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Torres N, de Montalivet E, Borntrager Q, Benahmed S, Legrain A, Adesso E, Aubert N, Sauter-Starace F, Costecalde T, Martel F, Ratel D, Gaude C, Auboiroux V, Piallat B, Aksenova T, Molet J, Chabardes S. Focal cooling: An alternative treatment for drug-resistant epilepsy in a mesial temporal lobe epilepsy primate model-A preliminary study. Epilepsia 2024. [PMID: 38794998 DOI: 10.1111/epi.18012] [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: 10/25/2023] [Revised: 05/01/2024] [Accepted: 05/01/2024] [Indexed: 05/27/2024]
Abstract
OBJECTIVE Focal cooling is emerging as a relevant therapy for drug-resistant epilepsy (DRE). However, we lack data on its effectiveness in controlling seizures that originate in deep-seated areas like the hippocampus. We present a thermoelectric solution for focal brain cooling that specifically targets these brain structures. METHODS A prototype implantable device was developed, including temperature sensors and a cannula for penicillin injection to create an epileptogenic zone (EZ) near the cooling tip in a non-human primate model of epilepsy. The mesial temporal lobe was targeted with repeated penicillin injections into the hippocampus. Signals were recorded from an sEEG (Stereoelectroencephalography) lead placed 2 mm from the EZ. Once the number of seizures had stabilized, focal cooling was applied, and temperature and electroclinical events were monitored using a customized detection algorithm. Tests were performed on two Macaca fascicularis monkeys at three temperatures. RESULTS Hippocampal seizures were observed 40-120 min post-injection, their duration and frequency stabilized at around 120 min. Compared to the control condition, a reduction in the number of hippocampal seizures was observed with cooling to 21°C (Control: 4.34 seizures, SD 1.704 per 20 min vs Cooling to 21°C: 1.38 seizures, SD 1.004 per 20 min). The effect was more pronounced with cooling to 17°C, resulting in an almost 80% reduction in seizure frequency. Seizure duration and number of interictal discharges were unchanged following focal cooling. After several months of repeated penicillin injections, hippocampal sclerosis was observed, similar to that recorded in humans. In addition, seizures were identified by detecting temperature variations of 0.3°C in the EZ correlated with the start of the seizures. SIGNIFICANCE In epilepsy therapy, the ultimate aim is total seizure control with minimal side effects. Focal cooling of the EZ could offer an alternative to surgery and to existing neuromodulation devices.
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Affiliation(s)
- Napoleon Torres
- CEA, LETI, Clinatec, Universite Grenoble Alpes, Grenoble, France
| | | | | | - Selimen Benahmed
- CEA, LETI, Clinatec, Universite Grenoble Alpes, Grenoble, France
| | - Antoine Legrain
- CEA, LETI, Clinatec, Universite Grenoble Alpes, Grenoble, France
| | - Eleonora Adesso
- CEA, LETI, Clinatec, Universite Grenoble Alpes, Grenoble, France
| | - Nicolas Aubert
- CEA, LETI, Clinatec, Universite Grenoble Alpes, Grenoble, France
| | | | | | - Felix Martel
- CEA, LETI, Clinatec, Universite Grenoble Alpes, Grenoble, France
| | - David Ratel
- CEA, LETI, Clinatec, Universite Grenoble Alpes, Grenoble, France
| | - Christophe Gaude
- CEA, LETI, Clinatec, Universite Grenoble Alpes, Grenoble, France
| | | | - Brigitte Piallat
- Inserm, U1216, Grenoble Institute of Neurosciences, Universite Grenoble Alpes, Grenoble, France
| | - Tetiana Aksenova
- CEA, LETI, Clinatec, Universite Grenoble Alpes, Grenoble, France
| | - Jenny Molet
- CEA, LETI, Clinatec, Universite Grenoble Alpes, Grenoble, France
| | - Stephan Chabardes
- CEA, LETI, Clinatec, Universite Grenoble Alpes, Grenoble, France
- Department of Neurosurgery, Inserm, U1216, Universite Grenoble Alpes, Grenoble, France
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Bidirectional alterations in brain temperature profoundly modulate spatiotemporal neurovascular responses in-vivo. Commun Biol 2023; 6:185. [PMID: 36797344 PMCID: PMC9935519 DOI: 10.1038/s42003-023-04542-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 01/31/2023] [Indexed: 02/18/2023] Open
Abstract
Neurovascular coupling (NVC) is a mechanism that, amongst other known and latent critical functions, ensures activated brain regions are adequately supplied with oxygen and glucose. This biological phenomenon underpins non-invasive perfusion-related neuroimaging techniques and recent reports have implicated NVC impairment in several neurodegenerative disorders. Yet, much remains unknown regarding NVC in health and disease, and only recently has there been burgeoning recognition of a close interplay with brain thermodynamics. Accordingly, we developed a novel multi-modal approach to systematically modulate cortical temperature and interrogate the spatiotemporal dynamics of sensory-evoked NVC. We show that changes in cortical temperature profoundly and intricately modulate NVC, with low temperatures associated with diminished oxygen delivery, and high temperatures inducing a distinct vascular oscillation. These observations provide novel insights into the relationship between NVC and brain thermodynamics, with important implications for brain-temperature related therapies, functional biomarkers of elevated brain temperature, and in-vivo methods to study neurovascular coupling.
