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Palopoli-Trojani K, Schmidt SL, Baringer KD, Slotkin TA, Peters JJ, Turner DA, Grill WM. Temporally non-regular patterns of deep brain stimulation (DBS) enhance assessment of evoked potentials while maintaining motor symptom management in Parkinson's disease (PD). Brain Stimul 2023; 16:1630-1642. [PMID: 37863388 PMCID: PMC10872419 DOI: 10.1016/j.brs.2023.10.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 09/25/2023] [Accepted: 10/11/2023] [Indexed: 10/22/2023] Open
Abstract
BACKGROUND Traditional deep brain stimulation (DBS) at fixed regular frequencies (>100 Hz) is effective in treating motor symptoms of Parkinson's disease (PD). Temporally non-regular patterns of DBS are a new parameter space that may help increase efficacy and efficiency. OBJECTIVE To compare the effects of temporally non-regular patterns of DBS to traditional regularly-spaced pulses. METHODS We simultaneously recorded local field potentials (LFP) and monitored motor symptoms (tremor and bradykinesia) in persons with PD during DBS in subthalamic nucleus (STN). We quantified both oscillatory activity and DBS local evoked potentials (DLEPs) from the LFP. RESULTS Temporally non-regular patterns were as effective as traditional pulse patterns in modulating motor symptoms, oscillatory activity, and DLEPs. Moreover, one of our novel patterns enabled recording of longer duration DLEPs during clinically effective stimulation. CONCLUSIONS Stimulation gaps of 50 ms can be used to increase efficiency and to enable regular assessment of long-duration DLEPs while maintaining effective symptom management. This may be a promising paradigm for closed-loop DBS with biomarker assessment during the gaps.
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Affiliation(s)
| | - Stephen L Schmidt
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Karley D Baringer
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Theodore A Slotkin
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, USA
| | - Jennifer J Peters
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Dennis A Turner
- Department of Biomedical Engineering, Duke University, Durham, NC, USA; Department of Neurobiology and Department of Neurosurgery, Duke University, Durham, NC, USA
| | - Warren M Grill
- Department of Biomedical Engineering, Duke University, Durham, NC, USA; Department of Neurobiology and Department of Neurosurgery, Duke University, Durham, NC, USA; Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA.
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2
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Bava JM, Wang Z, Bick SK, Englot DJ, Constantinidis C. Improving Visual Working Memory with Cholinergic Deep Brain Stimulation. Brain Sci 2023; 13:917. [PMID: 37371395 PMCID: PMC10296349 DOI: 10.3390/brainsci13060917] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 05/30/2023] [Accepted: 05/31/2023] [Indexed: 06/29/2023] Open
Abstract
Acetylcholine is a critical modulatory neurotransmitter for cognitive function. Cholinergic drugs improve cognitive performance and enhance neuronal activity in the sensory and association cortices. An alternative means of improving cognitive function is through the use of deep brain stimulation. Prior animal studies have demonstrated that stimulation of the nucleus basalis of Meynert through DBS improves cognitive performance on a visual working memory task to the same degree as cholinesterase inhibitors. Additionally, unlike current pharmacological treatments for neurocognitive disorders, DBS does not lose efficacy over time and adverse effects are rare. These findings suggest that DBS may be a promising alternative for treating cognitive impairments in neurodegenerative disorders such as Alzheimer's disease. Thus, further research and human trials should be considered to assess the potential of DBS as a therapeutic treatment for these disorders.
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Affiliation(s)
- Janki M. Bava
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37235, USA; (J.M.B.); (D.J.E.)
| | - Zhengyang Wang
- Neuroscience Program, Vanderbilt University, Nashville, TN 37235, USA;
| | - Sarah K. Bick
- Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA;
| | - Dario J. Englot
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37235, USA; (J.M.B.); (D.J.E.)
- Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA;
| | - Christos Constantinidis
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37235, USA; (J.M.B.); (D.J.E.)
- Neuroscience Program, Vanderbilt University, Nashville, TN 37235, USA;
- Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA;
- Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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3
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Classification of electrically-evoked potentials in the parkinsonian subthalamic nucleus region. Sci Rep 2023; 13:2685. [PMID: 36792646 PMCID: PMC9932154 DOI: 10.1038/s41598-023-29439-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 02/06/2023] [Indexed: 02/17/2023] Open
Abstract
Electrically evoked compound action potentials (ECAPs) generated in the subthalamic nucleus (STN) contain features that may be useful for titrating deep brain stimulation (DBS) therapy for Parkinson's disease. Delivering a strong therapeutic effect with DBS therapies, however, relies on selectively targeting neural pathways to avoid inducing side effects. In this study, we investigated the spatiotemporal features of ECAPs in and around the STN across parameter sweeps of stimulation current amplitude, pulse width, and electrode configuration, and used a linear classifier of ECAP responses to predict electrode location. Four non-human primates were implanted unilaterally with either a directional (n = 3) or non-directional (n = 1) DBS lead targeting the sensorimotor STN. ECAP responses were characterized by primary features (within 1.6 ms after a stimulus pulse) and secondary features (between 1.6 and 7.4 ms after a stimulus pulse). Using these features, a linear classifier was able to accurately differentiate electrodes within the STN versus dorsal to the STN in all four subjects. ECAP responses varied systematically with recording and stimulating electrode locations, which provides a subject-specific neuroanatomical basis for selecting electrode configurations in the treatment of Parkinson's disease with DBS therapy.
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4
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Dale J, Schmidt SL, Mitchell K, Turner DA, Grill WM. Evoked potentials generated by deep brain stimulation for Parkinson's disease. Brain Stimul 2022; 15:1040-1047. [DOI: 10.1016/j.brs.2022.07.048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 04/18/2022] [Accepted: 07/20/2022] [Indexed: 11/29/2022] Open
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Chen Y, Ma B, Hao H, Li L. Removal of Electrocardiogram Artifacts From Local Field Potentials Recorded by Sensing-Enabled Neurostimulator. Front Neurosci 2021; 15:637274. [PMID: 33912002 PMCID: PMC8071948 DOI: 10.3389/fnins.2021.637274] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 02/17/2021] [Indexed: 01/11/2023] Open
Abstract
Sensing-enabled neurostimulators are an advanced technology for chronic observation of brain activities, and show great potential for closed-loop neuromodulation and as implantable brain-computer interfaces. However, local field potentials (LFPs) recorded by sensing-enabled neurostimulators can be contaminated by electrocardiogram (ECG) signals due to complex recording conditions and limited common-mode-rejection-ratio (CMRR). In this study, we propose a solution for removing such ECG artifacts from local field potentials (LFPs) recorded by a sensing-enabled neurostimulator. A synchronized monopolar channel was added as an ECG reference, and two pre-existing methods, i.e., template subtraction and adaptive filtering, were then applied. ECG artifacts were successfully removed and the performance of the method was insensitive to residual stimulation artifacts. This approach to removal of ECG artifacts broadens the range of applications of sensing-enabled neurostimulators.
