Longitudinal Study of Cognitive Functioning in Adults with Juvenile Idiopathic Arthritis

To prospectively evaluate possible decline of cognitive functions in adult patients with juvenile idiopathic arthritis (JIA) and identify associated factors.

We performed a 24-month prospective observational study of adults (≥16 years) with JIA. The primary outcome measure was decline in cognitive function defined as a worsening of ≥2 points on the scales of the subsets administered to evaluate the different cognitive areas using the Wechsler Adult Intelligence Scale (WAIS) after 24 months: attention/concentration (digit span); verbal function (vocabulary); visual-spatial organization (block design); working memory (letter-number sequencing); and problem solving (similarities). Other variables included average inflammatory activity using C-reactive protein and composite activity indexes, comorbidity, and treatment. Logistic regression was performed to identify factors associated with cognitive decline.

The study population comprised 52 patients with JIA. Of these, 15 (28.8%) had cognitive decline at V24. The most affected functions were working memory (17.3%), attention/concentration (9.6%), verbal function (7.7%), visual-spatial organization (7.7%), and problem solving (3.8%). There were no significant differences in the median direct or scale scores for the cognitive functions evaluated between V0 and V24 for the whole sample. The factors associated with cognitive decline in patients with JIA were average C-reactive protein (OR [95% CI], 1.377 [1.060-1.921]; p = 0.039), depression (OR [95% CI], 3.691 [1.294-10.534]; p = 0.015), and treatment with biologics (OR [95% CI], 0.188 [0.039-0.998]; p = 0.046).

Cognitive decline was detected in almost one third of adults with JIA after 24 months of follow-up. Systemic inflammatory activity in JIA patients was related to cognitive decline. Patients treated with biologics had a lower risk of decline in cognitive functions.