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Lange F, Verma V, Harvey-Jones K, Mitra S, Tachtsidis I. Neonatal Brain Temperature Monitoring Based on Broadband Near-Infrared Spectroscopy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1438:167-172. [PMID: 37845456 DOI: 10.1007/978-3-031-42003-0_26] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2023]
Abstract
We present here the initial development of a novel algorithm based on broadband near-infrared spectroscopy (bNIRS) data to estimate the changes in brain temperature (BT) in neonates. We first explored the validity of the methodology on a simple numerical phantom and reported good agreements between the theoretical and retrieved values of BT and hemodynamic parameters changes, which are the parameters usually targeted by bNIRS. However, we noted an underestimation of the absolute values of temperature and haemoglobins' concentration changes when large variations of tissue saturation were induced, probably due to a crosstalk between the species in this specific case. We then tested this methodology on data acquired on 2 piglets during a protocol that induces seizures. We showed that despite a decrease in rectal temperature (RT) over time (-0.1048 °C 1.5 h after seizure induction, 95% CI: -0.1035 to -0.1061 °C), BT was raising (0.3122 °C 1.5 h after seizure induction, 95% CI: 0.3207 to 0.3237 °C). We also noted that the piglet displaying the largest decrease in RT also displays the highest increase in BT, which could be a marker of the severity of the seizure induced brain injury. These initial results are encouraging and show that having access to the changes in BT non-invasively could help to better understand the impact of BT on injury severity and to improve the current cooling methodologies in the neonatal neurocritical care following neonatal encephalopathy.
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Affiliation(s)
- F Lange
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK.
| | - V Verma
- Institute for Women's Health, University College London, London, UK
| | - K Harvey-Jones
- Institute for Women's Health, University College London, London, UK
| | - S Mitra
- Institute for Women's Health, University College London, London, UK
| | - I Tachtsidis
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
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4
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Premcheska S, Lederer M, Kaczmarek AM. The importance, status, and perspectives of hybrid lanthanide-doped upconversion nanothermometers for theranostics. Chem Commun (Camb) 2022; 58:4288-4307. [PMID: 35258046 DOI: 10.1039/d1cc07164e] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Theranostics combines diagnostics and therapy in a single multifunctional system. Multifunctional upconversion luminescent lanthanide-doped nanothermometers for theranostic purposes offer non-invasive and sensitive multimodal performance in the biomedical field over traditional temperature measurement methods. Despite existing challenges, various studies on hybrid upconversion nanothermometers show substantial progress for (bio)imaging, temperature sensing, photodynamic and photothermal therapy, as well as drug delivery applications. The beauty of such an approach is that it unfolds possibilities to combine diagnostics and therapy in a single particle, which can modify the way certain diseases are treated, hence change the entire healthcare scene.
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Affiliation(s)
- Simona Premcheska
- NanoSensing Group, Department of Chemistry, Ghent University, Krijgslaan 281-S3, 9000 Ghent, Belgium.
| | - Mirijam Lederer
- NanoSensing Group, Department of Chemistry, Ghent University, Krijgslaan 281-S3, 9000 Ghent, Belgium.
| | - Anna M Kaczmarek
- NanoSensing Group, Department of Chemistry, Ghent University, Krijgslaan 281-S3, 9000 Ghent, Belgium.
