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Fisher RS. Deep brain stimulation of thalamus for epilepsy. Neurobiol Dis 2023; 179:106045. [PMID: 36809846 DOI: 10.1016/j.nbd.2023.106045] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 02/10/2023] [Accepted: 02/13/2023] [Indexed: 02/22/2023] Open
Abstract
Neuromodulation (neurostimulation) is a relatively new and rapidly growing treatment for refractory epilepsy. Three varieties are approved in the US: vagus nerve stimulation (VNS), deep brain stimulation (DBS) and responsive neurostimulation (RNS). This article reviews thalamic DBS for epilepsy. Among many thalamic sub-nuclei, DBS for epilepsy has been targeted to the anterior nucleus (ANT), centromedian nucleus (CM), dorsomedial nucleus (DM) and pulvinar (PULV). Only ANT is FDA-approved, based upon a controlled clinical trial. Bilateral stimulation of ANT reduced seizures by 40.5% at three months in the controlled phase (p = .038) and 75% by 5 years in the uncontrolled phase. Side effects related to paresthesias, acute hemorrhage, infection, occasional increased seizures, and usually transient effects on mood and memory. Efficacy was best documented for focal onset seizures in temporal or frontal lobe. CM stimulation may be useful for generalized or multifocal seizures and PULV for posterior limbic seizures. Mechanisms of DBS for epilepsy are largely unknown, but animal work points to changes in receptors, channels, neurotransmitters, synapses, network connectivity and neurogenesis. Personalization of therapies, in terms of connectivity of the seizure onset zone to the thalamic sub- nucleus and individual characteristics of the seizures, might lead to improved efficacy. Many questions remain about DBS, including the best candidates for different types of neuromodulation, the best targets, the best stimulation parameters, how to minimize side effects and how to deliver current noninvasively. Despite the questions, neuromodulation provides useful new opportunities to treat people with refractory seizures not responding to medicines and not amenable to resective surgery.
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Affiliation(s)
- Robert S Fisher
- Department of Neurology and Neurological Sciences and Neurosurgery by Courtesy, Department of Neurology and Neurological Sciences, Stanford University School of Medicine, 213 Quarry Road, Room 4865, Palo Alto, CA 94304, USA.
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Deep brain stimulation of the anterior nuclei of the thalamus in focal epilepsy. Clin Neurophysiol 2022; 144:1-7. [PMID: 36193600 DOI: 10.1016/j.clinph.2022.09.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 08/24/2022] [Accepted: 09/03/2022] [Indexed: 11/23/2022]
Abstract
OBJECTIVE To review the therapeutic effects of deep brain stimulation of the anterior nuclei of the thalamus (ANT-DBS) and the predictors of its effectiveness, safety, and adverse effects. METHODS A comprehensive search of the medical literature (PubMed) was conducted to identify relevant articles investigating ANT-DBS therapy for epilepsy. Out of 332 references, 77 focused on focal epilepsies were reviewed. RESULTS The DBS effect is probably due to decreased synchronization of epileptic activity in the cortex. The potential mechanisms from cellular to brain network levels are presented. The ANT might participate actively in the network elaborating focal seizures. The effects of ANT-DBS differed in various studies; ANT-DBS was linked with a 41% seizure frequency reduction at 1 year, 69% at 5 years, and 75% at 7 years. The most frequently reported adverse effects, depression and memory impairment, were considered non-serious in the long-term follow-up view. ANT-DBS also has been used in a few cases to treat status epilepticus. CONCLUSIONS We reviewed the clinical literature and identified several factors that may predict seizure outcome following DBS therapy. More large-scale trials are required since there is a need to explore stimulation settings, apply patient-tailored therapy, and identify the presurgical predictors of patient response. SIGNIFICANCE A critical review of the published literature on ANT-DBS in focal epilepsy is presented. ANT-DBS mechanisms are not fully understood; possible explanations are provided. Biomarkers of ANT-DBS effectiveness may lead to patient-tailored therapy.
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Structural connectivity of the ANT region based on human ex-vivo and HCP data. Relevance for DBS in ANT for epilepsy. Neuroimage 2022; 262:119551. [DOI: 10.1016/j.neuroimage.2022.119551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 05/19/2022] [Accepted: 08/06/2022] [Indexed: 11/16/2022] Open
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Ilyas A, Snyder KM, Thomas TM, Tandon N. Optimal targeting of the anterior nucleus of the thalamus for epilepsy: a meta-analysis. J Neurosurg 2022; 137:1582-1590. [PMID: 35395631 DOI: 10.3171/2022.2.jns212550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 02/10/2022] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Deep brain stimulation (DBS) of the anterior nucleus of the thalamus (ANT) has been shown to be an effective therapeutic option for select patients with limbic epilepsy. However, the optimal target and electrode position for this indication remains undefined. Therefore, the objective of this systematic review and meta-analysis is to quantify the association between active contact location and outcomes across all published series of ANT DBS. METHODS A literature search using PRISMA criteria was performed to identify all studies that reported both active contact locations and outcomes of DBS in the ANT for epilepsy. Patient, disease, treatment, and outcome data were extracted for statistical analysis. Contact locations of responders (defined as ≥ 50% seizure reduction at last follow-up) versus nonresponders to DBS were analyzed on a common reference frame. Centers of mass, weighted by clinical response, were computed for the contacts in each cohort. RESULTS From 555 studies that were screened for review, a total of 7 studies comprising 162 patients met criteria for inclusion and were analyzed. Across the cohort, the mean duration of epilepsy was 23 years and the mean pre-DBS seizure frequency was 56 seizures per month. DBS electrodes were implanted using direct targeting in 5 studies (n = 62, 38% of patient cohort) via a transventricular electrode trajectory in 4 studies (n = 123, 76%). At the mean follow-up duration of 2.3 years, 56% of patients were considered responders. Active contacts of responders were 1.6 mm anterior (95% CI 1.5-1.6 mm, p < 0.001) compared to those of nonresponders and were adjacent to the mammillothalamic tract (MTT). CONCLUSIONS Accurate targeting of the ANT is crucial to successful DBS outcomes in epilepsy. These findings suggest that stimulation within the ANT subregions adjacent to the MTT improves outcomes.
