Advances in Technical Aspects of Deep Brain Stimulation Surgery.

BACKGROUND: Deep brain stimulation has become an established technology for the treatment of patients with a wide variety of conditions, including movement disorders, psychiatric disorders, epilepsy, and pain. Surgery for implantation of DBS devices has enhanced our understanding of human physiology, which in turn has led to advances in DBS technology. Our group has previously published on these advances, proposed future developments, and examined evolving indications for DBS. SUMMARY: The crucial roles of structural MR imaging pre-, intra-, and post-DBS procedure in target visualization and confirmation of targeting are described, with discussion of new MR sequences and higher field strength MRI enabling direct visualization of brain targets. The incorporation of functional and connectivity imaging in procedural workup and their contribution to anatomical modelling is reviewed. Various tools for targeting and implanting electrodes, including frame-based, frameless, and robot-assisted, are surveyed, and their pros and cons are described. Updates on brain atlases and various software used for planning target coordinates and trajectories are presented. The pros and cons of asleep versus awake surgery are discussed. The role and value of microelectrode recording and local field potentials are described, as well as the role of intraoperative stimulation. Technical aspects of novel electrode designs and implantable pulse generators are presented and compared.

Staphylococcus Aureus Swabbing and Decolonization Before Neuromodulation Procedures: A Systematic Review and Meta-Analysis.

INTRODUCTION: Staphylococcus aureus (S aureus) is the foremost bacterial cause of surgical-site infection (SSI) and is a common source of neuromodulation SSI. Endogenous colonization is an independent risk factor for SSI; however, this risk has been shown to diminish with screening and decolonization. MATERIALS AND METHODS: A systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using the PubMed, Cochrane Library, and Embase data bases from inception to January 1, 2022, for the purposes of identifying all studies reporting on the use of S aureus swabbing and/or decolonization before neuromodulation procedures. A random-effects meta-analysis was performed using the metaphor package in R to calculate odds ratios (OR). RESULTS: Five observational cohort studies were included after applying the inclusion and exclusion criteria. The average study duration was 6.6 ± 3.8 years. Three studies included nasal screening as a prerequisite for subsequent decolonization. Type of neuromodulation included spinal cord stimulation in two studies, deep brain stimulation in two studies, intrathecal baclofen in one study, and sacral neuromodulation in one study. Overall, 860 and 1054 patients were included in a control or intervention (ie, screening and/or decolonization) group, respectively. A combination of nasal mupirocin ointment and a body wash, most commonly chlorhexidine gluconate soap, was used to decolonize throughout. Overall infection rates were observed at 59 of 860 (6.86%) and ten of 1054 (0.95%) in the control and intervention groups, respectively. Four studies reported a significant difference. The OR for intervention (screen and/or decolonization) vs no intervention was 0.19 (95% CI, 0.09-0.37; p < 0.001). Heterogeneity between studies was nonsignificant (I2 = 0.43%, τ2 = 0.00). CONCLUSIONS: Preoperative S aureus swabbing and decolonization resulted in significantly decreased odds of infection in neuromodulation procedures. This measure may represent a worthwhile tool to reduce neuromodulation SSI, warranting further investigation.

Characterizing Complications of Intracranial Responsive Neurostimulation Devices for Epilepsy Through a Retrospective Analysis of the Federal MAUDE Database.

