Patients diagnosed with complex regional pain syndrome (CRPS) demonstrate significant structural and functional brain changes in regions associated with movement and pain, according to a study published in the Journal of Pain.
In this study, investigators compared patients with a new diagnosis of CRPS (n=12; diagnosis in past 10 months) with patients with long-term CRPS (n=16; average symptom duration, 7 years), and patients with no CRPS (n=16).
The patients with newly diagnosed CRPS exhibited reduced perfusion and gray matter volume in brain regions associated with the limbic system, somatosensory cortex, and spatial body perception, indicating brain plasticity during the early stages of the disease.
Gray matter volume was unchanged in patients with long-term CRPS, but this population had increased perfusion in the motor cortex. In patients with long-term CRPS, a negative correlation between gray matter volume in brain regions associated with pain processing and average levels of pain was established.
Patient medications were not accounted for in this study, preventing the researchers from establishing a connection between observed brain changes and disease vs therapy. In addition, the small sample size may have limited detection power in this imaging study.
This analysis indicates brain plasticity during short- and long-term CRPS, which may help investigators “understand the diversity in outcomes and treatment response and hopefully improve treatment planning.”
Shokouhi M, Clarke C, Morley-Forster P, et al. Structural and functional brain changes at early and late stages of complex regional pain syndrome [published online October 13, 2017]. J Pain. doi:10.1016/j.jpain.2017.09.007