Eligible participants were referred to a physician not involved in the study and provided with detailed information about the experimental protocol. In- formed consent was obtained from each participant prior to treatment allocation. Patients were randomly assigned to either NCTE (group 1) or TTE (group 2) using a random sequence generator (www.random. org). Allocation concealment was performed using closed envelopes, and the assignment code of each patient revealed to the researcher who performed the treatment only at the beginning of the therapeu- tic protocol. Information pertaining to demograph- ics, education, lifestyle habits, pain duration, emo- tional distress, comorbidities and medications was collected using a dedicated questionnaire