scholarly journals Advancing Directional Deep Brain Stimulation Array Technology

Author(s):  
Julia P. Slopsema ◽  
Robert Cass ◽  
Mark Hjelle ◽  
Matthew D. Johnson

The degree to which deep brain stimulation (DBS) therapy can effectively treat various brain disorders depends on how well one can selectively stimulate one or more axonal pathways within the brain. There is rapidly growing clinical interest in DBS lead implant designs with electrode arrangements that can better target axonal pathways of interest, especially in cases where the optimal target is immediately adjacent to a pathway that when stimulated will elicit adverse side effects. Numerical modeling has demonstrated that DBS leads with four radially segmented electrodes provide the best balance of directional targeting capability while minimizing the overall number of electrode contacts [1]. Here, we present a novel 4×4 DBS lead (16-channel electrode array) with the same form factor and materials as current 4 or 8-channel FDA-approved DBS leads. Electrode impedance spectroscopy was performed for three of these 4×4 DBS leads showing reliable electrode impedances before and after implantation within the brain.

2019 ◽  
pp. 158-173

Background: Parkinson’s disease (PD) is a progressive neurodegenerative disorder caused by a dopamine deficiency that presents with motor symptoms. Visual disorders can occur concomitantly but are frequently overlooked. Deep brain stimulation (DBS) has been an effective treatment to improve tremors, stiffness and overall mobility, but little is known about its effects on the visual system. Case Report: A 75-year-old Caucasian male with PD presented with longstanding binocular diplopia. On baseline examination, the best-corrected visual acuity was 20/25 in each eye. On observation, he had noticeable tremors with an unsteady gait. Distance alternating cover test showed exophoria with a right hyperphoria. Near alternating cover test revealed a significantly larger exophoria accompanied by a reduced near point of convergence. Additional testing with a 24-2 Humphrey visual field and optical coherence tomography (OCT) of the nerve and macula were unremarkable. The patient underwent DBS implantation five weeks after initial examination, and the device was activated four weeks thereafter. At follow up, the patient still complained of intermittent diplopia. There was no significant change in the manifest refraction or prism correction. On observation, the patient had remarkably improved tremors with a steady gait. All parameters measured were unchanged. The patient was evaluated again seven months after device activation. Although vergence ranges at all distances were improved, the patient was still symptomatic for intermittent diplopia. OCT scans of the optic nerve showed borderline but symmetric thinning in each eye. All other parameters measured were unchanged. Conclusion: The case found no significant changes on ophthalmic examination after DBS implantation and activation in a patient with PD. To the best of the authors’ knowledge, there are no other cases in the literature that investigated the effects of DBS on the visual system pathway in a patient with PD before and after DBS implantation and activation.


2007 ◽  
Vol 107 (5) ◽  
pp. 989-997 ◽  
Author(s):  
Yasushi Miyagi ◽  
Fumio Shima ◽  
Tomio Sasaki

Object The goal of this study was to focus on the tendency of brain shift during stereotactic neurosurgery and the shift's impact on the unilateral and bilateral implantation of electrodes for deep brain stimulation (DBS). Methods Eight unilateral and 10 bilateral DBS electrodes at 10 nuclei ventrales intermedii and 18 subthalamic nuclei were implanted in patients at Kaizuka Hospital with the aid of magnetic resonance (MR) imaging–guided and microelectrode-guided methods. Brain shift was assessed as changes in the 3D coordinates of the anterior and posterior commissures (AC and PC) with MR images before and immediately after the implantation surgery. The positions of the implanted electrodes, based on the midcommissural point and AC–PC line, were measured both on x-ray films (virtual position) during surgery and the postoperative MR images (actual position) obtained on the 7th day postoperatively. Results Contralateral and posterior shift of the AC and PC were the characteristics of unilateral and bilateral procedures, respectively. The authors suggest the following. 1) The first unilateral procedure elicits a unilateral air invasion, resulting in a contralateral brain shift. 2) During the second procedure in the bilateral surgery, the contralateral shift is reset to the midline and, at the same time, the anteroposterior support by the contralateral hemisphere against gravity is lost due to a bilateral air invasion, resulting in a significant posterior (caudal) shift. Conclusions To note the tendency of the brain to shift is very important for accurate implantation of a DBS electrode or high frequency thermocoagulation, as well as for the prediction of therapeutic and adverse effects of stereotactic surgery.


