Cognitive dysfunction is a common problem in systemic lupus erythematosus (SLE) but the cause is still unclear; measuring it can be difficult and, as such, treatment options are limited. We examined cognitive function (CF) in a stable SLE group using both behavioural and imaging techniques. Associations for cognitive dysfunction in SLE were also explored.

  <>Methods: 36 stable SLE (SLE 1997 ACR Criteria) and 30 healthy controls (HC) were recruited. Demographics clinical features, psychological questionnaires and blood samples were collected. We compared periventricular hyperintensities (PVH), deep white matter hyperintensities (DWMH), brainstem and basal ganglia features.  CF was assessed using selected tests from the CANTAB®, and fMRI was used to examine blood-oxygen-level dependent (BOLD) responses to a working memory and attention task (n-back) and a facial emotional processing task (FERT). The fMRI data was modelled using SPM12. All other data was analysed using SPSS 22.   <>Results:

SLE patients had significantly higher scores for depression and fatigue and they also had higher levels of IL-6, high sensitivity CRP, VCAM-1 and BlyS (Table 1). The SLE group performed significantly worse on a behavioural task of sustained attention (p=0.002) but similarly on all other cognitive tasks. They had more and larger perivascular spaces (PVS) in the centrum semiovale (CSO-VRS), χ²=15.50, p<0.001, compared to the HC group. We also found altered BOLD signals compared to the HC group for the n-back task in regions associated with the default mode network during the working memory condition and in the lingual gyrus during the attention condition. For the FERT task, during the sadness condition, differences were also found   (Figure 1). The attenuated BOLD signal in the right superior temporal gyrus positively correlated with VCAM-1 (r=0.53, p=0.01), and SLICC/ACR-DI score (r_s=0.56, p=0.005). The attenuated BOLD signal in the lingual gyrus positively correlated with the BILAG total score (r_s=0.45, p=0.033) and IL-6 (r_s=0.44, p=0.036).

                                               
<>Conclusion:

Structural and functional changes related to cognition in SLE may, in part, be influenced by inflammation and aspects of disease including pre-existing damage. Also, the compensatory brain mechanisms used by the SLE group to maintain adequate CF may make SLE patients more susceptible to emotional interference during non-emotional cognitive tasks. Whilst multifactorial in nature, certain aspects of SLE CF may be sensitive to changes in disease status and thus to targeted therapeutic interventions.