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Wakuya M, Inoue T, Imoto H, Maruta Y, Nomura S, Suzuki M, Yamakawa T. Epileptic seizure–related changes in electrocorticogram, cortical temperature, and cerebral hemodynamics obtained via an implantable multimodal multichannel probe during preoperative monitoring: illustrative case. JOURNAL OF NEUROSURGERY: CASE LESSONS 2022; 3:CASE21694. [PMID: 36130540 PMCID: PMC9379634 DOI: 10.3171/case21694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 01/20/2022] [Indexed: 12/02/2022]
Abstract
BACKGROUND Electrocorticography (EcoG) plays an essential role in the preoperative evaluation of epilepsy, despite its high invasiveness. Brain temperature and cerebral hemodynamics also reflect brain activity. This study examined whether a multimodal multichannel probe that simultaneously records EcoG, cortical temperature, and cerebral hemodynamics can contribute to improving the assessment of epileptic seizures. After preoperative monitoring was performed in a patient with epilepsy, three generalized seizures and two focal seizures were observed. OBSERVATIONS A short-term power increase in the alternating current spectrogram, high-amplitude slow waves in direct current potential, an increase in cortical temperature, an increase in oxyhemoglobin (HbO2) concentration and total hemoglobin (HbT) concentration, and a decrease in deoxyhemoglobin (HHb) concentration, followed by a decrease in HbO2 and HbT concentrations and an increase in HHb concentration, were observed in generalized seizures. However, no changes in these pathophysiological signals were observed in focal seizures. LESSONS Seizure-related changes regarding generalized seizures were consistent with the results of previous studies. The results of generalized and focal seizures indicate that epileptic brain activity propagated from the epileptic focus in the right frontal lobe to the measurement area near the motor cortex in generalized seizures but not in focal seizures.
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Affiliation(s)
- Manami Wakuya
- Department of Computer Science and Electrical Engineering, Graduate School of Science and Technology, Kumamoto University, Kumamoto, Kumamoto, Japan; and
| | - Takao Inoue
- Departments of Advanced ThermoNeuroBiology and
| | - Hirochika Imoto
- Neurosurgery, Yamaguchi University School of Medicine, Ube, Yamaguchi, Japan
| | - Yuich Maruta
- Neurosurgery, Yamaguchi University School of Medicine, Ube, Yamaguchi, Japan
| | - Sadahiro Nomura
- Neurosurgery, Yamaguchi University School of Medicine, Ube, Yamaguchi, Japan
| | | | - Toshitaka Yamakawa
- Department of Computer Science and Electrical Engineering, Graduate School of Science and Technology, Kumamoto University, Kumamoto, Kumamoto, Japan; and
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Verma V, Lange F, Bainbridge A, Harvey-Jones K, Robertson NJ, Tachtsidis I, Mitra S. Brain temperature monitoring in newborn infants: Current methodologies and prospects. Front Pediatr 2022; 10:1008539. [PMID: 36268041 PMCID: PMC9577084 DOI: 10.3389/fped.2022.1008539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 09/15/2022] [Indexed: 02/02/2023] Open
Abstract
Brain tissue temperature is a dynamic balance between heat generation from metabolism, passive loss of energy to the environment, and thermoregulatory processes such as perfusion. Perinatal brain injuries, particularly neonatal encephalopathy, and seizures, have a significant impact on the metabolic and haemodynamic state of the developing brain, and thereby likely induce changes in brain temperature. In healthy newborn brains, brain temperature is higher than the core temperature. Magnetic resonance spectroscopy (MRS) has been used as a viable, non-invasive tool to measure temperature in the newborn brain with a reported accuracy of up to 0.2 degrees Celcius and a precision of 0.3 degrees Celcius. This measurement is based on the separation of chemical shifts between the temperature-sensitive water peaks and temperature-insensitive singlet metabolite peaks. MRS thermometry requires transport to an MRI scanner and a lengthy single-point measurement. Optical monitoring, using near infrared spectroscopy (NIRS), offers an alternative which overcomes this limitation in its ability to monitor newborn brain tissue temperature continuously at the cot side in real-time. Near infrared spectroscopy uses linear temperature-dependent changes in water absorption spectra in the near infrared range to estimate the tissue temperature. This review focuses on the currently available methodologies and their viability for accurate measurement, the potential benefits of monitoring newborn brain temperature in the neonatal intensive care unit, and the important challenges that still need to be addressed.
