Quantitative susceptibility mapping in the thalamus and basal ganglia of systemic lupus erythematosus patients with neuropsychiatric complaints

Advanced neuroimaging in systemic lupus erythematosus: identifying biomarkers for cognitive dysfunction

BACKGROUND

Cognitive dysfunction (CD) is a common manifestation of central nervous system involvement in patients with systemic lupus erythematosus (SLE). Patients with SLE may develop CD insidiously at an early stage of the disease, and the lack of a standardized diagnostic test poses a major challenge in prompt diagnosis and management of these patients. This review summaries the current application of various magnetic resonance imaging (MRI) techniques for patients with SLE complicated with CD, aiming to identify potential quantitative neuroimaging biomarkers for patients with SLE and CD.

METHODS

We systematically searched several databases between January 2003 to December 2024. We screened retrospective and prospective studies based on search criteria keywords (including structural or functional MRI, cognitive function, lupus, and systemic lupus erythematosus) to identify peer-reviewed articles that reported advanced structural and functional MRI metrics and evaluated CD in human patients with SLE.

RESULTS

123 studies (19 Bold-MRI studies, 9 DTI studies, 2 ASL studies, 4 MTI studies, 5 machine learning, and 84 other studies) were identified. Neuroimaging findings show that patients with CD have abnormal manifestations in the limbic system, hippocampus, corpus callosum, and frontal cortex, and these manifestations are closely related to cognitive functions. The most commonly affected cognitive domains are memory, attention, and executive ability. Multimodal MRI, integrating structural, functional, and perfusion parameters, combined with machine learning, can effectively predict cognitive function.

CONCLUSION

Advanced MRI analysis can identify the abnormalities in the whole brain and local brain regions associated with CD in patients with SLE. The integration of machine learning and multimodal MRI offers new perspectives for early identification and mechanistic studies of CD in SLE patients. More studies are needed to identify potential neuroimaging biomarkers to facilitate early diagnosis, timely treatment, and accurate prognosis for SLE patients with CD.

Alterations in cerebral perfusion and corresponding brain functional networks in systemic lupus erythematosus with cognitive impairment

Cognitive impairment (CI) frequently occurs in patients with systemic lupus erythematosus (SLE) and may result from neuroinflammation processes and neurovascular changes in the brain. The cerebral hemodynamics underlying SLE with CI (SLE-CI) remain unclear. 97 patients with SLE and 51 heathy controls (HCs) matched for age and gender underwent MRI. The CI status of patients was measured using the MoCA, and we classify those with a score of 28 or above as the SLE cognitive normal group (SLE-NC). 3D T1-weighted, ASL and resting-state functional (rs-fMRI) sequences were obtained. Seed-based functional connectivity (FC) was calculated using the cerebral blood flow (CBF) results. Compared with SLE-NC, patients with SLE-CI had higher CBF in the left hippocampus, thalamus, and cerebellum crus II and lower CBF in the left frontal lobe. Secondary analyses revealed that compared with patients with SLE-NC, patients with SLE-CI had increased FC of the left insula gyrus when the left cerebellum crus II was set as the seed region and decreased FC in the homolateral para-hippocampus when the left hippocampus was set as the seed region. These structural, functional, and network changes may serve as potential biomarkers for cognitive impairment in SLE-CI patients.

Serotonin Syndrome-Mimicking Manifestations in a Patient with Systemic Lupus Erythematosus

Neuropsychiatric systemic lupus erythematosus (NPSLE) is a complication of systemic lupus erythematosus with diverse clinical presentations sharing common features with variable neurologic disorders. Magnetic resonance imaging (MRI) may provide imaging evidence of structural brain abnormalities associated with symptoms of NPSLE. Serotonin syndrome is a toxidrome characterized by altered mental status, autonomic hyperactivity, and neuromuscular abnormalities. It is mostly caused by medications that increase serotonin and is rarely reported as a manifestation of neuropsychiatric lupus. We presented the case of a 24-year-old Taiwanese woman with a history of systemic lupus erythematosus diagnosed at 21 years of age. The initial clinical and laboratory presentations upon diagnosis included fever, arthritis, hypocomplementemia, positive antinuclear antibody, anti-double-stranded DNA antibody, and anti-ribosomal P antibody. Her condition once remained stable under oral glucocorticoids and immunosuppressants, but she developed sudden-onset consciousness disturbance, incoherent speech, and unsteady gait ten days before our assessment. A high fever of up to 39 °C with tremor and clonus occurred at the intensive care unit. Brain MRI revealed symmetric T2 hyperintensity without diffusion restriction over the bilateral globus pallidus. High-dose pulse glucocorticoid and rituximab were prescribed during her admission and the neuropsychiatric symptoms diminished upon treatment. No alternation in mental status or involuntary movements were noted at follow-up. Our patient was diagnosed with neuropsychiatric lupus, with clinical symptoms and image findings mimicking those of serotonin syndrome. Neuroimaging, such as MRI, detects various structural brain abnormalities and may provide pathophysiological evidence of clinical manifestations.