OBJECTIVES: Responsive neurostimulation is an innovative modality in the treatment of medication-refractory epilepsy for patients who are not suitable candidates for surgical intervention. While being a potentially life-changing treatment option for many individuals with epilepsy, little is known about the system's complications aside from its performance in initial clinical trials. Therefore, the goal of this study was to characterize all reported complications of the RNS system made to the Food & Drug Administration since its approval. MATERIALS AND METHODS: The Manufacturer and User Facility Device Experience (MAUDE) database was queried for entries reported under "implanted brain stimulator for epilepsy" through the dates of November 1, 2013, to March 1, 2020. After correction of duplicate entries, each was sorted into complication types based on the entries' narrative descriptions. RESULTS: The searched yielded 241 unique complication events. The most common complications were attributed to infections (40%) and lead breaks (12%). Other reported complications included poor wound healing (10%) and intrinsic device failure (7%). Focal neurological deficits were found in 2%. Over half (67%) of the reported complications required return to the operating room for revision or explant. The remainder of the adverse events were self-resolved or treated with either medication or software adjustment. CONCLUSIONS: Future research endeavors should attempt to optimize the implantable device for preventing infections. The data of complications provided by this review will also aid physicians in providing the most accurate informed consent for patients when deciding to undergo implantation with the responsive neurostimulation system.

Intrathecal baclofen, selective dorsal rhizotomy, and extracorporeal shockwave therapy for the treatment of spasticity in cerebral palsy: a systematic review.

Cerebral palsy (CP) is a chronic congenital disorder as the result of abnormal brain development. Children suffering from CP often battle debilitating chronic spasticity, which has been the focus of recent academic literature. In this systematic review, the authors aim to update the current neuromodulation procedures for the treatment of spasticity associated with CP in all age groups. A systematic review following was conducted using PubMed from inception to 2020. After initial title and abstract screening, 489 articles were identified, and 48 studies met the inclusion criteria for this review. In total, a majority of the published articles of treatments for CP were reporting the use of selective dorsal rhizotomy (SDR) (54%), and the remainder were of intrathecal baclofen (ITB) pumps (29%) and extracorporeal shockwave therapy (ESWT) (17%). Each method was found to have improvement of spasticity at a rate that achieved statistical significance. ITB pump therapy is an all-encompassing method of treating spasticity in children from CP, as it allows for a less invasive treatment that can be titrated to individual patient needs; however, its disadvantages include its long-term maintenance requirements. SDR appears to be an effective method for permanent spasticity relief in young patients. ESWT is a more recent and innovative technique for offering relief of spasticity while being minimally invasiveness. Further studies are needed to establish optimal frequencies and sites of application for ESWT.

Complications associated with deep brain stimulation for Parkinson's disease: a MAUDE study.

INTRODUCTION: Deep brain stimulation (DBS) is a common surgical option for the treatment of medically refractory Parkinson's disease (PD). Manufacturer and User Facility Device Experience (MAUDE), a United States Food and Drug Administration (FDA)-compiled database of adverse event reports related to medical devices, is a public resource that can provide insight into the relative frequency of complications and patient complaints. MATERIALS AND METHODS: We accessed the MAUDE database and queried for adverse reports for deep brain stimulators implanted for PD from January 1, 2009 to December 31, 2018. Complaints were classified into device malfunction, patient non-compliance, patient complaint, surgically managed complications (i.e. complications that are corrected via surgery), and death. Patient complaints were further stratified into ineffective stimulation, shock, overstimulation, battery-related problems, or pain at the pulse generator site. Surgically managed complications were classified as intraoperative complications, impedance, migration, erosion, infection, lead fracture, and lead disconnection. Each event could receive multiple classifications and subclassifications. RESULTS: A total of 4,189 adverse event reports was obtained. These encompassed 2,805 patient complaints. Within this group, 797 (28%) events were classified as ineffective stimulation. There were 1,382 surgically managed complications, 104 (8%) of which were intraoperative complications, 757 (55%) documented impedance issues, 381 (28%) infections, and 413 (30%) lead-related issues. There were 53 documented deaths. CONCLUSIONS: The MAUDE database has potential use as a real time monitor for elucidating the relative occurrence of complications associated with deep brain stimulation. It also allows for the analysis of device-related complications in specific patient populations. Although the database is useful in this endeavor, it requires improvements particularly in the standardization of reporting adverse events.

Paediatric deep brain stimulation: ethical considerations in malignant Tourette syndrome.