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Affiliation(s)
- Vinita Verma
- Institute for Women's Health, University College London, London, United Kingdom
| | - Frederic Lange
- Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Alan Bainbridge
- Medical Physics and Engineering, University College London Hospital, London, United Kingdom
| | - Kelly Harvey-Jones
- Institute for Women's Health, University College London, London, United Kingdom
| | - Nicola J Robertson
- Institute for Women's Health, University College London, London, United Kingdom
| | - Ilias Tachtsidis
- Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Subhabrata Mitra
- Institute for Women's Health, University College London, London, United Kingdom
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Hannan S, Aristovich K, Faulkner M, Avery J, Walker MC, Holder DS. Imaging slow brain activity during neocortical and hippocampal epileptiform events with electrical impedance tomography. Physiol Meas 2021; 42:014001. [PMID: 33361567 DOI: 10.1088/1361-6579/abd67a] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVE Electrical impedance tomography (EIT) is an imaging technique that produces tomographic images of internal impedance changes within an object using surface electrodes. It can be used to image the slow increase in cerebral tissue impedance that occurs over seconds during epileptic seizures, which is attributed to cell swelling due to disturbances in ion homeostasis following hypersynchronous neuronal firing and its associated metabolic demands. In this study, we characterised and imaged this slow impedance response during neocortical and hippocampal epileptiform events in the rat brain and evaluated its relationship to the underlying neural activity. APPROACH Neocortical or hippocampal seizures, comprising repeatable series of high-amplitude ictal spikes, were induced by electrically stimulating the sensorimotor cortex or perforant path of rats anaesthetised with fentanyl-isoflurane. Transfer impedances were measured during ≥30 consecutive seizures, by applying a sinusoidal current through independent electrode pairs on an epicortical array, and combined to generate an EIT image of slow activity. MAIN RESULTS The slow impedance responses were consistently time-matched to the end of seizures and EIT images of this activity were reconstructed reproducibly in all animals (p < 0.03125, N = 5). These displayed foci of activity that were spatially confined to the facial somatosensory cortex and dentate gyrus for neocortical and hippocampal seizures, respectively, and encompassed a larger volume as the seizure progressed. Centre-of-mass analysis of reconstructions revealed that this activity corresponded to the true location of the epileptogenic zone, as determined by EEG recordings and fast neural EIT measurements which were obtained simultaneously. SIGNIFICANCE These findings suggest that the slow impedance response presents a reliable marker of hypersynchronous neuronal activity during epileptic seizures and can thus be utilised for investigating the mechanisms of epileptogenesis in vivo and for aiding localisation of the epileptogenic zone during presurgical evaluation of patients with refractory epilepsies.
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Affiliation(s)
- Sana Hannan
- Department of Medical Physics and Biomedical Engineering, University College London, United Kingdom
| | - Kirill Aristovich
- Department of Medical Physics and Biomedical Engineering, University College London, United Kingdom
| | - Mayo Faulkner
- Wolfson Institute for Biomedical Research, University College London, United Kingdom
| | - James Avery
- Department of Surgery and Cancer, Imperial College London, United Kingdom
| | - Matthew C Walker
- UCL Queen Square Institute of Neurology, University College London, United Kingdom
| | - David S Holder
- Department of Medical Physics and Biomedical Engineering, University College London, United Kingdom
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Sultan S, Acharya Y, Barrett N, Hynes N. A pilot protocol and review of triple neuroprotection with targeted hypothermia, controlled induced hypertension, and barbiturate infusion during emergency carotid endarterectomy for acute stroke after failed tPA or beyond 24-hour window of opportunity. ANNALS OF TRANSLATIONAL MEDICINE 2020; 8:1275. [PMID: 33178807 PMCID: PMC7607101 DOI: 10.21037/atm-2020-cass-14] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
An alternative to tissue plasminogen activator (tPA) failure has been a daunting challenge in ischemic stroke management. As tPA is time-dependent, delays can occur in definitive treatment while passively waiting to observe a clinical response to intravenous thrombolysis. Until today, uncertainty exists in the management strategy of wake-up stroke patients or those presenting beyond the therapeutic tPA window. Clinical dilemmas in these situations can prolong the transitional period of inertia, resulting in an adverse neurological outcome. We propose and review an innovative approach called triple neuro-protection (TNP), which encompasses three technical domains-targeted hypothermia, systemic induced hypertension, and barbiturates infusion, to protect the brain during carotid endarterectomy after failed tPA and/or beyond the 24-hour therapeutic mechanical thrombectomy window. This proposal assimilates discussion on the clinical evidence of the individual domains of TNP with our own clinical experience with TNP. Our first TNP was successfully employed in a 55-year-old man in 2015 while performing emergency carotid endarterectomy after he was referred to us 72 hours post tPA failure. The patient had a successful clinical outcome despite being in therapeutic inertia with 90–99% ipsilateral carotid stenosis and contralateral occlusion on presentation. In the last five years, we have safely used TNP in 25 selected cases with favourable clinical outcomes.
