Patient Li**, male, 56 years old, retired worker, was admitted to the hospital with right upper extremity pain after a right clavicle fracture for 5 years. Five years ago, the patient’s motorcycle accident caused a fracture of the right clavicle, resulting in injury to the right brachial plexus nerve. After the injury, the right upper limb could not move and sensation was completely lost. Ni Bing, Department of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, started to have persistent pain in the right upper extremity 3 months after the injury, which was over-electricity-like and knife-like pain with paroxysmal aggravation. The patient felt that the amputated limb was still there, and the original pain did not improve. At the time of admission to our hospital, the patient was taking 10 tablets of oral aminoglutethimide and 2 intramuscular injections of prednisolone daily. He had stomach bleeding several times due to overdose of oral pain medication. He attempted suicide twice because of unbearable pain, but his family found him in time and failed. He had a history of diabetes mellitus for 10 years, but did not regularly monitor his blood glucose level and took oral metformin tablets intermittently. On admission: right eyelid slightly drooping, little sweating on the right face. The right upper limb was absent, and the phantom limb sensation was obvious in the right upper limb, with pain located in the hand and elbow of the phantom limb, as well as in the shoulder and axilla of the stump. Sensory activity of the lower extremity was normal. VAS score: 4-5 points for basal pain and 9-10 points for burst pain. A general score of 10 is the kind of pain that has not been experienced in this lifetime, to the point of not wanting to live. Check MRI of cervical spine: right nerve root cuff cyst in the spinal canal and enlarged dorsolateral sulcus of the right spinal cord. (The picture is reversed) Admission diagnosis Brachial plexus avulsion Phantom limb pain Right old clavicle fracture Type 2 diabetes mellitus After admission, blood glucose was adjusted and stabilized, followed by destruction of the right C5-T1 dorsal spinal cord root into the medullary area in the prone position under general anesthesia. Dorsal Root Entry Zone (DREZ) surgery was performed. Intraoperative microscopic photo The patient’s phantom limb and stump pain completely disappeared, and the bilateral lower limb movement and sensation were basically normal at 1 year postoperative follow-up by telephone.