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Affiliation(s)
- Yue Chen
- National Engineering Laboratory for Neuromodulation, Tsinghua University, Beijing, China
| | - Bozhi Ma
- National Engineering Laboratory for Neuromodulation, Tsinghua University, Beijing, China
| | - Hongwei Hao
- National Engineering Laboratory for Neuromodulation, Tsinghua University, Beijing, China
| | - Luming Li
- National Engineering Laboratory for Neuromodulation, Tsinghua University, Beijing, China.,Precision Medicine & Healthcare Research Center, Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen, China.,International Data Group (IDG)/McGovern Institute for Brain Research at Tsinghua University, Beijing, China.,Institute of Epilepsy, Beijing Institute for Brain Disorders, Beijing, China
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6
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Insausti-Delgado A, López-Larraz E, Omedes J, Ramos-Murguialday A. Intensity and Dose of Neuromuscular Electrical Stimulation Influence Sensorimotor Cortical Excitability. Front Neurosci 2021; 14:593360. [PMID: 33519355 PMCID: PMC7845652 DOI: 10.3389/fnins.2020.593360] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 11/30/2020] [Indexed: 12/13/2022] Open
Abstract
Neuromuscular electrical stimulation (NMES) of the nervous system has been extensively used in neurorehabilitation due to its capacity to engage the muscle fibers, improving muscle tone, and the neural pathways, sending afferent volleys toward the brain. Although different neuroimaging tools suggested the capability of NMES to regulate the excitability of sensorimotor cortex and corticospinal circuits, how the intensity and dose of NMES can neuromodulate the brain oscillatory activity measured with electroencephalography (EEG) is still unknown to date. We quantified the effect of NMES parameters on brain oscillatory activity of 12 healthy participants who underwent stimulation of wrist extensors during rest. Three different NMES intensities were included, two below and one above the individual motor threshold, fixing the stimulation frequency to 35 Hz and the pulse width to 300 μs. Firstly, we efficiently removed stimulation artifacts from the EEG recordings. Secondly, we analyzed the effect of amplitude and dose on the sensorimotor oscillatory activity. On the one hand, we observed a significant NMES intensity-dependent modulation of brain activity, demonstrating the direct effect of afferent receptor recruitment. On the other hand, we described a significant NMES intensity-dependent dose-effect on sensorimotor activity modulation over time, with below-motor-threshold intensities causing cortical inhibition and above-motor-threshold intensities causing cortical facilitation. Our results highlight the relevance of intensity and dose of NMES, and show that these parameters can influence the recruitment of the sensorimotor pathways from the muscle to the brain, which should be carefully considered for the design of novel neuromodulation interventions based on NMES.
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Affiliation(s)
- Ainhoa Insausti-Delgado
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany
- International Max Planck Research School (IMPRS) for Cognitive and Systems Neuroscience, Tübingen, Germany
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - Eduardo López-Larraz
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany
- Bitbrain, Zaragoza, Spain
| | - Jason Omedes
- Instituto de Investigación en Ingeniería de Aragón (I3A), Zaragoza, Spain
- Departamento de Informática e Ingeniería de Sistemas (DIIS), University of Zaragoza, Zaragoza, Spain
| | - Ander Ramos-Murguialday
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany
- Neurotechnology Laboratory, TECNALIA, Basque Research and Technology Alliance (BRTA), Donostia-San Sebastián, Spain
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7
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Subramaniam S, Blake DT, Constantinidis C. Cholinergic Deep Brain Stimulation for Memory and Cognitive Disorders. J Alzheimers Dis 2021; 83:491-503. [PMID: 34334401 PMCID: PMC8543284 DOI: 10.3233/jad-210425] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2021] [Indexed: 12/20/2022]
Abstract
Memory and cognitive impairment as sequelae of neurodegeneration in Alzheimer's disease and age-related dementia are major health issues with increasing social and economic burden. Deep brain stimulation (DBS) has emerged as a potential treatment to slow or halt progression of the disease state. The selection of stimulation target is critical, and structures that have been targeted for memory and cognitive enhancement include the Papez circuit, structures projecting to the frontal lobe such as the ventral internal capsule, and the cholinergic forebrain. Recent human clinical and animal model results imply that DBS of the nucleus basalis of Meynert can induce a therapeutic modulation of neuronal activity. Benefits include enhanced activity across the cortical mantle, and potential for amelioration of neuropathological mechanisms associated with Alzheimer's disease. The choice of stimulation parameters is also critical. High-frequency, continuous stimulation is used for movement disorders as a way of inhibiting their output; however, no overexcitation has been hypothesized in Alzheimer's disease and lower stimulation frequency or intermittent patterns of stimulation (periods of stimulation interleaved with periods of no stimulation) are likely to be more effective for stimulation of the cholinergic forebrain. Efficacy and long-term tolerance in human patients remain open questions, though the cumulative experience gained by DBS for movement disorders provides assurance for the safety of the procedure.
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Affiliation(s)
- Saravanan Subramaniam
- Department of Neurobiology & Anatomy, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - David T. Blake
- Brain and Behavior Discovery Institute, Department of Neurology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Christos Constantinidis
- Department of Neurobiology & Anatomy, Wake Forest School of Medicine, Winston-Salem, NC, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
- Neuroscience Program, Vanderbilt University, Nashville, TN, USA
- Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
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8
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Vissani M, Isaias IU, Mazzoni A. Deep brain stimulation: a review of the open neural engineering challenges. J Neural Eng 2020; 17:051002. [PMID: 33052884 DOI: 10.1088/1741-2552/abb581] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Deep brain stimulation (DBS) is an established and valid therapy for a variety of pathological conditions ranging from motor to cognitive disorders. Still, much of the DBS-related mechanism of action is far from being understood, and there are several side effects of DBS whose origin is unclear. In the last years DBS limitations have been tackled by a variety of approaches, including adaptive deep brain stimulation (aDBS), a technique that relies on using chronically implanted electrodes on 'sensing mode' to detect the neural markers of specific motor symptoms and to deliver on-demand or modulate the stimulation parameters accordingly. Here we will review the state of the art of the several approaches to improve DBS and summarize the main challenges toward the development of an effective aDBS therapy. APPROACH We discuss models of basal ganglia disorders pathogenesis, hardware and software improvements for conventional DBS, and candidate neural and non-neural features and related control strategies for aDBS. MAIN RESULTS We identify then the main operative challenges toward optimal DBS such as (i) accurate target localization, (ii) increased spatial resolution of stimulation, (iii) development of in silico tests for DBS, (iv) identification of specific motor symptoms biomarkers, in particular (v) assessing how LFP oscillations relate to behavioral disfunctions, and (vi) clarify how stimulation affects the cortico-basal-ganglia-thalamic network to (vii) design optimal stimulation patterns. SIGNIFICANCE This roadmap will lead neural engineers novel to the field toward the most relevant open issues of DBS, while the in-depth readers might find a careful comparison of advantages and drawbacks of the most recent attempts to improve DBS-related neuromodulatory strategies.
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Affiliation(s)
- Matteo Vissani
- The BioRobotics Institute, Scuola Superiore Sant'Anna, 56025 Pisa, Italy. Department of Excellence in Robotics and AI, Scuola Superiore Sant'Anna, 56025 Pisa, Italy
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9
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Schmidt SL, Brocker DT, Swan BD, Turner DA, Grill WM. Evoked potentials reveal neural circuits engaged by human deep brain stimulation. Brain Stimul 2020; 13:1706-1718. [PMID: 33035726 DOI: 10.1016/j.brs.2020.09.028] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 09/29/2020] [Accepted: 09/30/2020] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Deep brain stimulation (DBS) is an effective therapy for reducing the motor symptoms of Parkinson's disease, but the mechanisms of action of DBS and neural correlates of symptoms remain unknown. OBJECTIVE To use the neural response to DBS to reveal connectivity of neural circuits and interactions between groups of neurons as potential mechanisms for DBS. METHODS We recorded activity evoked by DBS of the subthalamic nucleus (STN) in humans with Parkinson's disease. In follow up experiments we also simultaneously recorded activity in the contralateral STN or the ipsilateral globus pallidus from both internal (GPi) and external (GPe) segments. RESULTS DBS local evoked potentials (DLEPs) were stereotyped across subjects, and a biophysical model of reciprocal connections between the STN and the GPe recreated DLEPs. Simultaneous STN and GP recordings during STN DBS demonstrate that DBS evoked potentials were present throughout the basal ganglia and confirmed that DLEPs arose from the reciprocal connections between the STN and GPe. The shape and amplitude of the DLEPs were dependent on the frequency and duration of DBS and were correlated with resting beta band oscillations. In the frequency domain, DLEPs appeared as a 350 Hz high frequency oscillation (HFO) independent of the frequency of DBS. CONCLUSIONS DBS evoked potentials suggest that the intrinsic dynamics of the STN and GP are highly interlinked and may provide a promising new biomarker for adaptive DBS.