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Affiliation(s)
- Sherif Sultan
- Western Vascular Institute, Department of Vascular and Endovascular Surgery, University Hospital Galway, National University of Ireland, Galway, Ireland.,Department of Vascular & Endovascular Surgery, Galway Clinic, Royal College of Surgeons of Ireland/National University of Ireland Affiliated Teaching Hospitals, Doughiska, Galway, Ireland
| | - Yogesh Acharya
- Western Vascular Institute, Department of Vascular and Endovascular Surgery, University Hospital Galway, National University of Ireland, Galway, Ireland
| | - Nora Barrett
- Western Vascular Institute, Department of Vascular and Endovascular Surgery, University Hospital Galway, National University of Ireland, Galway, Ireland
| | - Niamh Hynes
- Department of Vascular & Endovascular Surgery, Galway Clinic, Royal College of Surgeons of Ireland/National University of Ireland Affiliated Teaching Hospitals, Doughiska, Galway, Ireland
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Zhou J, Del Rosal B, Jaque D, Uchiyama S, Jin D. Advances and challenges for fluorescence nanothermometry. Nat Methods 2020; 17:967-980. [PMID: 32989319 DOI: 10.1038/s41592-020-0957-y] [Citation(s) in RCA: 160] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 08/17/2020] [Indexed: 12/12/2022]
Abstract
Fluorescent nanothermometers can probe changes in local temperature in living cells and in vivo and reveal fundamental insights into biological properties. This field has attracted global efforts in developing both temperature-responsive materials and detection procedures to achieve sub-degree temperature resolution in biosystems. Recent generations of nanothermometers show superior performance to earlier ones and also offer multifunctionality, enabling state-of-the-art functional imaging with improved spatial, temporal and temperature resolutions for monitoring the metabolism of intracellular organelles and internal organs. Although progress in this field has been rapid, it has not been without controversy, as recent studies have shown possible biased sensing during fluorescence-based detection. Here, we introduce the design principles and advances in fluorescence nanothermometry, highlight application achievements, discuss scenarios that may lead to biased sensing, analyze the challenges ahead in terms of both fundamental issues and practical implementations, and point to new directions for improving this interdisciplinary field.
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Affiliation(s)
- Jiajia Zhou
- Institute for Biomedical Materials & Devices (IBMD), Faculty of Science, University of Technology Sydney, Sydney, Australia.
| | - Blanca Del Rosal
- ARC Centre of Excellence for Nanoscale Biophotonics, RMIT University, Melbourne, Australia
| | - Daniel Jaque
- Nanobiology Group, Instituto Ramón y Cajal de Investigación Sanitaria, IRYCIS, Madrid, Spain. .,Fluorescence Imaging Group, Departamento de Física de Materiales-Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain.
