Corticolimbic Circuitry in Chronic Pain Tracks Pain Intensity Relief Following Exposure In Vivo

Area of Science:

• Neuroscience
• Psychology
• Medical Imaging

Background:

• Chronic pain affects many individuals, with some experiencing relief from exposure in vivo (EXP) treatment.
• Understanding the mechanisms behind this pain relief is crucial, as it is not an explicit treatment target.
• This study investigates brain plasticity and pretreatment factors associated with pain relief in chronic pain patients undergoing EXP.

Purpose of the Study:

• To characterize brain plasticity in patients with chronic pain receiving EXP.
• To explore pretreatment factors that predict pain relief after EXP.
• To understand the neural mechanisms underlying pain relief in chronic pain.

Main Methods:

• Longitudinal study using resting-state functional magnetic resonance imaging (rsFC) in 30 chronic pain patients.
• Seed-based rsFC analyses were conducted with seeds in the amygdala, hippocampus, and nucleus accumbens.
• Comparison with pain-free control data and assessment of pain relief and catastrophizing.

Main Results:

• Pain relief following EXP was variable; 60% of patients reported clinically relevant improvement.
• Decreased amygdala rsFC over time was observed but not linked to pain relief.
• Greater pain relief correlated with decreased hippocampus rsFC and reduced catastrophizing, and lower pretreatment nucleus accumbens rsFC.

Conclusions:

• Hippocampus connectivity changes are associated with pain relief post-EXP.
• Pretreatment nucleus accumbens connectivity may have prognostic value for pain relief.
• Findings support the role of corticolimbic circuitry in chronic pain and identify potential mechanisms and prognostic factors.