Hippocampal atrophy in systemic lupus erythematosus

Animal models of neuropsychiatric systemic lupus erythematosus: deciphering the complexity and guiding therapeutic development

Systemic lupus erythematosus (SLE) poses formidable challenges due to its multifaceted etiology while impacting multiple tissues and organs and displaying diverse clinical manifestations. Genetic and environmental factors contribute to SLE complexity, with relatively limited approved therapeutic options. Murine models offer insights into SLE pathogenesis but do not always replicate the nuances of human disease. This review critically evaluates spontaneous and induced animal models, emphasizing their validity and relevance to neuropsychiatric SLE (NPSLE). While these models undoubtedly contribute to understanding disease pathophysiology, discrepancies persist in mimicking some NPSLE intricacies. The lack of literature addressing this issue impedes therapeutic progress. We underscore the urgent need for refining models that truly reflect NPSLE complexities to enhance translational fidelity. We encourage a comprehensive, creative translational approach for targeted SLE interventions, balancing scientific progress with ethical considerations to eventually improve the management of NPSLE patients. A thorough grasp of these issues informs researchers in designing experiments, interpreting results, and exploring alternatives to advance NPSLE research.

Implications of Inflammatory Processes on a Developing Central Nervous System in Childhood-Onset Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that is increasingly affecting pediatric and adult populations. Neuropsychiatric manifestations (ie, cognitive dysfunction and mood disorders) appear to occur with greater severity and poorer prognosis in childhood-onset SLE (cSLE) versus adult-onset SLE, negatively impacting school function, self-management, and psychosocial health, as well as lifelong health-related quality of life. In this review, we describe pathogenic mechanisms active in cSLE, such as maladaptive inflammatory processes and ischemia, which are hypothesized to underpin central phenotypes in patients with cSLE, and the role of alterations in protective central nervous system (CNS) barriers (ie, the blood-brain barrier) are also discussed. Recent findings derived from novel neuroimaging approaches are highlighted because the methods employed in these studies hold potential for identifying CNS abnormalities that would otherwise remain undetected with conventional multiple resonance imaging studies (eg, T2-weighted or fluid-attenuated inversion recovery sequences). Furthermore, we propose that a more robust presentation of neuropsychiatric symptoms in cSLE is in part due to the harmful impact of a chronic inflammatory insult on a developing CNS. Although the immature status of the CNS may leave patients with cSLE more vulnerable to harboring neuropsychiatric manifestations, the same property may represent a greater urgency to reverse the maladaptive effects associated with a proneuroinflammatory state, provided that effective diagnostic tools and treatment strategies are available. Finally, considering the crosstalk among the CNS and other organ systems affected in cSLE, we postulate that a finer understanding of this interconnectivity and its role in the clinical presentation in cSLE is warranted.

Cytoarchitectureal changes in hippocampal subregions of the NZB/W F1 mouse model of lupus

Over 50% of clinical patients affected by the systemic lupus erythematosus disease display impaired neurological cognitive functions and psychiatric disorders, a form called neuropsychiatric systemic lupus erythematosus. Hippocampus is one of the brain structures most sensitive to the cognitive deficits and psychiatric disorders related to neuropsychiatric lupus. The purpose of this study was to compare, layer by layer, neuron morphology in lupus mice model NZB/W F1 versus Wild Type mice. By a morphometric of cells identified on Nissl-stained sections, we evaluated structural alterations between NZB/W F1 and Wild Type mice in seven hippocampal subregions: Molecular dentate gyrus, Granular dentate gyrus, Polymorph dentate gyrus, Oriens layer, Pyramidal layer, Radiatum layer and Lacunosum molecular layer. By principal component analysis we distinguished healthy Wild Type from NZB/W F1 mice. In NZB/W F1 mice hippocampal cytoarchitecture, the neuronal cells resulted larger in size and more regular than those of Wild Type. In NZB/W F1, neurons were usually denser than in WT. The Pyramidal layer neurons were much denser in Wild Type than in NZB/W F1. Application of principal component analysis, allowed to distinguish NZB/W F1 lupus mice from healthy, showing as NZBW subjects presented a scattered distribution and intrasubject variability. Our results show a hypertrophy of the NZB/W F1 hippocampal neurons associated with an increase in perikaryal size within the CA1, CA2, CA3 region and the DG. These results help advance our understanding on hippocampal organization and structure in the NZB/W F1 lupus model, suggesting the hypothesis that the different subregions could be differentially affected in neuropsychiatric systemic lupus erythematosus disease. Leveraging an in-depth analysis of the morphology of neural cells in the hippocampal subregions and applying dimensionality reduction using PCA, we propose an efficient methodology to distinguish pathological NZBW mice from WT mice."

Altered hippocampal connectivity dynamics predicts memory performance in neuropsychiatric lupus: a resting-state fMRI study using cross-recurrence quantification analysis

OBJECTIVE

Τo determine whole-brain and regional functional connectivity (FC) characteristics of patients with neuropsychiatric SLE (NPSLE) or without neuropsychiatric manifestations (non-NPSLE) and examine their association with cognitive performance.

METHODS

Cross-recurrence quantification analysis (CRQA) of resting-state functional MRI (rs-fMRI) data was performed in 44 patients with NPSLE, 20 patients without NPSLE and 35 healthy controls (HCs). Volumetric analysis of total brain and specific cortical and subcortical regions, where significant connectivity changes were identified, was performed. Cognitive status of patients with NPSLE was assessed by neuropsychological tests. Group comparisons on nodal FC, global network metrics and regional volumetrics were conducted, and associations with cognitive performance were estimated (at p<0.05 false discovery rate corrected).

RESULTS

FC in patients with NPSLE was characterised by increased modularity (mean (SD)=0.31 (0.06)) as compared with HCs (mean (SD)=0.27 (0.06); p=0.05), hypoconnectivity of the left (mean (SD)=0.06 (0.018)) and right hippocampi (mean (SD)=0.051 (0.0.16)), and of the right amygdala (mean (SD)=0.091 (0.039)), as compared with HCs (mean (SD)=0.075 (0.022), p=0.02; 0.065 (0.019), p=0.01; 0.14 (0.096), p=0.05, respectively). Hyperconnectivity of the left angular gyrus (NPSLE/HCs: mean (SD)=0.29 (0.26) and 0.10 (0.09); p=0.01), left (NPSLE/HCs: mean (SD)=0.16 (0.09) and 0.09 (0.05); p=0.01) and right superior parietal lobule (SPL) (NPSLE/HCs: mean (SD)=0.25 (0.19) and 0.13 (0.13), p=0.01) was noted in NPSLE versus HC groups. Among patients with NPSLE, verbal episodic memory scores were positively associated with connectivity (local efficiency) of the left hippocampus (r²=0.22, p=0.005) and negatively with local efficiency of the left angular gyrus (r²=0.24, p=0.003). Patients without NPSLE displayed hypoconnectivity of the right hippocampus (mean (SD)=0.056 (0.014)) and hyperconnectivity of the left angular gyrus (mean (SD)=0.25 (0.13)) and SPL (mean (SD)=0.17 (0.12)).

CONCLUSION

By using dynamic CRQA of the rs-fMRI data, distorted FC was found globally, as well as in medial temporal and parietal brain regions in patients with SLE, that correlated significantly and adversely with memory capacity in NPSLE. These results highlight the value of dynamic approaches to assessing impaired brain network function in patients with lupus with and without neuropsychiatric symptoms.

