Cervical Epidural Steroid Injection: Parasagittal versus Midline Approach in Patients with Unilateral Cervical Radicular Pain; A Randomized Clinical Trial

Objective: To compare parasagittal interlaminar cervical epidural steroid injection (PSIL-CESI) and the classic midline interlaminar cervical epidural steroid injection (MIL-CESI) in terms of pain relief and functional improvement in patients with unilateral upper extremity radicular pain.Methods: This was a randomized clinical trial being conducted in a single pain center in Tehran. Twenty-six patients were allocated into two groups of 13, undergoing either PSIL-CESI or MIL-CESI. After confirmation of radiocontrast spread in the epidural space by fluoroscopic guidance, dexamethasone 8 mg and bupivacaine 0.125% in a volume of 5 ml were delivered to the epidural space. Evaluation of functional state and pain intensity before and 1 month after the procedure was accomplished using the neck disability index (NDI) and the numeric rating scale (NRS) respectively.Results: Demographic and baseline characteristics of the cases showed no significant statistical difference. Improvements in the NDI and the NRS were observed in both groups; meanwhile, improvements were more pronounced in the PSIL-CESI group as compared to the MIL-CESI group (P<0.001). With the PSIL approach the ventral spread of radiocontrast was significantly higher (38%) than with the MIL approach (0.7%) (P<0.001). All patients in PSIL group showed radiocontrast spread ipsilateral to the painful side and all patients in the MIL group showed a midline distribution of radiocontrast.Conclusion: PSIL-CESI provides superior pain relief and improvement of functional disability in patients with unilateral upper extremity radicular pain in comparison to the classic MIL-CESI.Clinical trial registry: IRCT20180524039816N1