Although classically considered from a neuro-centric vantage point, is now well known that pain involves interaction between the immune and nervous systems. Neuro-immune interactions occur all along the pain axis from the tissues to the peripheral neurons, the dorsal root ganglia, the spinal cord and supraspinal centres. Immune cells from mast cells, macrophages, T cells and B cells, to the Schwann cells of neurons, and the glia cells in the spinal cord and brain, release diverse inflammatory mediators including cytokines and chemokines. Fundamental mechanisms underlying pain enhancement by immune cells are diverse and differ between nociceptive, neuropathic and nociplastic pain conditions. The involvement of the immune system in pain provides enormous potential for interventions to address pain by targeting these mechanisms. These interventions include pharmacological and genetic treatments, as well as non-pharmacological treatments with the potential to impact systemic and CNS immune activity, such as exercise, diet and treatments targeting psychosocial and behavioural features (e.g., sleep and stress). Logically, treatment efficacy should depend on matching the treatment to the relevant neuro-immune mechanism. The aim of this review is to provide a foundation to understand the relevance of neuro-immune interactions to the development and persistence of chronic pain, and its implications for treatment. We provide an overview of the role of neuroinflammation in pain, evidence that this contributes to human pain conditions, and how this can guide matching the right treatments to the right person.
Background: There is increasing interest in uncovering working mechanisms of physiotherapy interventions. Advanced medical imaging enables in-vivo visualisation and quantification of neuroinflammation. This case report reveals for the first time how neuroinflammation in the nervous system may change following neural tissue management.
Case description: A 56-year-old man presented with a 9-month history of left C7 painful radiculopathy. He reported arm and neck pain, and numbness in the C7 dermatome. Elbow extension strength was reduced. The neurodynamic test (median nerve) was positive. MRI confirmed nerve root compression due to disc herniation C6/C7. Dynamic [11C]DPA713 PET/CT imaging revealed neuroinflammation at the neuroforamen and spinal cord. While being on the surgical waitlist, he received six weeks of neural tissue management, which included 12 sessions of nerve and joint mobilisation, and a home program of neurodynamic exercises.
Outcome: At 6-weeks follow-up, arm and neck pain intensity had markedly reduced, which was maintained at 6 months. These improvements coincided with a substantial decrease in neuroinflammation at the affected neuroforamen (PET/CT: VT: from 12.96 to 6.21). No meaningful decrease was observed in the spinal cord (VT: from 6.43 to 5.38).
Discussion: Following six weeks of neural tissue management, in vivo measures of neuroinflammation reduced substantially at the affected nerve roots and dorsal root ganglion, which coincided with decreased neck and arm pain.
Conclusion: Changes in neuroinflammation exceeding the smallest detectable difference can be measured following neural tissue management in a patient with painful cervical radiculopathy. A randomised trial to validate these findings is warranted.

