Structural Neuroplasticity Following Cognitive Behavioral Therapy for the Treatment of Chronic Musculoskeletal Pain: A Randomized Controlled Trial with Secondary MRI Outcomes

Abstract

The extent of white matter (WM) and Grey matter (GM) structural neuroplasticity following cognitive behavioral therapy for chronic pain management remains undetermined. In the current study, we investigated structural alterations in GM morphometry, as well as WM complexity and connectivity, before and after an 11-week group CBT for the treatment of chronic musculoskeletal pain. We hypothesized that effective pain management would influence WM structural metrics indicative of brain plasticity, particularly within cognitive and limbic circuitry as well as GM volume within pain matrix structures. To determine this, patients were randomized into two groups: 1) CBT group that received CBT once-weekly for 11-weeks, or 2) EDU group consisting of an active patient control group that received educational materials by mail. All subjects completed behavioral assessments and underwent neuroimaging at: baseline prior to any intervention (TP1), 11-weeks following either CBT or EDU (TP2), and four months following completion of the intervention (TP3). CBT resulted in significant clinical improvements, assessed via behavioral self-reports, compared to EDU. Compared to EDU, region of interest WM analysis revealed several fiber tracts that had significantly increased WM complexity following CBT intervention, including the bilateral posterior internal capsule and the left cingulum within the temporal lobe. Conversely, several tracts exhibited a decrease in WM complexity including the right external capsule, the left posterior internal capsule, and the right cingulum within the temporal lobe. Changes in clinical outcomes were predictive of alterations in WM complexity metrics immediately following intervention and at long-term follow-up. No between-group differences were observed in either WM connectivity or GM volume. In conclusion, psychotherapeutic interventions such as group CBT influence coping strategies for effective pain relief that influence WM microstructure, however, the mechanisms of these changes remain undetermined. Future studies will be required to uncover the biological underpinnings of these alterations in pain populations.