Peripheral Nerve Stimulation With High-Frequency Electromagnetic Coupling at the Sural and Posterior Tibial Nerves for the Treatment of Complex Regional Pain Syndrome in Lower Extremities: Case Report.

BACKGROUND

Complex regional pain syndrome (CRPS) type 1 is a debilitating condition that is notoriously difficult to treat due to its various manifestations. Peripheral nerve stimulation (PNS) is generally recommended when a patient's symptoms are refractory to conservative measures, as CRPS often is. We present one case of CRPS with intractable lower extremity pain managed effectively with PNS.

CASE REPORT: A 32-year-old man developed CRPS after a work-related accident that resulted in multiple injuries, including a crushed pelvis, injured left lower extremity, and a fractured face and skull. After pelvic and hip reconstruction, the patient was left with numbness, tingling, and pain in the left foot affecting functional activities and sleep. Previous therapies, including nerve blocks, physical therapy, narcotics, opioids, anticonvulsants, antidepressants, and nonsteroidal anti-inflammatory drugs, did not alleviate symptoms. The placement of a PNS device, however, led to significant improvement.

RESULTS

Pain scores at baseline compared to 12-month follow-up decreased from 6/10 to 2/10 at rest and from 8/10 to 4/10 with activity. Average hours of sleep per night increased from 4 to 8 hours (an improvement of 100%). Antidepressants have been discontinued and opioids reduced to an as-needed basis (once every few days). The patient reports decreased sensitivity to cold, reduced swelling, and improved color changes in the foot. In addition, the patient has been able to increase activity, such as walking, standing, and wearing closed-toed shoes, from 20 minutes to now 4 hours at a time with pain levels maintained at a 4/10.

CONCLUSIONS

Subthreshold PNS utilizing high-frequency electromagnetic coupling at the posterior tibial and sural nerves successfully relieved the patient's chronic, debilitating pain in the lower extremity as a result of CRPS.