Gilles de la Tourette syndrome (TS) is a childhood neuropsychiatric disorder characterised by the presence of motor and vocal tics. Patients with malignant TS experience severe disease sequelae; risking morbidity and mortality due to tics, self-harm, psychiatric comorbidities and suicide. By definition, those cases termed 'malignant' are refractory to all conventional psychiatric and pharmacological regimens. In these instances, deep brain stimulation (DBS) may be efficacious. Current 2015 guidelines recommend a 6-month period absent of suicidal ideation before DBS is offered to patients with TS. We therefore wondered whether it may be ethically justifiable to offer DBS to a minor with malignant TS. We begin with a discussion of non-maleficence and beneficence. New evidence suggests that suicide risk in young patients with TS has been underestimated. In turn, DBS may represent an invaluable opportunity for children with malignant TS to secure future safety, independence and fulfilment. Postponing treatment is associated with additional risks. Ultimately, we assert this unique risk-benefit calculus justifies offering DBS to paediatric patients with malignant TS. A multidisciplinary team of clinicians must determine whether DBS is in the best interest of their individual patients. We conclude with a suggestion for future TS-DBS guidelines regarding suicidal ideation. The importance of informed consent and assent is underscored.

Endoscopic Infraorbital Microdissection for Localized V2 Trigeminal Neuralgia.

Trigeminal neuralgia is a chronic and debilitating syndrome characterized by short paroxysms of lancinating facial pain. Patients may be medically managed; however, in cases of medically refractory trigeminal neuralgia, surgical management is often required. Our objective was to present and describe a technique for endoscopic microdissection of the infraorbital nerve, a peripheral method of management for refractory V2 trigeminal neuralgia in patients without evidence of neurovascular compression. The technique is designed to spare sensation in unaffected portions of the V2 distribution. We present 2 patients with medically refractory V2 trigeminal neuralgia localized to the lateral midface who underwent infraorbital microdissection. After first confirming that there was no neurovascular compression on imaging in these patients, we administered infraorbital bupivacaine injections to localize the symptomatic nerve. The nerve was then accessed via a 1.5-cm buccogingival incision, and the connective tissue sheath was incised. The nerve fascicles were bluntly separated, and the symptomatic branches were cauterized with fine-tipped monopolar cautery. Both patients reported complete resolution of their pain postoperatively and were pain free at last follow-up. They reported some hypoesthesia in the lateral face; however, they retained some sensation in the medial upper lip, midface, and nose. Infraorbital microdissection is a safe and effective technique for symptomatic management of V2 trigeminal neuralgia while sparing sensation in asymptomatic portions of the dermatome.

Neuromodulatory hacking: a review of the technology and security risks of spinal cord stimulation.

BACKGROUND: Spinal cord stimulation (SCS) is a neuromodulatory technique used to relieve chronic pain. Previous instances of malicious remote control of implantable medical devices, including insulin delivery pumps and implantable cardiac defibrillators, have been documented. Though no cases of neuromodulatory hacking have been recorded outside of the academic setting, an understanding of SCS technology and the possible consequences of manipulation is important in promoting safety. METHODS: We review the components and implantation protocol of a SCS system, the functionality and technological specifications for SCS systems in the global market based on their device manuals, and patient- and clinician-specific adjustable factors. Furthermore, we assess documented instances of implantable medical device hacking and speculate on the potential harms of targeting SCS systems. RESULTS: SCS systems from Abbott Laboratories, Boston Scientific, Medtronic, and Nevro have unique functionality and technological specifications. Six parameters in device control can potentially be targeted and elicit various harms, including loss of therapeutic effect, accelerated battery drainage, paresthesia in unintended locations, muscle weakness or dysfunction, tissue burn, and electrical shock. CONCLUSIONS: Based on the history of implantable medical device hacking, SCS systems may also be susceptible to manipulation. As the prevalence of SCS use increases and SCS systems continuously evolve in the direction of wireless control and compatibility with mobile devices, appropriate measures should be taken by manufacturers and governmental agencies to ensure safety.

