Effects of systemic lupus erythematosus on the brain: a systematic review of structural MRI findings and their relationships with cognitive dysfunction.

Background: Cognitive dysfunction (CD) is highly prevalent in systemic lupus erythematosus (SLE), yet the underlying mechanisms are poorly understood. Neuroimaging utilising advanced MRI metrics may yield mechanistic insights. We conducted a systematic review of neuroimaging studies to investigate the relationship between structural and diffusion MRI metrics and CD in SLE.

Methods: We systematically searched several databases between January 2000 and October 2023 according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Retrospective and prospective studies were screened for search criteria keywords (including structural or diffusion MRI, cognitive function and SLE) to identify peer-reviewed articles reporting advanced structural MRI metrics and evaluating CD in human patients with SLE.

Results: Eighteen studies (8 structural MRI, 9 diffusion MRI and 1 with both modalities) were included; sample sizes ranged from 11 to 120 participants with SLE. Neurocognitive assessments and neuroimaging techniques, parameters and processing differed across articles. The most frequently affected cognitive domains were memory, psychomotor speed and attention; while abnormal structural and/or diffusion MRI metrics were found more consistently in the hippocampus, corpus callosum and frontal cortex of patients with SLE, with and without clinically diagnosed central nervous system involvement.

Conclusion: Advanced structural MRI analysis can identify total and regional brain abnormalities associated with CD in patients with SLE, with potential to enhance clinical assessment. Future collaborative, longitudinal studies of neuroimaging in SLE are needed to better characterise CD, with focus on harmonised neurocognitive assessments, neuroimaging acquisitions and postprocessing analyses and improved clinical characterisation of SLE cohorts.