Repeated Ultrasound-Guided Lumbar Sympathetic Block for Refractory Painful Diabetic Peripheral Neuropathy: The First Case from Mzuzu Central Hospital, Malawi

Junyi Ren^1,2, Francis Masoo², Yingpu Zhu^*3,4

1.Department of Anesthesiology, Baoji Central Hospital, Baoji, China

2. Department of Anesthesiology, Mzuzu Central Hospital, Mzuzu, Malawi
3. Department of Endocrine, Xi’an Xidian Group Hospital, Xi’an, China
4. Department of Medicine, Mzuzu Central Hospital, Mzuzu, Malawi

• Corresponding Author:Yingpu Zhu; E-mail: zypjade-96722@163.com

Abstract
Background
Painful diabetic peripheral neuropathy (PDPN) is a common complication of diabetes mellitus characterized by chronic neuropathic pain, sleep disturbance, and impaired quality of life. Although pharmacological therapies remain the cornerstone of treatment, many patients experience inadequate symptom control. Access to advanced interventional pain management techniques, including radiofrequency ablation and neuromodulation, remains limited in many healthcare settings. We report the first case of ultrasound-guided lumbar sympathetic block (LSB) performed for refractory PDPN at Mzuzu Central Hospital, Malawi.
Case Presentation
A 19-year-old woman with a 9-year history of type 1 diabetes mellitus presented with bilateral lower-limb neuropathic pain that had persisted for 6 years and progressively worsened over the preceding 3 years. Symptoms were more severe in the right lower limb, with a baseline Numerical Rating Scale (NRS) score of 8/10. Clinical features included burning pain, stabbing pain, numbness, allodynia, sleep disturbance, and impaired mobility. The Douleur Neuropathique 4 (DN4) score was 8/10. Previous treatment with amitriptyline, gabapentin, vitamin B supplementation, diclofenac, and tramadol failed to provide satisfactory symptom relief.
The patient underwent four ultrasound-guided right lumbar sympathetic blocks using 10 mL of 1% lidocaine between May 15 and May 25, 2026. Pain intensity decreased from an NRS score of 8 to 4 immediately after the first procedure and from 5 to 1 after the second procedure. Complete pain relief was achieved before the third procedure and was maintained throughout the two-week follow-up period. Skin temperature increased by approximately 0.9–1.0°C after each block. No procedure-related complications were observed.
Conclusion
Repeated ultrasound-guided lumbar sympathetic block provided substantial and sustained pain relief in refractory PDPN. This minimally invasive, low-cost, and reproducible technique may represent a practical therapeutic option for selected patients with refractory neuropathic pain and may be particularly valuable in settings where access to advanced pain interventions is limited.
Keywords: painful diabetic peripheral neuropathy; lumbar sympathetic block; ultrasound guidance; neuropathic pain; Malawi