gms | German Medical Science

Objective: Chronic lumbar pain remains a difficult to address symptom in spite of advances made in electrode design and implantation techniques for SCS. Trials with subcutaneous electrodes implanted within or around the painful section often end in frustration. Recently we introduced electro-acupuncture mapping as a test tool for PNS. A case series and a treatment algorithm for lumbar nerve field stimulation based on mapping results are presented.

Methods: 16 patients with chronic lumbar pain underwent electro-acupuncture mapping twice and subsequent electrode implantation. A positive test result resembles paresthesia and numbness within the pain area provoking lasting pain reduction for more than 1 hour. Two electrodes (4 or 8 contacts) were placed at sites of optimal test stimulation.

Results: Electro-acupuncture mapping revealed optimal stimulation sites far lateral to the pain area in proximity to a region where branches of the segmental rami dorsalis surface. With low stimulation intensity, a confluent field of paresthesia across the midline was observed. Lasting and additional pain relief after implantation could be seen in 14 out of 16 treated patients. The superior effect relies on 2 electrodes. Cycling stimulation ensures stable pain control. Mean pain reduction is 80%. Mean follow-up is 12 months.

Conclusions: By standardizing approach and patient selection, lumbar nerve field stimulation provided predictable and lasting pain control in our series. If our results could be reproduced in a larger trial, lumbar nerve field stimulation yields potential as a secure therapeutic option for chronic lumbar pain as a standalone therapy or in combination with SCS.