TNF and complex regional pain syndrome: Nonetheless, Ludwig et al. [24] and Fischer et al. [25] didn’t found any significant differences in terms of serum or CSF concentrations of interleukin-6 and TNF-α and plasma levels of MDA, F2-isoprostanes, and 8-hydroxy-2-deoxyguanosine between patients with or without painful polyneuropathies and Complex Regional Pain Syndrome.