The Neurostimulation Appropriateness Consensus Committee (NACC): Recommendations on Best Practices for Cervical Neurostimulation.

INTRODUCTION: The International Neuromodulation Society convened a multispecialty group of physicians based on expertise with international representation to establish evidence-based guidance on the use of neurostimulation in the cervical region to improve outcomes. This Neurostimulation Appropriateness Consensus Committee (NACC) project intends to provide evidence-based guidance for an often-overlooked area of neurostimulation practice. MATERIALS AND METHODS: Authors were chosen based upon their clinical expertise, familiarity with the peer-reviewed literature, research productivity, and contributions to the neuromodulation literature. Section leaders supervised literature searches of MEDLINE, BioMed Central, Current Contents Connect, Embase, International Pharmaceutical Abstracts, Web of Science, Google Scholar, and PubMed from 2017 (when NACC last published guidelines) to the present. Identified studies were graded using the US Preventive Services Task Force criteria for evidence and certainty of net benefit. Recommendations are based on the strength of evidence or consensus when evidence was scant. RESULTS: The NACC examined the published literature and established evidence- and consensus-based recommendations to guide best practices. Additional guidance will occur as new evidence is developed in future iterations of this process. CONCLUSIONS: The NACC recommends best practices regarding the use of cervical neuromodulation to improve safety and efficacy. The evidence- and consensus-based recommendations should be utilized as a guide to assist decision making when clinically appropriate.

Prevention of Implant-Associated Infection in Neuromodulation: Review of the Literature and Prototype of a Novel Protective Implant Coating.

Background: Implanting hardware into surgical sites increases the rate of infection associated with these sites. Without novel efforts to reduce this rate of infection, we can expect to see an increase in the number of hardware-associated infections as more patients are implanted with these devices. These infections often necessitate the removal of these devices resulting in a significant financial and clinical burden to patients. We developed a prototype antibiotic coating using products that are both low cost and that can be sourced easily. Our study aims to test the effectiveness of this coating against bacteria commonly observed in hospital-associated infections. Methods: The antibiotic coating was prepared by combining one gram of vancomycin and 500 mg of ciprofloxacin in 50 mL of glycerol. The coating was examined for inhibition of growth of Pseudomonas aeruginosa PA14 and Staphylococcus aureus AH2486 and compared with the bacterial growth of the above bacteria in glycerol alone. The growth curves were plotted measuring the bacterial growth at 5 h intervals. Results: The results of the growth curves clearly demonstrate a lack of bacterial growth when these bacteria are combined with glycerol combined with our selected antibiotic agents. Conclusion: There appears to be a limited interest from device companies in developing new strategies for infection prevention associated with neurosurgical hardware, and we propose that this prototype will be an effective and low-cost solution to a large problem.

Deep Brain Stimulation of the Hypothalamus Leads to Increased Metabolic Rate in Refractory Obesity.

OBJECTIVE: Obesity has become a worldwide epidemic, with very few long-term successful treatment options for refractory disease. Deep brain stimulation (DBS) of the bilateral lateral hypothalamus (LH) in refractory obesity has been performed safely. However, questions remain regarding the optimal settings and its effects on metabolic rate. The goals of our experiment were to determine the optimal DBS settings and the actual effect of optimal stimulation on energy expenditure. METHODS: After bilateral LH DBS implantation, 2 subjects with treatment refractory obesity underwent 4 days of metabolic testing. The subjects slept overnight in a respiratory chamber to measure their baseline sleep energy expenditure, followed by 4 consecutive days of resting metabolic rate (RMR) testing at different stimulation settings. On day 4, the optimized DBS settings were used, and sleep energy expenditure was measured again overnight in the room calorimeter. RESULTS: During daily testing, the RMR fluctuated acutely with changes in stimulation settings and returned to baseline immediately after turning off the stimulation. Optimal stimulation settings selected for participants showed a 20% and 16% increase in RMR for the 2 participants. Overnight sleep energy expenditure measurements at these optimized settings on day 4 yielded a 10.4% and 4.8% increase over the baseline measurements for the 2 participants. CONCLUSIONS: These findings have demonstrated the efficacy of optimized DBS of the LH on increasing the RMR acutely and maintaining this increase during overnight sleep. These promising preliminary findings have laid the groundwork for the possible treatment of refractory obesity with DBS.

