Principles of Stereotactic Surgery.

Background And Objectives: Stereotactic procedures are used to manage a diverse set of patients across a variety of clinical contexts. The stereotactic devices and software used in these procedures vary between surgeons, but the fundamental principles that constitute safe and accurate execution do not. The aim of this work is to describe these principles to equip readers with a generalizable knowledge base to execute and understand stereotactic procedures.

A General Framework for Characterizing Inaccuracy in Stereotactic Systems.

Background And Objectives: Identifying and characterizing sources of targeting error in stereotactic procedures is essential to maximizing accuracy, potentially improving surgical outcomes. We aim to describe a generic framework which characterizes sources of stereotactic inaccuracy.

Methods: We assembled a list of stereotactic systems: ROSA, Neuromate, Mazor Renaissance, ExcelsiusGPS, Cirq, STarFix (FHC), Nexframe, ClearPoint, CRW, and Leksell.

National trends of Laser interstitial thermal therapy (LITT) and Vagus Nerve stimulation (VNS) for refractory epilepsy in adult patients: A Nationwide Inpatient Sample based propensity score matched analysis.

Objective: The aim of our study was to report the national trends of Vagus nerve stimulation (VNS) and Laser interstitial thermal therapy (LITT) and compare their outcomes in patients with medically refractory epilepsy (RE).

Methods: Nationwide Inpatient Sample database (NIS, 1998-2018) was used to extract the data using the ICD-9/10 codes. Adult patients (>18 years) with a primary diagnosis of RE who underwent either VNS or LITT were included.

National 22-year epilepsy surgery landscape shows increasing open and minimally invasive pediatric epilepsy surgery.

Objectives: A surgical "treatment gap" in pediatric epilepsy persists despite the demonstrated safety and effectiveness of surgery. For this reason, the national surgical landscape should be investigated such that an updated assessment may more appropriately guide health care efforts.

Methods: In our retrospective cross-sectional observational study, the National Inpatient Sample (NIS) database was queried for individuals 0 to <18 years of age who had an International Classification of Diseases (ICD) code for drug-resistant epilepsy (DRE).

A Novel Closed-Loop Electrical Brain Stimulation Device Featuring Wireless Low-Energy Ultrasound Power and Communication.

Objectives: This study aimed to indicate the feasibility of a prototype electrical neuromodulation system using a closed-loop energy-efficient ultrasound-based mechanism for communication, data transmission, and recharging.

Materials And Methods: Closed-loop deep brain stimulation (DBS) prototypes were designed and fabricated with ultrasonic wideband (UsWB) communication technology and miniaturized custom electronics. Two devices were implanted short term in anesthetized Göttingen minipigs (N = 2).

Focused stimulation of dorsal versus ventral subthalamic nucleus enhances action-outcome learning in patients with Parkinson's disease.

Deep brain stimulation of the subthalamic nucleus is an effective treatment for the clinical motor symptoms of Parkinson's disease, but may alter the ability to learn contingencies between stimuli, actions and outcomes. We investigated how stimulation of the functional subregions in the subthalamic nucleus (motor and cognitive regions) modulates stimulus-action-outcome learning in Parkinson's disease patients. Twelve Parkinson's disease patients with deep brain stimulation of the subthalamic nucleus completed a probabilistic stimulus-action-outcome task while undergoing ventral and dorsal subthalamic nucleus stimulation (within subjects, order counterbalanced).

Progressive Multifocal Encephalopathy Holmes Tremor Successfully Treated with Bilateral Deep Brain Stimulation.

Background: We report a patient with bilateral HT treated with DBS.

Case Report: A 58-year-old man diagnosed with HIV/AIDS and progressive multifocal leukoencephalopathy (PML) presented with 20 years of bilateral arm tremor refractory to therapy. DBS was implanted on the left ventral intermediate nucleus and posterior subthalamic area (VIM/PSA).

Spinal Cord Stimulation for Parkinson's Disease: A Systematic Review and Meta-Analysis of Pain and Motor Outcomes.

Background: Spinal cord stimulation (SCS) has been investigated as a potential therapeutic option for managing refractory symptoms in patients with Parkinson's disease (PD).

Objective: This systematic review and meta-analysis aimed to evaluate the safety and efficacy of SCS in PD.

