Are behaviour and motor performances of rheumatoid arthritis patients influenced by subclinical cognitive impairments? A clinical and neuroimaging study

Abstract

Objective: To determine whether some behavioural manifestations and poor motor performances in patients affected by rheumatoid arthritis (RA) are due to subclinical cognitive defects.

Methods: We performed a psychometric assessment of 30 patients affected by RA exploring several cognitive domains such as memory, visual-spatial integration, motor planning, mental flexibility, relating performances with morphological and functional neuroimaging (MRI and SPECT). We also related the cognitive data with the Ritchie and Lee indexes and other clinical parameters.

Results: We found an impairment in visual-spatial tasks in 71% of patients with a high correlation to activity and disease severity as expressed by the Ritchie and Lee indexes (p < 0.005; p < 0.01). Furthermore, we detected in 38% of patients some difficulties in mental flexibility related to the Lee Index (p < 0.05). These poor performances are related to hypoperfusion of the frontal and parietal lobes as detected by brain SPECT; this finding is more evident in patients with brain white matter alterations on MRI.

Conclusions: Our data allow us to hypothesize that manual dexterity could be due to a disconnection between subcortical white matter and parietal-frontal lobes because of microangiopathy; furthermore, a chronic reduction in sensorial stimuli by impaired joints could lead to produce an alteration in motor planning cognitive processes.