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.

Differential Effects of Extracellular Vesicles from Two Different Glioblastomas on Normal Human Brain Cells.

Glioblastomas (GBMs) are dreadful brain tumors with abysmal survival outcomes. GBM extracellular vesicles (EVs) dramatically affect normal brain cells (largely astrocytes) constituting the tumor microenvironment (TME). We asked if EVs from different GBM patient-derived spheroid lines would differentially alter recipient brain cell phenotypes.

Comparison of beta peak detection algorithms for data-driven deep brain stimulation programming strategies in Parkinson's disease.

Oscillatory activity within the beta frequency range (13-30 Hz) serves as a Parkinson's disease biomarker for tailoring deep brain stimulation (DBS) treatments. Currently, identifying clinically relevant beta signals, specifically frequencies of peak amplitudes within the beta spectral band, is a subjective process. To inform potential strategies for objective clinical decision making, we assessed algorithms for identifying beta peaks and devised a standardized approach for both research and clinical applications.

Neurophysiologic Characteristics of the Anterior Nucleus of the Thalamus during Deep Brain Stimulation Surgery for Epilepsy.

Introduction: Anterior nucleus of the thalamus (ANT) deep brain stimulation (DBS) is an increasingly promising treatment option for refractory epilepsy. Optimal therapeutic benefit has been associated with stimulation at the junction of ANT and the mammillothalamic tract (mtt), but electrophysiologic markers of this target are lacking. The present study examined microelectrode recordings (MER) during DBS to identify unique electrophysiologic characteristics of ANT and the ANT-mtt junction.

Subthalamic nucleus synchronization between beta band local field potential and single-unit activity in Parkinson's disease.

Local field potential (LFP) oscillations in the beta band (13-30 Hz) in the subthalamic nucleus (STN) of Parkinson's disease patients have been implicated in disease severity and treatment response. The relationship between single-neuron activity in the STN and regional beta power changes remains unclear. We used spike-triggered average (STA) to assess beta synchronization in STN.

A tale of two tumors: differential, but detrimental, effects of glioblastoma extracellular vesicles (EVs) on normal human brain cells.

Glioblastomas (GBMs) are dreadful brain tumors with abysmal survival outcomes. GBM EVs dramatically affect normal brain cells (largely astrocytes) constituting the tumor microenvironment (TME). EVs from different patient-derived GBM spheroids induced differential transcriptomic, secretomic, and proteomic effects on cultured astrocytes/brain tissue slices as GBM EV recipients.

Immunocompetent isolated cerebral mucormycosis presenting with obstructive hydrocephalus: illustrative case.

Background: Isolated cerebral mucormycosis is rare in immunocompetent adults and is only sparsely reported to be associated with obstructive hydrocephalus.

Observations: Here, the authors report a case of obstructive hydrocephalus secondary to central nervous system mucormycosis without other systems or rhino-orbital involvement and its technical surgical management. A 23-year-old, incarcerated, immunocompetent patient with history of intravenous (IV) drug use presented with syncope.

Case report: Clinical efficacy of deep brain stimulation contacts corresponds to local field potential signals in a patient with obsessive-compulsive disorder.

Introduction: Deep brain stimulation (DBS) is often effective in treating severe obsessive-compulsive disorder (OCD) when traditional therapeutic approaches have failed. However, optimizing DBS programming is a time-consuming process. Recent research in movement disorders suggests that local field potentials can dramatically speed up the process of identifying the optimal contacts for stimulation, but this has not yet been tested in a patient with OCD.

A Transcriptomic Comparative Study of Cranial Vasculature.

In genetic studies of cerebrovascular diseases, the optimal vessels to use as controls remain unclear. Our goal is to compare the transcriptomic profiles among 3 different types of control vessels: superficial temporal artery (STA), middle cerebral arteries (MCA), and arteries from the circle of Willis obtained from autopsies (AU). We examined the transcriptomic profiles of STA, MCA, and AU using RNAseq.

Two-photon microendoscope for label-free imaging in stereotactic neurosurgery.

We demonstrate a gradient refractive index (GRIN) microendoscope with an outer diameter of ∼1.2 mm and a length of ∼186 mm that can fit into a stereotactic surgical cannula. Two photon imaging at an excitation wavelength of 900 nm showed a field of view of ∼180 microns and a lateral and axial resolution of 0.

Comparison of Monopolar Review to Fixed Parameter Fractionation in Deep Brain Stimulation.

Background: Technological advancements in deep brain stimulation (DBS) require methodological changes in programming. Fractionalization poses significant practical challenges for the most common approach for assessing DBS efficacy, monopolar review (MR).

Objectives: Two DBS programming methods: MR and fixed parameter vertical and horizontal fractionalization (FPF) were compared.

Oscillatory beta dynamics inform biomarker-driven treatment optimization for Parkinson's disease.

Parkinson's disease (PD) is a neurodegenerative disorder characterized by loss of dopaminergic neurons and dysregulation of the basal ganglia. Cardinal motor symptoms include bradykinesia, rigidity, and tremor. Deep brain stimulation (DBS) of select subcortical nuclei is standard of care for medication-refractory PD.

Pilot Study to Investigate the Use of In-Clinic Sensing to Identify Optimal Stimulation Parameters for Deep Brain Stimulation Therapy in Parkinson's Disease.