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Affiliation(s)
- Stephen L Schmidt
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - David T Brocker
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Brandon D Swan
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Dennis A Turner
- Department of Biomedical Engineering, Duke University, Durham, NC, USA; Department of Neurobiology, Duke University Medical Center, Durham, NC, USA; Department of Neurosurgery, Duke University Medical Center, Durham, NC, USA
| | - Warren M Grill
- Department of Biomedical Engineering, Duke University, Durham, NC, USA; Department of Neurobiology, Duke University Medical Center, Durham, NC, USA; Department of Neurosurgery, Duke University Medical Center, Durham, NC, USA.
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10
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Hoang KB, Turner DA. The Emerging Role of Biomarkers in Adaptive Modulation of Clinical Brain Stimulation. Neurosurgery 2020; 85:E430-E439. [PMID: 30957145 DOI: 10.1093/neuros/nyz096] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 03/01/2019] [Indexed: 11/14/2022] Open
Abstract
Therapeutic brain stimulation has proven efficacious for treatment of nervous system diseases, exerting widespread influence via disease-specific neural networks. Activation or suppression of neural networks could theoretically be assessed by either clinical symptom modification (ie, tremor, rigidity, seizures) or development of specific biomarkers linked to treatment of symptomatic disease states. For example, biomarkers indicative of disease state could aid improved intraoperative localization of electrode position, optimize device efficacy or efficiency through dynamic control, and eventually serve to guide automatic adjustment of stimulation settings. Biomarkers to control either extracranial or intracranial stimulation span from continuous physiological brain activity, intermittent pathological activity, and triggered local phenomena or potentials, to wearable devices, blood flow, biochemical or cardiac signals, temperature perturbations, optical or magnetic resonance imaging changes, or optogenetic signals. The goal of this review is to update new approaches to implement control of stimulation through relevant biomarkers. Critical questions include whether adaptive systems adjusted through biomarkers can optimize efficiency and eventually efficacy, serve as inputs for stimulation adjustment, and consequently broaden our fundamental understanding of abnormal neural networks in pathologic states. Neurosurgeons are at the forefront of translating and developing biomarkers embedded within improved brain stimulation systems. Thus, criteria for developing and validating biomarkers for clinical use are important for the adaptation of device approaches into clinical practice.
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Affiliation(s)
- Kimberly B Hoang
- Department of Neurosurgery, MD Anderson Cancer Center, Houston, Texas
| | - Dennis A Turner
- Departments of Neurosurgery, Duke University Medical Center, Durham, North Carolina.,Department of Neurobiology, Duke University Medical Center, Durham, North Carolina.,Department of Biomedical Engineering, Duke University, Durham, North Carolina
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11
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Schmidt SL, Peters JJ, Turner DA, Grill WM. Continuous deep brain stimulation of the subthalamic nucleus may not modulate beta bursts in patients with Parkinson's disease. Brain Stimul 2020; 13:433-443. [PMID: 31884188 PMCID: PMC6961347 DOI: 10.1016/j.brs.2019.12.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 11/19/2019] [Accepted: 12/10/2019] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Neural oscillations represent synchronous neuronal activation and are ubiquitous throughout the brain. Oscillatory activity often includes brief high-amplitude bursts in addition to background oscillations, and burst activity may predict performance on working memory, motor, and comprehension tasks. OBJECTIVE We evaluated beta burst activity as a possible biomarker for motor symptoms in Parkinson's disease (PD). The relationship between beta amplitude dynamics and motor symptoms is critical for adaptive DBS for treatment of PD. METHODS We applied threshold-based and support vector machine (SVM) analyses of burst parameters to a defined on/off oscillator and to intraoperative recordings of local field potentials from the subthalamic nucleus of 16 awake patients with PD. RESULTS Filtering and time-frequency analysis techniques critically influenced the accuracy of identifying burst activity. Threshold-based analysis lead to biased results in the presence of changes in long-term beta amplitude and accurate quantification of bursts with thresholds required unknowable a priori knowledge of the time in bursts. We therefore implemented an SVM analysis, and we did not observe changes in burst fraction, rate, or duration with the application of cDBS in the participant data, even though SVM analysis was able to correctly identify bursts of the defined on/off oscillator. CONCLUSION Our results suggest that cDBS of the STN may not change beta burst activity. Additionally, threshold-based analysis can bias the fraction of time spent in bursts. Improved analysis strategies for continuous and adaptive DBS may achieve improved symptom control and reduce side-effects.
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Affiliation(s)
- Stephen L Schmidt
- Biomedical Engineering Department, Duke University, Durham, NC, USA.
| | | | - Dennis A Turner
- Biomedical Engineering Department, Duke University, Durham, NC, USA; Neurobiology and Neurosurgery Departments, Duke University Medical Center, Durham, NC, USA
| | - Warren M Grill
- Biomedical Engineering Department, Duke University, Durham, NC, USA; Neurobiology and Neurosurgery Departments, Duke University Medical Center, Durham, NC, USA; Electrical and Computer Engineering Department, Duke University, Durham, NC, USA.
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12
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Amoozegar S, Pooyan M, Roughani M. Toward a closed-loop deep brain stimulation in Parkinson's disease using local field potential in parkinsonian rat model. Med Hypotheses 2019; 132:109360. [PMID: 31442919 DOI: 10.1016/j.mehy.2019.109360] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 08/04/2019] [Accepted: 08/11/2019] [Indexed: 02/06/2023]
Abstract
Deep brain stimulation (DBS) is an invasive method used for treating Parkinson's disease in its advanced stages. Nowadays, the initial adjustment of DBS parameters and their automatic matching proportion to the progression of the disease is viewed as one of the research areas discussed by the researchers, which is called closed-loop DBS. Various studies were conducted regarding finding the signal(s) which reflects different symptoms of the disease. Local Field Potential (LFP) is one of the signals that is suitable for using as feedback, because it can be recorded by the same implemented electrodes for stimulation. The present study aimed to identify the distinguishing features of patients from healthy individuals using LFP signals. METHODS In the present study, LFP was recorded from the rats in sham and parkinsonian model groups. After evaluating the signals in the frequency domain, sixty-six features were extracted from power spectral density of LFPs. The features were classified by Support Vector Machine (SVM) to determine the ability of features for separating parkinsonian rats from healthy ones. Finally, the most effective features were selected for distinguishing between the sham and parkinsonian model groups using a genetic algorithm. RESULTS The results indicated that the frequency domain features of LFP signals from rats have capacity of using them as a feedback for closed-loop DBS. The accuracy of the Support Vector Machine classification using all 66 features was 80.42% which increased to 84.41% using 38 features selected by genetic algorithm. The proposed method not only increase the accuracy, but it also reduce computation by decreasing the number of the effective features. The results indicate the significant capacity of the proposed method for identifying the effective high-frequency features to control the closed-loop DBS. CONCLUSIONS The ability of using LFP signals as feedback in closed-loop DBS was shown by extracting useful information in frequency bands below and above 100 Hz regarding LFP signals of parkinsonian rats and sham ones. Based on the results, features at frequencies above 100 Hz were more powerful and robust than below 100 Hz. The genetic algorithm was used for optimizing the classification problem.