Neuromodulation Therapies for Alcohol Addiction: A Literature Review.

OBJECTIVES: The goal of this review is to explore alternative neurological therapies in the treatment of alcohol use disorder; including transcranial direct current stimulation (tDCS), transcranial magnetic stimulation, deep brain stimulation (DBS), electroconvulsive therapy (ECT), and the off-label use of the GABAB receptor agonist baclofen. METHODS: A comprehensive literature search was conducted through EBSCOhost regarding the neurological therapies in the treatment of alcoholism discussed in this paper. RESULTS: To date, few studies have been conducted on the subject, sample sizes are consistently small, and long-term abstinence appears a common problem. tDCS has shown to temporarily reduce alcohol cravings but with a high number of long-term relapses, 50-70%. DBS and TMS, similarly, fail to overcome high relapse rates. In one DBS study, for example, only two of five patients achieved prolonged abstinence. ECT seems to avoid such problems, but only a single case study exists to date. As such, no solid conclusions can be made regarding its success in alcohol addiction treatment. Baclofen, however, implicated in studies with comparatively larger patient samples and higher efficacy rates, presents with great promise, particularly in patients with more severe forms of AUD. In one of the largest observational studies to date (100 subjects) 92% of patients reported craving suppression and long-term relapse rates were low. The side-effects of oral baclofen (i.e., somnolence, insomnia, dizziness, paresthesia, etc.) though, pose a principle limitation to its administration in alcohol addiction. CONCLUSIONS: Based on current information in the literature, the authors advocate that, following more extensive research on oral baclofen and its indications in the treatment of alcohol addiction, intrathecal administration be the next logical therapeutic option to be explored. In particular, those patients with severe AUD, requiring high doses of the medication, may benefit, as it eliminates the systemic side effects associated with oral baclofen.

Investigating Complications Associated With Occipital Nerve Stimulation: A MAUDE Study.

OBJECTIVES: The objectives of this study are to utilize the MAUDE data base to enhance our understanding of the complication profile for Occipital Nerve Stimulation, a therapy for which the current level of evidence is limited. Additionally, it is our objective to describe a systematic approach to processing the MAUDE data, which addresses its flaws and enhances its utility. METHODS: From the FDA website, we accessed adverse events reports from the MAUDE data base for devices used in Occipital Nerve Stimulation between June 30, 2007 and June 30, 2017. All reports were sorted into an overall classification for types of adverse events, types of patient complaints, and types of specific device-related complications. We then evaluated for the total number of adverse event reports that contained each of the patient complains and device-related complications. RESULTS: A total of 1233 adverse event records were obtained. Eight hundred twenty-two records were classified as surgically manageable post-operative complications, 121 as device malfunction, 29 as patient compliance issues, and 27 as intra-operative complications. Two hundred thirty-seven records were not classified. A total of 683 records contained patient complaints including 467 complaints of ineffective stimulation, 122 complaints of inappropriate or over-stimulation, 50 complaints of device-shock, and 44 complaints of IPG site pain. We found 581 post-operative device-related complications, which included 206 instances of lead migration, 157 reports of lead erosion, 155 infections, 46 lead-fractures, and 17 lead disconnections. CONCLUSION: The MAUDE data base is a useful tool to investigate device related complications and helps fill the current gap in ONS data. Reviewing the types and frequencies of complications reported over the years allows clinicians with less personal experience to have a more realistic expectation of complications and make informed decisions based on the patient's unique needs. Additionally, patient complaint data are useful in establishing more realistic expectations for patient outcomes.

Deep Brain Stimulation for the Treatment of Dejerine-Roussy Syndrome.

