our results also indicated that the 3T-DKI and 7T-DTI protocols used here may be adjusted to increase effect sizes.

Multi-lesion radiomics model for discrimination of relapsing-remitting multiple sclerosis and neuropsychiatric systemic lupus erythematosus

OBJECTIVES

To develop an MRI-based multi-lesion radiomics model for discrimination of relapsing-remitting multiple sclerosis (RRMS) and its mimicker neuropsychiatric systemic lupus erythematosus (NPSLE).

METHODS

A total of 112 patients with RRMS (n = 63) or NPSLE (n = 49) were assigned to training and test sets with a ratio of 3:1. All lesions across the whole brain were manually segmented on T2-weighted fluid-attenuated inversion recovery images. For each single lesion, 371 radiomics features were extracted and trained using machine learning algorithms, producing Radiomics Index for Lesion (RIL) for each lesion and a single-lesion radiomics model. Then, for each subject, single lesions were assigned to one of two disease courts based on their distance to decision threshold, and a Radiomics Index for Subject (RIS) was calculated as the mean RIL value of lesions on the higher-weighted court. Accordingly, a subject-level discrimination model was constructed and compared with performances of two radiologists.

RESULTS

The subject-based discrimination model satisfactorily differentiated RRMS and NPSLE in both training (AUC = 0.967, accuracy = 0.892, sensitivity = 0.917, and specificity = 0.872) and test sets (AUC = 0.962, accuracy = 0.931, sensitivity = 1.000, and specificity = 0.875), significantly better than the single-lesion radiomics method (training: p < 0.001; test: p = 0.001) Besides, the discrimination model significantly outperformed the senior radiologist in the training set (training: p = 0.018; test: p = 0.077) and the junior radiologist in both the training and test sets (training: p = 0.008; test: p = 0.023).

CONCLUSIONS

The multi-lesion radiomics model could effectively discriminate between RRMS and NPSLE, providing a supplementary tool for accurate differential diagnosis of the two diseases.

KEY POINTS

• Radiomic features of brain lesions in RRMS and NPSLE were different. • The multi-lesion radiomics model constructed using a merging strategy was comprehensively superior to the single-lesion-based model for discrimination of RRMS and NPSLE. • The RRMS-NPSLE discrimination model showed a significantly better performance or a trend toward significance than the radiologists.

Central Nervous System Systemic Lupus Erythematosus: Pathophysiologic, Clinical, and Imaging Features

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by multiple immunologic abnormalities and has the potential to involve the central nervous system (CNS). The prevalence of SLE seems to be growing, possibly because of earlier diagnosis and improved survival; however, the associated mortality is still high. The mortality is associated with disease-related risk factors such as lupus disease activity, young age, and organ damage or with antiphospholipid syndrome (APS). Neuropsychiatric SLE (NPSLE), which is caused by SLE-related CNS involvement, comprises a broad range of neurologic and psychiatric manifestations with varying severity, which can make this disease indistinguishable from other conditions that are unrelated to SLE. No unifying pathophysiology has been found in the etiology of NPSLE, suggesting that this condition has multiple contributors such as various immune effectors and the brain-intrinsic neuroimmune interfaces that are breached by the immune effectors. The postulated neuroimmune interfaces include the blood-brain barrier, blood-cerebrospinal fluid barrier, meningeal barrier, and glymphatic system. On the basis of the immunologic, pathologic, and imaging features of NPSLE, the underlying pathophysiology can be classified as vasculitis and vasculopathy, APS, demyelinating syndrome, or autoimmune antibody-mediated encephalitis. Each pathophysiology has different imaging characteristics, although the imaging and pathophysiologic features may overlap. Moreover, there are complications due to the immunocompromised status caused by SLE per se or by SLE treatment. Radiologists and clinicians should become familiar with the underlying mechanisms, radiologic findings, and complications of NPSLE, as this information may aid in the diagnosis and treatment of NPSLE. Online supplemental material is available for this article. ^©RSNA, 2022.

Abnormal cortical thickness and structural covariance networks in systemic lupus erythematosus patients without major neuropsychiatric manifestations

BACKGROUND

Non-neuropsychiatric systemic lupus erythematosus (non-NPSLE) has been confirmed to have subtle changes in brain structure before the appearance of obvious neuropsychiatric symptoms. Previous literature mainly focuses on brain structure loss in non-NPSLE; however, the results are heterogeneous, and the impact of structural changes on the topological structure of patients' brain networks remains to be determined. In this study, we combined neuroimaging and network analysis methods to evaluate the changes in cortical thickness and its structural covariance networks (SCNs) in patients with non-NPSLE.

METHODS

We compare the cortical thickness of non-NPSLE patients (N=108) and healthy controls (HCs, N=88) using both surface-based morphometry (SBM) and regions of interest (ROI) methods, respectively. After that, we analyzed the correlation between the abnormal cortical thickness results found in the ROI method and a series of clinical features. Finally, we constructed the SCNs of two groups using the regional cortical thickness and analyzed the abnormal SCNs of non-NPSLE.

RESULTS

By SBM method, we found that cortical thickness of 34 clusters in the non-NPSLE group was thinner than that in the HC group. ROI method based on Destrieux atlas showed that cortical thickness of 57 regions in the non-NPSLE group was thinner than that in the HC group and related to the course of disease, autoantibodies, the cumulative amount of immunosuppressive agents, and cognitive psychological scale. In the SCN analysis, the cortical thickness SCNs of the non-NPSLE group did not follow the small-world attribute at a few densities, and the global clustering coefficient appeared to increase. The area under the curve analysis showed that there were significant differences between the two groups in clustering coefficient, degree, betweenness, and local efficiency. There are a total of seven hubs for non-NPSLE, and five hubs in HCs, the two groups do not share a common hub distribution.