| | - Seiichi Uchiyama
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Dayong Jin
- Institute for Biomedical Materials & Devices (IBMD), Faculty of Science, University of Technology Sydney, Sydney, Australia.,Department of Biomedical Engineering, Southern University of Science and Technology, Guangdong, China
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Harris SS, Boorman LW, Das D, Kennerley AJ, Sharp PS, Martin C, Redgrave P, Schwartz TH, Berwick J. Physiological and Pathological Brain Activation in the Anesthetized Rat Produces Hemodynamic-Dependent Cortical Temperature Increases That Can Confound the BOLD fMRI Signal. Front Neurosci 2018; 12:550. [PMID: 30154690 PMCID: PMC6102348 DOI: 10.3389/fnins.2018.00550] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 07/20/2018] [Indexed: 11/24/2022] Open
Abstract
Anesthetized rodent models are ubiquitous in pre-clinical neuroimaging studies. However, because the associated cerebral morphology and experimental methodology results in a profound negative brain-core temperature differential, cerebral temperature changes during functional activation are likely to be principally driven by local inflow of fresh, core-temperature, blood. This presents a confound to the interpretation of blood-oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) data acquired from such models, since this signal is also critically temperature-dependent. Nevertheless, previous investigation on the subject is surprisingly sparse. Here, we address this issue through use of a novel multi-modal methodology in the urethane anesthetized rat. We reveal that sensory stimulation, hypercapnia and recurrent acute seizures induce significant increases in cortical temperature that are preferentially correlated to changes in total hemoglobin concentration (Hbt), relative to cerebral blood flow and oxidative metabolism. Furthermore, using a phantom-based evaluation of the effect of such temperature changes on the BOLD fMRI signal, we demonstrate a robust inverse relationship between both variables. These findings suggest that temperature increases, due to functional hyperemia, should be accounted for to ensure accurate interpretation of BOLD fMRI signals in pre-clinical neuroimaging studies.
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Affiliation(s)
- Samuel S Harris
- Neurovascular and Neuroimaging Research Group, Department of Psychology, University of Sheffield, Sheffield, United Kingdom
| | - Luke W Boorman
- Neurovascular and Neuroimaging Research Group, Department of Psychology, University of Sheffield, Sheffield, United Kingdom
| | - Devashish Das
- Neurovascular and Neuroimaging Research Group, Department of Psychology, University of Sheffield, Sheffield, United Kingdom
| | - Aneurin J Kennerley
- Neurovascular and Neuroimaging Research Group, Department of Psychology, University of Sheffield, Sheffield, United Kingdom
| | - Paul S Sharp
- Neurovascular and Neuroimaging Research Group, Department of Psychology, University of Sheffield, Sheffield, United Kingdom
| | - Chris Martin
- Neurovascular and Neuroimaging Research Group, Department of Psychology, University of Sheffield, Sheffield, United Kingdom
| | - Peter Redgrave
- Neurovascular and Neuroimaging Research Group, Department of Psychology, University of Sheffield, Sheffield, United Kingdom
| | - Theodore H Schwartz
- Department of Neurological Surgery, Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, United States
| | - Jason Berwick
- Neurovascular and Neuroimaging Research Group, Department of Psychology, University of Sheffield, Sheffield, United Kingdom
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Tokiwa T, Inoue T, Fujii M, Ishizuka S, Aou S, Kida H, Maruta Y, Yamakawa T, Nomura S, Suzuki M, Yamakawa T. Penicillin-induced epileptiform activity elevates focal brain temperature in anesthetized rats. Neurosci Res 2013; 76:257-60. [DOI: 10.1016/j.neures.2013.05.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Revised: 04/09/2013] [Accepted: 05/01/2013] [Indexed: 11/24/2022]
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12
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Kim I, Fok HHR, Li Y, Jackson TN, Gluckman BJ. Polymer substrate temperature sensor array for brain interfaces. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2012; 2011:3286-9. [PMID: 22255041 DOI: 10.1109/iembs.2011.6090892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We developed an implantable thin film transistor temperature sensor (TFT-TS) to measure temperature changes in the brain. These changes are assumed to be associated with cerebral metabolism and neuronal activity. Two prototype TFT-TSs were designed and tested in-vitro: one with 8 diode-connected single-ended sensors, and the other with 4 pairs of differential-ended sensors in an array configuration. The sensor elements are 25 ~ 100 pm in width and 5 μm in length. The TFT-TSs were fabricated based on high-speed ZnO TFT process technology on flexible polyimide substrates (50 μm thick, 500 μm width, 20 mm length). In order to interface external signal electronics, they were directly bonded to a prototype printed circuit board using anisotropic conductive films The prototypes were characterized between 23 ~ 38 °C using a commercial temperature sensor and custom-designed temperature controlled oven. The maximum sensitivity of 40 mV/°C was obtained from the TFT-TS.
