BDNF and Bartsocas-Papas syndrome 1: Although urinary BDNF may not be the ideal effect biomarker to address CNS alterations due to its secretion by kidneys and bladder tissues (Ece et al., 2019), several studies have highlighted its use as an indicator of visceral chronic pain such as Bladder Pain Syndrome/Interstitial Cystitis (BPS/IC) and Chronic Prostatitis/Chronic Pelvic Pain Syndrome.