CONCLUSION

Extensive and obvious reduction in cortical thickness and abnormal topological organization of SCNs are observed in non-NPSLE patients. The observed abnormalities may not only be the realization of brain damage caused by the disease, but also the contribution of the compensatory changes within the nervous system.

Cerebral Microstructure Analysis by Diffusion-Based MRI in Systemic Lupus Erythematosus: Lessons Learned and Research Directions

Diffusion-based magnetic resonance imaging (MRI) studies, namely diffusion-weighted imaging (DWI) and diffusion-tensor imaging (DTI), have been performed in the context of systemic lupus erythematosus (SLE), either with or without neuropsychiatric (NP) involvement, to deepen cerebral microstructure alterations. These techniques permit the measurement of the variations in random movement of water molecules in tissues, enabling their microarchitecture analysis. While DWI is recommended as part of the initial MRI assessment of SLE patients suspected for NP involvement, DTI is not routinely part of the instrumental evaluation for clinical purposes, and it has been mainly used for research. DWI and DTI studies revealed less restricted movement of water molecules inside cerebral white matter (WM), expression of a global loss of WM density, occurring in the context of SLE, prevalently, but not exclusively, in case of NP involvement. More advanced studies have combined DTI with other quantitative MRI techniques, to further characterize disease pathogenesis, while brain connectomes analysis revealed structural WM network disruption. In this narrative review, the authors provide a summary of the evidence regarding cerebral microstructure analysis by DWI and DTI studies in SLE, focusing on lessons learned and future research perspectives.

Quantitative MRI adds to neuropsychiatric lupus diagnostics

OBJECTIVE

Attributing neuropsychiatric manifestations to SLE is often challenging. Brain white matter lesions are frequent in SLE at MRI, but their diagnostic role is unclear. Here, we assessed whether white matter lesions count, volume and distribution measurement can help in the diagnosis of neuropsychiatric systemic lupus erythematosus (NPSLE).

METHODS

Brain dual-echo and 3D T1-weighted sequences were acquired from 32 patients with SLE and 32 healthy controls with a 3 T-scanner and employed to derive T2-hyperintense lesion volume (T2LV), number (T2LN) and probability maps (LPM) using a semi-automatic local thresholding segmentation technique. NPSLE was classified as per the ACR nomenclature, the Italian Society for Rheumatology algorithm and by clinical impression. Clinical descriptors including the SLE International Collaborating Clinics/ACR damage index (SDI) were also recorded.

RESULTS

Higher T2LV were observed in SLE vs healthy controls (P < 0.001) and in NPSLE vs other SLE (P =0.006). Patients with NPSLE also had higher T2LN (P =0.003) compared with other SLE. In SLE, T2LPM revealed a high prevalence of lesions in the splenium of the corpus callosum, right superior longitudinal fasciculus and right corona radiata. T2LV and T2LN correlated with SLE duration (rho = 0.606; P <0.001 and rho = 0.483; P =0.005, respectively) and age (rho = 0.478; P =0.006 and rho = 0.362; P = 0.042, respectively). T2LV also correlated with SDI (rho = 0.352; P =0.048). SLE patients with fatigue had lower T2LN (P =0.038) compared with patients without fatigue. Thresholds of T2LV ≥ 0.423 cm3 or of T2LN ≥ 12 were associated with definite NPSLE and improved the classification of patients with possible NPSLE per clinical impression.

CONCLUSION

Brain white matter lesions (WML) quantitation adds to NPSLE diagnostics.

Structural Changes on MRI Demonstrate Specific Cerebellar Involvement in SLE Patients-A VBM Study

The purpose of this study is to investigate possible differences in brain structure, as measured by T1-weighted MRI, between patients with systemic lupus erythematosus (SLE) and healthy controls (HC), and whether any observed differences were in turn more severe in SLE patients with neuropsychiatric manifestations (NPSLE) than those without (non-NPSLE). Structural T1-weighted MRI was performed on 69 female SLE patients (mean age = 35.8 years, range = 18-51 years) and 24 age-matched female HC (mean age = 36.8 years, range = 23-52 years) in conjunction with neuropsychological assessment using the CNS Vital Signs test battery. T1-weighted images were preprocessed and analyzed by FSL-VBM. The results show that SLE patients had lower grey matter probability values than the control group in the VIIIa of the cerebellum bilaterally, a region that has previously been implied in sensorimotor processing in human and non-human primates. No structural differences for this region were found between NPSLE and non-NPSLE patients. VBM values from the VIIIa region showed a weak positive correlation with the psychomotor speed domain from CNS Vital Signs (p = 0.05, r = 0.21), which is in line with its presumed role as a sensorimotor processing area.

Anatomical integrity within the inferior fronto-occipital fasciculus and semantic processing deficits in schizophrenia spectrum disorders

The core symptoms of schizophrenia spectrum disorders (SSD) include abnormal semantic processing which may rely on the ventral language stream of the human brain. Thus, structural disruption of the ventral language stream may play an important role in semantic deficits observed in SSD patients. Therefore, we compared white matter tract integrity in SSD patients and healthy controls using diffusion tensor imaging combined with probabilistic fiber tractography. For the ventral language stream, we assessed the inferior fronto-occipital fasciculus [IFOF], inferior longitudinal fasciculus, and uncinate fasciculus. The arcuate fasciculus and corticospinal tract were used as control tracts. In SSD patients, the relationship between semantic processing impairments and tract integrity was analyzed separately. Three-dimensional tract reconstructions were performed in 45/44 SSD patients/controls ("Bern sample") and replicated in an independent sample of 24/24 SSD patients/controls ("Basel sample"). Multivariate analyses of fractional anisotropy, mean, axial, and radial diffusivity of the left IFOF showed significant differences between SSD patients and controls (p_(FDR-corr) < 0.001, η_p² = 0.23) in the Bern sample. Axial diffusivity (AD) of the left UF was inversely correlated with semantic impairments (r = -0.454, p_(FDR-corr) = 0.035). In the Basel sample, significant group differences for the left IFOF were replicated (p < .01, η_p² = 0.29), while the correlation between AD of the left IFOF and semantic processing decline (r = -0.376, p = .09) showed a statistical trend. No significant effects were found for the dorsal language stream. This is direct evidence for the importance of the integrity of the ventral language stream, in particular the left IFOF, in semantic processing deficits in SSD.