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Affiliation(s)
- Insoo Kim
- Department of Engineering Sciences and Mechanics, The Pennsylvania State University, University Park, PA16802, USA. insoo@ psu.edu
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Toward rational design of electrical stimulation strategies for epilepsy control. Epilepsy Behav 2010; 17:6-22. [PMID: 19926525 PMCID: PMC2818293 DOI: 10.1016/j.yebeh.2009.10.017] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Accepted: 10/12/2009] [Indexed: 11/21/2022]
Abstract
Electrical stimulation is emerging as a viable alternative for patients with epilepsy whose seizures are not alleviated by drugs or surgery. Its attractions are temporal and spatial specificity of action, flexibility of waveform parameters and timing, and the perception that its effects are reversible unlike resective surgery. However, despite significant advances in our understanding of mechanisms of neural electrical stimulation, clinical electrotherapy for seizures relies heavily on empirical tuning of parameters and protocols. We highlight concurrent treatment goals with potentially conflicting design constraints that must be resolved when formulating rational strategies for epilepsy electrotherapy, namely, seizure reduction versus cognitive impairment, stimulation efficacy versus tissue safety, and mechanistic insight versus clinical pragmatism. First, treatment markers, objectives, and metrics relevant to electrical stimulation for epilepsy are discussed from a clinical perspective. Then the experimental perspective is presented, with the biophysical mechanisms and modalities of open-loop electrical stimulation, and the potential benefits of closed-loop control for epilepsy.
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14
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Bagić A, Theodore WH, Boudreau EA, Bonwetsch R, Greenfield J, Elkins W, Sato S. Towards a non-invasive interictal application of hypothermia for treating seizures: a feasibility and pilot study. Acta Neurol Scand 2008; 118:240-4. [PMID: 18355392 PMCID: PMC5256640 DOI: 10.1111/j.1600-0404.2008.01008.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To evaluate the feasibility and safety of head-neck cooling in conscious normal volunteers (10) and patients with medically refractory epilepsy (5) without causing shivering. PATIENTS AND METHODS We used a non-invasive head-neck cooling system (CoolSystems Inc., Lincoln, CA, USA). The tympanic temperature (TT) and intestinal temperature (IT) were measured as two measurements of 'core temperature' (CT), and multi-site external temperatures, several physiologic variables and EEG were monitored. Seizure counts over 4-week precooling, treatment and follow-up phases were compared. RESULTS All 15 participants completed all the cooling sessions without significant complaints. At the end of 60 min of cooling, scalp temperature fell on average by 12.2 degrees C (P < 0.001), TT by 1.67 degrees C (P < 0.001), and IT by 0.12 degrees C (P = NS). Average weekly seizure frequency decreased from 2.7 to 1.7 events per patient per week (MANOVA: P < 0.05). CONCLUSIONS Non-invasive head-neck cooling is safe and well-tolerated. Initial pilot data in patients suggest that additional therapeutic studies are warranted.
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Affiliation(s)
- A Bagić
- EEG Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, MD, USA.
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Kauppinen RA, Vidyasagar R, Childs C, Balanos GM, Hiltunen Y. Assessment of human brain temperature by 1H MRS during visual stimulation and hypercapnia. NMR IN BIOMEDICINE 2008; 21:388-95. [PMID: 17894424 DOI: 10.1002/nbm.1204] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Brain temperature is determined by the interplay between the cerebral metabolic rate of oxygen (CMRO2) and cerebral blood flow (CBF). In this study, single-voxel 1H nuclear MRS, with an accuracy of +/-0.2 degrees C for temperature determination, was used at 3 T to measure human brain temperature during visual stimulation (which increases both CBF and CMRO2) and hypercapnia (which increases CBF only). Visual stimulation had no detectable effect on brain temperature in the parenchyma showing blood oxygenation level dependent activation. Hypercapnia, leading to an increase in the end tidal CO2 by 8 +/- 2 mm Hg above the baseline, caused a short-lasting decrease in brain temperature of 0.30 +/- 0.33 degrees C. These results indicate that increased CBF may be a key factor, bringing about a small decrease in brain temperature during brain activation. However, the increase in CBF is not sufficient to lower brain temperature in the presence of a concomitant increase in endogenous heat production.
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Affiliation(s)
- Risto A Kauppinen
- School of Sport and Exercise Sciences, University of Birmingham, Birmingham, UK.
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