The Effect of Adding a Local Anesthetic to Transforaminal Epidural Injection in Cervical Disc Herniation.

The study is designed as a double-blind, prospective, randomized controlled trial. Blindness is ensured by having different researchers performing the interventional procedures and monitoring the pain diaries, thus preventing them from knowing which procedure is performed on which patient. Patient randomization will be performed using computer assistance. After obtaining approval from the hospital ethics committee, clinical trials will be initiated. Patients who present to the Department of Neurology, Algology Division, ADÜTF between 2025-2026 and undergo DRG-PRF and TFAESI for radicular pain due to cervical disc herniation will be divided into two groups. Patients in Group 1 will undergo DRG-PRF and TFAESI with the addition of local anesthetic. Patients in Group 2 will undergo DRG-PRF and TFAESI without the addition of local anesthetic. During the study, NRS score measurements will be taken to assess pain intensity in patients in both Group 1 and Group 2 before the procedure and at 1, 3, and 6 months post-procedure follow-ups. Neurological and musculoskeletal examinations will be performed during routine check-ups before the procedure and at 1, 3, and 6 months after the procedure, and any developing side effects will be recorded.

The interventional treatment procedure is performed in the operating room under sterile conditions, in the supine position, using a C-arm fluoroscopy device. The first intervertebral foramen visible under fluoroscopy is C2-C3. Once the appropriate cervical space is identified, the C-arm fluoroscopy device is directed obliquely to 45-65 degrees until the cervical neural foramen is visualized as a circle. The cannula insertion site is determined. The skin and subcutaneous tissue are anesthetized with 2% lidocaine. A 5 cm long RF cannula with a 5 mm active tip is advanced towards the 6 o'clock position of the neural foramina. The needle is advanced until it contacts the superior facet joint, then guided into the foramen. After entering the foramen, to avoid direct intrathecal or spinal cord damage, the needle is advanced to the facet column and into the epidural space while anteroposterior views are obtained with fluoroscopy. Approximately 0.5 mL of non-ionizing contrast agent is injected to confirm needle placement. The spread of radiopaque material, which adheres to the periradicular membrane, is observed both within the foramen and around the nerve root during fluoroscopy. If abnormal sensation, vibration, or pain is observed with a stimulus less than 0.7 Volts for sensory stimulation, or if a pulse is felt in the arm with a stimulus less than 2.0 Volts for motor stimulation, it is assumed that the catheter needle has been placed near the dorsal root ganglion. Subsequently, patients in Group 1 are given 4 mg dexamethasone + 20 mg lidocaine, and patients in Group 2 are given 4 mg dexamethasone. The radiofrequency generator is adjusted so that the temperature of the catheter needle tip does not exceed 42 ºC, and it is subjected to pulsed radiofrequency treatment for 4 minutes. Patient response will be determined based on the reduction in pain at follow-up examinations at 1, 3, and 6 months after the procedure as follows: good response \> 50% reduction, poor response \< 50% reduction, or no change, no response.