Structural and functional brain connectomes in patients with systemic lupus erythematosus

BACKGROUND AND PURPOSE

Systemic lupus erythematosus (SLE) is an immune-mediated disease that may affect the nervous system. We explored the topographical organization of structural and functional brain connectivity in patients with SLE and its correlation with neuropsychiatric (NP) involvement and autoantibody profiles.

METHODS

Graph theoretical analysis was applied to diffusion tensor magnetic resonance imaging (MRI) and resting-state functional MRI data from 32 patients with SLE and 32 age- and sex-matched healthy controls. Structural and functional connectivity matrices between 116 cortical/subcortical brain regions were estimated using a bivariate correlation analysis, and global and nodal network metrics were calculated.

RESULTS

Structural, but not functional, global network properties (strength, transitivity, global efficiency and path length) were abnormal in patients with SLE versus controls (P < 0.0001), especially in patients with anti-double-stranded DNA (ADNA) autoantibodies (P = 0.03). No difference was found according to NP involvement or anti-phospholipid autoantibody status. Patients with SLE and controls shared identical structural hubs and the majority of functional hubs. In patients with SLE, all structural hubs showed reduced strength and clustering coefficient compared with controls (P from 0.001 to <0.0001), especially in patients with ADNA autoantibodies. Only a few differences in functional hub properties were found between patients with SLE and controls. Structural and functional hub measures did not differ according to NP involvement or anti-phospholipid autoantibody status. Significant correlations were found between clinical, MRI and network measures (r from -0.56 to 0.60, P from 0.0003 to 0.05).

CONCLUSIONS

Abnormalities of global and nodal structural connectivity occur in patients with SLE, especially with ADNA autoantibodies, with a diffuse disruption of structural integrity. Functional network integrity may contribute to preserve clinical functions.

Evaluation of oxygen extraction fraction in systemic lupus erythematosus patients using quantitative susceptibility mapping

The purposes of this study are to assess the oxygen extraction fraction (OEF) changes on MRI-based quantitative susceptibility mapping (QSM) in systemic lupus erythematosus (SLE) patients and to determine whether QSM-OEF is associated with disease activity in SLE. We enrolled 42 SLE patients and 20 healthy subjects (HS) who had no pathologies on conventional brain MRI. Disease activity was assessed using SLE Disease Activity Index (SLEDAI). For the measurement of QSM-OEF, QSM data were analysed using the Perfusion Mismatch Analyzer software program. Spearman's or Pearson's correlation coefficients were calculated, and independent predictors were identified through a multiple linear regression analysis. QSM-OEF was significantly higher in SLE than that in HS (51.3 ± 10.1 vs. 40.5 ± 3.7, p < 0.001). QSM-OEF was positively correlated with SLEDAI and the presence of neuropsychiatric symptom (NPS) scores (ρ = 0.663, p < 0.001 and ρ = 0.340, p = 0.028). At multiple linear regression analysis, SLEDAI and NPS were independently associated with QSM-OEF (standardized β = 0.426, p = 0.016 and standardized β = 6.148, p = 0.029). In the SLE patients, QSM-OEF is associated with disease activity, which might predict an increased risk of stroke in SLE.

White-matter integrity in patients with systemic lupus erythematosus and memory deficits

PURPOSE

Cognitive dysfunction is common in neuropsychiatric systemic lupus erythematosus (SLE). Memory is a commonly affected cognitive domain. Clinically, however, it is difficult to detect memory deficits. The objective of this study is to evaluate whether normal controls and SLE patients with and without memory deficit differ in terms of white-matter integrity.

METHODS

Twenty SLE patients with memory deficit were compared to 47 SLE patients without memory deficit and 22 sex-, age-, and education-matched control individuals. Diffusion tensor imaging (DTI) was performed in a 1.5-Tesla scanner. For tract-based spatial statistics analysis, a white-matter skeleton was created. A permutation-based inference with 5000 permutations with a threshold of p < 0.05 was used to identify abnormalities in fractional anisotropy (FA). The mean diffusivity (MD), radial diffusivity (RD) and axial diffusivity (AD) were also projected onto the mean FA skeleton.

RESULTS

Compared to controls, SLE patients with and without memory deficit had decreased FA in: bilateral anterior thalamic radiation, inferior fronto-occipital fasciculus, superior longitudinal fasciculus, uncinate fasciculus, corticospinal tract, genu, and body of the corpus callosum. SLE patients with and without memory deficit also presented increased MD and RD values compared to controls in these areas. Comparison between SLE patients with and without memory deficit did not present significant differences in DTI parameters.

CONCLUSION

DTI can detect extensive abnormalities in the normal-appearing white matter of SLE patients with and without memory deficit, compared to controls. However, there was no difference, in terms of white-matter integrity, between the groups of SLE patients.

Magnetic resonance imaging in neuropsychiatric systemic lupus erythematosus: current state of the art and novel approaches

Systemic lupus erythematosus is a chronic, inflammatory, immune-mediated disease affecting 0.1% of the general population. Neuropsychiatric manifestations in systemic lupus erythematosus have been more frequently recognized and reported in recent years, occurring in up to 75% of patients during the disease course. Magnetic resonance imaging is known to be a useful tool for the detection of structural brain abnormalities in neuropsychiatric systemic lupus erythematosus patients because of the excellent soft-tissue contrast observed with MRI and the ability to acquire multiplanar images. In addition to conventional magnetic resonance imaging techniques to evaluate the presence of atrophy and white matter lesions, several different magnetic resonance imaging techniques have been used to identify microstructural or functional abnormalities. This review will highlight different magnetic resonance imaging techniques, including the advanced magnetic resonance imaging methods used to determine central nervous system involvement in systemic lupus erythematosus.

