Faculty Bibliography

Out of approximately 600 deep brain stimulation surgeries performed at our center over 10 years, 5 patients received "rescue"

Palliative cervical cordotomy can be performed via percutaneous radiofrequency ablation of the lateral C1-2 spinothalamic tract. This rare procedure can be safe, effective, and advantageous in mitigating medically intractable unilateral extremity pain for selected patients with end-stage cancer. This report reviews the indications, techniques, risks, and potential benefits of cordotomy. We describe our recent experience treating 3 patients with CT-guided C1-2 cordotomy and provide the first characterization of spinal cord diffusion MR imaging changes associated with successful cordotomy.

OBJECTIVES/OBJECTIVE:The Implantable Systems Performance Registry (ISPR) was created to monitor the product performance of Medtronic Spinal Cord Stimulation (SCS) and implanted intrathecal drug infusion systems available in the United States. MATERIALS AND METHODS/METHODS:Data were collected on 2605 patients from 44 centers from various geographic regions across the United States implanting and following patients with SCS systems between June 25, 2004 and January 31, 2014. Actuarial life table methods are used to estimate device performance over time. Of the 2605 patients, 1490 (57.2%) were female, 1098 (42.1%) were male and 17 (0.7%) did not provide gender data. The average age at enrollment was 56.3 years (range: 4-97, SD = 14.3) and average follow-up time was 20.1 months (SD = 22.5). RESULTS:Currently the estimates of device survival from neurostimulator-related events exceed 97% for all neurostimulator models across the applicable follow-up time points and all applicable extension models had greater than 95% survival from extension events. The majority of product performance events were lead-related. At 5 years of follow-up, all applicable lead families, with the exception of the Pisces-Quad LZ family, had greater than 75% survival from lead events. CONCLUSIONS:The ISPR is designed to serve as an ongoing source of system and device-related information with a focus on "real-world" safety and product performance. ISPR data continue to be used to guide future product development efforts aimed at improving product reliability and quality.

BACKGROUND: Targeting the subthalamic nucleus (STN) for deep brain stimulation (DBS) using standard stereotactic coordinates in conjunction with high-resolution magnetic resonance imaging (MRI) generally results in effective symptomatic relief for the cardinal motor features of Parkinson's disease (PD). The angle of approach, however, influences the resultant field of stimulation and can lead to undesired side effects. METHODS: We review a case where symptomatic improvement was accompanied by significant side effects despite reasonable STN stereotactic base coordinates. Revision of the lead using similar base coordinates but a significantly different angle of approach greatly improved the outcome. RESULTS: Stimulation ventromedial to the STN improved tremors but brought about dysarthria and dystonia. Computer-based stimulation field modeling helped understand the regions associated with the side effects and illustrate the difference between pre- and post-revision stimulation fields. CONCLUSION: Lead angle can impact DBS outcome and should be taken into consideration.

BACKGROUND AND PURPOSE: Obtaining high-resolution brain MR imaging in patients with a previously implanted deep brain stimulator has been challenging and avoided by many centers due to safety concerns relating to implantable devices. We present our experience with a practical clinical protocol at 1.5T by using 2 magnet systems capable of achieving presurgical quality imaging in patients undergoing bilateral, staged deep brain stimulator insertion. MATERIALS AND METHODS: Protocol optimization was performed to minimize the specific absorption rate while providing image quality necessary for adequate surgical planning of the second electrode placement. We reviewed MR imaging studies performed with a minimal specific absorption rate protocol in patients with a deep brain stimulator in place at our institution between February 1, 2012, and August 1, 2015. Images were reviewed by a neuroradiologist and a functional neurosurgeon. Image quality was qualitatively graded, and the presence of artifacts was noted. RESULTS: Twenty-nine patients (22 with Parkinson disease, 6 with dystonia, 1 with essential tremor) were imaged with at least 1 neuromodulation implant in situ. All patients were imaged under general anesthesia. There were 25 subthalamic and 4 globus pallidus implants. Nineteen patients were preoperative for the second stage of bilateral deep brain stimulator placement; 10 patients had bilateral electrodes in situ and were being imaged for other neurologic indications, including lead positioning. No adverse events occurred during or after imaging. Mild device-related local susceptibility artifacts were present in all studies, but they were not judged to affect overall image quality. Minimal aliasing artifacts were seen in 7, and moderate motion, in 4 cases on T1WI only. All preoperative studies were adequate for guidance of a second deep brain stimulator placement. CONCLUSIONS: An optimized MR imaging protocol that minimizes the specific absorption rate can be used to safely obtain high-quality images in patients with previously implanted deep brain stimulators, and these images are adequate for surgical guidance.

