Wireless Peripheral Nerve Stimulation in the Management of Debilitating Extremity Pain from Meralgia Paresthetica and Complex Regional Pain Syndrome: Report of Two Case Illustrations

Laura Tyler Perryman*¹, Jana Kubias², Stefan Stockli³ and Daniel Herschkowitz⁴

Received: September 24, 2018;   Published: October 01, 2018

DOI: 10.26717/BJSTR.2018.09.001806

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Abstract

Peripheral Nerve Stimulation [PNS] is an accepted method of neuromodulation in the management of chronic refractory pain, although there is no specialized equipment available today to be accommodated in the peripheral nerve space. PNS employs the standard spinal cord stimulation [SCS] device that comes with bulky and cumbersome components responsible for several adverse events as well as failures. We describe two chronic debilitating afflictions of peripheral nerves viz. Meralgia Paresthetica [MP] of the lower extremity and complex regional pain syndrome [CRPS] of the upper extremity, treated by wireless peripheral nerve stimulation [WPNS] that requires implantation of a single device, notably without an implantable pulse generator [IPG] or its accessories.

Device Description: WPNS is a single implantable neural stimulator that encases a stimulating electrode [with 4 or 8 contacts], a microprocessor and antenna to communicate with pulse generator by wireless access. The external transmitter is in a wearable antenna assembly [WAA] worn by the patient in close proximity to the implant. This device, unlike the conventional PNS equipment, does not require an IPG.

Case illustrations: A case of MP was diagnosed after the patient underwent an arthroscopic repair of knee joint which was complicated by infection leading to necrotizing fasciitis. Patient required multiple medications and interventions including neurolysis of femoral cutaneous femoral nerve that gave temporary relief. After multiple non-surgical procedures like nerve blocks, physical therapy and cryo-ablation of the cutaneous nerve patient was taken up for WPNS, using a Freedom stimulator with 4 contacts [Stimwave Technologies, Pompano Beach, FL, USA] implanted along the course of the femoral cutaneous nerve. The second case of CRPS type 1, followed blunt trauma to the right upper extremity resulting in intractable pain with allodynia unresponsive to physical therapy, nerve blocks combined with opioid medications. A diagnosis of refractory CRPS was entertained and the patient received placement of two WPNS electrodes [FR4A-RCV-A0 with tines, Generation 1 and FR4A-RCV-B0 with tines, Generation 1] along the ulnar and median nerves under image guidance. Both patients during the follow up had shown prompt symptomatic relief without any adverse events and required minimal pain medication.

Conclusion: WPNS is minimally invasive, single step procedure involving implantation of a single device providing effective relief in debilitating peripheral nerve conditions like MP and CRPS. It does not require an IPG or its accessories thus minimizing the implant related complications and failures.

Keywords: Wireless Neuromodulation; Peripheral Nerve Stimulation; Meralgia Paresthetica; Complex Regional Pain Syndrome

Abbreviations: PNS: Peripheral Nerve Stimulation; SCS: Spinal Cord Stimulation; MP: Meralgia Paresthetica; CRPS: Complex Regional Pain Syndrome; WPNS: Wireless Peripheral Nerve Stimulation; IPG: Implantable Pulse Generator; WAA: Wearable Antenna Assembly; WPG: Wireless Power Generator; RF: Radiofrequency; VAS: Visual Analogue Scale

Abstract | Introduction | Case Report of MP| WPNS Technology | Discussion | References|