Thoracic sympathetic block with botulinum toxin A for complex regional pain syndrome: a retrospective case series

Interv Pain Med. 2026 May 25;5(2):100774. doi: 10.1016/j.inpm.2026.100774. eCollection 2026 Jun.

ABSTRACT

BACKGROUND: Sympathetic interventions are frequently used in complex regional pain syndrome (CRPS). However, the evidence is inconclusive, and the response may depend on phenotype, anatomical target, and treatment durability. For upper-extremity CRPS, clinical data on thoracic sympathetic block (TSB) with botulinum toxin type A (BoNT-A) are lacking.

OBJECTIVE: To describe patient characteristics, procedural details, and clinical and thermographic outcomes after computed tomography (CT)-guided TSB with BoNT-A in upper-extremity CRPS.

METHODS: We performed a retrospective single-center case series of consecutive adults with upper-extremity CRPS who underwent CT-guided TSB with BoNT-A between January 2023 and March 2026. For each procedure, medical records were reviewed to descriptively assess pain change, duration of effect, repeat procedures, thermographic change, and adverse events.

RESULTS: Six patients underwent 7 procedures. Most suffered from persistent, treatment-refractory CRPS. Responses varied: 3 patients experienced a clinically meaningful analgesic benefit, 1 had thermographic improvement without clear analgesic benefit, and 2 had no meaningful response. No serious procedure-related complications were observed.

CONCLUSION: CT-guided TSB with BoNT-A was feasible in this small retrospective series of refractory upper-extremity CRPS. Responses were heterogeneous, and thermographic improvement was not always accompanied by pain relief. The findings may prompt hypotheses regarding phenotype-based patient selection and the role of thermography.

PMID:42238955 | PMC:PMC13226239 | DOI:10.1016/j.inpm.2026.100774