A critical analysis of the tools to evaluate neuropsychiatric lupus

Neuropsychiatric symptoms occur commonly in patients with systemic lupus erythematosus, but they are not always due to active disease. It is crucial to identify cases that are due to active systemic lupus erythematosus so that appropriate treatment can be instituted. There is no single serological or imaging test that distinguishes active neuropsychiatric systemic lupus erythematosus from neuropsychiatric manifestations caused by other factors such as infection. Most patients with neuropsychiatric systemic lupus erythematosus have generalised features of disease activity. Raised anti-dsDNA and low C3 complement levels are often seen, but are not an invariable guide. The presence of antiphospholipid antibodies is more suggestive of thrombotic than inflammatory causation. A number of other autoantibody tests have been proposed as biomarkers for neuropsychiatric systemic lupus erythematosus, but results in clinical studies have been inconsistent and none has so far entered routine clinical practice. Cerebrospinal fluid features and magnetic resonance imaging appearances are non-specific in neuropsychiatric systemic lupus erythematosus, but are useful in excluding other causes of neuropsychiatric symptoms. Newer magnetic resonance imaging sequences show promise for distinguishing new neuropsychiatric systemic lupus erythematosus activity from previous damage and recent research suggests these may correlate with changes in cognitive function in patients with systemic lupus erythematosus. However, formal cognitive testing is seldom carried out in the acute setting.

Reduction of Cerebral and Corpus Callosum Volumes in Childhood-Onset Systemic Lupus Erythematosus: A Volumetric Magnetic Resonance Imaging Analysis

OBJECTIVE

There have been few studies in which the prevalence of cerebral atrophy in childhood-onset systemic lupus erythematosus (SLE) was evaluated using magnetic resonance imaging (MRI) volumetric measurements. This study was undertaken to determine the prevalence of cerebral and corpus callosum atrophy in childhood-onset SLE and to determine the possible relationships between atrophy and clinical, laboratory, and treatment features of the disease.

METHODS

We included 76 patients with childhood-onset SLE (69 female and 7 male; median age 16 years) and 66 age- and sex-matched healthy controls. Neurologic manifestations were analyzed according to the American College of Rheumatology (ACR) criteria. These SLE patients were further assessed for clinical and laboratory manifestations of SLE, disease activity (using the SLE Disease Activity Index), damage (using the Systemic Lupus International Collaborating Clinics/ACR Damage Index), and current and cumulative drug exposures. Scans were performed with a Philips 3.0T MRI scanner using a standardized protocol.

RESULTS

Childhood-onset SLE patients had significantly smaller cerebral and corpus callosum volumes than controls (median cerebral volume 1,067.9 cm(3) versus 1,172.7 cm(3) and median corpus callosum volume 11.6 cm(3) versus 13.7 cm(3) ; P < 0.001). The presence of structural abnormalities was observed in 42 patients (55.3%) with childhood-onset SLE. The presence of cerebral atrophy was associated with anticardiolipin antibodies (aCL) (P = 0.02), anti-double-stranded DNA (P = 0.02), and cumulative corticosteroid dose (P = 0.04). The presence of corpus callosum atrophy was associated with low complement level (P = 0.006) and acute confusional state (P = 0.01). Serum levels of S100B or high molecular weight neurofilament and the presence of anti-ribosomal P were not associated with atrophy.

CONCLUSION

Structural brain abnormalities were observed in 55.3% of the patients and were associated with neuropsychiatric manifestations, aCL, and corticosteroid use. To determine permanent neurologic damage, longitudinal studies must be conducted in these patients.

Fatigue and cognitive function in systemic lupus erythematosus: associations with white matter microstructural damage. A diffusion tensor MRI study and meta-analysis

Objective The objective of this study was to investigate fatigue and cognitive impairments in systemic lupus erythematous (SLE) in relation to diffuse white matter microstructural brain damage. Methods Diffusion tensor MRI, used to generate biomarkers of brain white matter microstructural integrity, was obtained in patients with SLE and age-matched controls. Fatigue and cognitive function were assessed and related to SLE activity, clinical data and plasma biomarkers of inflammation and endothelial dysfunction. Results Fifty-one patients with SLE (mean age 48.8 ± 14.3 years) were included. Mean diffusivity (MD) was significantly higher in all white matter fibre tracts in SLE patients versus age-matched healthy controls ( p < 0.0001). Fatigue in SLE was higher than a normal reference range ( p < 0.0001) and associated with lower MD ( ß = -0.61, p = 0.02), depression ( ß = 0.17, p = 0.001), anxiety ( ß = 0.13, p = 0.006) and higher body mass index ( ß = 0.10, p = 0.004) in adjusted analyses. Poorer cognitive function was associated with longer SLE disease duration ( p = 0.003) and higher MD ( p = 0.03) and, in adjusted analysis, higher levels of IL-6 ( ß = -0.15, p = 0.02) but not with MD. Meta-analysis (10 studies, n = 261, including the present study) confirmed that patients with SLE have higher MD than controls. Conclusion Patients with SLE have more microstructural brain white matter damage for age than the general population, but this does not explain increased fatigue or lower cognition in SLE. The association between raised IL-6 and worse current cognitive function in SLE should be explored in larger datasets.

Advanced MRI techniques: biomarkers in neuropsychiatric lupus

Objectives

The objective of this study was to determine whether advanced MRI could provide biomarkers for diagnosis and prognosis in neuropsychiatric systemic lupus erythematosus (NPSLE).

