Comparison of Cognitive Functions between Healthy Controls and Individuals with Chronic Low Back Pain with High and Low Pain Catastrophizing: A Cross-sectional Study.

OBJECTIVES: Researchers suggested that the interruptive effects of chronic pain on cognitive functions may be modulated by the level of pain catastrophizing (PC). However, in individuals with chronic low back pain (CLBP), domains of cognitive function that may be affected by the level of PC remain largely unclear. Therefore, this study was aimed to compare cognitive functions between healthy controls and individuals with CLBP with high and low PC. METHODS: This cross-sectional study examined cognitive functions of 42 individuals with CLBP and 21 healthy controls. The PC scale was used to stratify participants with CLBP into high and low PC. Participants performed 5 cognitive tests from the Cambridge Neuropsychological Test Automated Battery, namely five-choice reaction time, rapid visual processing, spatial working memory, attention switching task, and stop signal task. RESULTS: The statistical analyses revealed that compared to individuals with CLBP with low PC and healthy controls, individuals with high PC demonstrated greater values of the between errors (P=0.01), reaction latency (P<0.001), and stop signal reaction time variables (P=0.004, P=0.003, respectively) but lower values of probability of hit (P=0.02, P=0.01, respectively), A' (P=0.01, P<0.001, respectively), and percent correct trials variables (P=0.002, P<0.001, respectively). DISCUSSION: The results of the current study showed deficits in sustained attention, working memory, cognitive flexibility, and inhibitory control in individuals with CLBP with high PC. From a clinical perspective, therapeutic interventions targeting PC should be considered to decrease catastrophic thinking about pain in individuals with CLBP. Additional research is warranted to explore cognitive functioning as an outcome of these interventions in individuals with CLBP.

Differences in dynamic balance control based on pain catastrophizing level in individuals with nonspecific chronic low back pain.

BACKGROUND: Pain catastrophization (PC) is related to motor control changes in individuals with nonspecific chronic low back pain (NSCLBP). However, differences in dynamic balance control based on the level of PC still remain unclear in these individuals. OBJECTIVE: The aim of this study was to compare the dynamic balance control between healthy controls and individuals with NSCLBP with high and low PC. METHODS: Forty individuals with NSCLBP and 20 healthy participants were enrolled in this cross-sectional study. Individuals with NSCLBP were classified into two groups of high and low PC. Dynamic balance control was assessed using the Modified Star Excursion Balance Test (MSEBT), Five-Time Sit-to-Stand Test (FTSST), and Timed Up and Go Test (TUGT). RESULTS: Statistical analyses showed that mean values of reach distances in the anterior, posteromedial, and posterolateral directions of the MSEBT were significantly lower in individuals with NSCLBP with high PC compared to low PC (p = .04, p = .01, and p = .04, respectively) and healthy controls (p < .001, p = .001, and p = .006, respectively). In addition, for both the FTSS and TUG tests, the mean time was significantly greater in individuals with NSCLBP with high PC compared to low PC (p < .001 and p = .004, respectively) and healthy controls (p < .001). CONCLUSIONS: Our results showed poor dynamic balance control in individuals with NSCLBP with high PC. This suggests that PC could contribute to the impaired dynamic balance control in individuals with NSCLBP. Combining balance exercises and cognitive-behavioral treatments targeting PC may be useful for the improvement of dynamic balance control in individuals with NSCLBP with high PC.