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Zhao Y, Wei Y, Wang Y, So RHY, Chan CCH, Cheung RTF, Wilkins A. Identification of the human cerebral cortical hemodynamic response to passive whole-body movements using near-infrared spectroscopy. Front Neurol 2023; 14:1280015. [PMID: 38152645 PMCID: PMC10751349 DOI: 10.3389/fneur.2023.1280015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2023] [Accepted: 11/08/2023] [Indexed: 12/29/2023] Open
Abstract
The human vestibular system is crucial for motion perception, balance control, and various higher cognitive functions. Exploring how the cerebral cortex responds to vestibular signals is not only valuable for a better understanding of how the vestibular system participates in cognitive and motor functions but also clinically significant in diagnosing central vestibular disorders. Near-infrared spectroscopy (NIRS) provides a portable and non-invasive brain imaging technology to monitor cortical hemodynamics under physical motion. Objective This study aimed to investigate the cerebral cortical response to naturalistic vestibular stimulation induced by real physical motion and to validate the vestibular cerebral cortex previously identified using alternative vestibular stimulation. Approach Functional NIRS data were collected from 12 right-handed subjects when they were sitting in a motion platform that generated three types of whole-body passive translational motion (circular, lateral, and fore-and-aft). Main results The study found that different cortical regions were activated by the three types of motion. The cortical response was more widespread under circular motion in two dimensions compared to lateral and fore-and-aft motions in one dimensions. Overall, the identified regions were consistent with the cortical areas found to be activated in previous brain imaging studies. Significance The results provide new evidence of brain selectivity to different types of motion and validate previous findings on the vestibular cerebral cortex.
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Affiliation(s)
- Yue Zhao
- HKUST-Shenzhen Research Institute, Shenzhen, China
- Department of Industrial Engineering and Decision Analytics, Hong Kong University of Science and Technology, Kowloon, Hong Kong SAR, China
| | - Yue Wei
- HKUST-Shenzhen Research Institute, Shenzhen, China
- Department of Basic Psychology, School of Psychology, Shenzhen University, Shenzhen, China
| | - Yixuan Wang
- HKUST-Shenzhen Research Institute, Shenzhen, China
- Bio-Engineering Graduate Program, School of Engineering, Hong Kong University of Science and Technology, Kowloon, Hong Kong SAR, China
| | - Richard H. Y. So
- HKUST-Shenzhen Research Institute, Shenzhen, China
- Department of Industrial Engineering and Decision Analytics, Hong Kong University of Science and Technology, Kowloon, Hong Kong SAR, China
| | - Chetwyn C. H. Chan
- Department of Psychology, The Education University of Hong Kong, Tai Po, Hong Kong SAR, China
| | - Raymond T. F. Cheung
- Department of Medicine, School of Clinical Medicine, University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Arnold Wilkins
- Centre for Brain Studies, University of Essex, Colchester, United Kingdom
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Gallagher A, Wallois F, Obrig H. Functional near-infrared spectroscopy in pediatric clinical research: Different pathophysiologies and promising clinical applications. NEUROPHOTONICS 2023; 10:023517. [PMID: 36873247 PMCID: PMC9982436 DOI: 10.1117/1.nph.10.2.023517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 02/07/2023] [Indexed: 06/18/2023]
Abstract
Over its 30 years of existence, functional near-infrared spectroscopy (fNIRS) has matured into a highly versatile tool to study brain function in infants and young children. Its advantages, amongst others, include its ease of application and portability, the option to combine it with electrophysiology, and its relatively good tolerance to movement. As shown by the impressive body of fNIRS literature in the field of cognitive developmental neuroscience, the method's strengths become even more relevant for (very) young individuals who suffer from neurological, behavioral, and/or cognitive impairment. Although a number of studies have been conducted with a clinical perspective, fNIRS cannot yet be considered as a truly clinical tool. The first step has been taken in this direction by studies exploring options in populations with well-defined clinical profiles. To foster further progress, here, we review several of these clinical approaches to identify the challenges and perspectives of fNIRS in the field of developmental disorders. We first outline the contributions of fNIRS in selected areas of pediatric clinical research: epilepsy, communicative and language disorders, and attention-deficit/hyperactivity disorder. We provide a scoping review as a framework to allow the highlighting of specific and general challenges of using fNIRS in pediatric research. We also discuss potential solutions and perspectives on the broader use of fNIRS in the clinical setting. This may be of use to future research, targeting clinical applications of fNIRS in children and adolescents.
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Affiliation(s)
- Anne Gallagher
- CHU Sainte-Justine University Hospital, Université de Montréal, LIONLab, Cerebrum, Department of Psychology, Montréal, Quebec, Canada
| | - Fabrice Wallois
- Université de Picardie Jules Verne, Inserm U1105, GRAMFC, Amiens, France
| | - Hellmuth Obrig
- University Hospital and Faculty of Medicine Leipzig/Max Planck Institute for Human Cognitive and Brain Sciences, Department of Neurology, Clinic for Cognitive Neurology, Leipzig, Germany
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Nourhashemi M, Mahmoudzadeh M, Heberle C, Wallois F. Preictal neuronal and vascular activity precedes the onset of childhood absence seizure: direct current potential shifts and their correlation with hemodynamic activity. NEUROPHOTONICS 2023; 10:025005. [PMID: 37114185 PMCID: PMC10128878 DOI: 10.1117/1.nph.10.2.025005] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 03/20/2023] [Indexed: 06/19/2023]
Abstract
SIGNIFICANCE AIMS The neurovascular mechanisms underlying the initiation of absence seizures and their dynamics are still not well understood. The objective of this study was to better noninvasively characterize the dynamics of the neuronal and vascular network at the transition from the interictal state to the ictal state of absence seizures and back to the interictal state using a combined electroencephalography (EEG), functional near-infrared spectroscopy (fNIRS), and diffuse correlation spectroscopy (DCS) approach. The second objective was to develop hypotheses about the neuronal and vascular mechanisms that propel the networks to the 3-Hz spikes and wave discharges (SWDs) observed during absence seizures. APPROACHES We evaluated the simultaneous changes in electrical (neuronal) and optical dynamics [hemodynamic, with changes in (Hb) and cerebral blood flow] of 8 pediatric patients experiencing 25 typical childhood absence seizures during the transition from the interictal state to the absence seizure by simultaneously performing EEG, fNIRS, and DCS. RESULTS Starting from ∼ 20 s before the onset of the SWD, we observed a transient direct current potential shift that correlated with alterations in functional fNIRS and DCS measurements of the cerebral hemodynamics detecting the preictal changes. DISCUSSION Our noninvasive multimodal approach highlights the dynamic interactions between the neuronal and vascular compartments that take place in the neuronal network near the time of the onset of absence seizures in a very specific cerebral hemodynamic environment. These noninvasive approaches contribute to a better understanding of the electrical hemodynamic environment prior to seizure onset. Whether this may ultimately be relevant for diagnostic and therapeutic approaches requires further evaluation.
