Cognitive Change and Relaxation as Key Mechanisms of Treatment Outcome in Chronic Pain: Evidence From Routine Care

Current evidence does not support the routine use of cognitive behavioural therapy in total knee arthroplasty: A systematic review

Background

There is a significant dissatisfaction rate in patients undergoing total knee arthroplasty (TKA), and poor mental health in patients is increasingly recognized as a major contributor to dissatisfaction. The aim was to review the effectiveness of cognitive behavioural therapy (CBT) in improving pain and functional outcomes of patients undergoing TKA and highlight important aspects that may be crucial for improvement.

Methods

A systematic search was conducted in adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Studies were included if they were randomized control trials that included patients undergoing unilateral or bilateral TKA, with CBT as an intervention compared against usual care, and reported outcomes in pain, knee function and any psychological outcomes as measured.

Results

Eight RCTs were selected which included 683 participants. The timings of CBT delivery, profiles of therapists, and outcome measures reported varied across the studies. Overall, 3 studies reported significant improvement in pain outcomes, 3 studies reported significant improvement in functional outcomes and 5 studies reported significant improvements in psychological outcomes.

Conclusion

Current evidence does not support the efficacy of CBT as current literature is too heterogenous. Further studies with homogenous CBT methods are required to further ascertain the true relationship between CBT and postoperative outcomes of TKA. Future studies should consider the points set out in this review, such as the importance of revisiting CBTskills, providing individualized therapy, having a supervisory team to support the fidelity of interventions, and identifying which group of patients would best benefit from CBT.

Neuroimaging Mechanism of Cognitive Behavioral Therapy in Pain Management

Purpose. To review the recent neuroimaging studies on cognitive-behavioral therapy (CBT) for pain management, with the aim of exploring possible mechanisms of CBT. Recent Findings. Current studies can be divided into four categories, mixed pain, fibromyalgia, migraine, and experimental pain, based on the type of disease included, with the same or different changes of brain regions after CBT intervention. According to structural and functional MRI analyses, changes of brain gray matter volume, activation and deactivation of brain regions, and intrinsic connectivity between brain regions were observed after CBT sessions. The brain regions involved mainly included some areas related to cognitive and emotional regulation. After comparison, the DLPFC, OFC, VLPFC, PCC and amygdala were found to be recurrent in multiple studies and may be key regions for CBT intervention in pain management. In the treatment of mixed chronic pain, CBT may decrease the gray matter volume of DLPFC, reduce ICN connection of OFC within the DAN network, and increase fALFF of the PCC. For FM intervention, CBT may activate the bilateral OFC and VLPFC, while in migraine, only the right OFC, VLPFC, and DLPFC were found to be more activated after CBT. In addition, the differential action of the left and right amygdala has also been shown in the latest study of migraine. In heat-evoked pain, CBT may increase the deactivation of the PCC, the connectivity between the DMN and right VLPFC, while diminishing the deactivation of VLPFC. Summary. After CBT, the brain showed stronger top-down pain control, cognitive reassessment, and altered perception of stimulus signals (chronic pain and repeated acute pain). The DLPFC, OFC, VLPFC, PCC, and amygdala may be the key brain regions in CBT intervention of pain.