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Affiliation(s)
- Sana Amoozegar
- Department of Biomedical Engineering, Faculty of Engineering, Shahed University, Tehran, Iran
| | - Mohammad Pooyan
- Department of Biomedical Engineering, Faculty of Engineering, Shahed University, Tehran, Iran.
| | - Mehrdad Roughani
- Department of Physiology, Faculty of Medical Sciences, Shahed University, Tehran, Iran
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13
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Sinclair NC, Fallon JB, Bulluss KJ, Thevathasan W, McDermott HJ. On the neural basis of deep brain stimulation evoked resonant activity. Biomed Phys Eng Express 2019. [DOI: 10.1088/2057-1976/ab366e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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14
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Parker JL, Obradovic M, Hesam Shariati N, Gorman RB, Karantonis DM, Single PS, Laird‐Wah J, Bickerstaff M, Cousins MJ. Evoked Compound Action Potentials Reveal Spinal Cord Dorsal Column Neuroanatomy. Neuromodulation 2019; 23:82-95. [DOI: 10.1111/ner.12968] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 02/27/2019] [Accepted: 03/19/2019] [Indexed: 01/03/2023]
Affiliation(s)
- John L. Parker
- Saluda Medical Pty Ltd. Artarmon NSW Australia
- Graduate School of Biomedical Engineering, University of New South Wales Kensington NSW Australia
| | | | | | - Robert B. Gorman
- Saluda Medical Pty Ltd. Artarmon NSW Australia
- Northern Clinical School, University of Sydney Sydney Australia
| | | | | | | | | | - Michael J. Cousins
- Pain Management Research Institute and Kolling Institute, University of Sydney at the Royal North Shore Hospital St Leonards NSW Australia
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15
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Michelson NJ, Eles JR, Vazquez AL, Ludwig KA, Kozai TDY. Calcium activation of cortical neurons by continuous electrical stimulation: Frequency dependence, temporal fidelity, and activation density. J Neurosci Res 2018; 97:620-638. [PMID: 30585651 DOI: 10.1002/jnr.24370] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 11/20/2018] [Accepted: 11/28/2018] [Indexed: 01/18/2023]
Abstract
Electrical stimulation of the brain has become a mainstay of fundamental neuroscience research and an increasingly prevalent clinical therapy. Despite decades of use in basic neuroscience research and the growing prevalence of neuromodulation therapies, gaps in knowledge regarding activation or inactivation of neural elements over time have limited its ability to adequately interpret evoked downstream responses or fine-tune stimulation parameters to focus on desired responses. In this work, in vivo two-photon microscopy was used to image neuronal calcium activity in layer 2/3 neurons of somatosensory cortex (S1) in male C57BL/6J-Tg(Thy1-GCaMP6s)GP4.3Dkim/J mice during 30 s of continuous electrical stimulation at varying frequencies. We show frequency-dependent differences in spatial and temporal somatic responses during continuous stimulation. Our results elucidate conflicting results from prior studies reporting either dense spherical activation of somas biased toward those near the electrode, or sparse activation of somas at a distance via axons near the electrode. These findings indicate that the neural element specific temporal response local to the stimulating electrode changes as a function of applied charge density and frequency. These temporal responses need to be considered to properly interpret downstream circuit responses or determining mechanisms of action in basic science experiments or clinical therapeutic applications.
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Affiliation(s)
- Nicholas J Michelson
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada
| | - James R Eles
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania.,Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Alberto L Vazquez
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania.,Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Neurobiology, University of Pittsburgh, Pittsburgh, Pennsylvania.,Center for Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Kip A Ludwig
- Department of Biomedical Engineering, University of Wisconsin Madison, Madison, Wisconsin.,Department of Neurological Surgery, University of Wisconsin Madison, Madison, Wisconsin
| | - Takashi D Y Kozai
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania.,Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, Pennsylvania.,Center for Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania.,McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.,NeuroTech Center, University of Pittsburgh Brain Institute, Pittsburgh, Pennsylvania
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16
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Jung H, Kim J, Nam Y. Recovery of early neural spikes from stimulation electrodes using a DC-coupled low gain high resolution data acquisition system. J Neurosci Methods 2018; 304:118-125. [PMID: 29709657 DOI: 10.1016/j.jneumeth.2018.04.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 04/16/2018] [Accepted: 04/18/2018] [Indexed: 11/29/2022]
Abstract
BACKGROUND Neural responses to electrical stimulation provide valuable information to probe and study the network function. Especially, recording neural responses from the stimulated site provides improved neural interfacing method. However, it is difficult to measure short-delayed responses at the stimulated electrode due to the saturation of the amplifier after stimulation which is called "stimulus artifact". Despite the advances in handling stimulation artifacts, it is still very challenging to deal with the artifacts if one tries to stimulate and record from the same electrode. NEW METHOD In this paper, we developed a system consisting of 24 bit ADC and low gain DC-amplifier which allows us to record the entire responses including saturation-free stimulus artifact and neural responses with excellent resolution. RESULTS Our approach showed saturation-free recording after stimulation, which makes it possible to recover neural spike as early as in 2 ms at the stimulating electrode with digital elimination methods. COMPARISON WITH EXISTING METHODS With our system we could record neural signals after stimulation that was difficult with high gain and high pass filtered recording system due to amplifier saturation. CONCLUSIONS Our new system can enhance interface performance with its higher robustness and with simple system configuration.
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Affiliation(s)
- Hyunjun Jung
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Jintae Kim
- Department of Electronics Engineering, Konkuk University, Seoul, Republic of Korea
| | - Yoonkey Nam
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea.
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17
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YOUNG D, WILLETT F, MEMBERG WD, MURPHY B, WALTER B, SWEET J, MILLER J, HOCHBERG LR, KIRSCH RF, AJIBOYE AB. Signal processing methods for reducing artifacts in microelectrode brain recordings caused by functional electrical stimulation. J Neural Eng 2018; 15:026014. [PMID: 29199642 PMCID: PMC5818316 DOI: 10.1088/1741-2552/aa9ee8] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
OBJECTIVE Functional electrical stimulation (FES) is a promising technology for restoring movement to paralyzed limbs. Intracortical brain-computer interfaces (iBCIs) have enabled intuitive control over virtual and robotic movements, and more recently over upper extremity FES neuroprostheses. However, electrical stimulation of muscles creates artifacts in intracortical microelectrode recordings that could degrade iBCI performance. Here, we investigate methods for reducing the cortically recorded artifacts that result from peripheral electrical stimulation. APPROACH One participant in the BrainGate2 pilot clinical trial had two intracortical microelectrode arrays placed in the motor cortex, and thirty-six stimulating intramuscular electrodes placed in the muscles of the contralateral limb. We characterized intracortically recorded electrical artifacts during both intramuscular and surface stimulation. We compared the performance of three artifact reduction methods: blanking, common average reference (CAR) and linear regression reference (LRR), which creates channel-specific reference signals, composed of weighted sums of other channels. MAIN RESULTS Electrical artifacts resulting from surface stimulation were 175 × larger than baseline neural recordings (which were 110 µV peak-to-peak), while intramuscular stimulation artifacts were only 4 × larger. The artifact waveforms were highly consistent across electrodes within each array. Application of LRR reduced artifact magnitudes to less than 10 µV and largely preserved the original neural feature values used for decoding. Unmitigated stimulation artifacts decreased iBCI decoding performance, but performance was almost completely recovered using LRR, which outperformed CAR and blanking and extracted useful neural information during stimulation artifact periods. SIGNIFICANCE The LRR method was effective at reducing electrical artifacts resulting from both intramuscular and surface FES, and almost completely restored iBCI decoding performance (>90% recovery for surface stimulation and full recovery for intramuscular stimulation). The results demonstrate that FES-induced artifacts can be easily mitigated in FES + iBCI systems by using LRR for artifact reduction, and suggest that the LRR method may also be useful in other noise reduction applications.