BACKGROUND/AIMS: Patients who suffer from Dejerine-Roussy syndrome commonly experience severe poststroke hemibody pain which has historically been attributed to thalamic lesions. Despite pharmacological treatment, a significant proportion of the population is resistant to traditional therapy. Deep brain stimulation is often appropriate for the treatment of resistant populations. In this review we aim to summarize the targets that are used to treat Dejerine-Roussy syndrome and provide insight into their clinical efficacy. METHODS: In reviewing the literature, we defined stimulation success as achievement of a minimum of 50% pain relief. RESULTS: Contemporary targets for deep brain stimulation are the ventral posterior medial/ventral posterior lateral thalamic nuclei, periaqueductal/periventricular gray matter, the ventral striatum/anterior limb of the internal capsule, left centromedian thalamic nuclei, the nucleus ventrocaudalis parvocellularis internis, and the posterior limb of the internal capsule. CONCLUSIONS: Due to technological advancements in deep brain stimulation, its therapeutic effects must be reevaluated. Despite a lack of controlled evidence, deep brain stimulation has been effectively used as a therapeutic in clinical pain management. Further clinical investigation is needed to definitively evaluate the therapeutic efficacy of deep brain stimulation in treating the drug-resistant patient population.

Occipital nerve stimulation.

Occipital nerve stimulation (ONS) is a form of neuromodulation therapy aimed at treating intractable headache and craniofacial pain. The therapy utilizes neurostimulating electrodes placed subcutaneously in the occipital region and connected to a permanently implanted programmable pulse generator identical to those used for dorsal column/spinal cord stimulation. The presumed mechanisms of action involve modulation of the trigeminocervical complex, as well as closure of the physiologic pain gate. ONS is a reversible, nondestructive therapy, which can be tailored to a patient's individual needs. Typically, candidates for successful ONS include those patients with migraines, Chiari malformation, or occipital neuralgia. However, recent MRSA infections, unrealistic expectations, and psychiatric comorbidities are generally contraindications. As with any invasive procedure, complications may occur including lead migration, infection, wound erosion, device failure, muscle spasms, and pain. The success of this therapy is dependent on careful patient selection, a preimplantation trial, meticulous implantation technique, programming strategies, and complication avoidance.

Dynamic stabilization: a nidus for infection?

INTRODUCTION: Dynamic stabilization offers an adjunct to fusion with motion preservation. In comparison, standard instrumented fusion (if) consists of titanium screws and rods/plates, which do not allow for motion at the level of the fusion. The reported infection rate following a standard if ranges from 0.2% to 7%. METHODS: a retrospective chart review of 142 patients who underwent posterior lumbar stabilization procedures was conducted. Ten patients received dynamic stabilization and 132 patients had a standard if. Rates of infection, requiring hardware removal, were compared between the aforementioned groups. RESULTS: Of the 132 patients undergoing posterior if, three developed a deep wound infection requiring removal of hardware (2.3%). Of the 10 patients undergoing dynamic stabilization, three developed a deep wound infection (30%) with 2 requiring removal of hardware (20%), secondary to persistent deep wound infection or osteomyelitis at the pedicle screw sites. There was a significantly increased risk of deep wound infection (p < 0.0001) with the use of dynamic stabilization compared to standard if. CONCLUSIONS: Our series demonstrates that the infection rate in patients undergoing dynamic stabilization is higher than the infection rate for instrumented fusion without a significant difference in comorbidity scores. We postulate that the polycarbonate urethane spacer acts as a medium for bacteria, whereas the titanium screws and rods are smooth, solid, and inert, resulting in a lower risk of infection.

The history of craniotomy for headache treatment.

Both the history of headache and the practice of craniotomy can be traced to antiquity. From ancient times through the present day, numerous civilizations and scholars have performed craniotomy in attempts to treat headache. Today, surgical intervention for headache management is becoming increasingly more common due to improved technology and greater understanding of headache. By tracing the evolution of the understanding of headache alongside the practice of craniotomy, investigators can better evaluate the mechanisms of headache and the therapeutic treatments used today.

Alternative treatment of intracranial hypotension presenting as postdural puncture headaches using epidural fibrin glue patches: two case reports.

