This prospective, randomized, double-blind, placebo-controlled clinical trial aims to evaluate the analgesic efficacy of ultrasound-guided intermediate cervical plexus block (ICB) in patients undergoing vagus nerve stimulation (VNS) implantation surgery under general anesthesia. Participants are randomly assigned to receive either an ultrasound-guided ICB with 10 mL of 0.25% bupivacaine or a placebo injection with 10 mL of normal saline following induction of general anesthesia. The primary outcome is total postoperative morphine consumption during the first 24 hours after surgery. Secondary outcomes include intraoperative remifentanil consumption, postoperative pain intensity assessed using the Numeric Rating Scale (NRS), time to first analgesic request, length of hospital stay, and postoperative seizure incidence.