Assessing cognitive functions in non-neuropsychiatric childhood systemic lupus erythematosus: Cross-sectional study

Systemic Lupus Erythematosus (SLE) is an autoimmune disease characterized by multisystem, including neuropsychiatric, involvement. The nervous system is affected in 20-27 % of patients within approximately two years after diagnosis. This study aimed to examine neurocognitive impairment in childhood-onset SLE (cSLE) patients before the development of any neurological, psychiatric, or cognitive manifestations.

The study included 98 children and adolescents. Of these, 34 (35 %) were cSLE groups, and the remaining formed two control groups: 31 (31 %) oligoarticular Juvenile Idiopathic Arthritis (oJIA) patients served as a "patient control" group, and 33 (34 %) healthy participants socio-demographically matched to the cSLE and oJIA patients formed the healthy control (HC) group. None of the subjects in the study exhibited neurological or psychiatric symptoms.

The Wechsler Intelligence Scale for Children-IV (WISC-IV) was applied to all groups. Test results showed that the Perceptual Reasoning Index Score (PRIS) was significantly lower in cSLE than in HC (F(2, 95) = 3.365, p = 0.042, Tukey HSD: p = 0.01). 'Comprehension' subtest scores were significantly lower in the cSLE group compared to the HC group (H(2) = 8.133, p = 0.017; U = 352.5, p = 0.009). Similarly, 'symbol search' subtest scores were significantly lower in the cSLE group compared to the HC group (F(2, 95) = 3.545, p = 0.036, Tukey HSD: p = 0.014).

Our results revealed that cSLE may have neurocognitive impairment without presenting any symptoms. Early detection is possible with the neurocognitive test WISC-IV. These results support the inclusion of objective neurocognitive assessment methods into the routine clinical follow-up of childhood-onset SLE.