Cranial plate anchoring of spinal cord stimulation paddle leads: technical note.

BACKGROUND: Lead migration is a frequent complication of spinal cord stimulation (SCS) and requires revision surgery. The evolution of wider paddle leads has necessitated more extensive laminotomy and epidural adhesiolysis, which may increase the risk of lead migration. OBJECTIVE: We describe a novel anchoring technique for SCS paddle leads with use of a cranial "dogbone" plate. METHODS: We retrospectively reviewed a consecutive series of 11 patients who underwent placement of paddle lead spinal cord stimulators with titanium plate anchoring. Patients were followed for a mean of 29.5 months from SCS implantation (range, 5-65 months). A 4-hole linear titanium cranial plate and two 4-mm screws were used to tightly affix the proximal paddle lead wiring to the lamina below the laminotomy defect. RESULTS: All patients continue to have satisfactory spinal cord stimulation with no loss of efficacy or need for revision. No complications have been attributed to titanium plate anchoring, and there have been no cases of lead migration with this technique. Titanium plate anchoring added minimal time (approximately 3-5 minutes) to the operative case. CONCLUSION: We report a safe and effective anchoring technique for paddle lead SCS with the use of a cranial plate. Our experience has been that this technique, which anchors the proximal lead wiring to the remaining lamina at the inferior laminotomy defect, is superior to anchoring methods that rely on suturing of lead wiring.

Deep brain stimulation for obesity--from theoretical foundations to designing the first human pilot study.

Obesity is perhaps an evolutionary consequence of a species reared with intermittent caloric reward. Humans are hardwired to enjoy food, and our bodies voraciously extract and store energy from food as if each meal was the last. As an amalgam of behavioral and metabolic disturbance, obesity is an attractive target for deep brain stimulation (DBS) since neuromodulation may be able to influence both eating behavior and metabolism. The current pandemic proportions of obesity combined with the failures and morbidity of modern treatments remain the impetus behind the application of DBS to this complex disease. We review the rationale and scientific foundations for obesity DBS and explain how this preclinical evidence has helped sculpt the design of the first human pilot study.

Cervicomedullary junction spinal cord stimulation for head and facial pain.

OBJECTIVE: To review our experience with cervicomedullary junction spinal cord stimulation (SCS), to alleviate head and facial pain. BACKGROUND: There is a dearth of literature regarding the use of spinal cord stimulation for treating head and facial pain. DESIGN: We performed a Boolean search of the electronic medical record (1990-2009) and identified 35 patients (9 men, 26 women) for whom the senior author (J.J.M) trialed paddle lead cervicomedullary junction stimulation (CMJ-S) for intractable head or facial pain. Twenty-five patients (71.4%) had a successful trial with subsequent implantation of SCS hardware and 10 patients (28.6%) experienced a failed trial. Pain syndromes were categorized into diagnostic groups: trigeminal deafferentation pain (TDP), trigeminal neuropathic pain (TNP), occipital pain/neuralgia, post-herpetic neuralgia (PHN), and post-stroke facial pain. Follow-up via structured telephone interview was obtained in 25 patients (71.4%). RESULTS: Among the 25 patients available for follow-up, 16 patients (64%) underwent implantation and 9 patients (36%) had a failed trial of CMJ-S. The mean patient age and length of follow-up was 47.3 years old (20-78 years old) and 53.4 months (2-120 months), respectively. On a 0-10 pain intensity scale (0 being no pain and 10 being the worst degree of pain), a mean pretrial pain level of 9.6 (range 7-10) had been reduced to a mean of 4.8 (0-10) at follow-up. Successful trial and subsequent implantation occurred in 7 patients with TDP (70%), 4 patients with TNP (80%), both patients with PHN (100%), and in the single patient with post-stroke facial pain (100%) but in only 2 patients (28.6%) with occipital neuralgia/pain. At the time of telephone interview, 4 of the implanted patents (25%) had their hardware removed because of loss of effectiveness (3) and infection (1). The other 12 implanted patients (75%) continue to use CMJ-S on a daily basis and insist that it has improved their quality of life. Six current users (50%) of CMJ-S have been able to decrease their use of oral pain medications. Complications in the implanted group included infection (1), uncomfortable paresthesias from breakdown of connecting wire insulation (1), and gradual loss of effectiveness (3). CONCLUSIONS: Our preliminary experience suggests that patients suffering from TDP, TNP, and PHN may respond favorably to CMJ-S whereas patients with occipital neuralgia/pain are rarely palliated by this neuromodulatory approach.