Background: Deep brain stimulation (DBS) programming is time intensive. Recent advances in sensing technology of local field potentials (LFPs) may enable improvements. Few studies have compared the use of this technology with standard of care.

Somatic Variants in SVIL in Cerebral Aneurysms.

Background And Objectives: While somatic mutations have been well-studied in cancer, their roles in other complex traits are much less understood. Our goal is to identify somatic variants that may contribute to the formation of saccular cerebral aneurysms.

Methods: We performed whole-exome sequencing on aneurysm tissues and paired peripheral blood.

Quantifying neuro-motor correlations during awake deep brain stimulation surgery using markerless tracking.

The expanding application of deep brain stimulation (DBS) therapy both drives and is informed by our growing understanding of disease pathophysiology and innovations in neurosurgical care. Neurophysiological targeting, a mainstay for identifying optimal, motor responsive targets, has remained largely unchanged for decades. Utilizing deep learning-based computer vision and related computational methods, we developed an effective and simple intraoperative approach to objectively correlate neural signals with movements, automating and standardizing the otherwise manual and subjective process of identifying ideal DBS electrode placements.

Automatic extraction of upper-limb kinematic activity using deep learning-based markerless tracking during deep brain stimulation implantation for Parkinson's disease: A proof of concept study.

Optimal placement of deep brain stimulation (DBS) therapy for treating movement disorders routinely relies on intraoperative motor testing for target determination. However, in current practice, motor testing relies on subjective interpretation and correlation of motor and neural information. Recent advances in computer vision could improve assessment accuracy.

An update on advanced therapies for Parkinson's disease: From gene therapy to neuromodulation.

Advanced Parkinson's disease (PD) is characterized by increasingly debilitating impaired movements that include motor fluctuations and dyskinesias. At this stage of the disease, pharmacological management can result in unsatisfactory clinical benefits and increase the occurrence of adverse effects, leading to the consideration of advanced therapies. The scope of this review is to provide an overview of currently available therapies for advanced PD, specifically levodopa-carbidopa intestinal gel, continuous subcutaneous apomorphine infusion, radiofrequency ablation, stereotactic radiosurgery, MRI-guided focused ultrasound, and deep brain stimulation.

Novel targets in deep brain stimulation for movement disorders.

The neurosurgical treatment of movement disorders, primarily via deep brain stimulation (DBS), is a rapidly expanding and evolving field. Although conventional targets including the subthalamic nucleus (STN) and internal segment of the globus pallidus (GPi) for Parkinson's disease and ventral intermediate nucleus of the thalams (VIM) for tremor provide substantial benefit in terms of both motor symptoms and quality of life, other targets for DBS have been explored in an effort to maximize clinical benefit and also avoid undesired adverse effects associated with stimulation. These novel targets primarily include the rostral zona incerta (rZI), caudal zona incerta (cZI)/posterior subthalamic area (PSA), prelemniscal radiation (Raprl), pedunculopontine nucleus (PPN), substantia nigra pars reticulata (SNr), centromedian/parafascicular (CM/PF) nucleus of the thalamus, nucleus basalis of Meynert (NBM), dentato-rubro-thalamic tract (DRTT), dentate nucleus of the cerebellum, external segment of the globus pallidus (GPe), and ventral oralis (VO) complex of the thalamus.

Transient cardiac asystole during vagus nerve stimulator implantation: A case report.

Background: Vagal nerve stimulation (VNS) is a Food and Drug Administration approved therapy for seizures with a suggested mechanism of action consisting of cortical desynchronization, facilitated through broad release of inhibitory neurotransmitters in the cortex and brainstem. The vagus nerve contains visceral afferents that transmit sensory signals centrally, from locations that include the heart and the aorta. Although the vagus nerve serves a role in cardiac function, electrical stimulation with VNS has rarely resulted in adverse cardiac events.

Use of Three-Dimensional Printed Brain Models During Deep Brain Stimulation Surgery Consultation for Patient Health Literacy: A Randomized Controlled Investigation.

Background: Advanced therapies in neurosurgery, such as deep brain stimulation (DBS), would benefit from improved patient education materials. Three-dimensional (3D) printed anatomical models represent a recent development for improving patient education for neurosurgical procedures.

Methods: In this study, 40 patients undergoing DBS surgery consultation were randomly assigned to 1 of 2 groups: an experimental group, which received a demonstration of DBS therapeutic neuroanatomical targets in a 3D printed brain model plus standard patient education (PE), or a control group, which received standard PE alone.

Motor context modulates substantia nigra pars reticulata spike activity in patients with Parkinson's disease.

Objective: The severity of motor symptoms in Parkinson's disease (PD) depends on environmental conditions. For example, the presence of external patterns such as a rhythmic tone can attenuate bradykinetic impairments. However, the neural mechanisms for this context-dependent attenuation (e.

Deep Brain Stimulation of the Ventral Intermediate Nucleus of the Thalamus in Writer's Cramp: A Case Report.

Background: Globus pallidus internus (GPi) deep brain stimulation (DBS) and thalamotomy are interventions for writer's cramp (WC). Ventralis intermedius nucleus (VIM) DBS is targeted for tremor, however, many aspects of VIM DBS remained underexplored in WC.

Case Report: A 62-year-old man with WC underwent DBS.