Efficacy of Sympathetic Nerve Blocks in Pediatric Outpatients with Central Sensitization of Pain

Purpose: Central sensitization (CS) is distinguished by an increased sensitivity to painful stimuli, due to a lower pain threshold or an altered response to pain. Clinically, CS frequently presents as enhanced sensitivity to a painful stimulus, triggering of pain by nonpainful events, and expansion of the receptive field. There is currently no standardized treatment for CS. Therapy is normally attempted through medications, lifestyle modifications, stress management, cognitive-behavioral therapy, physical therapy, interventional pain procedures, and occasionally surgery but evidence supporting specific treatments is lacking. Interventional nerve blocks are relatively common for the relief of chronic pain in adults but not in pediatric patients. To the best of our knowledge, this is the largest report examining the use of sympathetic nerve blocks for the relief of chronic pain in children. Methods: This study was a retrospective, chart review of pediatric patients treated between January 2009 and March 2018 for conditions that cause CS at Cook Children’s Medical Center. Patients included were between ages 0-21 years at the time of the procedure. Demographics, diagnoses, pain scores (FACES, VAS, NAS, FLACC; each measured on 10-point Likert scales), patient report of complications, activities of daily living and improvements in limb function were reviewed for each patient. Though each patient had 1-5 procedures, study analysis was limited to the first procedure. Results: There were 69 distinct patients (56 female; 63 white; median age 14.68 years, range 3.54-19.27). Common diagnoses treated include complex regional pain syndrome (45 patients) and abdominal pain (15 patients). Most patients demonstrated improvements in leg functionality (77%), hand functionality (76%), and overall functionality (71%). Pain scores improved after intervention for 74% of patients, and on average, patients reported a statistically significant improvement in the pain score from before (Mean=5.39; SD=3.02) to after (Mean=1.38; SD=2.08) intervention, P Conclusions: Sympathetic nerve blocks are both effective and safe for the short-term treatment of CS in children. Additional research should be done to determine long-term effectiveness and safety in this population.