Restless legs syndrome and cognitive function among adults: a systematic review and meta-analysis.

BACKGROUND
Changes in the cognitive function of patients with restless legs syndrome is a growing area of research. Although several studies have been performed to investigate the association between restless legs syndrome (RLS) and cognitive function, the outcomes are still controversial. The meta-analysis aimed to elucidate the relationship between RLS and cognition, including global cognition and various cognitive domains including memory, attention, executive function, and spatial cognition.


METHODS
We searched the MEDLINE, EMBASE, and Web of Science databases from inception to November 2022 to screen eligible records. The means and standard deviations of cognitive test scores were obtained to calculate the standard mean difference and 95% confidence intervals.


RESULTS
A total of 1437 records were collected from the initial search and 16 records involving 4635 individuals were ultimately included in the systematic review and meta-analysis. Our data suggest negative associations between RLS and global cognition (SMD, - 0.42; 95% CI - 0.72 to - 0.11; I2 = 76.6%) and attention (SMD, - 0.43; 95% CI - 0.73 to - 0.12; I2 = 85.3%). No significant differences in memory (SMD, - 0.01; 95% CI - 0.31 to 0.28; I2 = 68.0%), executive function (SMD, - 0.10; 95% CI, - 0.30 to 0.11; I2 = 52.1%), or spatial cognition (SMD, - 0.17; 95% CI - 0.38 to 0.03; I2 = 58.5%) were observed between the RLS and control groups. Moreover, the strength of the results was modified by age but not by sex or region.


CONCLUSIONS
Our findings suggest that RLS is negatively correlated with cognitive function, particularly global cognition and attention. However, the causal relationship, considering more confounders, is worthy of further exploration.