Methods

Our prospective study included 28 systemic lupus erythematosus (SLE) patients with primary central NPSLE, 22 patients without NPSLE and 20 healthy controls. We used visual scales to evaluate atrophy and white matter hyperintensities, voxel-based morphometry and Freesurfer to measure brain volume, plus diffusion-tensor imaging (DTI) to assess white matter (WM) and gray matter (GM) damage. We compared the groups and correlated MRI abnormalities with clinical data.

Results

NPSLE patients had less GM and WM than controls ( p = 0.042) in the fronto-temporal regions and corpus callosum. They also had increased diffusivities in the temporal lobe WM ( p < 0.010) and reduced fractional anisotropy in the right frontal lobe WM ( p = 0.018). High clinical scores, longstanding disease, and low serum C3 were associated with atrophy, lower fractional anisotropy and higher diffusivity in the fronto-temporal lobes. Antimalarial treatment correlated negatively with atrophy in the frontal cortex and thalamus; it was also associated with lower diffusivity in the fronto-temporal WM clusters.

Conclusions

Atrophy and microstructural damage in fronto-temporal WM and GM in NPSLE correlate with severity, activity and the time from disease onset. Antimalarial treatment seems to give some brain-protective effects.

Brain morphology and cortical thickness variations in systemic lupus erythematosus patients: Differences among neurological, psychiatric, and nonneuropsychiatric manifestations

PURPOSE

To determine whether systemic lupus erythematosus (SLE) affecting subcortical white matter volumes, deep gray matter volumes, and cortical thickness differ between groups of SLE patients with psychiatric (P-SLE), neurological (N-SLE), or nonneuropsychiatric (non-NPSLE) presentations.

MATERIALS AND METHODS

Sixty-seven participants were divided into three groups (P-SLE [n = 19], N-SLE [n = 12], and non-NPSLE [n = 36]) and examined with a 1.5T MRI scanner. The images were segmented in FreeSurfer software into volumetric and cortical thickness measures using T₁ 3D magnetization prepared rapid gradient echo-weighted imaging. For comparative analyses of volume, multivariate analyses of covariance (MANCOVA) were applied followed by Bonferroni post-hoc tests, with age as a covariate. For cortical thickness analyses, the groups were compared with the Query Design Estimate Contrast tool adjusted for age.

RESULTS

Globus pallidus volumes in both left (P ≤ 0.01) and right (P ≤ 0.05) hemispheres were larger in the N-SLE group than in the non-NPSLE group, and the left GP volume was greater in the N-SLE group than in the P-SLE group (P ≤ 0.05) (MANCOVA, post-hoc Bonferroni). The P-SLE group presented with thinning of cortical areas relative to the N-SLE (predominantly in the left parietal and right frontal and parietal regions) (P ≤ 0.05) and non-NPSLE (predominantly in parietal and occipital regions) (P ≤ 0.05) groups, whereas the N-SLE group presented with thickening of cortical areas (mostly right frontal and left parietal regions) relative to the non-NPSLE (P ≤ 0.05) and P-SLE groups.

CONCLUSION

N-SLE patients had greater local volumes and cortical thicknesses than the other two groups, whereas P-SLE patients presented with decreased volumes and cortical thinning. These findings provide evidence of distinct neuroanatomical abnormalities in neurological versus psychiatric manifestations of SLE.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 3 J. MAGN. RESON. IMAGING 2017;46:150-158.

The diagnosis and clinical management of the neuropsychiatric manifestations of lupus

Neuropsychiatric (NP) involvement in Systemic Lupus Erythematosus (SLE), can be a severe and troubling manifestation of the disease that heavily impacts patient's health, quality of life and disease outcome. It is one of the most complex expressions of SLE which can affect central, peripheral and autonomous nervous system. Complex interrelated pathogenetic mechanisms, including genetic factors, vasculopathy, vascular occlusion, neuroendocrine-immune imbalance, tissue and neuronal damage mediated by autoantibodies, inflammatory mediators, blood brain barrier dysfunction and direct neuronal cell death can be all involved. About NPSLE a number of issues are still matter of debate: from classification and burden of NPSLE to attribution and diagnosis. The role of neuroimaging and new methods of investigation still remain pivotal and rapidly evolving as well as is the increasing knowledge in the pathogenesis. Overall, two main pathogenetic pathways have been recognized yielding different clinical phenotypes: a predominant ischemic-vascular one involving large and small blood vessels, mediated by aPL, immune complexes and leuko-agglutination which it is manifested with more frequent focal NP clinical pictures and a predominantly inflammatory-neurotoxic one mediated by complement activation, increased permeability of the BBB, intrathecal migration of autoantibodies, local production of immune complexes and pro-inflammatory cytokines and other inflammatory mediators usually appearing as diffuse NP manifestations. In the attempt to depict a journey throughout NPSLE from diagnosis to a reasoned therapeutic approach, classification, epidemiology, attribution, risk factors, diagnostic challenges, neuroimaging techniques and pathogenesis will be considered in this narrative review based on the most relevant and recent published data.

Diffusion tensor imaging in children with tuberous sclerosis complex: tract-based spatial statistics assessment of brain microstructural changes

BACKGROUND

There is evidence of microstructural changes in normal-appearing white matter of patients with tuberous sclerosis complex.

OBJECTIVE

To evaluate major white matter tracts in children with tuberous sclerosis complex using tract-based spatial statistics diffusion tensor imaging (DTI) analysis.

MATERIALS AND METHODS

Eight children (mean age ± standard deviation: 8.5 ± 5.5 years) with an established diagnosis of tuberous sclerosis complex and 8 age-matched controls were studied. The imaging protocol consisted of T1-weighted high-resolution 3-D spoiled gradient-echo sequence and a spin-echo, echo-planar diffusion-weighted sequence. Differences in the diffusion indices were evaluated using tract-based spatial statistics.