INTRODUCTION: Intracranial hypotension is a neurologic syndrome characterized by orthostatic headaches and, radiographically, by dural thickening and enhancement as well as subdural collections. Several of etiologies exist, including surgical dural violations, lumbar puncture, or spontaneous cerebrospinal fluid leak. Current management includes conservative management consisting of bed rest, caffeine, and hydration. When conservative management fails, open surgical or percutaneous options are considered. Currently, the gold standard in percutaneous management of intracranial hypotension involves the epidural injection of autologous blood. Recently, some therapies for intracranial hypotension have employed the use of epidural fibrin glue. CASE PRESENTATION: Two cases of patients with persistent postdural puncture headaches are presented. Epidural fibrin glue injection alleviated the orthostatic headaches of two patients with intracranial hypotension. CONCLUSION: Although consideration must be afforded for the potential risks of viral transmission and aseptic meningitis, the utilization of epidural fibrin glue injection as an alternative or adjunct to the epidural blood patch in the treatment of intracranial hypotension should be further investigated.

High-Value Epilepsy Care in the United States: Predictors of Increased Costs and Complications from the National Inpatient Sample Database 2016-2019.

BACKGROUND: For patients with medically refractory epilepsy, newer minimally invasive techniques such as laser interstitial thermal therapy (LITT) have been developed in recent years. This study aims to characterize trends in the utilization of surgical resection versus LITT to treat medically refractory epilepsy, characterize complications, and understand the cost of this innovative technique to the public. METHODS: The National Inpatient Sample database was queried from 2016 to 2019 for all patients admitted with a diagnosis of medically refractory epilepsy. Patient demographics, hospital length of stay, complications, and costs were tabulated for all patients who underwent LITT or surgical resection within these cohorts. RESULTS: A total of 6019 patients were included, 223 underwent LITT procedures, while 5796 underwent resection. Significant predictors of increased patient charges for both cohorts included diabetes (odds ratio: 1.7, confidence interval [CI]: 1.44-2.19), infection (odds ratio: 5.12, CI 2.73-9.58), and hemorrhage (odds ratio: 2.95, CI 2.04-4.12). Procedures performed at nonteaching hospitals had 1.54 greater odds (CI 1.02-2.33) of resulting in a complication compared to teaching hospitals. Insurance status did significantly differ (P = 0.001) between those receiving LITT (23.3% Medicare; 25.6% Medicaid; 44.4% private insurance; 6.7 Other) and those undergoing resection (35.3% Medicare; 22.5% Medicaid; 34.7% private Insurance; 7.5% other). When adjusting for patient demographics, LITT patients had shorter length of stay (2.3 vs. 8.9 days, P < 0.001), lower complication rate (1.9% vs. 3.1%, P = 0.385), and lower mean hospital ($139,412.79 vs. $233,120.99, P < 0.001) and patient ($55,394.34 vs. $37,756.66, P < 0.001) costs. CONCLUSIONS: The present study highlights LITT's advantages through its association with lower costs and shorter length of stay. The present study also highlights the associated predictors of LITT versus resection, such as that most LITT cases happen at academic centers for patients with private insurance. As the adoption of LITT continues, more data will become available to further understand these issues.

The use of deep brain stimulation in Tourette's syndrome.

Tourette's syndrome (TS) is a childhood neuropsychiatric disorder characterized by multiple involuntary motor and vocal tics. It is commonly associated with other behavioral disorders including attention-deficit/hyperactivity disorder, obsessive-compulsive disorder, anxiety, depression, and self-injurious behaviors. Tourette's syndrome can be effectively managed with psychobehavioral and pharmacological treatments, and many patients experience an improvement in tics in adulthood. However, symptoms may persist and cause severe impairment in a small subset of patients despite available therapies. In recent years, deep brain stimulation (DBS) has been shown to be a promising treatment option for such patients. Since the advent of its use in 1999, multiple targets have been identified in DBS for TS, including the medial thalamus, globus pallidus internus, globus pallidus externus, anterior limb of the internal capsule/nucleus accumbens, and subthalamic nucleus. While the medial thalamus is the most commonly reported trajectory, the optimal surgical target for TS is still a topic of much debate. This paper provides a review of the available literature regarding the use of DBS for TS.

