Relationships between brain metabolite levels, functional connectivity, and negative mood in urologic chronic pelvic pain syndrome patients compared to controls: A MAPP research network study.
Full article:Until recently, the predominant pathology of chronic pelvic pain conditions was thought to reside in the peripheral tissues. However, mounting evidence from neuroimaging studies suggests an important role of the central nervous system in the pathogenesis of these conditions. .... abnormal GABA and choline levels in the brain of UCPPS patients compared to controls. Low GABA levels have been identified in other pain syndromes and might contribute to CNS hyper-excitability in these conditions.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5702874/
I have long believed that trigger points can be caused not only by psychological tension, but also by a direct and subconscious stimulation from the CNS. This is just a hunch at this stage, but results like the one above are suggestive.