Localization of cervical and cervicomedullary stimulation leads for pain treatment using median nerve somatosensory evoked potential collision testing.

OBJECT: Spinal cord stimulation (SCS) is being currently used to treat medically refractory pain syndromes involving the face, trunk, and extremities. Unlike thoracic SCS surgery, during which patients can be awakened from conscious sedation to confirm good lead placement, safe placement of paddle leads in the cervical spine has required general anesthesia. Using intraoperative neurophysiological monitoring, which is routinely performed during these cases at the authors' institution, the authors developed an electrophysiological technique to intraoperatively lateralize lead placement in the cervical epidural space. METHODS: Data from 44 patients undergoing median and tibial nerve somatosensory evoked potential (SSEP) monitoring during cervical laminectomy or hemilaminectomy for placement or replacement of dorsal column stimulators were retrospectively reviewed. Paddle leads were positioned laterally or just off midline and parallel to the axis of the cervical spinal cord to effectively treat what was most commonly a predominant unilateral pain syndrome. During SSEP recording, the spinal cord stimulator was activated at 1.0 V and increased in increments of 1.0 V to a maximum of 6.0 V. A unilateral reduction or abolishment of SSEP amplitude was regarded as an indicator of lateralized placement of the stimulator. A bilateral diminutive effect on SSEPs was interpreted as a midline or near midline lead placement. RESULTS: Epidural stimulation abolished or significantly reduced SSEP amplitudes in all patients undergoing placement for a unilateral pain syndrome. In 15 patients, electrodes were repositioned intraoperatively to achieve the most robust SSEP amplitude reduction or abolishment using the lowest epidural stimulation intensity. In all cases in which a significant unilateral reduction in SSEP was observed, the patient reported postoperative sensory alterations in target locations predicted by intraoperative SSEP changes. Placement of cervical spinal cord stimulators for bilateral pain syndromes often resulted in bilateral but asymmetrical SSEP changes. In no cases were significant SSEP changes, other than those induced using the device to directly stimulate the dorsal surface of the spinal cord, observed. No case of new postoperative neurological deficit was observed. CONCLUSIONS: Somatosensory evoked potentials can be used safely and successfully for predicting the lateralization of cervical spinal cord stimulator placement. Moreover, they can also intraoperatively alert the surgical team to inadvertent displacement of a lead during anchoring. Further studies are needed to determine whether apart from assisting with proper lateralization, SSEP collision testing may help to optimize electrode positioning and improve pain control outcomes.

Simultaneous intrathecal opioid pump and spinal cord stimulation for pain management: analysis of 11 patients with failed back surgery syndrome.

Dual-modality management of failed back surgery syndrome (FBSS) using a combination of an intrathecal opioid pump (IOP) and spinal cord stimulator (SCS) has not been investigated. The authors performed a retrospective review of 11 patients (8 men, 3 women) with FBSS who underwent nonsimultaneous surgical implantation of both an IOP and a thoracic SCS. Chart review and structured phone interviews were performed to obtain follow-up. Of the two modalities, 3 patients (27%) had an IOP placed first and 8 patients (73%) had a SCS implanted initially. Mean follow-up was 41.7 months (3-97 months). All 11 patients (100%) stated that the dual-modality treatment improved their quality of life and all continue to use both an IOP and SCS for pain control. Six patients (55%) felt that the IOP provided superior pain relief as compared to the SCS, 4 patients (36%) felt that IOP and SCS provided a similar degree of pain relief, and 1 patient (9%) said the SCS provided better pain relief than the IOP. Nine patients (82%) claimed that dual-modality treatment improved their activities of daily living. Nine patients (82%) reported that the combination of IOP and SCS treatment had allowed them to significantly decrease their oral pain medication requirements. Seven patients (64%) had hardware-related complications which required surgery; of this group, 2 patients (18%) needed more than one operation. Six patients (55%) had minor postoperative complications, which were managed nonoperatively. Overall, 10 patients (91%) were glad that they had implantation of both an IOP and SCS and would recommend this combined therapy to other patients. Dual neuroaugmentative treatment with an IOP and thoracic SCS can be safely performed and may provide satisfactory pain relief in appropriately selected patients with FBSS.