Method: A comprehensive literature search was conducted on PubMed and Web of Science to identify SCS studies reporting Unified Parkinson Disease Rating Scale-III (UPDRS-III) or Visual Analogue Scale (VAS) score changes in PD cohorts with at least 3 patients and a follow-up period of at least 1 month.

Long-term outcomes of mesial temporal laser interstitial thermal therapy for drug-resistant epilepsy and subsequent surgery for seizure recurrence: a multi-centre cohort study.

Background: Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) is a minimally invasive alternative to surgical resection for drug-resistant mesial temporal lobe epilepsy (mTLE). Reported rates of seizure freedom are variable and long-term durability is largely unproven. Anterior temporal lobectomy (ATL) remains an option for patients with MRgLITT treatment failure.

Ogilvie's syndrome after paddle spinal cord stimulator implantation: An experience report.

Spinal cord stimulation (SCS) is an emerging technology to treat chronic pain from complex regional pain syndrome (CPRS) neuropathy and post-laminectomy syndrome. A rarely reported postoperative complication of SCS paddle implantation is abdominal pain that can result from thoracic radiculopathy. Ogilvie's syndrome (OS) is a disorder characterized by acute dilatation of the colon in the absence of an anatomic lesion that obstructs the flow of intestinal contents, which has seldom been observed after spine surgery.

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.

Evidence for Thalamic Responsive Neurostimulation in Treatment of Adult and Pediatric Epilepsy.

Responsive neurostimulation (RNS) has well-established efficacy in patients with identifiable seizure foci. Emerging evidence suggests the feasibility of expanding this treatment to patients with nonfocal or multifocal epileptic profiles with thalamic targeting. Our institution performed two successful implantations of thalamic RNS (tRNS) targeting the centromedian nucleus of the thalamus (CMT), and 1-year postoperative outcomes are provided.

Feasibility of Transcranial Motor Evoked Potentials and Electromyography during MRI-Guided Laser Interstitial Thermal Therapy for Glioblastoma.

Background: Intraoperative neuromonitoring (IONM) is routinely used during neurosurgical procedures. Magnetic resonance imaging (MRI)-guided laser interstitial thermal therapy (LITT) is increasingly being used in patients with various brain lesions. Use of IONM (transcranial motor evoked potential [TcMEP] and electromyography [EMG]) during LITT of a brain lesion has not been described previously.

Effects of deep brain stimulation target on the activation and suppression of action impulses.

Objective: Deep brain stimulation (DBS) is an effective treatment to improve motor symptoms in Parkinson's disease (PD). The Globus Pallidus (GPi) and the Subthalamic Nucleus (STN) are the most targeted brain regions for stimulation and produce similar improvements in PD motor symptoms. However, our understanding of stimulation effects across targets on inhibitory action control processes is limited.

Combined Responsive Neurostimulation and Focal Resection for Super Refractory Status Epilepticus: A Systematic Review and Illustrative Case Report.

Objective: Super-refractory status epilepticus (SRSE) is a neurologic emergency with high mortality and morbidity. Although medical algorithms typically are effective, when they do fail, options may be limited, and neurosurgical intervention should be considered.

Methods: We report a case of SRSE treated acutely with responsive neurostimulation (RNS) and focal surgical resection after intracranial monitoring.

A new paradigm for investigating real-world social behavior and its neural underpinnings.

Eye tracking and other behavioral measurements collected from patient-participants in their hospital rooms afford a unique opportunity to study natural behavior for basic and clinical translational research. We describe an immersive social and behavioral paradigm implemented in patients undergoing evaluation for surgical treatment of epilepsy, with electrodes implanted in the brain to determine the source of their seizures. Our studies entail collecting eye tracking with other behavioral and psychophysiological measurements from patient-participants during unscripted behavior, including social interactions with clinical staff, friends, and family in the hospital room.

Essential tremor impairs the ability to suppress involuntary action impulses.

Essential tremor (ET) is a movement disorder characterized primarily by action tremor which affects the regulation of movements. Disruptions in cerebello-thalamocortical networks could interfere with cognitive control over actions in ET, for example, the ability to suppress a strong automatic impulse over a more appropriate action (conflict control). The current study investigated whether ET impacts conflict control proficiency.

Developing Predictor Models of Postoperative Verbal Fluency After Deep Brain Stimulation Using Preoperative Neuropsychological Assessment.