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Affiliation(s)
- Mina Nourhashemi
- Université de Picardie Jules Verne, Inserm U1105, GRAMFC, CURS, Amiens, France
| | - Mahdi Mahmoudzadeh
- Université de Picardie Jules Verne, Inserm U1105, GRAMFC, CURS, Amiens, France
- Amiens University Hospital, Pediatric Neurophysiology Unit, Amiens, France
| | - Claire Heberle
- Amiens University Hospital, Pediatric Neurophysiology Unit, Amiens, France
| | - Fabrice Wallois
- Université de Picardie Jules Verne, Inserm U1105, GRAMFC, CURS, Amiens, France
- Amiens University Hospital, Pediatric Neurophysiology Unit, Amiens, France
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Optical Monitoring in Neonatal Seizures. Cells 2022; 11:cells11162602. [PMID: 36010678 PMCID: PMC9407001 DOI: 10.3390/cells11162602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 07/30/2022] [Accepted: 08/16/2022] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Neonatal seizures remain a significant cause of morbidity and mortality worldwide. The past decade has resulted in substantial progress in seizure detection and understanding the impact seizures have on the developing brain. Optical monitoring such as cerebral near-infrared spectroscopy (NIRS) and broadband NIRS can provide non-invasive continuous real-time monitoring of the changes in brain metabolism and haemodynamics. AIM To perform a systematic review of optical biomarkers to identify changes in cerebral haemodynamics and metabolism during the pre-ictal, ictal, and post-ictal phases of neonatal seizures. METHOD A systematic search was performed in eight databases. The search combined the three broad categories: (neonates) AND (NIRS) AND (seizures) using the stepwise approach following PRISMA guidance. RESULTS Fifteen papers described the haemodynamic and/or metabolic changes observed with NIRS during neonatal seizures. No randomised controlled trials were identified during the search. Studies reported various changes occurring in the pre-ictal, ictal, and post-ictal phases of seizures. CONCLUSION Clear changes in cerebral haemodynamics and metabolism were noted during the pre-ictal, ictal, and post-ictal phases of seizures in neonates. Further studies are necessary to determine whether NIRS-based methods can be used at the cot-side to provide clear pathophysiological data in real-time during neonatal seizures.
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Dynamics of cortical oxygenation during immediate adaptation to extrauterine life. Sci Rep 2021; 11:22041. [PMID: 34764396 PMCID: PMC8586152 DOI: 10.1038/s41598-021-01674-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 11/02/2021] [Indexed: 11/09/2022] Open
Abstract
The neonatal transition involves physiological modifications as a consequence of the complexity of the perinatal period. Various strategies can be used to attain the same level of postnatal cerebral oxygenation, depending on the status of the infant at birth. We evaluated such strategies by recording 20 full-term newborns by near-infrared spectroscopy during the first 10 min of life. The acid–base status at birth revealed two clustered profiles of cerebral oxygenation dynamics. Lower pH and base excess and higher lactate levels were associated with more rapid attainment of the 95% maximal tissue oxygenation index value. These results suggest that metabolic mechanisms drive initial cerebral oxygenation dynamics during this critical period. These results confirm the capacity of newborns to develop multiple strategies to protect the brain.
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Arnal-Real C, Mahmoudzadeh M, Manoochehri M, Nourhashemi M, Wallois F. What Triggers the Interictal Epileptic Spike? A Multimodal Multiscale Analysis of the Dynamic of Synaptic and Non-synaptic Neuronal and Vascular Compartments Using Electrical and Optical Measurements. Front Neurol 2021; 12:596926. [PMID: 33643187 PMCID: PMC7907164 DOI: 10.3389/fneur.2021.596926] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 01/21/2021] [Indexed: 11/20/2022] Open
Abstract
Interictal spikes (IISs) may result from a disturbance of the intimate functional balance between various neuronal (synaptic and non-synaptic), vascular, and metabolic compartments. To better characterize the complex interactions within these compartments at different scales we developed a simultaneous multimodal-multiscale approach and measure their activity around the time of the IIS. We performed such measurements in an epileptic rat model (n = 43). We thus evaluated (1) synaptic dynamics by combining electrocorticography and multiunit activity recording in the time and time-frequency domain, (2) non-synaptic dynamics by recording modifications in light scattering induced by changes in the membrane configuration related to cell activity using the fast optical signal, and (3) vascular dynamics using functional near-infrared spectroscopy and, independently but simultaneously to the electrocorticography, the changes in cerebral blood flow using diffuse correlation spectroscopy. The first observed alterations in the measured signals occurred in the hemodynamic compartments a few seconds before the peak of the IIS. These hemodynamic changes were followed by changes in coherence and then synchronization between the deep and superficial neural networks in the 1 s preceding the IIS peaks. Finally, changes in light scattering before the epileptic spikes suggest a change in membrane configuration before the IIS. Our multimodal, multiscale approach highlights the complexity of (1) interactions between the various neuronal, vascular, and extracellular compartments, (2) neural interactions between various layers, (3) the synaptic mechanisms (coherence and synchronization), and (4) non-synaptic mechanisms that take place in the neuronal network around the time of the IISs in a very specific cerebral hemodynamic environment.