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.

Microstructural Changes in the Corpus Callosum in Systemic Lupus Erythematous

Central nervous system (CNS) involvement in childhood-onset systemic lupus erythematosus (cSLE) occurs in more than 50% of patients. Structural magnetic resonance imaging (MRI) has identified global cerebral atrophy, as well as the involvement of the corpus callosum and hippocampus, which is associated with cognitive impairment. In this cross-sectional study we included 71 cSLE (mean age 24.7 years (SD 4.6) patients and a disease duration of 11.8 years (SD 4.8) and two control groups: (1) 49 adult-onset SLE (aSLE) patients (mean age of 33.2 (SD 3.7) with a similar disease duration and (2) 58 healthy control patients (mean age of 29.9 years (DP 4.1)) of a similar age. All of the individuals were evaluated on the day of the MRI scan (Phillips 3T scanner). We reviewed medical charts to obtain the clinical and immunological features and treatment history of the SLE patients. Segmentation of the corpus callosum was performed through an automated segmentation method. Patients with cSLE had a similar mid-sagittal area of the corpus callosum in comparison to the aSLE patients. When compared to the control groups, cSLE and aSLE had a significant reduction in the mid-sagittal area in the posterior region of the corpus callosum. We observed significantly lower FA values and significantly higher MD, RD, and AD values in the total area of the corpus callosum and in the parcels B, C, D, and E in cSLE patients when compared to the aSLE patients. Low complement, the presence of anticardiolipin antibodies, and cognitive impairment were associated with microstructural changes. In conclusion, we observed greater microstructural changes in the corpus callosum in adults with cSLE when compared to those with aSLE. Longitudinal studies are necessary to follow these changes, however they may explain the worse cognitive function and disability observed in adults with cSLE when compared to aSLE.

Neuropsychiatric manifestations in childhood-onset systemic lupus erythematosus

Neuropsychiatric manifestations occur frequently and are challenging to diagnose in childhood-onset systemic lupus erythematosus (SLE). Most patients with childhood-onset SLE have neuropsychiatric events in the first 2 years of disease. 30-70% of patients present with more than one neuropsychiatric event during their disease course, with an average of 2-3 events per person. These symptoms are associated with disability and mortality. Serum, cerebrospinal fluid, and neuroimaging findings have been described in childhood-onset SLE; however, only a few have been validated as biomarkers for diagnosis, monitoring response to treatment, or prognosis. The aim of this Review is to describe the genetic risk, clinical and neuroimaging characteristics, and current treatment strategies of neuropsychiatric manifestations in childhood-onset SLE.

In vivo quantitative imaging of hippocampal inflammation in autoimmune neuroinflammatory conditions: a systematic review

The hippocampus is a morphologically complex region of the brain limbic system centrally involved in important cognitive, affective, and behavioural regulatory roles. It has exquisite vulnerability to neuroinflammatory processes, with some of its subregions found to be specific sites of neuroinflammatory pathology in ex-vivo studies. Optimizing neuroimaging correlates of hippocampal neuroinflammation would enable the direct study of functional consequences of hippocampal neuroinflammatory pathology, as well as the definition of therapeutic end-points for treatments targeting neuroinflammation, and their related affective or cognitive sequelae. However, in vivo traditional imaging of the hippocampus and its subregions is fraught with difficulties, due to methodological challenges deriving from its unique anatomical characteristics. The main objective of this review is to provide a current update on the characterization of quantitative neuroimaging correlates of hippocampal neuroinflammation by focusing on three prototypical autoimmune neuro-inflammatory conditions [multiple sclerosis (MS), systemic lupus erythematosus (SLE), and autoimmune encephalitis (AE)]. We focused on studies employing TSPO-targeting positron emission tomography (PET), quantitative magnetic resonance imaging (MRI), and spectroscopy techniques assumed to be sensitive to neuroinflammatory tissue changes. We found 18 eligible studies (14, 2, and 2 studies in MS, AE, and SLE, respectively). Across conditions, the largest effect was seen in TSPO PET and diffusion-weighted MRI studies. No study examined neuroinflammation-related changes at the hippocampal subfield level. Overall, results were largely inconsistent due to heterogeneous imaging methods, small sample sizes, and different population studies. We discuss how these data could inform future study design and conclude by suggesting further methodological directions aimed at improving the precision and sensitivity of neuroimaging techniques to characterize hippocampal neuroinflammatory pathology in the human brain.

Neurofilament light in plasma is a potential biomarker of central nervous system involvement in systemic lupus erythematosus

BACKGROUND

Neuropsychiatric manifestations (NP) are common in systemic lupus erythematosus (SLE). However, the pathophysiological mechanisms are not completely understood. Neurofilament light protein (NfL) is part of the neuronal cytoskeleton. Increased NfL concentrations, reflecting neurodegeneration, is observed in cerebrospinal fluid (CSF) in several neurodegenerative and neuroinflammatory conditions. We aimed to explore if plasma NfL could serve as a biomarker for central nervous system (CNS) involvement in SLE.

METHODS

Sixty-seven patients with SLE underwent neurological examination; 52 underwent lumbar puncture, while 62 underwent cerebral magnetic resonance imaging (MRI). We measured selected auto-antibodies and other laboratory variables postulated to have roles in NP pathophysiology in the blood and/or CSF. We used SPM12 software for MRI voxel-based morphometry.

RESULTS

Age-adjusted linear regression analyses revealed increased plasma NfL concentrations with increasing creatinine (β = 0.01, p < 0.001) and Q-albumin (β = 0.07, p = 0.008). We observed higher plasma NfL concentrations in patients with a history of seizures (β = 0.57, p = 0.014), impaired motor function (β = 0.36, p = 0.008), increasing disease activity (β = 0.04, p = 0.008), and organ damage (β = 0.10, p = 0.002). Voxel-based morphometry suggested an association between increasing plasma NfL concentrations and the loss of cerebral white matter in the corpus callosum and hippocampal gray matter.

CONCLUSION

Increased plasma NfL concentrations were associated with some abnormal neurological, cognitive, and neuroimaging findings. However, plasma NfL was also influenced by other factors, such as damage accrual, creatinine, and Q-albumin, thereby obscuring the interpretation of how plasma NfL reflects CNS involvement. Taken together, NfL in CSF seems a better marker of neuronal injury than plasma NfL in patients with SLE.

MRI-Based Classification of Neuropsychiatric Systemic Lupus Erythematosus Patients With Self-Supervised Contrastive Learning

Introduction/Purpose

Systemic lupus erythematosus (SLE) is a chronic auto-immune disease with a broad spectrum of clinical presentations, including heterogeneous neuropsychiatric (NP) syndromes. Structural brain abnormalities are commonly found in SLE and NPSLE, but their role in diagnosis is limited, and their usefulness in distinguishing between NPSLE patients and patients in which the NP symptoms are not primarily attributed to SLE (non-NPSLE) is non-existent. Self-supervised contrastive learning algorithms proved to be useful in classification tasks in rare diseases with limited number of datasets. Our aim was to apply self-supervised contrastive learning on T1-weighted images acquired from a well-defined cohort of SLE patients, aiming to distinguish between NPSLE and non-NPSLE patients.

Subjects and Methods

We used 3T MRI T1-weighted images of 163 patients. The training set comprised 68 non-NPSLE and 34 NPSLE patients. We applied random geometric transformations between iterations to augment our data sets. The ML pipeline consisted of convolutional base encoder and linear projector. To test the classification task, the projector was removed and one linear layer was measured. Validation of the method consisted of 6 repeated random sub-samplings, each using a random selection of a small group of patients of both subtypes.

