Presented at the 2013 AAPM Annual Meeting « Back

Intractable Right Inguinal Neuralgia Treated with Dorsal Column Stimulation After Failed Peripheral Nerve Stimulation: A Case Report

Thomas P. Pittelkow, DO MPH, pittelkow.thomas@mayo.edu¹, Susan M. Moeschler, MD¹, Bryan Hoelzer, MD¹, (1) Mayo Clinic, Rochester, Minnesota

Case Description: 62-year-old Caucasian female presented with intractable right inguinal neuralgia following inguinal herniorrhaphy complicated by infections requiring multiple revisions 10 years prior (1). Conservative medical management failed. Peripheral nerve blocks of the ilioinguinal, genitofemoral, and lateral femoral cutaneous nerves yielded successful yet transient relief. Surgical transection of the right genitofemoral nerve was unsuccessful. Peripheral nerve stimulation (PNS) of ilioinguinal and lateral femoral cutaneous nerves provided marked improvement; however, several lead revisions were required and symptom abatement was temporary. Ultimately, dorsal column stimulation (DCS) was considered to provide interruption of the proposed central sensitization and broaden the area of coverage. After a successful trial, DCS placement yielded excellent results with near complete resolution of inguinal neuropathic pain. Discussion: The use of PNS has been suggested to provide adequate coverage for focal neuropathic pain; however, despite multiple successful diagnostic nerve blocks and PNS trial, sustained coverage was not attained (2). DCS provides neuromodulatory signals centrally, minimizing the selectivity required with peripherally placed electrodes (3). Given the chronicity, it is feasible that primary afferent dysfunction persisted leading to eventual centralization effect. This atypical presentation shows that a centrally placed electrode may provide improved regional coverage by altering the central regulatory process of spontaneous and provoked sensations when compared to multiple peripherally placed electrodes. Conclusions: The field of PNS is growing rapidly. Unfortunately, there is not a panacea when it comes to treatment of neuropathic pain. DCS offers central inhibitory signal activation by altering afferent nociceptive input with documented results (3). References: 1) Loos, M.J.A., et al. Classifying Postherniorrhaphy Pain Syndromes Following Elective Inguinal Hernia Repair. World Jour Surgery 2007; 31(9): 1760–1765. 2) Rauchwerger, J.J., et al. On the Therapeutic Viability of Peripheral Nerve Stimulation for Ilioinguinal Neuralgia: Putative Mechanisms and Possible Utility. Pain Practice 2008; 8(2): 138–143. 3) Yakovlev, A.E., et al. Spinal Cord Stimulation as Alternative Treatment for Chronic Post-Herniorrhaphy Pain. Neuromodulation 2010; 13(4): 288–290.

Funding: None