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Affiliation(s)
- D. YOUNG
- Case Western Reserve Univ., Cleveland, OH
- FES Ctr. of Excellence, Rehab. R&D Service, Louis Stokes Cleveland Dept. of VA Med. Ctr., Cleveland, OH
| | - F. WILLETT
- Case Western Reserve Univ., Cleveland, OH
- FES Ctr. of Excellence, Rehab. R&D Service, Louis Stokes Cleveland Dept. of VA Med. Ctr., Cleveland, OH
- Dept of Neurosurgery, Stanford University, Stanford, CA
| | - W. D. MEMBERG
- Case Western Reserve Univ., Cleveland, OH
- FES Ctr. of Excellence, Rehab. R&D Service, Louis Stokes Cleveland Dept. of VA Med. Ctr., Cleveland, OH
| | - B. MURPHY
- Case Western Reserve Univ., Cleveland, OH
| | - B. WALTER
- Neurol., UH Cleveland Med. Ctr., Cleveland, OH
- Neurol., CWRU Sch. of Med., Cleveland, OH
| | - J. SWEET
- Neurosurg., UH Cleveland Med. Ctr., Cleveland, OH
- Neurolog. Surgery, CWRU Sch. of Med., Cleveland, OH
| | - J. MILLER
- Neurosurg., UH Cleveland Med. Ctr., Cleveland, OH
- Neurolog. Surgery, CWRU Sch. of Med., Cleveland, OH
| | - L. R. HOCHBERG
- Ctr. for Neurorestoration and Neurotechnology, Rehab. R&D Service, Dept. of VA Medical Center, Providence RI
- Sch. of Engin., Brown Univ., Providence, RI
- Neurol., Massachusetts Gen. Hosp., Boston, MA
- Neurol., Harvard Med. Sch., Boston, MA
- Inst. For Brain Sci., Brown Univ., Providence, RI
| | - R. F. KIRSCH
- Case Western Reserve Univ., Cleveland, OH
- FES Ctr. of Excellence, Rehab. R&D Service, Louis Stokes Cleveland Dept. of VA Med. Ctr., Cleveland, OH
| | - A. B. AJIBOYE
- Case Western Reserve Univ., Cleveland, OH
- FES Ctr. of Excellence, Rehab. R&D Service, Louis Stokes Cleveland Dept. of VA Med. Ctr., Cleveland, OH
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18
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Hoang KB, Cassar IR, Grill WM, Turner DA. Biomarkers and Stimulation Algorithms for Adaptive Brain Stimulation. Front Neurosci 2017; 11:564. [PMID: 29066947 PMCID: PMC5641319 DOI: 10.3389/fnins.2017.00564] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 09/25/2017] [Indexed: 11/29/2022] Open
Abstract
The goal of this review is to describe in what ways feedback or adaptive stimulation may be delivered and adjusted based on relevant biomarkers. Specific treatment mechanisms underlying therapeutic brain stimulation remain unclear, in spite of the demonstrated efficacy in a number of nervous system diseases. Brain stimulation appears to exert widespread influence over specific neural networks that are relevant to specific disease entities. In awake patients, activation or suppression of these neural networks can be assessed by either symptom alleviation (i.e., tremor, rigidity, seizures) or physiological criteria, which may be predictive of expected symptomatic treatment. Secondary verification of network activation through specific biomarkers that are linked to symptomatic disease improvement may be useful for several reasons. For example, these biomarkers could aid optimal intraoperative localization, possibly improve efficacy or efficiency (i.e., reduced power needs), and provide long-term adaptive automatic adjustment of stimulation parameters. Possible biomarkers for use in portable or implanted devices span from ongoing physiological brain activity, evoked local field potentials (LFPs), and intermittent pathological activity, to wearable devices, biochemical, blood flow, optical, or magnetic resonance imaging (MRI) changes, temperature changes, or optogenetic signals. First, however, potential biomarkers must be correlated directly with symptom or disease treatment and network activation. Although numerous biomarkers are under consideration for a variety of stimulation indications the feasibility of these approaches has yet to be fully determined. Particularly, there are critical questions whether the use of adaptive systems can improve efficacy over continuous stimulation, facilitate adjustment of stimulation interventions and improve our understanding of the role of abnormal network function in disease mechanisms.
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Affiliation(s)
- Kimberly B. Hoang
- Department of Neurosurgery, Duke University, Durham, NC, United States
| | - Isaac R. Cassar
- Department of Biomedical Engineering, Duke University, Durham, NC, United States
| | - Warren M. Grill
- Department of Neurosurgery, Duke University, Durham, NC, United States
- Department of Biomedical Engineering, Duke University, Durham, NC, United States
- Department of Neurobiology, Duke University Medical Center, Duke University, Durham, NC, United States
| | - Dennis A. Turner
- Department of Neurosurgery, Duke University, Durham, NC, United States
- Department of Neurobiology, Duke University Medical Center, Duke University, Durham, NC, United States
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19
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Brocker DT, Swan BD, So RQ, Turner DA, Gross RE, Grill WM. Optimized temporal pattern of brain stimulation designed by computational evolution. Sci Transl Med 2017; 9:eaah3532. [PMID: 28053151 PMCID: PMC5516784 DOI: 10.1126/scitranslmed.aah3532] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 06/15/2016] [Accepted: 11/18/2016] [Indexed: 11/02/2022]
Abstract
Brain stimulation is a promising therapy for several neurological disorders, including Parkinson's disease. Stimulation parameters are selected empirically and are limited to the frequency and intensity of stimulation. We varied the temporal pattern of deep brain stimulation to ameliorate symptoms in a parkinsonian animal model and in humans with Parkinson's disease. We used model-based computational evolution to optimize the stimulation pattern. The optimized pattern produced symptom relief comparable to that from standard high-frequency stimulation (a constant rate of 130 or 185 Hz) and outperformed frequency-matched standard stimulation in a parkinsonian rat model and in patients. Both optimized and standard high-frequency stimulation suppressed abnormal oscillatory activity in the basal ganglia of rats and humans. The results illustrate the utility of model-based computational evolution of temporal patterns to increase the efficiency of brain stimulation in treating Parkinson's disease and thereby reduce the energy required for successful treatment below that of current brain stimulation paradigms.
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Affiliation(s)
- David T Brocker
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| | - Brandon D Swan
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| | - Rosa Q So
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| | - Dennis A Turner
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
- Department of Neurosurgery, Duke University Medical Center, Durham, NC 27710, USA
| | - Robert E Gross
- Departments of Neurosurgery and Neurology, Emory University, Atlanta, GA 30322, USA
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Warren M Grill
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA.
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
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20
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Cortical neurostimulation for neuropathic pain: state of the art and perspectives. Pain 2016; 157 Suppl 1:S81-S89. [PMID: 26785160 DOI: 10.1097/j.pain.0000000000000401] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The treatment of neuropathic pain by neuromodulation is an objective for more than 40 years in modern clinical practice. With respect to spinal cord and deep brain structures, the cerebral cortex is the most recently evaluated target of invasive neuromodulation therapy for pain. In the early 90s, the first successes of invasive epidural motor cortex stimulation (EMCS) were published. A few years later was developed repetitive transcranial magnetic stimulation (rTMS), a noninvasive stimulation technique. Then, electrical transcranial stimulation returned valid and is currently in full development, with transcranial direct current stimulation (tDCS). Regarding transcranial approaches, the main studied and validated target was still the motor cortex, but other cortical targets are under investigation. The mechanisms of action of these techniques share similarities, especially between EMCS and rTMS, but they also have differences that could justify specific indications and applications. It is therefore important to know the principles and to assess the merit of these techniques on the basis of a rigorous assessment of the results, to avoid fad. Various types of chronic neuropathic pain syndromes can be significantly relieved by EMCS or repeated daily sessions of high-frequency (5-20 Hz) rTMS or anodal tDCS over weeks, at least when pain is lateralized and stimulation is applied to the motor cortex contralateral to pain side. However, cortical stimulation therapy remains to be optimized, especially by improving EMCS electrode design, rTMS targeting, or tDCS montage, to reduce the rate of nonresponders, who do not experience clinically relevant effects of these techniques.