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Affiliation(s)
- Cristian Arnal-Real
- Inserm U1105, GRAMFC, CURS, Université de Picardie Jules Verne, Amiens, France
| | - Mahdi Mahmoudzadeh
- Inserm U1105, GRAMFC, CURS, Université de Picardie Jules Verne, Amiens, France
| | - Mana Manoochehri
- Inserm U1105, GRAMFC, CURS, Université de Picardie Jules Verne, Amiens, France
| | - Mina Nourhashemi
- Inserm U1105, GRAMFC, CURS, Université de Picardie Jules Verne, Amiens, France
| | - Fabrice Wallois
- Inserm U1105, GRAMFC, CURS, Université de Picardie Jules Verne, Amiens, France
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Jabran Y, Mahmoudzadeh M, Martinez N, Heberlé C, Wallois F, Bourel-Ponchel E. Temporal and Spatial Dynamics of Different Interictal Epileptic Discharges: A Time-Frequency EEG Approach in Pediatric Focal Refractory Epilepsy. Front Neurol 2020; 11:941. [PMID: 33013634 PMCID: PMC7506028 DOI: 10.3389/fneur.2020.00941] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 07/20/2020] [Indexed: 11/13/2022] Open
Abstract
Objective: Characterization of the spatial and temporal dynamics of interictal epileptic discharges (IED) using time-frequency analysis (TFA) and electrical-source localization (ESL). Methods: TFA was performed on IED (spikes, spike waves, and polyspike waves) recorded by high-density-EEG (HD-EEG) in 19 refractory focal epileptic children. Temporal modulations related to IEDs were analyzed in a time window around the IED peaks [−1,000 to 1,000 ms]. Spatial modulations were analyzed by ESL in the time-frequency and time domains. Results: IED were associated with complex power spectral modulations. We observed increases in power spectrum (IPS) patterns specific to IED type. For spikes, the TFA pattern consisted of an IPS (−100 to +100 ms, 4–50 Hz). For spike waves, the IPS was followed by a second IPS (+100 to +400 ms, 4–10 Hz), corresponding to the slow wave. IPS patterns were preceded (−400 to −100 ms, 4–40 Hz), and followed (+100 to +400 ms) by a decrease in the power spectrum (DPS) (n = 8). For 14 out of 19 patients, at least one ESL method was concordant with the epileptogenic area. For the remaining five patients, all of them had temporal epilepsies. ESL in the time-frequency domain (DPS/IPS) provided concordant (n = 6) or complementary (n = 4) information to the ESL in the time domain concerning the epileptogenic zone. ESL in time-frequency domain (DPS/IPS) was the only method to provide concordant information concerning the epileptogenic zone in three patients. Significance: TFA demonstrates complex time-frequency modulations of the neuronal networks around IED, suggesting that the pathological mechanisms are initiated well before onset of the classical hyper-synchronization of the IED. Combining time and time-frequency analysis of the ESL provides complementary information to define the epileptogenic zone in refractory focal epilepsy.
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Affiliation(s)
- Younes Jabran
- INSERM UMR 1105, Research Group on Multimodal Analysis of Brain Function, University of Picardie Jules Verne, Amiens, France
| | - Mahdi Mahmoudzadeh
- INSERM UMR 1105, Research Group on Multimodal Analysis of Brain Function, University of Picardie Jules Verne, Amiens, France
| | - Nicolas Martinez
- INSERM UMR 1105, Research Group on Multimodal Analysis of Brain Function, University of Picardie Jules Verne, Amiens, France
| | - Claire Heberlé
- INSERM UMR 1105, Pediatric Neurophysiology Unit, Amiens University Hospital, Amiens, France
| | - Fabrice Wallois
- INSERM UMR 1105, Research Group on Multimodal Analysis of Brain Function, University of Picardie Jules Verne, Amiens, France.,INSERM UMR 1105, Pediatric Neurophysiology Unit, Amiens University Hospital, Amiens, France
| | - Emilie Bourel-Ponchel
- INSERM UMR 1105, Research Group on Multimodal Analysis of Brain Function, University of Picardie Jules Verne, Amiens, France.,INSERM UMR 1105, Pediatric Neurophysiology Unit, Amiens University Hospital, Amiens, France
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8
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Chen WL, Wagner J, Heugel N, Sugar J, Lee YW, Conant L, Malloy M, Heffernan J, Quirk B, Zinos A, Beardsley SA, Prost R, Whelan HT. Functional Near-Infrared Spectroscopy and Its Clinical Application in the Field of Neuroscience: Advances and Future Directions. Front Neurosci 2020; 14:724. [PMID: 32742257 PMCID: PMC7364176 DOI: 10.3389/fnins.2020.00724] [Citation(s) in RCA: 134] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 06/17/2020] [Indexed: 01/20/2023] Open
Abstract
Similar to functional magnetic resonance imaging (fMRI), functional near-infrared spectroscopy (fNIRS) detects the changes of hemoglobin species inside the brain, but via differences in optical absorption. Within the near-infrared spectrum, light can penetrate biological tissues and be absorbed by chromophores, such as oxyhemoglobin and deoxyhemoglobin. What makes fNIRS more advantageous is its portability and potential for long-term monitoring. This paper reviews the basic mechanisms of fNIRS and its current clinical applications, the limitations toward more widespread clinical usage of fNIRS, and current efforts to improve the temporal and spatial resolution of fNIRS toward robust clinical usage within subjects. Oligochannel fNIRS is adequate for estimating global cerebral function and it has become an important tool in the critical care setting for evaluating cerebral oxygenation and autoregulation in patients with stroke and traumatic brain injury. When it comes to a more sophisticated utilization, spatial and temporal resolution becomes critical. Multichannel NIRS has improved the spatial resolution of fNIRS for brain mapping in certain task modalities, such as language mapping. However, averaging and group analysis are currently required, limiting its clinical use for monitoring and real-time event detection in individual subjects. Advances in signal processing have moved fNIRS toward individual clinical use for detecting certain types of seizures, assessing autonomic function and cortical spreading depression. However, its lack of accuracy and precision has been the major obstacle toward more sophisticated clinical use of fNIRS. The use of high-density whole head optode arrays, precise sensor locations relative to the head, anatomical co-registration, short-distance channels, and multi-dimensional signal processing can be combined to improve the sensitivity of fNIRS and increase its use as a wide-spread clinical tool for the robust assessment of brain function.
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Affiliation(s)
- Wei-Liang Chen
- Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Neurology, Children's Hospital of Wisconsin, Milwaukee, WI, United States.,School of Medicine, University of Washington, Seattle, WA, United States
| | - Julie Wagner
- Department of Biochemical Engineering, Marquette University and Medical College of Wisconsin, Milwaukee, WI, United States
| | - Nicholas Heugel
- Department of Biochemical Engineering, Marquette University and Medical College of Wisconsin, Milwaukee, WI, United States
| | - Jeffrey Sugar
- Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Yu-Wen Lee
- Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Neurology, Children's Hospital of Wisconsin, Milwaukee, WI, United States
| | - Lisa Conant
- Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Marsha Malloy
- Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Neurology, Children's Hospital of Wisconsin, Milwaukee, WI, United States
| | - Joseph Heffernan
- Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Brendan Quirk
- Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Anthony Zinos
- Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Biochemical Engineering, Marquette University and Medical College of Wisconsin, Milwaukee, WI, United States
| | - Scott A Beardsley
- Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Biochemical Engineering, Marquette University and Medical College of Wisconsin, Milwaukee, WI, United States
| | - Robert Prost
- Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Harry T Whelan
- Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Neurology, Children's Hospital of Wisconsin, Milwaukee, WI, United States
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Ishihara Y, Sakai S, Yamakawa T, Inoue T, Suzuki M, Sakata T, Ueda Y. Intraoperative Cerebral Measurements Using Implantable Cortical Multimodality Probe. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2019:4372-4375. [PMID: 31946836 DOI: 10.1109/embc.2019.8856488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In this study, a multimodality probe that simultaneously measures electroencephalograms, cerebral hemodynamics, and brain surface temperature was developed. This probe has six channels, and each channel has a platinum electrode for cortical electroencephalogram measurements, light emitting diodes, and photodiodes for hemodynamic measurements using near-infrared spectroscopy (NIRS), and a thermistor for measuring the cerebral surface temperature (BrT). A probe with a width of 8.0 mm and maximum total thickness of 0.7 mm was fabricated using flexible printed circuit board technology for chronic intracranial placement. Brain activity using the prototype probe at the resected site was measured and its function performance was evaluated. Characteristic epileptogenic abnormal electroencephalograms accompanied by polarity reversal between channels occurred at 16 min and 38 s. It was concluded that the brain cells consumed oxygen during the occurrence of abnormal electroencephalograms. At this time, no noticeable change in HbT values could be confirmed.