Results

In the 6 trials, between 79% and 83% of the patients were correctly classified as NPSLE or non-NPSLE. For a qualitative evaluation of spatial distribution of the common features found in both groups, Gradient-weighted Class Activation Maps (Grad-CAM) were examined. Thresholded Grad-CAM maps show areas of common features identified for the NPSLE cohort, while no such communality was found for the non-NPSLE group.

Discussion/Conclusion

The self-supervised contrastive learning model was effective in capturing common brain MRI features from a limited but well-defined cohort of SLE patients with NP symptoms. The interpretation of the Grad-CAM results is not straightforward, but indicates involvement of the lateral and third ventricles, periventricular white matter and basal cisterns. We believe that the common features found in the NPSLE population in this study indicate a combination of tissue loss, local atrophy and to some extent that of periventricular white matter lesions, which are commonly found in NPSLE patients and appear hypointense on T1-weighted images.

Structure, Function, and Pharmacology of Glutamate Receptor Ion Channels

Many physiologic effects of l-glutamate, the major excitatory neurotransmitter in the mammalian central nervous system, are mediated via signaling by ionotropic glutamate receptors (iGluRs). These ligand-gated ion channels are critical to brain function and are centrally implicated in numerous psychiatric and neurologic disorders. There are different classes of iGluRs with a variety of receptor subtypes in each class that play distinct roles in neuronal functions. The diversity in iGluR subtypes, with their unique functional properties and physiologic roles, has motivated a large number of studies. Our understanding of receptor subtypes has advanced considerably since the first iGluR subunit gene was cloned in 1989, and the research focus has expanded to encompass facets of biology that have been recently discovered and to exploit experimental paradigms made possible by technological advances. Here, we review insights from more than 3 decades of iGluR studies with an emphasis on the progress that has occurred in the past decade. We cover structure, function, pharmacology, roles in neurophysiology, and therapeutic implications for all classes of receptors assembled from the subunits encoded by the 18 ionotropic glutamate receptor genes. SIGNIFICANCE STATEMENT: Glutamate receptors play important roles in virtually all aspects of brain function and are either involved in mediating some clinical features of neurological disease or represent a therapeutic target for treatment. Therefore, understanding the structure, function, and pharmacology of this class of receptors will advance our understanding of many aspects of brain function at molecular, cellular, and system levels and provide new opportunities to treat patients.

The diverse and complex modes of action of anti-NMDA receptor autoantibodies

NMDA receptors are ligand-gated ion channels that are found throughout the brain and are required for both brain development and many higher order functions. A variety of human patients with diverse clinical phenotypes have been identified that carry autoantibodies directed against NMDA receptor subunits. Here we focus on two general classes of autoantibodies, anti-GluN1 antibodies associated with anti-NMDA receptor encephalitis and anti-GluN2 antibodies associated with systemic lupus erythematosus (SLE). These two general classes of anti-NMDA receptor autoantibodies display a wide range of pathophysiological mechanisms from altering synaptic composition to gating of NMDARs. While we have made progress in understanding how these autoantibodies work at the molecular and cellular level, many unanswered questions remain including their long-term actions on brain function, the significance of clonal variations, and their effects on different NMDA receptor-expressing cell types in local circuits. This information will be needed to define fully the transition from anti-NMDA receptor autoantibodies to a clinical phenotype.

TWEAKing the Hippocampus: The Effects of TWEAK on the Genomic Fabric of the Hippocampus in a Neuropsychiatric Lupus Mouse Model

Neuropsychiatric manifestations of systemic lupus erythematosus (SLE), specifically cognitive dysfunction and mood disorders, are widely prevalent in SLE patients, and yet poorly understood. TNF-like weak inducer of apoptosis (TWEAK) has previously been implicated in the pathogenesis of neuropsychiatric lupus (NPSLE), and we have recently shown its effects on the transcriptome of the cortex of the lupus-prone mice model MRL/lpr. As the hippocampus is thought to be an important focus of NPSLE processes, we explored the TWEAK-induced transcriptional changes that occur in the hippocampus, and isolated several genes (Dnajc28, Syne2, transthyretin) and pathways (PI3K-AKT, as well as chemokine-signaling and neurotransmission pathways) that are most differentially affected by TWEAK activation. While the functional roles of these genes and pathways within NPSLE need to be further investigated, an interesting link between neuroinflammation and neurodegeneration appears to emerge, which may prove to be a promising novel direction in NPSLE research.

Different phenotypes of neuropsychiatric systemic lupus erythematosus are related to a distinct pattern of structural changes on brain MRI

Objectives

The underlying structural brain correlates of neuropsychiatric involvement in systemic lupus erythematosus (NPSLE) remain unclear, thus hindering correct diagnosis.

We compared brain tissue volumes between a clinically well-defined cohort of patients with NPSLE and SLE patients with neuropsychiatric syndromes not attributed to SLE (non-NPSLE). Within the NPSLE patients, we also examined differences between patients with two distinct disease phenotypes: ischemic and inflammatory.

Methods

In this prospective (May 2007 to April 2015) cohort study, we included 38 NPSLE patients (26 inflammatory and 12 ischemic) and 117 non-NPSLE patients. All patients underwent a 3-T brain MRI scan that was used to automatically determine white matter, grey matter, white matter hyperintensities (WMH) and total brain volumes. Group differences in brain tissue volumes were studied with linear regression analyses corrected for age, gender, and total intracranial volume and expressed as B values and 95% confidence intervals.

Results

NPSLE patients showed higher WMH volume compared to non-NPSLE patients (p = 0.004). NPSLE inflammatory patients showed lower total brain (p = 0.014) and white matter volumes (p = 0.020), and higher WMH volume (p = 0.002) compared to non-NPSLE patients. Additionally, NPSLE inflammatory patients showed lower white matter (p = 0.020) and total brain volumes (p = 0.038) compared to NPSLE ischemic patients.

Conclusion

We showed that different phenotypes of NPSLE were related to distinct patterns of underlying structural brain MRI changes. Especially the inflammatory phenotype of NPSLE was associated with the most pronounced brain volume changes, which might facilitate the diagnostic process in SLE patients with neuropsychiatric symptoms.

Key Points

• Neuropsychiatric systemic lupus erythematosus (NPSLE) patients showed a higher WMH volume compared to SLE patients with neuropsychiatric syndromes not attributed to SLE (non-NPSLE).

• NPSLE patients with inflammatory phenotype showed a lower total brain and white matter volume, and a higher volume of white matter hyperintensities, compared to non-NPSLE patients.

• NPSLE patients with inflammatory phenotype showed lower white matter and total brain volumes compared to NPSLE patients with ischemic phenotype.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-021-07970-2.

Cognitive Impairment in SLE: Mechanisms and Therapeutic Approaches

A wide range of patients with systemic lupus erythematosus (SLE) suffer from cognitive dysfunction (CD) which severely impacts their quality of life. However, CD remains underdiagnosed and poorly understood. Here, we discuss current findings in patients and in animal models. Strong evidence suggests that CD pathogenesis involves known mechanisms of tissue injury in SLE. These mechanisms recruit brain resident cells, in particular microglia, into the pathological process. While systemic immune activation is critical to central nervous system injury, the current focus of therapy is the microglial cell and not the systemic immune perturbation. Further studies are critical to examine additional potential therapeutic targets and more specific treatments based on the cause and progress of the disease.