RESULTS

Tract-based spatial statistics showed increased axial diffusivity in the children with tuberous sclerosis complex in the superior and anterior corona radiata, the superior longitudinal fascicle, the inferior fronto-occipital fascicle, the uncinate fascicle and the anterior thalamic radiation. No significant differences were observed in fractional anisotropy, mean diffusivity and radial diffusivity between patients and control subjects. No difference was found in the diffusion indices between the baseline and follow-up examination in the patient group.

CONCLUSION

Patients with tuberous sclerosis complex have increased axial diffusivity in major white matter tracts, probably related to reduced axonal integrity.

The Neurochemical and Microstructural Changes in the Brain of Systemic Lupus Erythematosus Patients: A Multimodal MRI Study

The diagnosis and pathology of neuropsychiatric systemic lupus erythematosus (NPSLE) remains challenging. Herein, we used multimodal imaging to assess anatomical and functional changes in brains of SLE patients instead of a single MRI approach generally used in previous studies. Twenty-two NPSLE patients, 21 non-NPSLE patients and 20 healthy controls (HCs) underwent 3.0 T MRI with multivoxel magnetic resonance spectroscopy, T1-weighted volumetric images for voxel based morphometry (VBM) and diffusional kurtosis imaging (DKI) scans. While there were findings in other basal ganglia regions, the most consistent findings were observed in the posterior cingulate gyrus (PCG). The reduction of multiple metabolite concentration was observed in the PCG in the two patient groups, and the NPSLE patients were more prominent. The two patient groups displayed lower diffusional kurtosis (MK) values in the bilateral PCG compared with HCs (p < 0.01) as assessed by DKI. Grey matter reduction in the PCG was observed in the NPSLE group using VBM. Positive correlations among cognitive function scores and imaging metrics in bilateral PCG were detected. Multimodal imaging is useful for evaluating SLE subjects and potentially determining disease pathology. Impairments of cognitive function in SLE patients may be interpreted by metabolic and microstructural changes in the PCG.

Structural brain lesions in inflammatory bowel disease

Central nervous system (CNS) complications or manifestations of inflammatory bowel disease deserve particular attention because symptomatic conditions can require early diagnosis and treatment, whereas unexplained manifestations might be linked with pathogenic mechanisms. This review focuses on both symptomatic and asymptomatic brain lesions detectable on imaging studies, as well as their frequency and potential mechanisms. A direct causal relationship between inflammatory bowel disease (IBD) and asymptomatic structural brain changes has not been demonstrated, but several possible explanations, including vasculitis, thromboembolism and malnutrition, have been proposed. IBD is associated with a tendency for thromboembolisms; therefore, cerebrovascular thromboembolism represents the most frequent and grave CNS complication. Vasculitis, demyelinating conditions and CNS infections are among the other CNS manifestations of the disease. Biological agents also represent a risk factor, particularly for demyelination. Identification of the nature and potential mechanisms of brain lesions detectable on imaging studies would shed further light on the disease process and could improve patient care through early diagnosis and treatment.

Automatic Segmentation of the Corpus Callosum Using a Cell-Competition Algorithm: Diffusion Tensor Imaging-Based Evaluation of Callosal Atrophy and Tissue Alterations in Patients With Systemic Lupus Erythematosus

OBJECTIVE

Patients with neuropsychiatric systemic lupus erythematosus (NPSLE) may exhibit corpus callosal atrophy and tissue alterations. Measuring the callosal volume and tissue integrity using diffusion tensor imaging (DTI) could help to differentiate patients with NPSLE from patients without NPSLE. Hence, this study aimed to use an automatic cell-competition algorithm to segment the corpus callosum and to investigate the effects of central nervous system (CNS) involvement on the callosal volume and tissue integrity in patients with SLE.

METHODS

Twenty-two SLE patients with (N = 10, NPSLE) and without (N = 12, non-NPSLE) CNS involvement and 22 control subjects were enrolled in this study. For volumetric measurement, a cell-competition algorithm was used to automatically delineate corpus callosal boundaries based on a midsagittal fractional anisotropy (FA) map. After obtaining corpus callosal boundaries for all subjects, the volume, FA, and mean diffusivity (MD) of the corpus callosum were calculated. A post hoc Tamhane's T2 analysis was performed to statistically compare differences among NPSLE, non-NPSLE, and control subjects. A receiver operating characteristic curve analysis was also performed to compare the performance of the volume, FA, and MD of the corpus callosum in differentiating NPSLE from other subjects.

RESULTS

Patients with NPSLE had significant decreases in volume and FA but an increase in MD in the corpus callosum compared with control subjects, whereas no significant difference was noted between patients without NPSLE and control subjects. The FA was found to have better performance in differentiating NPSLE from other subjects.

CONCLUSIONS

A cell-competition algorithm could be used to automatically evaluate callosal atrophy and tissue alterations. Assessments of the corpus callosal volume and tissue integrity helped to demonstrate the effects of CNS involvement in patients with SLE.

Advanced and Conventional Magnetic Resonance Imaging in Neuropsychiatric Lupus

Neuropsychiatric lupus is a major diagnostic challenge, and a main cause of morbidity and mortality in patients with systemic lupus erythematosus (SLE). Magnetic resonance imaging (MRI) is, by far, the main tool for assessing the brain in this disease. Conventional and advanced MRI techniques are used to help establishing the diagnosis, to rule out alternative diagnoses, and recently, to monitor the evolution of the disease. This review explores the neuroimaging findings in SLE, including the recent advances in new MRI methods.

Cognitive and White Matter Tract Differences in MS and Diffuse Neuropsychiatric Systemic Lupus Erythematosus

BACKGROUND AND PURPOSE

Multiple sclerosis and neuropsychiatric systemic lupus erythematosus are autoimmune diseases with similar CNS inflammatory and neurodegenerative characteristics. Our aim was to investigate white matter tract changes and their association with cognitive function in patients with MS and those with neuropsychiatric systemic lupus erythematosus compared with healthy controls by using diffusion tensor imaging.