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21
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Qian X, Chen Y, Feng Y, Ma B, Hao H, Li L. A Method for Removal of Deep Brain Stimulation Artifact From Local Field Potentials. IEEE Trans Neural Syst Rehabil Eng 2016; 25:2217-2226. [PMID: 28113981 DOI: 10.1109/tnsre.2016.2613412] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This paper presents a signal processing method for the electrophysiology simultaneously recorded during deep brain stimulation (DBS) as a research tool. Regarding the local field potential (LFP) signals recorded during stimulation, a novel method was proposed for removal of stimulation artifacts caused by the much stronger stimulating pulse compared to typical LFP. This artifact suppression method was tested and evaluated in an in vitro situation. The results indicate that the stimulation artifacts are well suppressed by this method. Secondly, this method was tested in vivo in Parkinson's disease (PD) patients. It was used to process the LFP signals recorded intraoperatively from PD patients to preliminarily explore the quantitative dependencies of beta band synchronization variations in the subthalamic nucleus (STNs) on the applied DBS parameters, including stimulation voltage, frequency and pulse width. The results confirm that DBS therapy can suppress excessive beta frequency activity and that the degree of attenuation increases with increasing DBS voltage within a range of 1-3 V and increasing DBS frequency within a range of 60-120 Hz. The proposed artifact suppression method provides technical support for exploring the direct effect of electrical stimulation on the brain activities.
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22
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Kim S, Callier T, Tabot GA, Gaunt RA, Tenore FV, Bensmaia SJ. Behavioral assessment of sensitivity to intracortical microstimulation of primate somatosensory cortex. Proc Natl Acad Sci U S A 2015; 112:15202-7. [PMID: 26504211 PMCID: PMC4679002 DOI: 10.1073/pnas.1509265112] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Intracortical microstimulation (ICMS) is a powerful tool to investigate the functional role of neural circuits and may provide a means to restore sensation for patients for whom peripheral stimulation is not an option. In a series of psychophysical experiments with nonhuman primates, we investigate how stimulation parameters affect behavioral sensitivity to ICMS. Specifically, we deliver ICMS to primary somatosensory cortex through chronically implanted electrode arrays across a wide range of stimulation regimes. First, we investigate how the detectability of ICMS depends on stimulation parameters, including pulse width, frequency, amplitude, and pulse train duration. Then, we characterize the degree to which ICMS pulse trains that differ in amplitude lead to discriminable percepts across the range of perceptible and safe amplitudes. We also investigate how discriminability of pulse amplitude is modulated by other stimulation parameters-namely, frequency and duration. Perceptual judgments obtained across these various conditions will inform the design of stimulation regimes for neuroscience and neuroengineering applications.
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Affiliation(s)
- Sungshin Kim
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637
| | - Thierri Callier
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637
| | - Gregg A Tabot
- Committee on Computational Neuroscience, University of Chicago, Chicago, IL 60637
| | - Robert A Gaunt
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA 15213
| | - Francesco V Tenore
- Research and Exploratory Development Department, Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723
| | - Sliman J Bensmaia
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637; Committee on Computational Neuroscience, University of Chicago, Chicago, IL 60637;
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23
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Connolly AT, Muralidharan A, Hendrix C, Johnson L, Gupta R, Stanslaski S, Denison T, Baker KB, Vitek JL, Johnson MD. Local field potential recordings in a non-human primate model of Parkinsons disease using the Activa PC + S neurostimulator. J Neural Eng 2015; 12:066012. [PMID: 26469737 DOI: 10.1088/1741-2560/12/6/066012] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Using the Medtronic Activa® PC + S system, this study investigated how passive joint manipulation, reaching behavior, and deep brain stimulation (DBS) modulate local field potential (LFP) activity in the subthalamic nucleus (STN) and globus pallidus (GP). APPROACH Five non-human primates were implanted unilaterally with one or more DBS leads. LFPs were collected in montage recordings during resting state conditions and during motor tasks that facilitate the expression of parkinsonian motor signs. These recordings were made in the naïve state in one subject, in the parkinsonian state in two subjects, and in both naïve and parkinsonian states in two subjects. MAIN RESULTS LFPs measured at rest were consistent over time for a given recording location and parkinsonian state in a given subject; however, LFPs were highly variable between subjects, between and within recording locations, and across parkinsonian states. LFPs in both naïve and parkinsonian states across all recorded nuclei contained a spectral peak in the beta band (10-30 Hz). Moreover, the spectral content of recorded LFPs was modulated by passive and active movement of the subjects' limbs. LFPs recorded during a cued-reaching task displayed task-related beta desynchronization in STN and GP. The bidirectional capabilities of the Activa® PC + S also allowed for recording LFPs while delivering DBS. The therapeutic effect of STN DBS on parkinsonian rigidity outlasted stimulation for 30-60 s, but there was no correlation with beta band power. SIGNIFICANCE This study emphasizes (1) the variability in spontaneous LFPs amongst subjects and (2) the value of using the Activa® PC + S system to record neural data in the context of behavioral tasks that allow one to evaluate a subject's symptomatology.
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24
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Kale RP, Kouzani AZ, Walder K, Berk M, Tye SJ. Evolution of optogenetic microdevices. NEUROPHOTONICS 2015; 2:031206. [PMID: 26158015 PMCID: PMC4481025 DOI: 10.1117/1.nph.2.3.031206] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 05/27/2015] [Indexed: 05/30/2023]
Abstract
Implementation of optogenetic techniques is a recent addition to the neuroscientists' preclinical research arsenal, helping to expose the intricate connectivity of the brain and allowing for on-demand direct modulation of specific neural pathways. Developing an optogenetic system requires thorough investigation of the optogenetic technique and of previously fabricated devices, which this review accommodates. Many experiments utilize bench-top systems that are bulky, expensive, and necessitate tethering to the animal. However, these bench-top systems can make use of power-demanding technologies, such as concurrent electrical recording. Newer portable microdevices and implantable systems carried by freely moving animals are being fabricated that take advantage of wireless energy harvesting to power a system and allow for natural movements that are vital for behavioral testing and analysis. An investigation of the evolution of tethered, portable, and implantable optogenetic microdevices is presented, and an analysis of benefits and detriments of each system, including optical power output, device dimensions, electrode width, and weight is given. Opsins, light sources, and optical fiber coupling are also discussed to optimize device parameters and maximize efficiency from the light source to the fiber, respectively. These attributes are important considerations when designing and developing improved optogenetic microdevices.
