Device review: Pulsante™ sphenopalatine ganglion microstimulator.

Cluster headache (CH) is a primary headache disorder. The use of neuromodulation in treatment of CH is well documented. The sphenopalatine ganglion (SPG) has long been a target for management of CH. Intervention at the level of the SPG can interrupt the trigemino-autonomic reflex, which mediates CH pain. The Pulsante system is the only device on the market created for SPG stimulation. The Pulsante device consists of the device body, a lead with six stimulating electrodes placed in the pterygopalatine fossa, and a fixation plate to allow anchoring of the device to the maxilla. Stimulation is administered via a patient-controlled handheld remote control held over the cheek. SPG stimulation is an important treatment option for CH patients.

Conservative Management of Neuropathic Pain in a Patient With Pancoast-Tobias Syndrome: A Case Report.

Pancoast-Tobias syndrome characterizes the signs and symptoms of a superior pulmonary sulcus tumor, and includes arm and shoulder pain, atrophy of intrinsic hand muscles, and ipsilateral Horner syndrome. The rarity and overall poor prognosis of patients with superior pulmonary sulcus tumors associated with Pancoast-Tobias syndrome has led to few reports detailing pain management strategies with adjunctive therapies, such as continuous infusions of ketamine and lidocaine, chemotherapy, radiation, and multimodal oral medication regimens. This case highlights the diagnosis and treatment of pain in a patient with Pancoast-Tobias syndrome.

Evaluation of an innovative spinal cord stimulator platform for the treatment of chronic pain.

Spinal cord stimulation (SCS) is an ever-evolving therapy for the treatment of chronic pain. Currently, there are four main companies offering a variety of options for SCS. The Intellis™ system is the latest offering from Medtronic (MN, USA). Intellis offers the smallest implantable SCS pulse generator available and is capable of multiple different modes of stimulation, some of which can be run simultaneously. With an intrinsic accelerometer, the device is capable of sensing various patient positions and can automatically adjust stimulation intensity. Intellis also offers the most comprehensive MRI conditionality to date. Additionally, the new Samsung/Android® (Seoul, South Korea) clinician programmer allows for easier programming than previous Medtronic programing systems. The programer can also generate patient activity and usage reports from implantable pulse generator data.

Utility of Radionuclide Bone Scintigraphy in Complex Regional Pain Syndrome.

PURPOSE OF REVIEW: To describe the current understanding of the role of three-phase bone scintigraphy (TPBS) in the diagnosis and management of complex regional pain syndrome (CRPS), discuss its advantages and limitations, and present three examples of TPBS patterns typically seen in CRPS patients. RECENT FINDINGS: CRPS is a debilitating disorder frequently presenting with pain to ordinarily non-painful stimuli, redness, swelling, following fractures, stroke, myocardial infarction, surgery, or even minor trauma, and its diagnosis, based on clinical criteria and supportive imaging findings, is difficult. Of the available adjunctive diagnostic imaging modalities, radionuclide bone scintigraphy using a TPBS protocol is the most sensitive and specific for detecting abnormalities commonly seen with this condition-classically, increased periarticular uptake on delayed phase of TPBS, with variable increased uptake on perfusion phases, depending on chronicity. Recent studies have (1) demonstrated a more heterogeneous correlation of TPBS findings with CRPS diagnosis using the current Budapest criteria than in studies using older criteria, (2) pointed to the utility of novel quantitative scintigraphic techniques, and (3) highlighted the value of the early perfusion phases of TPBS in predicting treatment response. TPBS remains a valuable imaging adjunct to clinical diagnosis of CRPS. In combination with a multi-modal analgesic approach, TPBS can be used to follow disease course and potentially treatment response, although prospective trials are needed to further delineate its role.

Survival Analysis of Occipital Nerve Stimulator Leads Placed under Fluoroscopic Guidance with and without Ultrasonography.