Combined Brain/Heart Magnetic Resonance Imaging in Systemic Lupus Erythematosus

Cardiovascular Disease (CVD) in Systemic Lupus Erythematosus (SLE) and Neuropsychiatric SLE (NPSLE) has an estimated prevalence of 50% and 40%, respectively and both constitute major causes of death among SLE patients. In this review, a combined brain/heart Magnetic Resonance Imaging (MRI) for SLE risk stratification has been proposed.

The pathophysiologic background of NPSLE includes microangiopathy, macroscopic infarcts and accelerated atherosclerosis. Classic brain MRI findings demonstrate lesions suggestive of NPSLE in 50% of the NPSLE cases, while advanced MRI indices can detect pre-clinical lesions in the majority of them, but their clinical impact still remains unknown. Cardiac involvement in SLE includes myo-pericarditis, valvular disease/endocarditis, Heart Failure (HF), coronary macro-micro-vascular disease, vasculitis and pulmonary hypertension. Classic and advanced Cardiovascular Magnetic Resonance (CMR) indices allow function and tissue characterization for early diagnosis and treatment follow-up of CVD in SLE.

Although currently, there are no clinical data supporting the combined use of brain/heart MRI in asymptomatic SLE, it may have a place in cases with clinical suspicion of brain/heart involvement, especially in patients at high risk for CVD/stroke such as SLE with antiphospholipid syndrome (SLE/APS), in whom concurrent cardiac and brain lesions have been identified. Furthermore, it may be of value in SLE with multi-organ involvement, NPSLE with concurrent cardiac involvement, and recent onset of arrhythmia and/or heart failure.

Hippocampal Atrophy in Systemic Lupus Erythematosus Patients without Major Neuropsychiatric Manifestations

This study was conducted to explore hippocampal structural changes and their possible associations with clinical characteristics, emotional status, and treatment regimens in patients with systemic lupus erythematosus (SLE) without major neuropsychiatric manifestations (non-NPSLE). Eighty-five non-NPSLE patients with normal conventional magnetic resonance imaging (MRI) and seventy-seven matched healthy control (HC) subjects were recruited. All participants underwent the standard high-resolution volumetric MRI. The bilateral hippocampal volume (HIPV) and hippocampal density (HIPD) were calculated, respectively, for each participant. We found that the bilateral HIPV and HIPD of the SLE patient group were significantly less than those of the HC group. The bilateral HIPV of female patients were significantly less than those of male patients. The SLE disease activity index (SLEDAI) was negatively correlated with the bilateral HIPV and the right HIPD. Urine protein quantity was negatively correlated with the bilateral HIPV and HIPD. Hydroxychloroquine (HCQ) showed a protective effect on right HIPV. In conclusion, we found that the early hippocampal atrophy could occur before obvious neuropsychiatric manifestations and might be associated with SLE disease activity and organ damages. Early detection and intervention of hippocampal damage might prevent the progression to NPSLE. More studies are needed to fully understand the underlying mechanisms of hippocampal atrophy in SLE.

Lupus autoantibodies act as positive allosteric modulators at GluN2A-containing NMDA receptors and impair spatial memory

Patients with Systemic lupus erythematosus (SLE) experience various peripheral and central nervous system manifestations including spatial memory impairment. A subset of autoantibodies (DNRAbs) cross-react with the GluN2A and GluN2B subunits of the NMDA receptor (NMDAR). We find that these DNRAbs act as positive allosteric modulators on NMDARs with GluN2A-containing NMDARs, even those containing a single GluN2A subunit, exhibiting a much greater sensitivity to DNRAbs than those with exclusively GluN2B. Accordingly, GluN2A-specific antagonists provide greater protection from DNRAb-mediated neuronal cell death than GluN2B antagonists. Using transgenic mice to perturb expression of either GluN2A or GluN2B in vivo, we find that DNRAb-mediated disruption of spatial memory characterized by early neuronal cell death and subsequent microglia-dependent pathologies requires GluN2A-containing NMDARs. Our results indicate that GluN2A-specific antagonists or negative allosteric modulators are strong candidates to treat SLE patients with nervous system dysfunction.

Systemic lupus erythematosus (SLE) is an autoimmune disorder which can have neurological manifestations, including autoantibody targeting of the NMDA receptor. In this study, the authors GluN2A subunit is a target of SLE autoantibodies, using sample derived from patient.

Large-Scale Validation of the Paddling Pool Task in the Clockmaze for Studying Hippocampus-Based Spatial Cognition in Mice

Rationally designed behavioral tests are important tools to assess the function of specific brain regions. The hippocampus is a crucial neural substrate for spatial cognition, and many studies have linked hippocampal dysfunction with defects on spatial learning and memory in neurological conditions ranging from Alzheimer’s disease to autoimmune syndromes, such as neuropsychiatric lupus. While our understanding of hippocampal function, from the molecular to the system levels, has increased dramatically over the last decades, this effort has not yet translated into efficacious therapies for cognitive impairment. We think that the availability of highly validated behavioral paradigms to measure cognition in mouse models is likely to enhance the potential success of preclinical therapeutic modalities. Here, we present an extensive study of the paddling pool task (PPT), first reported by Deacon and Rawlins, in which mice learn to escape from shallow water through a peripheral exit in a circular arena dubbed the clockmaze. We show that the PPT provides highly reliable results when assaying spatial cognition in C57/BL6 mice (120 males, 40 females) and BALB/c mice (40 males, 90 females). Additionally, we develop a robust algorithm for the assessment of escape strategies with clearly quantifiable readouts, enabling fine-granular phenotyping. Notably, the use of spatial strategy increases linearly across trials in the PPT. In a separate cohort of mice, we apply muscimol injections to silence the dorsal CA1 region of the hippocampus and show that the use of the spatial strategy in the PPT relies on the integrity of the dorsal hippocampus. Additionally, we compare directly the PPT and the Morris water maze (MWM) task in C57/BL6 mice (20 males, 20 females) and BALB/c mice (20 males, 20 females) and we find that the PPT induces significantly lower anxiety, exhaustion and hypothermia than the MWM. We conclude that the PPT provides a robust assessment of spatial cognition in mice, which can be applied in conjunction with other tests, to facilitate hypothesis testing and drug development to combat cognitive impairment.

Metabolic and microstructural alterations in the SLE brain correlate with cognitive impairment

To address challenges in the diagnosis of cognitive dysfunction (CD) related to systemic lupus erythematosus-associated (SLE-associated) autoimmune mechanisms rather than confounding factors, we employed an integrated approach, using resting-state functional (FDG-PET) and structural (diffusion tensor imaging [DTI]) neuroimaging techniques and cognitive testing, in adult SLE patients with quiescent disease and no history of neuropsychiatric illness. We identified resting hypermetabolism in the sensorimotor cortex, occipital lobe, and temporal lobe of SLE subjects, in addition to validation of previously published resting hypermetabolism in the hippocampus, orbitofrontal cortex, and putamen/GP/thalamus. Regional hypermetabolism demonstrated abnormal interregional metabolic correlations, associated with impaired cognitive performance, and was stable over 15 months. DTI analyses demonstrated 4 clusters of decreased microstructural integrity in white matter tracts adjacent to hypermetabolic regions and significantly diminished connecting tracts in SLE subjects. Decreased microstructural integrity in the parahippocampal gyrus correlated with impaired spatial memory and increased serum titers of DNRAb, a neurotoxic autoantibody associated with neuropsychiatric lupus. These findings of regional hypermetabolism, associated with decreased microstructural integrity and poor cognitive performance and not associated with disease duration, disease activity, medications, or comorbid disease, suggest that this is a reproducible, stable marker for SLE-associated CD that may be may be used for early disease detection and to discriminate between groups, evaluate response to treatment strategies, or assess disease progression.

