Ethical approval
pain
This study has been approved by the Ethics Committee of the Medical Faculty of the University of Würzburg (# 98/20). After oral and written information, discussion, and a reflection period of at least 24 h, patients who agreed to participate signed the consent form and were thus included in the study. Controls for NfL detection in the serum were healthy volunteers without pain or other known neurological conditions (Ethics approval # 242/17).