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

Abstract

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.

Keywords: Cognition disorders; Magnetic resonance imaging; Systemic lupus erythematosus; Temporal lobe.