Abnormal cerebral hemodynamics and blood-brain barrier permeability detected with perfusion MRI in systemic lupus erythematosus patients

OBJECTIVE

Dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI) has previously shown alterations in cerebral perfusion in patients with systemic lupus erythematosus (SLE). However, the results have been inconsistent, in particular regarding neuropsychiatric (NP) SLE. Thus, we investigated perfusion-based measures in different brain regions in SLE patients with and without NP involvement, and additionally, in white matter hyperintensities (WMHs), the most common MRI pathology in SLE patients.

MATERIALS AND METHODS

We included 3 T MRI images (conventional and DSC) from 64 female SLE patients and 19 healthy controls (HC). Three different NPSLE attribution models were used: the Systemic Lupus International Collaborating Clinics (SLICC) A model (13 patients), the SLICC B model (19 patients), and the American College of Rheumatology (ACR) case definitions for NPSLE (38 patients). Normalized cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) were calculated in 26 manually drawn regions of interest and compared between SLE patients and HC, and between NPSLE and non-NPSLE patients. Additionally, normalized CBF, CBV and MTT, as well as absolute values of the blood-brain barrier leakage parameter (K2) were investigated in WMHs compared to normal appearing white matter (NAWM) in the SLE patients.

RESULTS

After correction for multiple comparisons, the most prevalent finding was a bilateral significant decrease in MTT in SLE patients compared to HC in the hypothalamus, putamen, right posterior thalamus and right anterior insula. Significant decreases in SLE compared to HC were also found for CBF in the pons, and for CBV in the bilateral putamen and posterior thalamus. Significant increases were found for CBF in the posterior corpus callosum and for CBV in the anterior corpus callosum. Similar patterns were found for both NPSLE and non-NPSLE patients for all attributional models compared to HC. However, no significant perfusion differences were revealed between NPSLE and non-NPSLE patients regardless of attribution model. The WMHs in SLE patients showed a significant increase in all perfusion-based metrics (CBF, CBV, MTT and K2) compared to NAWM.

CONCLUSION

Our study revealed perfusion differences in several brain regions in SLE patients compared to HC, independently of NP involvement. Furthermore, increased K2 in WMHs compared to NAWM may indicate blood-brain barrier dysfunction in SLE patients. We conclude that our results show a robust cerebral perfusion, independent from the different NP attribution models, and provide insight into potential BBB dysfunction and altered vascular properties of WMHs in female SLE patients. Despite SLE being most prevalent in females, a generalization of our conclusions should be avoided, and future studies including all sexes are needed.

Cognitive dysfunction in SLE: An understudied clinical manifestation

Neuropsychiatric lupus (NPSLE) is a debilitating manifestation of SLE which occurs in a majority of SLE patients and has a variety of clinical manifestations. In the central nervous system, NPSLE may result from ischemia or penetration of inflammatory mediators and neurotoxic antibodies through the blood brain barrier (BBB). Here we focus on cognitive dysfunction (CD) as an NPSLE manifestation; it is common, underdiagnosed, and without specific therapy. For a very long time, clinicians ignored cognitive dysfunction and researchers who might be interested in the question struggled to find an approach to understanding mechanisms for this manifestation. Recent years, however, propelled by a more patient-centric approach to disease, have seen remarkable progress in our understanding of CD pathogenesis. This has been enabled through the use of novel imaging modalities and numerous mouse models. Overall, these studies point to a pivotal role of an impaired BBB and microglial activation in leading to neuronal injury. These insights suggest potential therapeutic modalities and make possible clinical trials for cognitive impairment.