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Affiliation(s)
- Rajas P. Kale
- Deakin University School of Engineering, Faculty of Science, Engineering, and Built Environment, 75 Pigdons Road, Waurn Ponds, Victoria 3216, Australia
- Mayo Clinic Department of Psychiatry and Psychology, 200 First Street SW, Rochester, Minnesota 55905, United States
| | - Abbas Z. Kouzani
- Deakin University School of Engineering, Faculty of Science, Engineering, and Built Environment, 75 Pigdons Road, Waurn Ponds, Victoria 3216, Australia
| | - Ken Walder
- Deakin University School of Medicine, 75 Pigdons Road, Waurn Ponds, Victoria 3216, Australia
| | - Michael Berk
- Deakin University, IMPACT Strategic Research Centre, Faulty of Health, School of Medicine, Barwon Health, Geelong, Victoria, Australia
- Orygen, National Centre of Excellence in Youth Mental Health, Department of Psychiatry, 35 Poplar Road, Parkville, Victoria 3052, Australia
- University of Melbourne, Florey Institute of Neuroscience and Mental Health, 30 Royal Parade, Parkville Victoria 3052, Australia
| | - Susannah J. Tye
- Mayo Clinic Department of Psychiatry and Psychology, 200 First Street SW, Rochester, Minnesota 55905, United States
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25
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Nagaraj V, Lee S, Krook-Magnuson E, Soltesz I, Benquet P, Irazoqui P, Netoff T. Future of seizure prediction and intervention: closing the loop. J Clin Neurophysiol 2015; 32:194-206. [PMID: 26035672 PMCID: PMC4455045 DOI: 10.1097/wnp.0000000000000139] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The ultimate goal of epilepsy therapies is to provide seizure control for all patients while eliminating side effects. Improved specificity of intervention through on-demand approaches may overcome many of the limitations of current intervention strategies. This article reviews the progress in seizure prediction and detection, potential new therapies to provide improved specificity, and devices to achieve these ends. Specifically, we discuss (1) potential signal modalities and algorithms for seizure detection and prediction, (2) closed-loop intervention approaches, and (3) hardware for implementing these algorithms and interventions. Seizure prediction and therapies maximize efficacy, whereas minimizing side effects through improved specificity may represent the future of epilepsy treatments.
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Affiliation(s)
- Vivek Nagaraj
- Graduate Program in Neuroscience, University of Minnesota
| | - Steven Lee
- Weldon School of Biomedical Engineering, Purdue University
| | | | - Ivan Soltesz
- Department of Anatomy & Neurobiology, University of California, Irvine
| | | | - Pedro Irazoqui
- Weldon School of Biomedical Engineering, Purdue University
| | - Theoden Netoff
- Graduate Program in Neuroscience, University of Minnesota
- Department of Biomedical Engineering, University of Minnesota
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26
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Kent AR, Swan BD, Brocker DT, Turner DA, Gross RE, Grill WM. Measurement of evoked potentials during thalamic deep brain stimulation. Brain Stimul 2014; 8:42-56. [PMID: 25457213 DOI: 10.1016/j.brs.2014.09.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 09/21/2014] [Accepted: 09/26/2014] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Deep brain stimulation (DBS) treats the symptoms of several movement disorders, but optimal selection of stimulation parameters remains a challenge. The evoked compound action potential (ECAP) reflects synchronized neural activation near the DBS lead, and may be useful for feedback control and automatic adjustment of stimulation parameters in closed-loop DBS systems. OBJECTIVES Determine the feasibility of recording ECAPs in the clinical setting, understand the neural origin of the ECAP and sources of any stimulus artifact, and correlate ECAP characteristics with motor symptoms. METHODS The ECAP and tremor response were measured simultaneously during intraoperative studies of thalamic DBS, conducted in patients who were either undergoing surgery for initial lead implantation or replacement of their internal pulse generator. RESULTS There was large subject-to-subject variation in stimulus artifact amplitude, which model-based analysis suggested may have been caused by glial encapsulation of the lead, resulting in imbalances in the tissue impedance between the contacts. ECAP recordings obtained from both acute and chronically implanted electrodes revealed that specific phase characteristics of the signal varied systematically with stimulation parameters. Further, a trend was observed in some patients between the energy of the initial negative and positive ECAP phases, as well as secondary phases, and changes in tremor from baseline. A computational model of thalamic DBS indicated that direct cerebellothalamic fiber activation dominated the clinically measured ECAP, suggesting that excitation of these fibers is critical in DBS therapy. CONCLUSIONS This work demonstrated that ECAPs can be recorded in the clinical setting and may provide a surrogate feedback control signal for automatic adjustment of stimulation parameters to reduce tremor amplitude.
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Affiliation(s)
- Alexander R Kent
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Brandon D Swan
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - David T Brocker
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Dennis A Turner
- Department of Neurobiology, Duke University Medical Center, Durham, NC, USA; Department of Surgery, Duke University Medical Center, Durham, NC, USA
| | - Robert E Gross
- Department of Neurosurgery, Emory University, Atlanta, GA, USA; Department of Neurology, Emory University, Atlanta, GA, USA; Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Warren M Grill
- Department of Biomedical Engineering, Duke University, Durham, NC, USA; Department of Neurobiology, Duke University Medical Center, Durham, NC, USA; Department of Surgery, Duke University Medical Center, Durham, NC, USA; Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA.
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27
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Liu J, Li S, Li X, Klein C, Rymer WZ, Zhou P. Suppression of stimulus artifact contaminating electrically evoked electromyography. NeuroRehabilitation 2014; 34:381-9. [PMID: 24419021 DOI: 10.3233/nre-131045] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Electrical stimulation of muscle or nerve is a very useful technique for understanding of muscle activity and its pathological changes for both diagnostic and therapeutic purposes. During electrical stimulation of a muscle, the recorded M wave is often contaminated by a stimulus artifact. The stimulus artifact must be removed for appropriate analysis and interpretation of M waves. OBJECTIVES The objective of this study was to develop a novel software based method to remove stimulus artifacts contaminating or superimposing with electrically evoked surface electromyography (EMG) or M wave signals. METHODS The multiple stage method uses a series of signal processing techniques, including highlighting and detection of stimulus artifacts using Savitzky-Golay filtering, estimation of the artifact contaminated region with Otsu thresholding, and reconstruction of such region using signal interpolation and smoothing. The developed method was tested using M wave signals recorded from biceps brachii muscles by a linear surface electrode array. To evaluate the performance, a series of semi-synthetic signals were constructed from clean M wave and stimulus artifact recordings with different degrees of overlap between them. RESULTS The effectiveness of the developed method was quantified by a significant increase in correlation coefficient and a significant decrease in root mean square error between the clean M wave and the reconstructed M wave, compared with those between the clean M wave and the originally contaminated signal. The validity of the developed method was also demonstrated when tested on each channel's M wave recording using a linear electrode array. CONCLUSIONS The developed method can suppress stimulus artifacts contaminating M wave recordings.
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Affiliation(s)
- Jie Liu
- Sensory Motor Performance Program, Rehabilitation Institute of Chicago, Chicago, IL, USA
| | - Sheng Li
- Department of Physical Medicine and Rehabilitation, University of Texas Health Science Center at Houston, Houston, TX, USA The Neurorehabilitation Research Laboratory, The Institute of Rehabilitation and Research (TIRR)-Memorial Hermann Hospital, Houston, TX, USA
| | - Xiaoyan Li
- Sensory Motor Performance Program, Rehabilitation Institute of Chicago, Chicago, IL, USA
| | - Cliff Klein
- Sensory Motor Performance Program, Rehabilitation Institute of Chicago, Chicago, IL, USA
| | - William Z Rymer
- Sensory Motor Performance Program, Rehabilitation Institute of Chicago, Chicago, IL, USA Department of Physical Medicine and Rehabilitation, Northwestern University, Chicago, IL, USA
| | - Ping Zhou
- Sensory Motor Performance Program, Rehabilitation Institute of Chicago, Chicago, IL, USA Department of Physical Medicine and Rehabilitation, Northwestern University, Chicago, IL, USA Institute of Biomedical Engineering, University of Science and Technology of China, Hefei, China
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28
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Kent AR, Grill WM. Analysis of deep brain stimulation electrode characteristics for neural recording. J Neural Eng 2014; 11:046010. [PMID: 24921984 DOI: 10.1088/1741-2560/11/4/046010] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
OBJECTIVE Closed-loop deep brain stimulation (DBS) systems have the potential to optimize treatment of movement disorders by enabling automatic adjustment of stimulation parameters based on a feedback signal. Evoked compound action potentials (ECAPs) and local field potentials (LFPs) recorded from the DBS electrode may serve as suitable closed-loop control signals. The objective of this study was to understand better the factors that influence ECAP and LFP recording, including the physical presence of the electrode, the geometrical dimensions of the electrode, and changes in the composition of the peri-electrode space across recording conditions. APPROACH Coupled volume conductor-neuron models were used to calculate single-unit activity as well as ECAP responses and LFP activity from a population of model thalamic neurons. MAIN RESULTS Comparing ECAPs and LFPs measured with and without the presence of the highly conductive recording contacts, we found that the presence of these contacts had a negligible effect on the magnitude of single-unit recordings, ECAPs (7% RMS difference between waveforms), and LFPs (5% change in signal magnitude). Spatial averaging across the contact surface decreased the ECAP magnitude in a phase-dependent manner (74% RMS difference), resulting from a differential effect of the contact on the contribution from nearby or distant elements, and decreased the LFP magnitude (25% change). Reductions in the electrode diameter or recording contact length increased signal energy and increased spatial sensitivity of single neuron recordings. Moreover, smaller diameter electrodes (500 µm) were more selective for recording from local cells over passing axons, with the opposite true for larger diameters (1500 µm). Changes in electrode dimensions had phase-dependent effects on ECAP characteristics, and generally had small effects on the LFP magnitude. ECAP signal energy and LFP magnitude decreased with tighter contact spacing (100 µm), compared to the original dimensions (1500 µm), with the opposite effect on the ECAP at longer contact-to-contact distances (2000 µm). Finally, acute edema reduced the single neuron and population ECAP signal energy, as well as LFP magnitude, and glial encapsulation had the opposite effect, after accounting for loss of cells in the peri-electrode space. SIGNIFICANCE This study determined recording conditions and electrode designs that influence ECAP and LFP recording fidelity.