Thoracic radiculopathy following spinal cord stimulator placement: case series.

OBJECTIVE: The clinical entity of thoracic radiculopathy following spinal cord stimulator (SCS) placement has not been previously described. MATERIALS AND METHODS: A retrospective review of prospectively acquired data on 172 patients, having undergone thoracic SCS placement at our institution, was performed. In addition, four patients were implanted at outside institutions, and were referred for revision. We examine our early experience with placement of thoracic SCS in surgically treated patients with chronic pain and 15 associated specific postoperative radicular pain complications along respective thoracic dermatomes. We postulate that preexisting thoracic spinal pathology affords less compliance in the placement of larger paddles, and subsequent radicular pain in a band-like abdominal fashion. RESULTS: A syndrome of thoracic radiculopathy, presenting as intractable lower thoracic or abdominal wall pain occurring in the immediate postoperative period, was identified in 15 patients. These patients subsequently underwent revision surgery, with either a more extensive laminectomy to further decompress the dorsal nerve roots or lead removal, both of which resulted in near immediate relief of symptoms. CONCLUSIONS: Thoracic radiculopathy may occur following SCS paddle lead placement. This clinical syndrome is characterized by its immediate postoperative development, band-like thoracic or abdominal pain pattern, severe pain that both overwhelms the incisional pain and is refractory to medications, and absence of motor deficit. The lateral placement of paddle leads increases the risk of radicular symptoms. Preoperative thoracic spine magnetic resonance imaging may be helpful in identifying patients who may be susceptible to this syndrome.

Dimitrios Zambakis' Scientific Hypothesis on the Transmission of Leprosy.

Dimitrios Zambakis was an acclaimed physician at his time, most recognized for his work on leprosy. He theorized that leprosy was a hereditary disease, receiving many awards for his work including the Cholera Medal of Honour (1854), Château-Villard Prize from the Faculty of Medicine in Paris (1898), The Montyon Prize, and the title of Pasha. However, his theory was routinely argued against and was later proven to be invalid. Leprosy is regarded as a contagious disease spread by contact and is not hereditary. The last name appears to be spelled in various ways (Zambakis, Zambaco). For this paper, "Dimitrios Zambakis" will be used.

Local Field Potentials in Deep Brain Stimulation: Investigation of the Most Cited Articles.

Objective: Deep brain stimulation (DBS) allows for direct electrical stimulation of neural circuitry and recording of local field potentials (LFPs). A bibliometric analysis can be implemented to identify studies that have shaped a research field and influenced future study; however, no such analysis investigating the implementation of LFPs in DBS has been performed. The objective of the present study was to identify the most highly cited articles pertaining to DBS LFPs to identify and evaluate the research that has contributed the most to this growing field. Methods: The Science Citation Index of the Web of Science was implemented to identify the top 84 most cited articles pertaining to DBS LFPs. Information regarding the publication, including author information and study aims, was extracted. Results: The most highly cited articles had had a mean of 109 citations and had been published between 2002 and 2019, with a mode in 2016. The articles had predominantly investigated the subthalamic nucleus (68% of clinical studies) in humans (83.8% of clinical studies). The studies of humans had recruited a mean of 12.5 subjects. Most of the identified articles (56.0%) had reported class III clinical evidence. Conclusions: The implementation of DBS LFPs is a novel field that is rapidly growing. However, a need exists for more studies with larger patient cohorts and more randomized controlled trials to further elucidate the benefits of this technology. These results will allow for the identification and recognition of the most influential studies pertaining to DBS LFPs, appreciation of the current and future research trends, and inform us regarding areas warranting further investigation.