BACKGROUND: Electrical stimulation of the greater occipital nerves is performed to treat pain secondary to chronic daily headaches and occipital neuralgia. The use of fluoroscopy alone to guide the surgical placement of electrodes near the greater occipital nerves disregards the impact of tissue planes on lead stability and stimulation efficacy. OBJECTIVE: We hypothesized that occipital neurostimulator (ONS) leads placed with ultrasonography combined with fluoroscopy would demonstrate increased survival rates and times when compared to ONS leads placed with fluoroscopy alone. STUDY DESIGN: A 2-arm retrospective chart review. SETTING: A single academic medical center. METHODS: This retrospective chart review analyzed the procedure notes and demographic data of patients who underwent the permanent implant of an ONS lead between July 2012 and August 2015. Patient data included the diagnosis (reason for implant), smoking tobacco use, disability, and age. ONS lead data included the date of permanent implant, the imaging modality used during permanent implant (fluoroscopy with or without ultrasonography), and, if applicable, the date and reason for lead removal. A total of 21 patients (53 leads) were included for the review. Chi-squared tests, Fishers exact tests, 2-sample t-tests, and Wilcoxon rank-sum tests were used to compare fluoroscopy against combined fluoroscopy and ultrasonography as implant methods with respect to patient demographics. These tests were also used to evaluate the primary aim of this study, which was to compare the survival rates and times of ONS leads placed with combined ultrasonography and fluoroscopy versus those placed with fluoroscopy alone. Survival analysis was used to assess the effect of implant method, adjusted for patient demographics (age, smoking tobacco use, and disability), on the risk of lead explant. RESULTS: Data from 21 patients were collected, including a total of 53 ONS leads. There was no statistically significant difference in the lead survival rate or time, disability, or patient age with respect to the implant method with or without ultrasonography. There was a statistically significant negative effect on the risk of explant with regards to lead removal in smoking patients compared to non-smoking patients (hazard ratio 0.36). There was also a statistically significant difference in smoking tobacco use with respect to the implant method, such that a greater number of patients whose leads were placed with combined fluoroscopy and ultrasonography had a history of smoking (P = 0.048). LIMITATIONS: This study is a retrospective chart review that had statistically significant differences in the patient groups and a small sample size. CONCLUSION: This study assessed the survival rates and times of ONS leads placed with ultrasonography and fluoroscopy versus fluoroscopy alone. We did not observe an effect to suggest that the incremental addition of ultrasound guidance to fluoroscopy as the intraoperative imaging modality used during the permanent implant of ONS leads yields statistically significant differences in lead survival rate or time. Medical comorbidities, including age and smoking status, may play a role in determining the risk of surgical revision and should be considered in future studies. KEY WORDS: Neuromodulation, peripheral nerve stimulation, occipital nerve stimulation, occipital neuralgia, chronic daily headaches, ultrasonography.

New modalities of neurostimulation: high frequency and dorsal root ganglion.

PURPOSE OF REVIEW: Neurostimulation is a well tolerated, cost-efficient, and effective method to treat chronic pain. Although spinal cord stimulation (SCS) has been shown to help patients, newer modalities such as burst, kilohertz-frequency, and dorsal root ganglion stimulation may provide greater pain relief, fewer paresthesias, and better outcomes. RECENT FINDINGS: Burst stimulation, programed as five-impulse burst at a frequency of 500 Hz, delivers more charge per second than conventional stimulation. Trials of burst stimulation have shown superior pain relief, decreased paresthesias, and patient preference compared with conventional SCS. Kilohertz-frequency SCS uses low-amplitude, high-frequency (10 kHz), and short-duration pulses. The SENZA trial showed superiority in both back and leg pain with greater pain relief as well as decreased opioid use. Dorsal root ganglion stimulation stimulates the ganglion cells allowing for precise targeting of pain regions. Multiple studies, including the ACCURATE trial, have shown superior pain relief in multiple conditions. SUMMARY: Improvements in pain control and patient satisfaction suggest that these new stimulation patterns will greatly increase the utility of neurostimulation; however, clinical trials with broader patient populations have to be done to support more extensive use of these therapies.

Insurance disparities in the outcomes of spinal cord stimulation surgery.

OBJECTIVES: The Affordable Care Act aims to expand health insurance and to help narrow existing health care disparities. Medicaid patients have previously been noted to be at an increased risk for impaired access to health care, delayed medical treatment, and the receipt of substandard care. Conversely, those with commercial insurance may be subject to overtreatment. The goal of this study was to evaluate how Medicaid versus commercial insurance status affects outcomes following spinal cord stimulation (SCS) surgery. MATERIALS AND METHODS: A retrospective cohort study of 13,774 patients underwent either percutaneous or paddle permanent SCS implantation, selected from the Thomson Reuter's MarketScan database between 2000 and 2009. Patients were characterized by age at initial procedure, gender, baseline comorbidity burden, procedure-associated diagnosis code, follow-up, and type of insurance (Medicaid vs. commercial insurance). Outcome measures included probability of reoperation, timing and type of reoperation, presence of postoperative complications (immediate, 30 days, and 90 days), and overall utilization of health resources postoperatively. Multivariate analysis was performed comparing the relative effect of insurance status on outcomes following initial surgery. RESULTS: Medicaid patients had greater healthcare resource utilization as measured by medications prescribed, emergency department visits, and length of stay; however, commercially insured patients had significantly higher overall costs ($110,908 vs. $64,644, p < 0.0001). Commercial and Medicaid patients did not significantly differ in their complication rates during the index hospitalization or at 30 days or 90 days postoperatively. The group were also not significantly different in their two-year reoperation rates (7.32% vs. 5.06%, p = 0.0513). CONCLUSIONS: There are substantial insurance disparities that affect healthcare utilization and overall cost following SCS. Efforts for national healthcare reform should examine system factors that will reduce socioeconomic disparities in outcomes following SCS.