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Affiliation(s)
- Alexander R Kent
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
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Beuter A, Lefaucheur JP, Modolo J. Closed-loop cortical neuromodulation in Parkinson's disease: An alternative to deep brain stimulation? Clin Neurophysiol 2014; 125:874-85. [PMID: 24555921 DOI: 10.1016/j.clinph.2014.01.006] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Revised: 01/12/2014] [Accepted: 01/14/2014] [Indexed: 02/04/2023]
Abstract
Deep brain stimulation (DBS) is usually performed to treat advanced Parkinson's disease (PD) patients with electrodes permanently implanted in basal ganglia while the stimulator delivers electrical impulses continuously and independently of any feedback (open-loop stimulation). Conversely, in closed-loop stimulation, electrical stimulation is delivered as a function of neuronal activities recorded and analyzed online. There is an emerging development of closed-loop DBS in the treatment of PD and a growing discussion about proposing cortical stimulation rather than DBS for this purpose. Why does it make sense to "close the loop" to treat parkinsonian symptoms? Could closed-loop stimulation applied to the cortex become a valuable therapeutic strategy for PD? Can mathematical modeling contribute to the development of this technique? We review the various evidences in favor of the use of closed-loop cortical stimulation for the treatment of advanced PD, as an emerging technique which might offer substantial clinical benefits for PD patients.
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Affiliation(s)
- Anne Beuter
- Institut Polytechnique de Bordeaux, Talence, France.
| | - Jean-Pascal Lefaucheur
- Université Paris Est Créteil, Faculté de Médecine, EA 4391, Créteil, France; Assistance Publique - Hôpitaux de Paris, Hôpital Henri Mondor, Service de Physiologie - Explorations Fonctionnelles, Créteil, France.
| | - Julien Modolo
- Lawson Health Research Institute, Human Threshold Research Group, London, ON, Canada; Western University, Departments of Medical Biophysics and Medical Imaging, London, ON, Canada
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Swan BD, Grill WM, Turner DA. Investigation of deep brain stimulation mechanisms during implantable pulse generator replacement surgery. Neuromodulation 2013; 17:419-24; discussion 424. [PMID: 24118257 DOI: 10.1111/ner.12123] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 06/11/2013] [Accepted: 08/27/2013] [Indexed: 01/11/2023]
Abstract
BACKGROUND Direct testing of deep brain stimulation (DBS) mechanisms in humans is needed to assess therapy and to understand stimulation effects. OBJECTIVE We developed an innovative paradigm for investigation of DBS on human movement disorders. Temporary connection to the DBS electrode during implantable pulse generator (IPG) replacement permitted analysis of novel patterns of stimulation on motor symptoms, which could enhance efficacy and improve battery life. MATERIALS AND METHODS Patients enrolled in this prospective, Institutional Review Board-approved study underwent IPG replacement using local (monitored) anesthesia. Following device explant, the DBS electrode was connected to an external, isolated electrical stimulator using a sterile adapter cable. Different temporal patterns of stimulation were delivered while quantifying upper-extremity tremor (tri-axial accelerometry) or bradykinesia (finger-tapping). Upon experiment completion, the new IPG was implanted. RESULTS Among 159 IPG replacements from 2005 to 2011, 56 patients agreed to the research study (16 essential tremor [ET], 31 Parkinson's disease [PD], 5 mixed ET/PD tremor, 3 multiple sclerosis, 1 tremor/myoclonus). Surgical procedures were extended by 42 ± 8.2 min in 37 patients completing the study. Motor symptoms varied with stimulation pattern, with some patterns showing improved tremor or bradykinesia control. No postoperative infections or complications were observed in the 159 patients. CONCLUSION IPG replacement occurs when the DBS/brain interface is stable and patients demonstrate symptom reduction with known stimulation parameters. Conducting research at this time point avoids DBS implant issues, including temporary microlesion effects, fluctuating electrode impedances, and technical limitations of contemporary IPGs, providing advantageous conditions to conduct translational DBS research with minimal additional risk to research subjects.
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Affiliation(s)
- Brandon D Swan
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
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Low-Gain, Low-Noise Integrated Neuronal Amplifier for Implantable Artifact-Reduction Recording System. JOURNAL OF LOW POWER ELECTRONICS AND APPLICATIONS 2013. [DOI: 10.3390/jlpea3030279] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Kent AR, Grill WM. Neural origin of evoked potentials during thalamic deep brain stimulation. J Neurophysiol 2013; 110:826-43. [PMID: 23719207 DOI: 10.1152/jn.00074.2013] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Closed-loop deep brain stimulation (DBS) systems could provide automatic adjustment of stimulation parameters and improve outcomes in the treatment of Parkinson's disease and essential tremor. The evoked compound action potential (ECAP), generated by activated neurons near the DBS electrode, may provide a suitable feedback control signal for closed-loop DBS. The objectives of this work were to characterize the ECAP across stimulation parameters and determine the neural elements contributing to the signal. We recorded ECAPs during thalamic DBS in anesthetized cats and conducted computer simulations to calculate the ECAP of a population of thalamic neurons. The experimental and computational ECAPs were similar in shape and had characteristics that were correlated across stimulation parameters (R(2) = 0.80-0.95, P < 0.002). The ECAP signal energy increased with larger DBS amplitudes (P < 0.0001) and pulse widths (P < 0.002), and the signal energy of secondary ECAP phases was larger at 10-Hz than at 100-Hz DBS (P < 0.002). The computational model indicated that these changes resulted from a greater extent of neural activation and an increased synchronization of postsynaptic thalamocortical activity, respectively. Administration of tetrodotoxin, lidocaine, or isoflurane abolished or reduced the magnitude of the experimental and computational ECAPs, glutamate receptor antagonists 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and D(-)-2-amino-5-phosphonopentanoic acid (APV) reduced secondary ECAP phases by decreasing postsynaptic excitation, and the GABAA receptor agonist muscimol increased the latency of the secondary phases by augmenting postsynaptic hyperpolarization. This study demonstrates that the ECAP provides information about the type and extent of neural activation generated during DBS, and the ECAP may serve as a feedback control signal for closed-loop DBS.
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Affiliation(s)
- Alexander R Kent
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708-0281, USA
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