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Spectral entropy indicates electrophysiological and hemodynamic changes in drug-resistant epilepsy - A multimodal MREG study. NEUROIMAGE-CLINICAL 2019; 22:101763. [PMID: 30927607 PMCID: PMC6444290 DOI: 10.1016/j.nicl.2019.101763] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 02/01/2019] [Accepted: 03/10/2019] [Indexed: 12/20/2022]
Abstract
Objective Epilepsy causes measurable irregularity over a range of brain signal frequencies, as well as autonomic nervous system functions that modulate heart and respiratory rate variability. Imaging dynamic neuronal signals utilizing simultaneously acquired ultra-fast 10 Hz magnetic resonance encephalography (MREG), direct current electroencephalography (DC-EEG), and near-infrared spectroscopy (NIRS) can provide a more comprehensive picture of human brain function. Spectral entropy (SE) is a nonlinear method to summarize signal power irregularity over measured frequencies. SE was used as a joint measure to study whether spectral signal irregularity over a range of brain signal frequencies based on synchronous multimodal brain signals could provide new insights in the neural underpinnings of epileptiform activity. Methods Ten patients with focal drug-resistant epilepsy (DRE) and ten healthy controls (HC) were scanned with 10 Hz MREG sequence in combination with EEG, NIRS (measuring oxygenated, deoxygenated, and total hemoglobin: HbO, Hb, and HbT, respectively), and cardiorespiratory signals. After pre-processing, voxelwise SEMREG was estimated from MREG data. Different neurophysiological and physiological subfrequency band signals were further estimated from MREG, DC-EEG, and NIRS: fullband (0–5 Hz, FB), near FB (0.08–5 Hz, NFB), brain pulsations in very-low (0.009–0.08 Hz, VLFP), respiratory (0.12–0.4 Hz, RFP), and cardiac (0.7–1.6 Hz, CFP) frequency bands. Global dynamic fluctuations in MREG and NIRS were analyzed in windows of 2 min with 50% overlap. Results Right thalamus, cingulate gyrus, inferior frontal gyrus, and frontal pole showed significantly higher SEMREG in DRE patients compared to HC. In DRE patients, SE of cortical Hb was significantly reduced in FB (p = .045), NFB (p = .017), and CFP (p = .038), while both HbO and HbT were significantly reduced in RFP (p = .038, p = .045, respectively). Dynamic SE of HbT was reduced in DRE patients in RFP during minutes 2 to 6. Fitting to the frontal MREG and NIRS results, DRE patients showed a significant increase in SEEEG in FB in fronto-central and parieto-occipital regions, in VLFP in parieto-central region, accompanied with a significant decrease in RFP in frontal pole and parietal and occipital (O2, Oz) regions. Conclusion This is the first study to show altered spectral entropy from synchronous MREG, EEG, and NIRS in DRE patients. Higher SEMREG in DRE patients in anterior cingulate gyrus together with SEEEG and SENIRS results in 0.12–0.4 Hz can be linked to altered parasympathetic function and respiratory pulsations in the brain. Higher SEMREG in thalamus in DRE patients is connected to disturbances in anatomical and functional connections in epilepsy. Findings suggest that spectral irregularity of both electrophysiological and hemodynamic signals are altered in specific way depending on the physiological frequency range. Simultaneous imaging methods indicate spectral irregularity in neurovascular and electrophysiological brain pulsations in DRE. Altered spectral entropy in EEG, NIRS and BOLD indicate dysfunctional brain pulsations in respiratory frequency in epilepsy. Spectral irregularity (0-5 Hz) of BOLD in right thalamus supports previous structural and functional findings in epilepsy.
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11
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Yamakawa T, Inoue T, Niwayama M, Oka F, Imoto H, Nomura S, Suzuki M. Implantable Multi-Modality Probe for Subdural Simultaneous Measurement of Electrophysiology, Hemodynamics, and Temperature Distribution. IEEE Trans Biomed Eng 2019; 66:3204-3211. [PMID: 30835208 DOI: 10.1109/tbme.2019.2902189] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OBJECTIVE The purpose of this paper is to demonstrate how the integration of the multi-channel measurement capabilities of near-infrared spectroscopy (NIRS), electrocorticography (ECoG), and negative temperature coefficient thermistor sensors into a single device compact enough for subdural implantation can provide beneficial information on various aspects of brain cortical activity and prove a powerful medical modality for pre-, intra-, and post-operative diagnoses in neurosurgery. METHODS The development of a flexible multi-modal multi-channel probe for the simultaneous measurement of the NIRS, ECoG, and surficial temperature obtained from the cerebral cortex was carried out. Photoelectric bare chips for NIRS channels, miniature temperature-coefficient thermistors for measuring localized temperature variation, and 3-mm-diameter platinum plates for ECoG recording were assembled on a polyimide-based flexible printed circuit to create six channels for each modality. A conformal coating of Parylene-C was applied on all the channels except the ECoG to make the probe surface biocompatible. RESULTS As a first-in-human study, the simultaneous measurement capability of the multi-modality probe, with sufficient signal-to-noise ratio and accuracy, to observe pathological neural activities in subjects during surgery and post-operative monitoring, with no complications two weeks since the implantation, was confirmed. CONCLUSION The feasibility of using a single device to assess the dynamic pathological activity from three different aspects was determined for human patients. SIGNIFICANCE The simultaneous and accurate multi-channel recording of electrical, hemodynamic, and thermographic cortical activities in a single device small enough for subdural implantation is likely to have major implications in neurosurgery and neuroscience.
