Fibromyalgia (FM) is a chronic pain syndrome of unknown etiology that can include subjective cognitive symptoms and variable evidence of cognitive dysfunction. Rates of occurrence and severity of cognitive impairment remain unclear. Additionally, comparison of this group with other pain conditions has been limited. The current cross-sectional study sought to identify rates of clinically significant cognitive impairment in FM and rheumatoid arthritis (RA) using an automated clinical rating approach.
A total of 61 females (32 with FM, 29 with RA) completed a comprehensive neuropsychological (NP) battery and an assessment of personality and psychological distress. All study measures were completed in one visit and all participants were recruited over the span of 3 years. Demographically corrected NP scores were used to compare participants with normative expectations and a summary score was calculated to compare groups on NP impairment.
Compared to normative expectations using a 1 standard deviation cutoff, moderately increased rates of cognitive deficits were observed in both groups (FM = 23.3%, RA = 34.5%), with most test scores in affected individuals falling in the mild to moderate ranges of impairment. Compared to RA, FM participants endorsed higher and significant levels of psychological symptoms overall. These were not associated with cognitive performance in either patient group.
Increased rates of cognitive dysfunction as well as psychological distress exist in both FM and RA compared to a normative sample. However, psychological distress was unrelated to cognition in both groups. These findings have implications regarding the clinical presentation of individuals with FM and RA.