Dos Hermanas

Researchers are investigating chronic neck pain, a common condition marked by increased sensitivity, muscle tightness, and limited movement. This trial focuses on neck pain linked to nearby organs around the diaphragm, which can cause referred pain through the phrenic nerve. The study aims to understand whether blocking this nerve can reduce neck pain and sensitivity when no clear neurological, traumatic, or infectious cause is present. The study compares two groups: one receives an ultrasound-guided injection of local anesthetics (lidocaine and bupivacaine) around the phrenic nerve to block pain signals, while the other group is given a placebo injection with saline. There is only one treatment session. Patients will be followed for one week, with measurements taken at several points to monitor changes in pain sensitivity and neck function. Participants will undergo evaluations including pressure pain threshold testing, pain scales, range of motion assessments, and questionnaires about neck symptoms. These assessments occur before the intervention and at 1 hour, 2 hours, 3 days, and 7 days afterward. The study also monitors safety and symptom changes throughout this period to evaluate the effect of the nerve blockade on neck pain.