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Dai X, Zhang T, Yang H, Tang J, Carney PR, Jiang H. Fast noninvasive functional diffuse optical tomography for brain imaging. JOURNAL OF BIOPHOTONICS 2018; 11:e201600267. [PMID: 28696034 DOI: 10.1002/jbio.201600267] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 04/23/2017] [Accepted: 06/29/2017] [Indexed: 05/23/2023]
Abstract
Advances in epilepsy studies have shown that specific changes in hemodynamics precede and accompany seizure onset and propagation. However, it has been challenging to noninvasively detect these changes in real time and in humans, due to the lack of fast functional neuroimaging tools. In this study, we present a functional diffuse optical tomography (DOT) method with the guidance of an anatomical human head atlas for 3-dimensionally mapping the brain in real time. Central to our DOT system is a human head interface coupled with a technique that can incorporate topological information of the brain surface into the DOT image reconstruction. The performance of the DOT system was tested by imaging motor tasks-involved brain activities on N = 6 subjects (3 epilepsy patients and 3 healthy controls). We observed diffuse areas of activations from the reconstructed [HbT] images of patients, relative to more focal activations for healthy subjects. Moreover, significant pretask hemodynamic activations were also seen in the motor cortex of patients, which indicated abnormal activities persistent in the brain of an epilepsy patient. This work demonstrates that fast functional DOT is a valuable tool for noninvasive 3-dimensional mapping of brain hemodynamics.
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Affiliation(s)
- Xianjin Dai
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida
| | - Tao Zhang
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida
| | - Hao Yang
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida
| | - Jianbo Tang
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida
| | - Paul R Carney
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Huabei Jiang
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida
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13
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Pushing the Boundaries of Neuroimaging with Optoacoustics. Neuron 2017; 96:966-988. [DOI: 10.1016/j.neuron.2017.10.022] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 09/22/2017] [Accepted: 10/16/2017] [Indexed: 02/07/2023]
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14
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Manoochehri M, Mahmoudzadeh M, Bourel-Ponchel E, Wallois F. Cortical light scattering during interictal epileptic spikes in frontal lobe epilepsy in children: A fast optical signal and electroencephalographic study. Epilepsia 2017; 58:2064-2072. [PMID: 29034451 DOI: 10.1111/epi.13926] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/25/2017] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Interictal epileptic spikes (IES) represent a signature of the transient synchronous and excessive discharge of a large ensemble of cortical heterogeneous neurons. Epilepsy cannot be reduced to a hypersynchronous activation of neurons whose functioning is impaired, resulting on electroencephalogram (EEG) in epileptic seizures or IES. The complex pathophysiological mechanisms require a global approach to the interactions between neural synaptic and nonsynaptic, vascular, and metabolic systems. In the present study, we focused on the interaction between synaptic and nonsynaptic mechanisms through the simultaneous noninvasive multimodal multiscale recording of high-density EEG (HD-EEG; synaptic) and fast optical signal (FOS; nonsynaptic), which evaluate rapid changes in light scattering related to changes in membrane configuration occurring during neuronal activation of IES. METHODS To evaluate changes in light scattering occurring around IES, three children with frontal IES were simultaneously recorded with HD-EEG and FOS. To evaluate change in synchronization, time-frequency representation analysis of the HD-EEG was performed simultaneously around the IES. To independently evaluate our multimodal method, a control experiment with somatosensory stimuli was designed and applied to five healthy volunteers. RESULTS Alternating increase-decrease-increase in optical signals occurred 200 ms before to 180 ms after the IES peak. These changes started before any changes in EEG signal. In addition, time-frequency domain EEG analysis revealed alternating decrease-increase-decrease in the EEG spectral power concomitantly with changes in the optical signal during IES. These results suggest a relationship between (de)synchronization and neuronal volume changes in frontal lobe epilepsy during IES. SIGNIFICANCE These changes in the neuronal environment around IES in frontal lobe epilepsy observed in children, as they have been in rats, raise new questions about the synaptic/nonsynaptic mechanisms that propel the neurons to hypersynchronization, as occurs during IES. We further demonstrate that this noninvasive multiscale multimodal approach is suitable for studying the pathophysiology of the IES in patients.
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Affiliation(s)
- Mana Manoochehri
- National Institute of Health and Medical Research Unit 1105, Research Group on Multimodal Analysis of Brain Function, University of Picardie Jules Verne, University Hospital Center South, Amiens, France
| | - Mahdi Mahmoudzadeh
- National Institute of Health and Medical Research Unit 1105, Research Group on Multimodal Analysis of Brain Function, University of Picardie Jules Verne, University Hospital Center South, Amiens, France
| | - Emilie Bourel-Ponchel
- National Institute of Health and Medical Research Unit 1105, Research Group on Multimodal Analysis of Brain Function, University of Picardie Jules Verne, University Hospital Center South, Amiens, France
| | - Fabrice Wallois
- National Institute of Health and Medical Research Unit 1105, Research Group on Multimodal Analysis of Brain Function, University of Picardie Jules Verne, University Hospital Center South, Amiens, France
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15
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Aarabi A, Osharina V, Wallois F. Effect of confounding variables on hemodynamic response function estimation using averaging and deconvolution analysis: An event-related NIRS study. Neuroimage 2017; 155:25-49. [PMID: 28450140 DOI: 10.1016/j.neuroimage.2017.04.048] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 04/12/2017] [Accepted: 04/20/2017] [Indexed: 11/17/2022] Open
Abstract
Slow and rapid event-related designs are used in fMRI and functional near-infrared spectroscopy (fNIRS) experiments to temporally characterize the brain hemodynamic response to discrete events. Conventional averaging (CA) and the deconvolution method (DM) are the two techniques commonly used to estimate the Hemodynamic Response Function (HRF) profile in event-related designs. In this study, we conducted a series of simulations using synthetic and real NIRS data to examine the effect of the main confounding factors, including event sequence timing parameters, different types of noise, signal-to-noise ratio (SNR), temporal autocorrelation and temporal filtering on the performance of these techniques in slow and rapid event-related designs. We also compared systematic errors in the estimates of the fitted HRF amplitude, latency and duration for both techniques. We further compared the performance of deconvolution methods based on Finite Impulse Response (FIR) basis functions and gamma basis sets. Our results demonstrate that DM was much less sensitive to confounding factors than CA. Event timing was the main parameter largely affecting the accuracy of CA. In slow event-related designs, deconvolution methods provided similar results to those obtained by CA. In rapid event-related designs, our results showed that DM outperformed CA for all SNR, especially above -5 dB regardless of the event sequence timing and the dynamics of background NIRS activity. Our results also show that periodic low-frequency systemic hemodynamic fluctuations as well as phase-locked noise can markedly obscure hemodynamic evoked responses. Temporal autocorrelation also affected the performance of both techniques by inducing distortions in the time profile of the estimated hemodynamic response with inflated t-statistics, especially at low SNRs. We also found that high-pass temporal filtering could substantially affect the performance of both techniques by removing the low-frequency components of HRF profiles. Our results emphasize the importance of characterization of event timing, background noise and SNR when estimating HRF profiles using CA and DM in event-related designs.
