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

Objectives: 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.

Methods: 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.

Results: 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).

Conclusion: 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.