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Affiliation(s)
- Adeel Ilyas
- 1Department of Neurological Surgery, University of Alabama at Birmingham, Alabama.,2Vivian L. Smith Department of Neurosurgery, McGovern Medical School at UT Health Houston, Texas.,3Texas Institute for Restorative Neurotechnologies, The University of Texas Health Science Center at Houston, Texas; and
| | - Kathryn M Snyder
- 2Vivian L. Smith Department of Neurosurgery, McGovern Medical School at UT Health Houston, Texas.,3Texas Institute for Restorative Neurotechnologies, The University of Texas Health Science Center at Houston, Texas; and
| | - Tessy M Thomas
- 2Vivian L. Smith Department of Neurosurgery, McGovern Medical School at UT Health Houston, Texas.,3Texas Institute for Restorative Neurotechnologies, The University of Texas Health Science Center at Houston, Texas; and
| | - Nitin Tandon
- 2Vivian L. Smith Department of Neurosurgery, McGovern Medical School at UT Health Houston, Texas.,3Texas Institute for Restorative Neurotechnologies, The University of Texas Health Science Center at Houston, Texas; and.,4Memorial Hermann Hospital, Texas Medical Center, Houston, Texas
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Deutschová B, Klimeš P, Jordan Z, Jurák P, Erőss L, Lamoš M, Halámek J, Daniel P, Rektor I, Fabo D. Thalamic oscillatory activity may predict response to deep brain stimulation of the anterior nuclei of the thalamus. Epilepsia 2021; 62:e70-e75. [PMID: 33755992 DOI: 10.1111/epi.16883] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 03/03/2021] [Accepted: 03/03/2021] [Indexed: 11/30/2022]
Abstract
We hypothesized that local/regional properties of stimulated structure/circuitry contribute to the effect of deep brain stimulation (DBS). We analyzed intracerebral electroencephalographic (EEG) recordings from externalized DBS electrodes targeted bilaterally in the anterior nuclei of the thalamus (ANT) in 12 patients (six responders, six nonresponders) with more than 1 year of follow-up care. In the bipolar local field potentials of the EEG, spectral power (PW) and power spectral entropy (PSE) were calculated in the passbands 1-4, 4-8, 8-12, 12-20, 20-45, 65-80, 80-200 and 200-500 Hz. The most significant differences between responders and nonresponders were observed in the BRIDGE area (bipolar recordings with one contact within the ANT and the second contact in adjacent tissue). In responders, PW was significantly decreased in the frequency bands of 65-80, 80-200, and 200-500 Hz (p < .05); PSE was significantly increased in all frequency bands (p < .05) except for 200-500 Hz (p = .06). The local EEG characteristics of ANT recorded after implantation may play a significant role in DBS response prediction.
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Affiliation(s)
- Barbora Deutschová
- Brno Epilepsy Center, Department of Neurology, St. Anne's University Hospital and the Faculty of Medicine, Masaryk University, Brno, Czech Republic.,Multimodal and Functional Neuroimaging Research Group, Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Petr Klimeš
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Zsofia Jordan
- Epilepsy Center, Department of Neurology, National Institute of Clinical Neurosciences, Budapest, Hungary
| | - Pavel Jurák
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Lorand Erőss
- Epilepsy Center, Department of Neurology, National Institute of Clinical Neurosciences, Budapest, Hungary
| | - Martin Lamoš
- Multimodal and Functional Neuroimaging Research Group, Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Josef Halámek
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Pavel Daniel
- Brno Epilepsy Center, Department of Neurology, St. Anne's University Hospital and the Faculty of Medicine, Masaryk University, Brno, Czech Republic.,Multimodal and Functional Neuroimaging Research Group, Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Ivan Rektor
- Brno Epilepsy Center, Department of Neurology, St. Anne's University Hospital and the Faculty of Medicine, Masaryk University, Brno, Czech Republic.,Multimodal and Functional Neuroimaging Research Group, Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Daniel Fabo
- Epilepsy Center, Department of Neurology, National Institute of Clinical Neurosciences, Budapest, Hungary
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