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

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.

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

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.

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.

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.