Title: HF10 salvage using in situ electrodes from traditional paresthesia-based manufactures: a case series
Authors: Christopher. R. Abrecht, MD, William S. Rosenberg, MD, Lawrence Poree, MD, PhD
Introduction: HF10 positions the distal tip of one electrode at T8 and the second tip at T9, while traditional SCS leads are placed based on paresthesia mapping. HF10 therapy has been shown to provide superior pain control and functional outcomes compared to traditional SCS therapy for chronic back and leg pain. There is also evidence that traditional SCS is an effective long-term treatment for CRPS.
Methods & Results: We present four patients with inadequate relief from traditional SCS. In case 1, a patient with degenerative scoliosis with axial back and hip pain with two Octrodes at T8-10 received relief of hip pain but not axial back pain. In case 2, a patient with FBSS with axial back and LLE radiculopathy with an Octad at T7-9 received only relief of leg pain. In case 3, a patient with FBSS with axial back pain with a Penta paddle at T7-8 had diminishing relief over time. In case 4, a patient with RLE CRPS with a Penta paddle at T9-10 was initially effective but became very positional over time. In case 5, a patient with neuropathic left arm pain from a traumatic brachial plexus avulsion with a surgically placed Quad lead at C3-5 had positional and not sufficiently dense coverage of his arm which diminished over time.
These patients then underwent successful trials, applying high frequency stimulation through the existing leads, with the traditional IPG ultimately replaced with an HF10 IPG. The entire trial and implant was performed through the IPG pocket without manipulating the intraspinal component of the system.
Table 2 shows that ultimately all patients reported a greater than 50% improvement in VAS and self-reported quality of life and functional status after HF10 salvage. As listed in Table 2, duration since salvage ranged from 3-8 months.
Discussion: This series suggests that HF10 therapy may be a salvage strategy for failed low frequency systems. HF10 may also be an effective treatment option even if there is only one electrode or if the electrodes are not placed at the recommended level of T9/10 for high frequency stimulation. Trialing such a salvage strategy can require minimal surgery as only access to the IPG pocket is required.
Gradual loss of analgesic effect has been identified in some series as the most common cause of long-term SCS failure. Nervous system plasticity and worsening of the underlying pathology that prompted implantation are among the suggested mechanisms behind this “tolerance.” Long-term follow up is required to assess if patient undergoing HF10 salvage also exhibit tolerance.
References: Kapural L, Yu C, Doust MW, et al. Novel 10-kHz High-frequency Therapy (HF10 Therapy) Is Superior to Traditional Low-frequency Spinal Cord Stimulation for the Treatment of Chronic Back and Leg Pain: The SENZA-RCT Randomized Controlled Trial. Anesthesiology. 2015; 23(4):851-60.
Kumar K, Toth C, Nath RK, Laing P: Epidural spinal cord stimulation for treatment of chronic pain: Some predictors of success. A fifteen year experience.Neurosurgery.1998; 50:110–121.
Poree L., Krames E., Pope J., Deer T.R., Levy R., Schultz L. Spinal Cord Stimulation as Treatment for Complex Regional Pain Syndrome Should Be Considered Earlier Than Last Resort Therapy. Neuromodulation. 2013; 16(2):125-41.