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Affiliation(s)
- Ardalan Aarabi
- Faculty of Medicine, University of Picardie Jules Verne, Amiens 80036, France; GRAMFC-Inserm U1105, University Research Center (CURS), University Hospital, Amiens, 80054 France.
| | - Victoria Osharina
- GRAMFC-Inserm U1105, University Research Center (CURS), University Hospital, Amiens, 80054 France
| | - Fabrice Wallois
- GRAMFC-Inserm U1105, University Research Center (CURS), University Hospital, Amiens, 80054 France; EFSN Pediatric (Pediatric Nervous System Functional Investigation Unit), CHU AMIENS - SITE SUD, Amiens, France
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16
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Bourel-Ponchel E, Mahmoudzadeh M, Berquin P, Wallois F. Local and Distant Dysregulation of Synchronization Around Interictal Spikes in BECTS. Front Neurosci 2017; 11:59. [PMID: 28239337 PMCID: PMC5301021 DOI: 10.3389/fnins.2017.00059] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 01/26/2017] [Indexed: 11/21/2022] Open
Abstract
Objective: High Density electroencephalography (HD EEG) is the reference non-invasive technique to investigate the dynamics of neuronal networks in Benign Epilepsy with Centro-Temporal Spikes (BECTS). Analysis of local dynamic changes surrounding Interictal Epileptic Spikes (IES) might improve our knowledge of the mechanisms that propel neurons to the hypersynchronization of IES in BECTS. Transient distant changes in the dynamics of neurons populations may also interact with neuronal networks involved in various functions that are impaired in BECTS patients. Methods: HD EEG (64 electrodes) of eight well-characterized BECTS patients (8 males; mean age: 7.2 years, range: 5–9 years) were analyzed. Unilateral IES were selected in 6 patients. They were bilateral and independent in 2 other patients. This resulted in a total of 10 groups of IES. Time-frequency analysis was performed on HD EEG epochs around the peak of the IES (±1000 ms), including phase-locked and non-phase-locked activities to the IES. The time frequency analyses were calculated for the frequencies between 4 and 200 Hz. Results: Time-frequency analysis revealed two patterns of dysregulation of the synchronization between neuronal networks preceding and following hypersynchronization of interictal spikes (±400 ms) in the epileptogenic zone. Dysregulation consists of either desynchronization (n = 6) or oscillating synchronization (n = 4) (4–50 Hz) surrounding the IES. The 2 patients with bilateral IES exhibited only local desynchronization whatever the IES considered. Distant desynchronization in low frequencies within the same window occurs simultaneously in bilateral frontal, temporal and occipital areas (n = 7). Significance: Using time-frequency analysis of HD EEG data in a well-defined population of BECTS, we demonstrated repeated complex changes in the dynamics of neuronal networks not only during, but also, before and after the IES. In the epileptogenic zone, our results found more complex reorganization of the local network than initially thought. In line with previous results obtained at a microscopic or macroscopic level, these changes suggested the variability strategies of neuronal assemblies to raise IES. Distant changes from the epileptogenic zone in desynchronization observed in the same time window suggested interactions between larger embedded networks and opened new avenues about their possible role in the underlying mechanism leading to cognitive deficits.
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Affiliation(s)
- Emilie Bourel-Ponchel
- Institut National de la Santé et de la Recherche Médicale U 1105, GRAMFC, CURS, CHU Amiens Picardie - Site SudSalouël, Amiens, France; Fonctional Exploration of the Pediatric Nervous System, CHU Amiens Picardie - Site SudSalouël, Amiens, France
| | - Mahdi Mahmoudzadeh
- Institut National de la Santé et de la Recherche Médicale U 1105, GRAMFC, CURS, CHU Amiens Picardie - Site SudSalouël, Amiens, France; Fonctional Exploration of the Pediatric Nervous System, CHU Amiens Picardie - Site SudSalouël, Amiens, France
| | - Patrick Berquin
- Institut National de la Santé et de la Recherche Médicale U 1105, GRAMFC, CURS, CHU Amiens Picardie - Site SudSalouël, Amiens, France; Neuropediatry Unit, CHU Amiens Picardie - Site SudSalouël, Amiens, France
| | - Fabrice Wallois
- Institut National de la Santé et de la Recherche Médicale U 1105, GRAMFC, CURS, CHU Amiens Picardie - Site SudSalouël, Amiens, France; Fonctional Exploration of the Pediatric Nervous System, CHU Amiens Picardie - Site SudSalouël, Amiens, France
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17
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Hemodynamic Changes Associated with Interictal Spikes Induced by Acute Models of Focal Epilepsy in Rats: A Simultaneous Electrocorticography and Near-Infrared Spectroscopy Study. Brain Topogr 2017; 30:390-407. [DOI: 10.1007/s10548-016-0541-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 12/15/2016] [Indexed: 02/07/2023]
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18
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Ledo A, Lourenço CF, Laranjinha J, Brett CMA, Gerhardt GA, Barbosa RM. Ceramic-Based Multisite Platinum Microelectrode Arrays: Morphological Characteristics and Electrochemical Performance for Extracellular Oxygen Measurements in Brain Tissue. Anal Chem 2017; 89:1674-1683. [DOI: 10.1021/acs.analchem.6b03772] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Ana Ledo
- Center
for Neuroscience and Cell Biology, University of Coimbra, 3004-504, Coimbra, Portugal
| | - Cátia F. Lourenço
- Center
for Neuroscience and Cell Biology, University of Coimbra, 3004-504, Coimbra, Portugal
| | - João Laranjinha
- Center
for Neuroscience and Cell Biology, University of Coimbra, 3004-504, Coimbra, Portugal
- Faculty
of Pharmacy, University of Coimbra, Health Sciences Campus, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal
| | - Christopher M. A. Brett
- Department
of Chemistry, Faculty of Sciences and Technology, University of Coimbra, 3004-535, Coimbra, Portugal
| | - Greg A. Gerhardt
- Center
for Microelectrode Technology (CenMeT), Department of Neuroscience, University of Kentucky Medical Center, Lexington, Kentucky 40536, United States
| | - Rui M. Barbosa
- Center
for Neuroscience and Cell Biology, University of Coimbra, 3004-504, Coimbra, Portugal
- Faculty
of Pharmacy, University of Coimbra, Health Sciences Campus, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal
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Manoochehri M, Mahmoudzadeh M, Osharina V, Wallois F. Shedding light on interictal epileptic spikes: An in vivo study using fast optical signal and electrocorticography. Epilepsia 2017; 58:608-616. [PMID: 28117493 DOI: 10.1111/epi.13689] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/27/2016] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Interictal epileptic spikes (IESs), apart from being a key marker of epileptic neuronal networks, constitute a nice model of the widespread endogenous phenomenon of neuronal hypersynchronization. Many questions concerning the mechanisms that drive neurons to hypersynchronize remain unresolved, but synaptic as well as nonsynaptic events are likely to be involved. In this study, changes in optical properties of neural tissues were observed in rats with penicillin-induced IES using fast optical signal (FOS) concomitantly with electrocorticography (ECoG). METHODS In this study, near-infrared optical imaging was used with ECoG to investigate variations in the optical properties of cortical tissue directly associated with neuronal activity in 15 rats. FOS changes correspond to variations of scattered light from neuronal tissue when neurons are activated. To independently evaluate our method, a control experiment on somatosensory was designed and applied to seven different rats. Time-frequency analysis was also used to track variations of (de)synchronization concomitantly with changes in optical signals during IES. RESULTS FOS responses revealed that changes in optical signals occurred 320 msec before to 370 msec after the IES peak. These changes started before any changes in ECoG signal. In addition, time-frequency domain electrocorticography revealed an alternating decrease-increase-decrease in the ECoG spectral power (pointing to desynchronization-synchronization-desynchronization), which occurred concomitantly with an increase-decrease-increase in relative optical signal during the IES. These results suggest a relationship between (de)synchronization and optical changes. SIGNIFICANCE These changes in the neuronal environment around IESs raise new questions about the mechanisms that induce changes in optical properties of neural tissues before the IES, which may provide suitable conditions for neuronal synchronization during IESs. FOS-ECoG constitutes a multimodal approach and opens new avenues to study the mechanisms of neuronal synchronization in the pathologic brain, which has clinical implications, at least in epilepsy.