Longitudinal evaluation of diffusion tensor imaging and cognition in systemic lupus erythematosus

Objective

This pilot study aimed to examine longitudinal changes in brain structure and function in patients with systemic lupus erythematosus (SLE) using diffusion tensor imaging (DTI) and neuropsychological testing.

Methods

Fifteen female SLE patients with no history of major neuropsychiatric (NP) manifestations had brain magnetic resonance imaging (MRI) with DTI at baseline and approximately 1.5 years later. At the same time points, a standardized battery of cognitive tests yielding a global cognitive impairment index (CII) was administered. At baseline, the SLE patients had mean age of 34.0 years (SD = 11.4), mean education of 14.9 years (SD = 2.1), and mean disease duration of 121.5 months (SD = 106.5). The MRI images were acquired with a 3T GE MRI scanner. A DTI sequence with 33 diffusion directions and b-value of 800 s/mm2 was used. Image acquisition time was about 10 minutes.

Results

No significant change in cognitive dysfunction (from the CII) was detected. Clinically evaluated MRI scans remained essentially unchanged, with 62% considered normal at both times, and the remainder showing white matter (WM) hyperintensities that remained stable or resolved. DTI showed decreased fractional anisotropy (FA) and increased mean diffusivity (MD) in bilateral cerebral WM and gray matter (GM) with no major change in NP status, medical symptoms, or medications over time. Lower FA was found in the following regions: left and right cerebral WM, and in GM areas including the parahippocampal gyrus, thalamus, precentral gyrus, postcentral gyrus, angular gyrus, parietal lobe, and cerebellum. Greater MD was found in the following regions: left and right cerebral WM, frontal cortex, left cerebral cortex, and the putamen.

Conclusions

This is the first longitudinal study of DTI and cognition in SLE, and results disclosed changes in both WM and GM without cognitive decline over an 18-month period. DTI abnormalities in our participants were not associated with emergent NP activity, medical decline, or medication changes, and the microstructural changes developed in the absence of macrostructural abnormalities on standard MRI. Microstructural changes may relate to ongoing inflammation, and the stability of cognitive function may be explained by medical treatment, the variability of NP progression in SLE, or the impact of cognitive reserve.

The role of ophthalmic imaging in central nervous system degeneration in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune connective tissue disorder that can involve any organ system. Central nervous system involvement can be a severe life threatening complication, ultimately resulting in severe neurodegenerative changes. Magnetic resonance imaging suggests that neurodegeneration, which may have deleterious effects on brain function, may occur early in SLE and experimental models suggest that neuroprotection may be feasible and beneficial. The retina is an extension of the brain. Recent ophthalmic imaging technologies are capable of identifying early changes in retinal and choroidal morphology and circulation that may reflect CNS degeneration. However, their utility in monitoring CNS involvement in SLE has been poorly studied as these have only been performed in small cohorts, in a cross-sectional design, non-quantitatively and without correlation to disease activity. The authors aim to review the current understanding of neurodegeneration associated with SLE, with particular focus on the visual pathway. We describe the neuropathology of the visual system in SLE and the evidence for retinal and choroidal neurodegenerative and microvascular changes using optical coherence tomography technology. We aim to describe the potential role of optical imaging modalities in NPSLE diagnosis and their likely impact on the study of neuronal function.

Abnormal increase of neuronal precursor cells and exacerbated neuroinflammation in the corpus callosum in murine model of systemic lupus erythematosus

Purpose: Systemic Lupus Erythematosus (SLE) is an autoimmune disease which is characterised by elevated levels of autoantibodies and cytokines in the body. Via alteration of the regulation of inflammation, damage to different organ systems, including the central nervous system (CNS), was found in SLE patients. Patients diagnosed with SLE were reported to suffer from different kinds of psychiatric signs and symptoms. As neurogenesis has been suggested to be a potential key player of psychiatric symptoms and emotional behavior disturbances, this study aims to investigate whether neurogenesis is altered in an animal model of SLE. Also, neuroinflammation was studied.

Methods: Female NZB/W F1 mice were used as an animal model of SLE. Animals were divided into two groups: 1. pre-diseased mice (lupus-prone NZB/W F1 female mice, age 10–15 weeks, negative for proteinuria and with basal levels of serum anti-dsDNA autoantibodies) and 2. diseased mice (NZB/W F1 female mice, > 25 weeks of age, with elevated serum levels of anti-dsDNA autoantibodies and with persistent proteinuria of > 3 mg/ml for more than 2 weeks). Comparisons of the levels of neurogenesis and neuroinflammtion between two groups of mice were studied by the immunohistochemistry.

Results: After the onset of SLE symptoms, a reduction of neurogenesis in the hippocampus was found, while there was a dramatic increase of doublecortin (DCX+) neuronal precursor cells in the corpus callosum (CC) and in the subventricular zone (SVZ). Meanwhile, exacerbated inflammation was present in the corpus callosum of the diseased mice, which was suggested by the increased number of GFAP+ cells and IBA-1+ cells.

Conclusions: To the best of our knowledge, this is the first study showing an increase of neuronal precursor cells in the corpus callosum of the female NZB/W F1 mice. The present study suggests a coincidence but not a causal relationship between neurogenesis and neuroinflammation. The present results have also provided new insight showing that the altered neurogenesis and neuroinflammation may be a potential neurological mechanism for the cognitive and mood disturbance found in the SLE patients.

A Conscious Resting State fMRI Study in SLE Patients Without Major Neuropsychiatric Manifestations

Neuropsychiatric systemic lupus erythematosus (NPSLE) is one of the main causes of death in patients with systemic lupus erythematosus (SLE). Signs and symptoms of NPSLE are heterogeneous, and it is hard to diagnose, and treat NPSLE patients in the early stage. We conducted this study to explore the possible brain activity changes using resting state functional magnetic resonance imaging (rs-fMRI) in SLE patients without major neuropsychiatric manifestations (non-NPSLE patients). We also tried to investigate the possible associations among brain activity, disease activity, depression, and anxiety. In our study, 118 non-NPSLE patients and 81 healthy controls (HC) were recruited. Rs-fMRI data were used to calculate the regional homogeneity (ReHo) in all participants. We found decreased ReHo values in the fusiform gyrus and thalamus and increased ReHo values in the parahippocampal gyrus and uncus. The disease activity was positively correlated with ReHo values of the cerebellum and negatively correlated with values in the frontal gyrus. Several brain areas showed correlations with depressive and anxiety statuses. These results suggested that abnormal brain activities might occur before NPSLE and might be the foundation of anxiety and depression symptoms. Early detection and proper treatment of brain dysfunction might prevent the progression to NPSLE. More studies are needed to understand the complicated underlying mechanisms.

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.

S100β is associated with cognitive impairment in childhood-onset systemic lupus erythematosus patients

Objective

To investigate serologic S100β protein levels in childhood-onset SLE patients (cSLE) and to elucidate their association with disease activity and neuropsychiatric (NP) manifestations.

