Assessment of Cognitive Impairment in Rheumatoid Arthritis

The objectives of our study were to assess the prevalence of cognitive impairment in Rheumatoid arthritis (RA) and to identify its predictive factors.

A 6-month cross-sectional case-control study englobing patients with RA was carried out. The cognitive evaluation was performed using the Mini Mental State Examination (MMSE), the frontal efficiency battery, the 5-word test, the clock drawing test and the Trail Making Test part-A (TMT-A). Linear regression analyses were conducted to identify predictors of cognitive impairment.

We included 35 RA patients and 35 controls. Concerning the RA group, the mean duration of the disease was 12.3 years [1-29 years]. RA was immunopositive in 80% of cases and erosive in 83% of cases. The global cognitive dysfunction assessed by MMSE score was 49%. Depending on the test used, the prevalence of cognitive impairment in RA ranged from 34% to 54%. RA patients presented poorer results regarding the TMT-A than the controls (p = 0.03). The other cognitive tests were comparable between the 2 groups. The main predictive independent factors of cognitive impairment among RA patients were advanced age (p = 0.002), rural environment (p = 0.007), low income (p = 0.01), recent course of RA (p = 0.006), low disease activity (p = 0.002) and low blood sugar (p = 0.003).

Global cognitive impairment in RA concerned 49% of our patients. Early identification of the factors associated with this cognitive dysfunction is necessary in order to improve the quality of life of patients.