2011 ◽  
Vol 70 (suppl_1) ◽  
pp. ons114-ons124 ◽  
Author(s):  
Nova B. Thani ◽  
Arul Bala ◽  
Christopher R. P. Lind

Abstract BACKGROUND: Accurate placement of a probe to the deep regions of the brain is an important part of neurosurgery. In the modern era, magnetic resonance image (MRI)-based target planning with frame-based stereotaxis is the most common technique. OBJECTIVE: To quantify the inaccuracy in MRI-guided frame-based stereotaxis and to assess the relative contributions of frame movements and MRI distortion. METHODS: The MRI-directed implantable guide-tube technique was used to place carbothane stylettes before implantation of the deep brain stimulation electrodes. The coordinates of target, dural entry point, and other brain landmarks were compared between preoperative and intraoperative MRIs to determine the inaccuracy. RESULTS: The mean 3-dimensional inaccuracy of the stylette at the target was 1.8 mm (95% confidence interval [CI], 1.5-2.1. In deep brain stimulation surgery, the accuracy in the x and y (axial) planes is important; the mean axial inaccuracy was 1.4 mm (95% CI, 1.1-1.8). The maximal mean deviation of the head frame compared with brain over 24.1 ± 1.8 hours was 0.9 mm (95% CI, 0.5-1.1). The mean 3-dimensional inaccuracy of the dural entry point of the stylette was 1.8 mm (95% CI, 1.5-2.1), which is identical to that of the target. CONCLUSION: Stylette positions did deviate from the plan, albeit by 1.4 mm in the axial plane and 1.8 mm in 3-dimensional space. There was no difference between the accuracies at the dura and the target approximately 70 mm deep in the brain, suggesting potential feasibility for accurate planning along the whole trajectory.


PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243438
Author(s):  
Hannah Ihme ◽  
Rainer K. W. Schwarting ◽  
Liana Melo-Thomas

Deep brain stimulation (DBS) of the colliculus inferior (IC) improves haloperidol-induced catalepsy and induces paradoxal kinesia in rats. Since the IC is part of the brain aversive system, DBS of this structure has long been related to aversive behavior in rats limiting its clinical use. This study aimed to improve intracollicular DBS parameters in order to avoid anxiogenic side effects while preserving motor improvements in rats. Catalepsy was induced by systemic haloperidol (0.5mg/kg) and after 60 min the bar test was performed during which a given rat received continuous (5 min, with or without pre-stimulation) or intermittent (5 x 1 min) DBS (30Hz, 200–600μA, pulse width 100μs). Only continuous DBS with pre-stimulation reduced catalepsy time. The rats were also submitted to the elevated plus maze (EPM) test and received either continuous stimulation with or without pre-stimulation, or sham treatment. Only rats receiving continuous DBS with pre-stimulation increased the time spent and the number of entries into the open arms of the EPM suggesting an anxiolytic effect. The present intracollicular DBS parameters induced motor improvements without any evidence of aversive behavior, pointing to the IC as an alternative DBS target to induce paradoxical kinesia improving motor deficits in parkinsonian patients.


2021 ◽  
pp. 405-420
Author(s):  
Georg Northoff

Neuroethics, located at the interface of conceptual and empirical dimensions, carries major implications for psychiatry, such as the neuroscientific basis of ethical concepts as moral agency. Drawing on data in neuroscience, this chapter highlights issues central to psychiatric ethics. First, it addresses a reductionistic model of the brain, often conceived as purely neuronal, and then it discusses empirical data suggesting that the brain’s activity is strongly aligned to its respective social (e.g., relation to others) and ecological (e.g., relation to the environment and nature) contexts; this implies a relational rather than reductionist model. Second, it suggests that self (e.g., the experience or sense of a self) and personhood (e.g., the person as existent independent of experience) must also be understood in such a social and ecological and, therefore, relational and spatio-temporal sense. Ethical concepts like agency, therefore, cannot be limited solely to the person and brain, but must rather be understood in a relational and neuro-ecological/social way. Third, it discusses deep brain stimulation as a treatment that promotes enhancement. In sum, this chapter presents findings in neuroscience that carry major implications for our view of brain, mental features, psychiatric disorders, and ethical issues like agency, responsibility, and enhancement.


2018 ◽  
pp. 135-184
Author(s):  
Walter Glannon

This chapter discusses functional neurosurgery designed to modulate dysfunctional neural circuits mediating sensorimotor, cognitive, emotional, and volitional capacities. The chapter assesses the comparative benefits and risks of neural ablation and deep brain stimulation as the two most invasive forms of neuromodulation. It discusses the question of whether individuals with a severe or moderately severe psychiatric disorder have enough cognitive and emotional capacity to weigh reasons for and against ablation or deep brain stimulation and give informed consent to undergo it. The chapter also discusses the obligations of investigators conducting these trials to research subjects. In addition, it examines the medical and ethical justification for a sham control arm in psychiatric neurosurgery clinical trials. It considers the therapeutic potential of optogenetics as a novel form of neuromodulation. The fact that this technique manipulates both genetic material and neural circuits and has been tested only in animal models makes it unclear what its benefit–risk ratio would be. The chapter concludes with a brief discussion of the potential of neuromodulation to stimulate endogenous repair and growth mechanisms in the brain.


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