gms | German Medical Science

Objective: Peripheral nerve stimulation (PNS) is known to deliver targeted relief of neuropathic pain in peripheral nerve disorders. All patients have to undergo invasive electrode placement and external test stimulation before feasibility and outcome become apparent. A minimally invasive test method to determine a favourable electrode position and predict stimulation outcome is missing. Aim of this ongoing single centre open label trail is to establish electro-acupuncture mapping as a test tool for PNS. The technique and preliminary results of seven patients are presented.

Methods: Patients with mononeuropathy and pharmacoresistant neuropathic pain are included. A rectangular pattern of acupuncture needles is placed subcutaneously to cover the proximity of the pain area. Thresholds and effects of 180 µs impulses at 2 Hz and 80 Hz are monitored at different sites. A score was developed to quantify effects. The test is repeated before all patients receive a subcutaneous or perineural octrode (ANS, SJM) at the site where electro-acupuncture caused most suitable effects for pain reduction. The implantation of a generator (EON mini, ANS SJM) follows after successful external test stimulation. Stimulation effects of electro-acupuncture, external and internal PNS are compared. A battery of scales is used for a standardized follow up (PD-Q, VAS, MOS Sleep Scale, FFbH, SF 12^®).

Results: 7 patients with posttraumatic or iatrogenic neuropathic pain have been treated so far. Electrode placements were subcutaneously in 5 and perineural in 2 patients. Electro-acupuncture predicted stimulation results correctly in all 7 patients with sufficient pain reduction in 5 and no lasting therapeutic effects in 2 patients. Median follow up is 9 months.

Conclusions: Electro-acupuncture is a minimal invasive technique used for pain management in TCM. Utilized as a mapping tool prior to PNS our preliminary results indicate a predictive value regarding optimal electrode placement and stimulation outcome.