Methods

We included 71 cSLE patients (67 females; median age 18 years; range 9–37 and 53 (47 females; median age of 20 years; range 6–29) age and sex matched healthy controls. Neurological manifestations were analysed according to the American College of Rheumatology (ACR) criteria. Cognitive evaluation was performed in all participants using Wechsler Intelligence Scale for Children (WISC-III) and Wechsler Adult Intelligence Scale (WAIS), according to age, and validated in Portuguese. SLE patients were further assessed for clinical and laboratory SLE manifestations, disease activity (SLE Disease Activity Index (SLEDAI)), damage (Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI)) and current drug exposures. Sera S100β protein levels were measured by enzyme-linked immunosorbent assay using commercial kits.

Results

The median S100β protein level was 116.55 pg/mL (range 1.53–468.50) in cSLE and 54.98 pg/mL (range 0.69–181.00) in healthy controls ( p < 0.001). An association was observed between S100β protein and NP manifestations ( p = 0.03). The S100β protein levels was associated with cognitive impairment in cSLE patients ( p = 0.006).

Conclusions

S100β protein levels are increased in cSLE with cognitive impairment. S100β may be considered a potential biomarker that underlies central nervous system (CNS) dysfunction, especially cognitive impairment.

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.

Retinal nerve fiber layer thickness and neuropsychiatric manifestations in systemic lupus erythematosus

Background

Cognitive impairment is frequent in systemic lupus erythematosus. Atrophy of the corpus callosum and hippocampus have been reported in patients with systemic lupus erythematosus, and diffusion tensor imaging studies have shown impaired white matter integrity, suggesting that white matter damage in systemic lupus erythematosus may underlie the cognitive impairment as well as other neuropsychiatric systemic lupus erythematosus manifestations. Retinal nerve fiber layer thickness, as assessed by optical coherence tomography, has been suggested as a biomarker for white matter damage in neurologic disorders such as multiple sclerosis, Alzheimer’s disease and Parkinson’s disease. Retinal nerve fiber layer thinning may occur early, even in patients with mild clinical symptoms.

Aim

The objective of this study was to assess the association of retinal nerve fiber layer thickness, as a biomarker of white matter damage in systemic lupus erythematosus patients, with neuropsychiatric systemic lupus erythematosus manifestations, including cognitive impairment.

Methods

Twenty-one consecutive patients with systemic lupus erythematosus underwent neuropsychological testing using a validated computerized battery of tests as well as the Rey-Auditory verbal learning test. All 21 patients, as well as 11 healthy, age matched controls, underwent optical coherence tomography testing to assess retinal nerve fiber layer thickness. Correlations between retinal nerve fiber layer thickness and results in eight cognitive domains assessed by the computerized battery of tests as well as the Rey-Auditory verbal learning test were assessed in patients with systemic lupus erythematosus, with and without neuropsychiatric systemic lupus erythematosus, and compared to retinal nerve fiber layer thickness in healthy controls.

Results

No statistically significant correlation was found between retinal nerve fiber layer thickness in patients with systemic lupus erythematosus as compared to healthy controls. When evaluating by subgroups, no correlation was found between patients with or without neuropsychiatric systemic lupus erythematosus or cognitive impairment and retinal nerve fiber layer thickness.

Conclusion

Retinal nerve fiber layer thickness of systemic lupus erythematosus patients was not found to be statistically different compared to controls. Within systemic lupus erythematosus patients there was no correlation between retinal nerve fiber layer thickness and cognitive impairment or other neuropsychiatric systemic lupus erythematosus manifestations.

Reduced volumes of the CA1 and CA4-dentate gyrus hippocampal subfields in systemic lupus erythematosus

Introduction There is evidence for hippocampal dysfunctions in systemic lupus erythematosus (SLE), which may contribute to neuropsychiatric impairments. However, fine structural alterations of the hippocampus have not been investigated in SLE. Methods We measured the volume of hippocampal subfields in 18 SLE patients and 20 healthy control individuals matched for age, gender, and education. The MRI protocol included structural T1 volumes (Philips Achieva 3T scanner, magnetization-prepared rapid acquisition gradient echo (MPRAGE)). For image processing, we used the neuGRID platform and the longitudinal pipeline of FreeSurfer v6.0 with the "hipposubfields" flag. Results Patients with SLE showed reduced volumes of CA1 (Cornu Ammonis 1) and CA4-dentate gyrus subfields relative to the control individuals. Smaller CA1 volumes were associated with worse performance on the Addenbrooke's Cognitive Examination. Conclusions These preliminary results indicate a prominent vulnerability and functional relevance of the CA1 hippocampal subfield in SLE.

Spatial Working Memory Impairment in Patients with Non-neuropsychiatric Systemic Lupus Erythematosus: A Blood-oxygen-level Dependent Functional Magnetic Resonance Imaging Study

OBJECTIVE

Using ethology and functional magnetic resonance imaging (fMRI) to explore mild cognitive dysfunction and spatial working memory (WM) impairment in patients with systemic lupus erythematosus (SLE) without overt neuropsychiatric symptoms (non-NPSLE) and to study whether any clinical biomarkers could serve as predictors of brain dysfunction in this disease.

METHODS

Eighteen non-NPSLE patients and 18 matched subjects were all tested using the Montreal cognitive assessment scale test and scanned using blood-oxygen-level dependent fMRI while performing the n-back task to investigate the activation intensity of some cognition-related areas.

RESULTS

Ethology results showed that non-NPSLE patients had mild cognitive dysfunction and memory dysfunction (p < 0.05). The fMRI scan confirmed a neural network consisting of bilateral dorsolateral prefrontal cortex (DLPFC), premotor area, parietal lobe, and supplementary motor area (SMA)/anterior cingulate cortex (ACC) that was activated during the n-back task, with right hemisphere dominance. However, only the right SMA/ACC showed a load effect in the non-NPSLE group; the activation intensity of most WM-related brain areas for the non-NPSLE group was lower than for the control group under 3 memory loads. Further, we found that the activation intensity of some cognition-related areas, including the bilateral caudate nucleus/insula and hippocampus/parahippocampal gyrus were lower than the control group under the memory loads. An inverse correlation existed between individual activation intensity and disease duration.

CONCLUSION

Non-NPSLE-related brain damage with right DLPFC-posterior parietal lobe and parahippocampal gyrus default network causes impairment of spatial WM and mild cognitive dysfunction. Patients with longer disease duration would be expected to exhibit increased central nervous system damage.

Neurological Manifestations in Systemic Lupus Erythematosus: A Single Centre Study from North East India

INTRODUCTION

Neurological manifestations although common in Systemic Lupus Erythematosus (SLE), are often not recognized due to their diversed and varied presentation. Therefore, the study was planned to highlight the pattern of neurological involvement in SLE to help in early recognition.

AIM

To study the pattern of neurological involvement in SLE and its correlation with disease activity and different investigation.

MATERIALS AND METHODS

This hospital based prospective observational study was carried out from August 2009 to July 2010. Diagnosed cases of SLE [based upon American Rheumatism Association (ARA) criteria] who presented with neurological manifestations at the time of diagnosis or develop during the course of the disease were included in the study. They were assessed clinically and investigated with neuroimaging and neurophysiological tests as applicable.