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Affiliation(s)
- Mana Manoochehri
- INSERM U 1105, GRAMFC, University of Picardie Jules Verne, Amiens, France
| | - Mahdi Mahmoudzadeh
- INSERM U 1105, GRAMFC, University of Picardie Jules Verne, Amiens, France
| | - Victoria Osharina
- INSERM U 1105, GRAMFC, University of Picardie Jules Verne, Amiens, France
| | - Fabrice Wallois
- INSERM U 1105, GRAMFC, University of Picardie Jules Verne, Amiens, France
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20
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Pellegrino G, Machado A, von Ellenrieder N, Watanabe S, Hall JA, Lina JM, Kobayashi E, Grova C. Hemodynamic Response to Interictal Epileptiform Discharges Addressed by Personalized EEG-fNIRS Recordings. Front Neurosci 2016; 10:102. [PMID: 27047325 PMCID: PMC4801878 DOI: 10.3389/fnins.2016.00102] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 02/29/2016] [Indexed: 11/13/2022] Open
Abstract
Objective: We aimed at studying the hemodynamic response (HR) to Interictal Epileptic Discharges (IEDs) using patient-specific and prolonged simultaneous ElectroEncephaloGraphy (EEG) and functional Near InfraRed Spectroscopy (fNIRS) recordings. Methods: The epileptic generator was localized using Magnetoencephalography source imaging. fNIRS montage was tailored for each patient, using an algorithm to optimize the sensitivity to the epileptic generator. Optodes were glued using collodion to achieve prolonged acquisition with high quality signal. fNIRS data analysis was handled with no a priori constraint on HR time course, averaging fNIRS signals to similar IEDs. Cluster-permutation analysis was performed on 3D reconstructed fNIRS data to identify significant spatio-temporal HR clusters. Standard (GLM with fixed HRF) and cluster-permutation EEG-fMRI analyses were performed for comparison purposes. Results: fNIRS detected HR to IEDs for 8/9 patients. It mainly consisted oxy-hemoglobin increases (seven patients), followed by oxy-hemoglobin decreases (six patients). HR was lateralized in six patients and lasted from 8.5 to 30 s. Standard EEG-fMRI analysis detected an HR in 4/9 patients (4/9 without enough IEDs, 1/9 unreliable result). The cluster-permutation EEG-fMRI analysis restricted to the region investigated by fNIRS showed additional strong and non-canonical BOLD responses starting earlier than the IEDs and lasting up to 30 s. Conclusions: (i) EEG-fNIRS is suitable to detect the HR to IEDs and can outperform EEG-fMRI because of prolonged recordings and greater chance to detect IEDs; (ii) cluster-permutation analysis unveils additional HR features underestimated when imposing a canonical HR function (iii) the HR is often bilateral and lasts up to 30 s.
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Affiliation(s)
- Giovanni Pellegrino
- Multimodal Functional Imaging Laboratory, Biomedical Engineering Department, Montreal Neurological Institute, McGill University Montreal, QC, Canada
| | - Alexis Machado
- Multimodal Functional Imaging Laboratory, Biomedical Engineering Department, Montreal Neurological Institute, McGill University Montreal, QC, Canada
| | - Nicolas von Ellenrieder
- Multimodal Functional Imaging Laboratory, Biomedical Engineering Department, Montreal Neurological Institute, McGill University Montreal, QC, Canada
| | - Satsuki Watanabe
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital Montreal, QC, Canada
| | - Jeffery A Hall
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital Montreal, QC, Canada
| | - Jean-Marc Lina
- Departement de Génie Electrique, Ecole de Technologie SupérieureMontreal, QC, Canada; Center of Advanced Research in Sleep Medicine, Hospital Du Sacre-CœurMontreal, QC, Canada; Centre de Recherches Mathematiques, University of MontréalMontreal, QC, Canada
| | - Eliane Kobayashi
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital Montreal, QC, Canada
| | - Christophe Grova
- Multimodal Functional Imaging Laboratory, Biomedical Engineering Department, Montreal Neurological Institute, McGill UniversityMontreal, QC, Canada; Department of Neurology and Neurosurgery, Montreal Neurological Institute and HospitalMontreal, QC, Canada; Centre de Recherches Mathematiques, University of MontréalMontreal, QC, Canada; Physics Department and Perform Center, Concordia UniversityMontreal, QC, Canada
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21
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Using patient-specific hemodynamic response function in epileptic spike analysis of human epilepsy: a study based on EEG-fNIRS. Neuroimage 2015; 126:239-55. [PMID: 26619785 DOI: 10.1016/j.neuroimage.2015.11.045] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 09/24/2015] [Accepted: 11/16/2015] [Indexed: 11/23/2022] Open
Abstract
Functional near-infrared spectroscopy (fNIRS) can be combined with electroencephalography (EEG) to continuously monitor the hemodynamic signal evoked by epileptic events such as seizures or interictal epileptiform discharges (IEDs, aka spikes). As estimation methods assuming a canonical shape of the hemodynamic response function (HRF) might not be optimal, we sought to model patient-specific HRF (sHRF) with a simple deconvolution approach for IED-related analysis with EEG-fNIRS data. Furthermore, a quadratic term was added to the model to account for the nonlinearity in the response when IEDs are frequent. Prior to analyzing clinical data, simulations were carried out to show that the HRF was estimable by the proposed deconvolution methods under proper conditions. EEG-fNIRS data of five patients with refractory focal epilepsy were selected due to the presence of frequent clear IEDs and their unambiguous focus localization. For each patient, both the linear sHRF and the nonlinear sHRF were estimated at each channel. Variability of the estimated sHRFs was seen across brain regions and different patients. Compared with the SPM8 canonical HRF (cHRF), including these sHRFs in the general linear model (GLM) analysis led to hemoglobin activations with higher statistical scores as well as larger spatial extents on all five patients. In particular, for patients with frequent IEDs, nonlinear sHRFs were seen to provide higher sensitivity in activation detection than linear sHRFs. These observations support using sHRFs in the analysis of IEDs with EEG-fNIRS data.