Background: Deep brain stimulation (DBS) for Parkinson disease provides significant improvement of motor symptoms but can also produce neurocognitive side effects. A decline in verbal fluency (VF) is among the most frequently reported side effects. Preoperative factors that could predict VF decline have yet to be identified.

Enhanced Interplay of Neuronal Coherence and Coupling in the Dying Human Brain.

The neurophysiological footprint of brain activity after cardiac arrest and during near-death experience (NDE) is not well understood. Although a hypoactive state of brain activity has been assumed, experimental animal studies have shown increased activity after cardiac arrest, particularly in the gamma-band, resulting from hypercapnia prior to and cessation of cerebral blood flow after cardiac arrest. No study has yet investigated this matter in humans.

Incidence of repeat procedures and healthcare utilization following surgery, radiosurgery, and percutaneous procedures in elderly patients with trigeminal neuralgia.

Objective: Management of trigeminal neuralgia (TN) in elderly patients poses significant challenges. The impact of different treatment modalities (surgery, radiosurgery [RS], and percutaneous techniques [PTs]) on healthcare utilization is not well defined in the management of TN in elderly patients. The aim of this study was to compare the long-term healthcare utilization metrics of different interventions in the management of elderly patients with TN.

The American Society for Stereotactic and Functional Neurosurgery Position Statement on Laser Interstitial Thermal Therapy for the Treatment of Drug-Resistant Epilepsy.

Magnetic resonance image-guided laser interstitial thermal therapy (MRgLITT) is a novel tool in the neurosurgical armamentarium for the management of drug-resistant epilepsy. Given the recent introduction of this technology, the American Society for Stereotactic and Functional Neurosurgery (ASSFN), which acts as the joint section representing the field of stereotactic and functional neurosurgery on behalf of the Congress of Neurological Surgeons and the American Association of Neurological Surgeons, provides here the expert consensus opinion on evidence-based best practices for the use and implementation of this treatment modality. Indications for treatment are outlined, consisting of failure to respond to, or intolerance of, at least 2 appropriately chosen medications at appropriate doses for disabling, localization-related epilepsy in the setting of well-defined epileptogenic foci, or critical pathways of seizure propagation accessible by MRgLITT.

Magnetically Guided Catheters, Micro- and Nanorobots for Spinal Cord Stimulation.

Spinal cord stimulation (SCS) is an established treatment for refractory pain syndromes and has recently been applied to improve locomotion. Several technical challenges are faced by surgeons during SCS lead implantation, particularly in the confined dorsal epidural spaces in patients with spinal degenerative disease, scarring and while targeting challenging structures such as the dorsal root ganglion. Magnetic navigation systems (MNS) represent a novel technology that uses externally placed magnets to precisely steer tethered and untethered devices.

Targeting for stereotactic radiosurgical thalamotomy based on tremor treatment response.

Objective: Stereotactic radiosurgery (SRS) treats severe, medically refractory essential tremor and tremor-dominant Parkinson disease. However, the optimal target for SRS treatment within the thalamic ventral intermediate nucleus (VIM) is not clearly defined. This work evaluates the precision of the physician-selected VIM target, and determines the optimal SRS target within the VIM by correlation between early responders and nonresponders.

Bone Cement Cranioplasty Reduces Cerebrospinal Fluid Leak Rate after Microvascular Decompression: A Single-Institutional Experience.

 Microvascular decompression (MVD) is a common surgical treatment for cranial nerve compression, though cerebrospinal fluid (CSF) leak is a known complication of this procedure. Bone cement cranioplasty may reduce rates of CSF leak.  To compare rates of CSF leak before and after implementation of bone cement cranioplasty for the reconstruction of cranial defects after MVD.

Noninvasive Thalamotomy for Refractory Tremor by Frameless Radiosurgery.

Purpose: We sought to determine whether a more widely accessible, noninvasive, frameless approach to radiosurgical thalamotomy would improve objective measures of refractory essential or parkinsonian tremor without added toxicity compared with reports of frame-based radiosurgery.

Methods And Materials: We conducted a single-arm pilot observational prospective trial of adult patients with essential or parkinsonian tremor from 2013 to 2019 and report results at 1-year follow-up. Patients were treated with frameless unilateral radiosurgical ablation of the thalamic ventral intermediate nucleus to a maximum dose of 160 Gy.