The proceedings of the 3rd Annual Deep Brain Stimulation Think Tank summarize the most contemporary clinical, electrophysiological, imaging, and computational work on DBS for the treatment of neurological and neuropsychiatric disease. Significant innovations of the past year are emphasized. The Think Tank's contributors represent a unique multidisciplinary ensemble of expert neurologists, neurosurgeons, neuropsychologists, psychiatrists, scientists, engineers, and members of industry. Presentations and discussions covered a broad range of topics, including policy and advocacy considerations for the future of DBS, connectomic approaches to DBS targeting, developments in electrophysiology and related strides toward responsive DBS systems, and recent developments in sensor and device technologies.

This paper provides an overview of current progress in the technological advances and the use of deep brain stimulation (DBS) to treat neurological and neuropsychiatric disorders, as presented by participants of the Fourth Annual DBS Think Tank, which was convened in March 2016 in conjunction with the Center for Movement Disorders and Neurorestoration at the University of Florida, Gainesveille FL, USA. The Think Tank discussions first focused on policy and advocacy in DBS research and clinical practice, formation of registries, and issues involving the use of DBS in the treatment of Tourette Syndrome. Next, advances in the use of neuroimaging and electrochemical markers to enhance DBS specificity were addressed. Updates on ongoing use and developments of DBS for the treatment of Parkinson's disease, essential tremor, Alzheimer's disease, depression, post-traumatic stress disorder, obesity, addiction were presented, and progress toward innovation(s) in closed-loop applications were discussed. Each section of these proceedings provides updates and highlights of new information as presented at this year's international Think Tank, with a view toward current and near future advancement of the field.

Tourette Syndrome (TS) is a neuropsychiatric disease characterized by a combination of motor and vocal tics. Deep brain stimulation (DBS), already widely utilized for Parkinson's disease and other movement disorders, is an emerging therapy for select and severe cases of TS that are resistant to medication and behavioral therapy. Over the last two decades, DBS has been used experimentally to manage severe TS cases. The results of case reports and small case series have been variable but in general positive. The reported interventions have, however, been variable, and there remain non-standardized selection criteria, various brain targets, differences in hardware, as well as variability in the programming parameters utilized. DBS centers perform only a handful of TS DBS cases each year, making large-scale outcomes difficult to study and to interpret. These limitations, coupled with the variable effect of surgery, and the overall small numbers of TS patients with DBS worldwide, have delayed regulatory agency approval (e.g., FDA and equivalent agencies around the world). The Tourette Association of America, in response to the worldwide need for a more organized and collaborative effort, launched an international TS DBS registry and database. The main goal of the project has been to share data, uncover best practices, improve outcomes, and to provide critical information to regulatory agencies. The international registry and database has improved the communication and collaboration among TS DBS centers worldwide. In this paper we will review some of the key operation details for the international TS DBS database and registry.

OBJECTIVE: In this study, we analyze device- and procedure-related adverse events (AEs) from a recent prospective, multicenter, double-blinded controlled study that utilized peripheral nerve stimulation (PNS) of occipital nerves for management of chronic migraine. METHODS: PNS device characteristics (lead length and spacing), surgical techniques including lead orientation (parallel or perpendicular to the nerve), and implantable pulse generator (IPG) placement (upper buttock, abdomen, infraclavicular, or lower axilla) in 157 patients were analyzed to identify any relationship with the AE incidence rate. Number of prior PNS implants performed (NPPIP) by the implanter and its relationship with different AE categories (hardware-related, biological, and stimulation-related events) and frequently observed device/procedure-related AEs (lead migration/fracture/breakage, persistent pain at the lead/IPG location, unintended/undesirable changes in stimulation, infection) were also evaluated. Three-way ANOVA tests were utilized to evaluate the dependence of AE occurrence on the variables described above. RESULTS: IPG pocket locations closer to the lead (e.g. infraclavicular region) were associated with a lower AE incidence rate (p < 0.05). Higher NPPIP was related to lower stimulation- and hardware-related AEs (p < 0.05), frequently observed AEs like lead migration, pain, and infection (p < 0.05), and procedure-related additional surgeries (p < 0.05). CONCLUSION: Implantation of the IPG closer to the lead location was associated with reduced AEs. PNS is a relatively new procedure, and the skill and precision in performing these procedures improves with experience. Our results demonstrate that as the implanter gains more experience with these procedures, a significant reduction in device- and procedure-related AEs may be expected.