RESULTS

In total, 52 consecutive patients with SLE were evaluated, 92% were female. The most common age group was 21 to 25 years. Nervous system involvement was found in 19 (36.54%) patients. Cognitive impairment was the most frequent manifestation, present in 11 (57.89%) patients followed by seizure disorder in eight patients (42.1%). Peripheral neuropathy was diagnosed in eight (42.1%), acute confusional state in six (31.57%) and headache and depression was diagnosed in five (26.31%) patients each. Less common manifestations were psychosis, movement disorder and aseptic meningitis. Percentage of neurological manifestations directly correlated with disease activity. A significant difference was found in Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score between the patients with Neuro Psychiatric Systemic Lupus Erythematosus (NPSLE) and those without NPSLE (32.42±16.34 Vs 17.3±10.6).

CONCLUSION

Neurological involvement in SLE is seen relatively early in the course of the disease with cognitive impairment being the most common manifestation and correlate with disease activity.

Abnormality in hippocampal signal intensity predicts atrophy in patients with systemic lupus erythematosus

Objectives

To quantify signal abnormalities in the hippocampus (Hsig) of patients with systemic lupus erythematosus (SLE) and to determine if Hsig predict hippocampal atrophy (HA) in SLE.

Methods

We included all SLE patients and healthy age- and sex-matched individuals with two magnetic resonance imaging (MRI) scans performed with a minimum of 1 year interval. All individuals underwent a standardized neuropsychological evaluation. Individual results were converted into standard scores and compared to normative data. SLE patients were additionally assessed for disease activity (SLE Disease Activity Index (SLEDAI)), damage (Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI)), and the presence of antiphospholipid antibodies. MRI was performed on an Elscint 2 T scanner and T1 inversion recovery and T2 coronal images were used for analysis. Volumetric (HV) and signal quantification (Hsig) were determined by standardized protocols.

Results

We included 54 SLE patients (48 women; mean age 32.2 ± 10.56 years). Hsig were found at study entry in 15 (45.5%) patients. Hsig in the body and tail of non-atrophic hippocampi correlated with progression of volume loss during the follow-up period ( r = 0.8, p < 0.001). The presence of Hsig in the head of atrophic hippocampi correlated with progression of HA ( r = 0.73, p = 0.005) during the same period. No correlation of Hsig and disease activity or prednisone dose was observed.

Conclusion

HA is frequently observed in SLE patients and volume loss is progressive in a subgroup of patients. The evaluation of Hsig is an easy tool to determine patients that may have progressive hippocampal volume loss and should be followed more closely with MRI and cognitive evaluation.

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.

The effects of corticosteroids on cognitive flexibility and decision-making in women with lupus

The aim of this study was to investigate the possible effects of corticosteroids in women with systemic lupus erythematosus (SLE) in two processes of executive function: cognitive flexibility and decision-making. To that end, we evaluated 121 women divided into three groups: 50 healthy women, 38 women with SLE not receiving corticosteroid treatment and 33 women with SLE receiving corticosteroid treatment. Cognitive flexibility was measured with the Trail Making Tests A and B; decision-making was measured with the Iowa Gambling Task. Additionally, demographic (age and education level), clinical (SLE Disease Activity Index (SLEDAI), Systemic Lupus International Collaborating Clinics (SLICC)/American College of Rheumatology (ACR) Damage Index (SDI) and disease duration) and psychological characteristics (stress vulnerability, perceived stress and psychopathic symptomatology) were evaluated. The results showed that both SLE groups displayed poorer decision-making than the healthy women ( p = 0.006) and also that the SLE group receiving corticosteroid treatment showed lower cognitive flexibility than the other two groups ( p = 0.030). Moreover, SLE patients showed poorer scores than healthy women on the following SCL-90-R subscales: somatisation ( p = 0.005), obsessions and compulsions ( p = 0.045), depression ( p = 0.004), hostility ( p = 0.013), phobic anxiety ( p = 0.005), psychoticism ( p = 0.016) and positive symptom total ( p = 0.001). In addition, both SLE groups were more vulnerable to stress ( p = 0.000). These findings help to understand the effects of corticosteroid treatment on cognitive flexibility and decision-making, in addition to the disease-specific effects suffered by women with SLE.

Impaired diffusion tensor imaging findings in the corpus callosum and cingulum may underlie impaired learning and memory abilities in systemic lupus erythematosus

BACKGROUND

Memory impairment is prevalent in systemic lupus erythematosus (SLE); however, its pathogenesis is unknown. In a previous functional magnetic resonance imaging (fMRI) study we demonstrated altered brain activity dynamics and less brain deactivation in patients with SLE as compared with healthy controls, when performing a learning and memory task. Our findings localized this impairment to the default mode network (DMN), and particularly to its anterior medial prefrontal cortex node. In addition, altered networking of the hippocampal subsystem of the DMN was seen in patients with SLE when performing this task, as well as atrophy of the left hippocampus. The present study aimed to search for a structural substrate for the altered recruitment pattern observed in fMRI studies using diffusion tensor imaging (DTI).

PATIENTS AND METHODS

Using DTI, we characterized brain diffusivity in 10 patients with SLE and nine healthy controls. Two tracts associated with the DMN were reconstructed: the corpus callosum (CC) and the cingulum bundle. The CC was segmented according to the Witelson segmentation scheme and the cingulum was segmented into superior and descending bundles.

RESULTS

A significant increase in mean diffusivity (MD) was seen in patients with SLE without neuropsychiatric SLE (NPSLE) as compared with healthy controls in all five segments of the CC (segment 1: p = 0.043; segment 2: p = 0.005; segment 3: p = 0.003; segment 4: p = 0.012; segment 5: p = 0.023) as well as in the descending portion of the left cingulum bundle (p = 0.026).

CONCLUSIONS

Increased MD values in the CC and the left cingulum may indicate impaired organization/reduced integrity of these tracts, which may underlie the abnormal pattern of brain activity recruitment of the DMN observed during a verbal learning and memory task. Taking into account the central role of the left hippocampus in verbal memory, the abnormal integrity of the left cingulum may contribute to the reduced performance of patients with SLE on verbal memory tasks.

Early cerebral volume reductions and their associations with reduced lupus disease activity in patients with newly-diagnosed systemic lupus erythematosus

We examined if cerebral volume reduction occurs very early during the course of systemic lupus erythematosus (SLE), and observed prospectively whether gray (GMV) and white matter volumes (WMV) of the brain would improve with lowered SLE disease activity. T1-weighted MRI brain images were obtained from 14 healthy controls (HC) and 14 newly-diagnosed SLE patients within 5 months of diagnosis (S1) and after achieving low disease activity (S2). Whole brain voxel-based morphometry was used to detect differences in the GMV and WMV between SLE patients and HC and those between SLE patients at S1 and S2. SLE patients were found to have lower GMV than HC in the middle cingulate cortex, middle frontal gyrus and right supplementary motor area, and lower WMV in the superior longitudinal fasciculus, cingulum cingulate gyrus and inferior fronto-occipital fasciculus at both S1 and S2. Whole-brain voxel-wise analysis revealed increased GMV chiefly in the prefrontal regions at S2 compared to S1 in SLE patients. The GMV increase in the left superior frontal gyrus was significantly associated with lowered SLE disease activity. In conclusion, GMV and WMV reduced very early in SLE patients. Reduction of SLE disease activity was accompanied by region-specific GMV improvement in the prefrontal regions.

