White matter lesions and brain atrophy in systemic lupus erythematosus patients : correlation to cognitive dysfunction in a cohort of systemic lupus erythematosus patients using different definition models for neuropsychiatric systemic lupus erythematosus

Aim: The aim of this study was to evaluate the extent of white matter lesions, atrophy of the hippocampus and corpus callosum, and their correlation with cognitive dysfunction (CD), in patients diagnosed with systemic lupus erythematosus (SLE). Methods: Seventy SLE patients and 25 healthy individuals (HIs) were included in the study. To evaluate the different SLE and neuropsychiatric SLE (NPSLE) definition schemes, patients were grouped both according to the American College of Rheumatology (ACR) definition, as well as the more stringent ACR-Systemic Lupus International Collaborating Clinics definition. Patients and HIs underwent a 3 Tesla brain MRI and a standardized neuropsychological test. MRI data were evaluated for number and volume of white matter lesions and atrophy of the hippocampus and corpus callosum. Differences between groups and subgroups were evaluated for significance. Number and volume of white matter lesions and atrophy of the hippocampus and corpus callosum were correlated to cognitive dysfunction. Results: The total volume of white matter lesions was significantly larger in SLE patients compared to HIs (p = 0.004). However, no significant differences were seen between the different SLE subgroups. Atrophy of the bilateral hippocampus was significantly more pronounced in patients with NPSLE compared to those with non-NPSLE (right: p = 0.010; left p = 0.023). Significant negative correlations between cognitive test scores on verbal memory and number and volume of white matter lesions were present. Conclusion: SLE patients have a significantly larger volume of white matter lesions on MRI compared to HIs and the degree of white matter lesion volume correlates to cognitive dysfunction, specifically to verbal memory. No significant differences in the number or volume of white matter lesions were identified between subgroups of SLE patients regardless of the definition model used