Brain white matter structural properties predict transition to chronic pain

Abstract

Neural mechanisms mediating the transition from acute to chronic pain remain largely unknown. In a longitudinal brain imaging study, we followed patients with a single subacute back pain (SBP) episode for over one year as their pain subsided (SBPr), or persisted (SBPp) representing a transition to chronic pain. We discovered brain white-matter structural abnormalities (in n=24 SBP; SBPp=12 and SBPr=12), as measured by diffusion tensor imaging (DTI), at entry into the study in SBPp in comparison to SBPr. These white matter fractional anisotropy (FA) differences accurately predicted pain persistence over the next year, which was validated in a second cohort (in n=22 SBP; SBPp=11 and SBPr=11), and showed no further alterations over a one-year period. Tractography analysis indicated that abnormal regional FA was linked to differential structural connectivity to medial vs. lateral prefrontal cortex. Local FA was correlated to functional connectivity between medial prefrontal cortex and nucleus accumbens in SBPr. As we have earlier shown that the latter functional connectivity accurately predicts transition to chronic pain, we can conclude that brain structural differences, most likely existing prior to the back pain inciting event and independent of the back pain, predisposes subjects to pain chronification.

Brain Areas Involved in Anticipation of Clinically Relevant Pain in Low Back Pain Populations With High Levels of Pain Behavior

“…Future investigations of whether WS change as the result of central sensitisation 6,36 should use a longitudinal study design in which some participants may go on to develop chronic LBP from the sub-acute stage.…”

Post-Traumatic Headache

“…89 Functional MRI (fMRI) has shown that the default-mode network (DMN), a network of brain areas active in a resting, non-focused state, is disrupted after TBI. 90 Imaging studies have an advantage over animal models for study of PTH in that headache can be more directly targeted as a symptom.…”

Spinal pain

“…13 The role of diagnostic and treatment approaches focusing on peripheral "pain generators" are evolving as the evidence for central modulation of pain intensity in chronic musculoskeletal pain grows. 14,15 The analgesic benefit of duloxetine in recent clinical trials of nondepressed patients with axial predominant chronic low back pain bolsters the search for therapeutic targets in the CNS. 16 Treatments shown to address the psychosocial variables that often modulate chronic pain intensity, such as fear avoidance and catastrophizing, are an essential concomitant of medical and procedural approaches.…”