MATERIALS AND METHODS

Thirty patients with relapsing-remitting MS and 23 patients with neuropsychiatric systemic lupus erythematosus matched for disease severity and duration and 43 healthy controls were scanned with 3T MR imaging. The DTI was postprocessed, corrected for lesions, and analyzed with tract-based spatial statistics. Cognitive assessment included examination of processing speed; visual, auditory/verbal, and visual-spatial memory; and sustained attention and executive function. Differences were considered significant at P < .05.

RESULTS

Tract-based spatial statistics analysis revealed significantly decreased fractional anisotropy and increased mean diffusivity in patients with MS compared with healthy controls, decreased fractional anisotropy in patients with MS compared with those with neuropsychiatric systemic lupus erythematosus, and an increased mean diffusivity in patients with neuropsychiatric systemic lupus erythematosus compared with healthy controls. Patients with MS showed decreased fractional anisotropy throughout central WM pathways, including the corpus callosum and the inferior longitudinal and fronto-occipital fasciculi compared with those with neuropsychiatric systemic lupus erythematosus. Altered cognitive scores in patients with MS were significantly associated with decreased fractional anisotropy and increased mean diffusivity in all examined domains, while in patients with diffuse neuropsychiatric systemic lupus erythematosus, only decreased fractional anisotropy in the superior WM pathways showed significant association with executive function.

CONCLUSIONS

Patients with MS and neuropsychiatric systemic lupus erythematosus showed widespread WM tract alterations outside overt lesions, though more severe changes were identified in patients with MS. The WM tract changes were associated with cognitive dysfunction in all explored domains only in patients with MS.

A multimodal MRI approach to identify and characterize microstructural brain changes in neuropsychiatric systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease with multi-organ involvement and results in neurological and psychiatric (NP) symptoms in up to 40% of the patients. To date, the diagnosis of neuropsychiatric systemic lupus erythematosus (NPSLE) poses a challenge due to the lack of neuroradiological gold standards. In this study, we aimed to better localize and characterize normal appearing white matter (NAWM) changes in NPSLE by combining data from two quantitative MRI techniques, diffusion tensor imaging (DTI) and magnetization transfer imaging (MTI). 9 active NPSLE patients (37 ± 13 years, all females), 9 SLE patients without NP symptoms (44 ± 11 years, all females), and 14 healthy controls (HC) (40 ± 9 years, all females) were included in the study. MTI, DTI and fluid attenuated inversion recovery (FLAIR) images were collected from all subjects on a 3 T MRI scanner. Magnetization transfer ratio (MTR), mean diffusivity (MD), fractional anisotropy (FA), radial diffusivity (RD), axial diffusivity (AD) maps and white matter lesion maps based on the FLAIR images were created for each subject. MTR and DTI data were then co-analyzed using tract-based spatial statistics and a cumulative lesion map to exclude lesions. Significantly lower MTR and FA and significantly higher AD, RD and MD were found in NPSLE compared to HC in NAWM regions. The differences in DTI measures and in MTR, however, were only moderately co-localized. Additionally, significant differences in DTI measures, but not in MTR, were found between NPSLE and SLE patients, suggesting that the underlying microstructural changes detected by MD are linked to the onset of NPSLE. The co-analysis of the anatomical distribution of MTI and DTI measures can potentially improve the diagnosis of NPSLE and contribute to the understanding of the underlying microstructural damage.

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NAWM is investigated in NPSLE and SLE using MTI and DTI.

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Differences in DTI and MTR between NPSLE and HC are widespread but only moderately co-localized.

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Significant differences in MD between SLE and NPSLE suggest link to onset of NPSLE.

Episodic memory impairment in systemic lupus erythematosus: involvement of thalamic structures

Episodic memory deficits in systemic lupus erythematosus (SLE) have been frequently reported in the literature; however, little is known about the neural correlates of these deficits. We investigated differences in the volumes of different brain structures of SLE patients with and without episodic memory impairments diagnosed by the Rey Auditory Verbal Learning Test (RAVLT). Groups were paired based on age, education, sex, Mini Mental State Examination score, accumulation of disease burden (SLICC), and focused attention dimension score. Patients underwent magnetic resonance imaging (MRI). Cortical volumetric reconstruction and segmentation of the MR images were performed with the FreeSurfer software program. SLE patients with episodic memory deficits presented shorter time of diagnosis than SLE patients without episodic memory deficits. ANOVA revealed that SLE patients with episodic memory deficits had a larger third ventricle volume than SLE patients without episodic memory deficits and controls. Additionally, covariance analysis indicated group effects on the bilateral thalamus and on the third ventricle. Our findings indicate that episodic memory may be impaired in SLE patients with normal hippocampal volume. In addition, the thalamus may undergo volumetric changes associated with episodic memory loss in SLE.

Brain abnormalities in newly diagnosed neuropsychiatric lupus: systematic MRI approach and correlation with clinical and laboratory data in a large multicenter cohort

OBJECTIVES

To describe brain magnetic resonance imaging (MRI) abnormalities in newly diagnosed neuropsychiatric lupus (NPSLE). To correlate them with clinical and laboratory data.

METHODS

This retrospective cross-sectional study included patients presenting NPSLE undergoing brain MRI within 6 months after onset between 2003 and 2012. Clinical and laboratory data were recorded. MRI findings were defined as inflammatory-like, large-vessel disease (LVD), and small-vessel disease (SVD); SVD was classified as white-matter hyperintensities (WMH), recent small subcortical infarcts, lacunes, microbleeds, and brain atrophy.