Olfactory impairment in patients with the fibromyalgia syndrome and systemic sclerosis

Patients with autoimmune diseases often present with olfactory impairment. The aim of the study was to assess the olfactory functions of female patients with fibromyalgia (FM) compared with patients with systemic sclerosis (SSc) and with healthy female controls. Olfactory functions were assessed in 24 patients with FM, 20 patients with SSc and 21 age-matched healthy controls. The sense of smell was evaluated using the Sniffin' Sticks test including the three stages of smell: threshold, discrimination, and identification (TDI) of the different odors. The severity of fibromyalgia was assessed using the fibromyalgia impact questionnaire (FIQ). The short form 36 (SF-36) questionnaire was also completed in order to seek a relationship between the patients perception of quality of life and the different aspects of the smell sense. Depression was evaluated in both FM and SSc patients utilizing the Beck depression inventory-II (BDI-II) questionnaire. Patients with FM had significantly lower TDI smell scores compared with both SSc patients and healthy controls (p < 0.005, One-Way ANOVA). Hyposmia (defined as TDI scores below 30) were observed in 14 of 24 (42 %) patients with FM compared to 3 of 20 (15 %) patients with SSc and 1 of the healthy controls (4.3 %) (p < 0.02). FM patients had significantly lower thresholds of smell compared to both healthy controls and patients with SSc (p < 0.001), whereas for patients with SSc only the ability to discriminate between odors was impaired (p < 0.006). We could not detect any statistical correlation between smell abilities and clinical manifestation of SSc or the FIQ and SF-36 scores among FM patients. However the correlation between depression, defined by the BDI-II score, and the sense of smell differed between patients with FM and patients with SSc. As only among SSc patients a lower sense of smell correlated with a higher BDI-II score (p = 0.02). Our findings suggest that there is a decrease in the sense of smell both in FM and SSc patients compared with healthy controls. However these impairments differ between patients group and might represent different mechanisms that affect the sense of smell.

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.

Selective Impairment of Spatial Cognition Caused by Autoantibodies to the N-Methyl-D-Aspartate Receptor

Patients with systemic lupus erythematosus (SLE) experience cognitive abnormalities in multiple domains including processing speed, executive function, and memory. Here we show that SLE patients carrying antibodies that bind DNA and the GluN2A and GluN2B subunits of the N-methyl-d-aspartate receptor (NMDAR), termed DNRAbs, displayed a selective impairment in spatial recall. Neural recordings in a mouse model of SLE, in which circulating DNRAbs penetrate the hippocampus, revealed that CA1 place cells exhibited a significant expansion in place field size. Structural analysis showed that hippocampal pyramidal cells had substantial reductions in their dendritic processes and spines. Strikingly, these abnormalities became evident at a time when DNRAbs were no longer detectable in the hippocampus. These results suggest that antibody-mediated neurocognitive impairments may be highly specific, and that spatial cognition may be particularly vulnerable to DNRAb-mediated structural and functional injury to hippocampal cells that evolves after the triggering insult is no longer present.

Global Cognitive Impairment in Systemic Lupus Erythematosus Patients: A Structural MRI Study

OBJECTIVE

This study investigated differences in subcortical brain volumes of SLE patients with cognitive deficits (SLE-CD) and SLE patients with normal cognitive performance (SLE-CN), regardless of the presence of other neuropsychiatric symptoms.

METHOD

We studied 40 patients divided into two-matched groups (SLE-CD n = 20; SLE-CN n = 20), with age ranging from 21 to 63 years old (100 % female) and 14.73 ± 10.18 years of diagnosis. Magnetic resonance imaging exams were performed on a 1.5 T scanner. A neuropsychological flexible battery was applied individually, including reasoning/problem-solving, praxis, episodic and working memory, processing speed, language/fluency, executive functions (inhibition and flexibility), and sustained attention. Z score ≤ - 2.0 in any dimension was considered as a cut-off for being considered to possess cognitive deficits. One-way analyses of covariance (ANCOVA) were performed to compare the brain structure volumes between groups. The analyses were controlled for the effects of lupus-related neuropsychiatric disorders.

RESULTS

SLE patients with cognitive deficits had significantly smaller volumes in the left hippocampus, amygdala, and the right hippocampus than SLE patients without cognitive deficits.

CONCLUSION

SLE patients with cognitive deficits appeared to have reduced temporal lobe structures when compared with SLE without cognitive deficits. These results corroborate a systems vulnerability model that investigated temporal lobe vulnerability during normal aging and in other neurological disorders.

Association of hippocampal atrophy with cerebrospinal fluid antibodies against the NR2 subtype of the N-methyl-D-aspartate receptor in patients with systemic lupus erythematosus and patients with primary Sjögren's syndrome

OBJECTIVE

Cognitive dysfunction is common in both systemic lupus erythematosus (SLE) and primary Sjögren's syndrome (SS). Antibodies against the NR2 subtype of the N-methyl-D-aspartate receptor (anti-NR2 antibodies) cause hippocampal atrophy and cognitive impairment in mice and have been associated with memory impairment in both patients with SLE and patients with primary SS. In addition, a reduced volume of hippocampal gray matter has been demonstrated in both SLE and primary SS. This study was undertaken to investigate whether there is a connection between the presence of anti-NR2 antibodies and hippocampal atrophy in human diseases.

METHODS

Fifty patients with SLE and 50 patients with primary SS underwent clinical examination and cerebral magnetic resonance imaging. Anti-NR2 antibodies in cerebrospinal fluid (CSF) were measured, and hippocampal gray matter volumes were compared between patients who were positive for and those who were negative for anti-NR2 antibodies.

RESULTS

Patients with anti-NR2 antibodies in CSF had less hippocampal gray matter than patients without these antibodies. No other differences regarding gray matter volumes in other parts of the brain were identified.

CONCLUSION

The present findings indicate that anti-NR2 antibodies in patients with SLE and primary SS cause neuronal death manifested as reduced hippocampal gray matter, as has been previously demonstrated in mice with autoimmune disease.

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

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

Neurocognitive impairment in corticosteroid-naive patients with active systemic lupus erythematosus: a prospective study

OBJECTIVE

Neurocognitive impairment (NCI) has been intensively studied in patients with systemic lupus erythematosus (SLE). However, those studies have mostly included patients who were treated with corticosteroids, which may itself induce NCI. We investigated NCI in corticosteroid-naive people with SLE who did not exhibit any overt neuropsychiatric manifestations.

METHODS

Forty-three inpatients with SLE who had no current or past neuropsychiatric history participated in the study. Patients and 30 healthy control subjects with similar demographic characteristics were given a 1-h battery of neuropsychological tests. NCI was defined as scores at least 2 SD below the mean of the healthy control group on at least 2 of the 7 neurocognitive domains. Results of clinical, laboratory, and neurologic tests were compared regarding the presence of NCI.

RESULTS

NCI was identified in 12 patients (27.9%) with SLE and in 2 control subjects (6.7%). Patients with SLE showed a significant impairment compared with controls on tasks assessing immediate recall, complex attention/executive function, and psychomotor speed. We identified psychomotor speed (Digit Symbol Substitution Test) as the factor that best differentiated the 2 groups. Further, we identified the score of the SLE Disease Activity Index 2000 as an independent risk factor for NCI in patients with SLE.

CONCLUSION

We conclude that reduced psychomotor speed is an SLE-specific pattern of NCI. Verbal-memory deficits that have been reported in patients with SLE were not evident among patients who were corticosteroid-naive. Our results indicate that impaired psychomotor speed may be added to the symptoms of early SLE.

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.