RESULTS

We included 108 patients (mean 40.6 ± 14.2 years; range 14-77), 91.7% women. The most frequent syndromes were headache (28.5%), cerebrovascular disease (15.5%), seizure (15.5%), and cognitive dysfunction (11.4%). Brain abnormalities were found in 59.3%. SVD was the most common (55.6%), followed by LVD (13%) and inflammatory-like lesions (6.5%). The most frequent SVD findings were WMH (53.7%), atrophy (18.5%), microbleeds (13.7%) and lacunes (11.1%). Cerebrovascular syndrome correlated with LVD (p = 0.001) and microbleeds (p = 0.002), cognitive dysfunction with WMH (p = 0.045) and myelopathy with inflammatory-like lesions (p = 0.020). Low C4 and CH50 correlated with inflammatory-like lesions (p < 0.001, p = 0.019) and lupus anticoagulant with WMH (p = 0.018), microbleeds (p = 0.002) and atrophy (p = 0.008).

CONCLUSIONS

Vascular disease is the hallmark of NPSLE. Certain syndromes and immunological patterns are prone to more extensive brain damage. MRI could provide significant clinical information and insights into the pathological substrate.

New insights into the impact of neuro-inflammation in rheumatoid arthritis

Rheumatoid arthritis (RA) is considered to be, in many respects, an archetypal autoimmune disease that causes activation of pro-inflammatory pathways resulting in joint and systemic inflammation. RA remains a major clinical problem with the development of several new therapies targeted at cytokine inhibition in recent years. In RA, biologic therapies targeted at inhibition of tumor necrosis factor alpha (TNFα) have been shown to reduce joint inflammation, limit erosive change, reduce disability and improve quality of life. The cytokine TNFα has a central role in systemic RA inflammation and has also been shown to have pro-inflammatory effects in the brain. Emerging data suggests there is an important bidirectional communication between the brain and immune system in inflammatory conditions like RA. Recent work has shown how TNF inhibitor therapy in people with RA is protective for Alzheimer's disease. Functional MRI studies to measure brain activation in people with RA to stimulus by finger joint compression, have also shown that those who responded to TNF inhibition showed a significantly greater activation volume in thalamic, limbic, and associative areas of the brain than non-responders. Infections are the main risk of therapies with biologic drugs and infections have been shown to be related to disease flares in RA. Recent basic science data has also emerged suggesting that bacterial components including lipopolysaccharide induce pain by directly activating sensory neurons that modulate inflammation, a previously unsuspected role for the nervous system in host-pathogen interactions. In this review, we discuss the current evidence for neuro-inflammation as an important factor that impacts on disease persistence and pain in RA.

Diminished white matter integrity in patients with systemic lupus erythematosus

Purpose

Systemic lupus erythematosus (SLE) is an autoimmune connective tissue disease that can affect the central nervous system. Neuropsychiatric symptoms are found in 25–70% of patients. Using diffusion tensor imaging (DTI) various studies have reported changes in white matter integrity in SLE patients with neuropsychiatric symptoms (NPSLE patients). The purpose of this study was to investigate, if regional changes in white matter integrity can also be detected in SLE patients without neuropsychiatric symptoms (non-NPSLE patients).

Methods

Applying DTI and tract based spatial statistics (TBSS) we investigated 19 NPSLE patients, 19 non-NPSLE and 18 healthy controls. Groups were matched for age and sex. Image pre-processing was performed using FSL, following the TBSS pipeline (eddy current correction, estimation of fractional anisotropy (FA), normalization, skeletonization of the group mean FA image). A general linear model with threshold-free cluster enhancement was used to assess significant differences between the three groups.

Results

Statistical analyses revealed several regions of decreased prefrontal white matter integrity (decreased FA) in both groups of SLE patients. The changes found in the non-NPSLE patients (as compared to healthy controls) overlapped with those in the NPSLE patients, but were not as pronounced.

Conclusions

Our data suggest that changes in regional white matter integrity, in terms of a decrease in FA, are present not only in NPSLE patients, but also in non-NPSLE patients, though to a lesser degree. We also demonstrate that the way statistical maps are corrected for multiple comparisons has a profound influence on whether alterations in white matter integrity in non-NPSLE patients are deemed significant.

Brain involvement in patients with inflammatory bowel disease: a voxel-based morphometry and diffusion tensor imaging study

OBJECTIVES

To investigate structural brain changes in inflammatory bowel disease (IBD).

METHODS

Brain magnetic resonance imaging (MRI) was performed on 18 IBD patients (aged 45.16 ± 14.71 years) and 20 aged-matched control subjects. The imaging protocol consisted of a sagittal-FLAIR, a T1-weighted high-resolution three-dimensional spoiled gradient-echo sequence, and a multisession spin-echo echo-planar diffusion-weighted sequence. Differences between patients and controls in brain volume and diffusion indices were evaluated using the voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS) methods, respectively. The presence of white-matter hyperintensities (WMHIs) was evaluated on FLAIR images.

RESULTS

VBM revealed decreased grey matter (GM) volume in patients in the fusiform and the inferior temporal gyrus bilaterally, the right precentral gyrus, the right supplementary motor area, the right middle frontal gyrus and the left superior parietal gyrus (p < 0.05). TBSS showed decreased axial diffusivity (AD) in the right corticospinal tract and the right superior longitudinal fasciculus in patients compared with controls. A larger number of WMHIs was observed in patients (p < 0.05).

CONCLUSIONS

Patients with IBD show an increase in WMHIs and GM atrophy, probably related to cerebral vasculitis and ischaemia. Decreased AD in major white matter tracts could be a secondary phenomenon, representing Wallerian degeneration.

KEY POINTS

• There is evidence of central nervous system involvement in IBD. • Diffusion tensor imaging detects microstructural brain abnormalities in IBD. • Voxel based morphometry reveals brain atrophy in IBD.