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22
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Zhang C, Bélanger S, Pouliot P, Lesage F. Measurement of Local Partial Pressure of Oxygen in the Brain Tissue under Normoxia and Epilepsy with Phosphorescence Lifetime Microscopy. PLoS One 2015; 10:e0135536. [PMID: 26305777 PMCID: PMC4549327 DOI: 10.1371/journal.pone.0135536] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 07/22/2015] [Indexed: 12/30/2022] Open
Abstract
In this work a method for measuring brain oxygen partial pressure with confocal phosphorescence lifetime microscopy system is reported. When used in conjunction with a dendritic phosphorescent probe, Oxyphor G4, this system enabled minimally invasive measurements of oxygen partial pressure (pO2) in cerebral tissue with high spatial and temporal resolution during 4-AP induced epileptic seizures. Investigating epileptic events, we characterized the spatio-temporal distribution of the "initial dip" in pO2 near the probe injection site and along nearby arterioles. Our results reveal a correlation between the percent change in the pO2 signal during the "initial dip" and the duration of seizure-like activity, which can help localize the epileptic focus and predict the length of seizure.
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Affiliation(s)
- Cong Zhang
- École Polytechnique de Montréal, Department of Electrical Engineering, C.P. 6079 succ.Centre-ville, Montreal, Quebec, Canada, H3C 3A7
| | - Samuel Bélanger
- École Polytechnique de Montréal, Department of Electrical Engineering, C.P. 6079 succ.Centre-ville, Montreal, Quebec, Canada, H3C 3A7
| | - Philippe Pouliot
- École Polytechnique de Montréal, Department of Electrical Engineering, C.P. 6079 succ.Centre-ville, Montreal, Quebec, Canada, H3C 3A7
- Montreal Heart Institute, 5000 Bélanger Est, Montreal, Quebec, Canada, H1T 1C8
| | - Frédéric Lesage
- École Polytechnique de Montréal, Department of Electrical Engineering, C.P. 6079 succ.Centre-ville, Montreal, Quebec, Canada, H3C 3A7
- Montreal Heart Institute, 5000 Bélanger Est, Montreal, Quebec, Canada, H1T 1C8
- * E-mail:
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Tang J, Xi L, Zhou J, Huang H, Zhang T, Carney PR, Jiang H. Noninvasive high-speed photoacoustic tomography of cerebral hemodynamics in awake-moving rats. J Cereb Blood Flow Metab 2015; 35:1224-32. [PMID: 26082016 PMCID: PMC4527999 DOI: 10.1038/jcbfm.2015.138] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 04/10/2015] [Accepted: 05/06/2015] [Indexed: 11/09/2022]
Abstract
We present a noninvasive method of photoacoustic tomography (PAT) for imaging cerebral hemodynamics in awake-moving rats. The wearable PAT (wPAT) system has a size of 15 mm in height and 33 mm in diameter, and a weight of ~8 g (excluding cabling). The wPAT achieved an imaging rate of 3.33 frames/s with a lateral resolution of 243 μm. Animal experiments were designed to show wPAT feasibility for imaging cerebral hemodynamics on awake-moving animals. Results showed that the cerebral oxy-hemoglobin and deoxy-hemoglobin changed significantly in response to hyperoxia; and, after the injection of pentylenetetrazol (PTZ), cerebral blood volume changed faster over time and larger in amplitude for rats in awake-moving state compared with rats under anesthesia. By providing a light-weight, high-resolution technology for in vivo monitoring of cerebral hemodynamics in awake-behaving animals, it will be possible to develop a comprehensive understanding on how activity alters hemodynamics in normal and diseased states.
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Affiliation(s)
- Jianbo Tang
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
| | - Lei Xi
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
| | - Junli Zhou
- Department of Pediatrics, University of Florida, Gainesville, Florida, USA
| | - Hua Huang
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
| | - Tao Zhang
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
| | - Paul R Carney
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
- Department of Pediatrics, University of Florida, Gainesville, Florida, USA
- Department of Neurology, University of Florida, Gainesville, Florida, USA
- Department of Neuroscience, University of Florida, Gainesville, Florida, USA
| | - Huabei Jiang
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
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24
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Rizki EE, Uga M, Dan I, Dan H, Tsuzuki D, Yokota H, Oguro K, Watanabe E. Determination of epileptic focus side in mesial temporal lobe epilepsy using long-term noninvasive fNIRS/EEG monitoring for presurgical evaluation. NEUROPHOTONICS 2015; 2:025003. [PMID: 26158007 PMCID: PMC4478938 DOI: 10.1117/1.nph.2.2.025003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 04/10/2015] [Indexed: 05/16/2023]
Abstract
Noninvasive localization of an epileptogenic zone is a fundamental step for presurgical evaluation of epileptic patients. Here, we applied long-term simultaneous functional near-infrared spectroscopy (fNIRS)/electroencephalogram (EEG) monitoring for focus diagnosis in patients with mesial temporal lobe epilepsy (MTLE). Six MTLE patients underwent long-term (8-16 h per day for 4 days) fNIRS/EEG monitoring for the occurrence of spontaneous seizures. Four spontaneous seizures were successfully recorded out of the six patients. To determine oxy-Hb amplitude, the period-average values of oxy-Hb across 20 s from the EEG- or clinically defined epileptic onset were calculated for both hemispheres from the simultaneously recorded fNIRS data. The average oxy-Hb values for the temporal lobe at the earlier EEG- or clinically defined epileptic onsets were greater for the epileptic side than for the contralateral side after EEG activity suppression, spike train, and clinical seizure in all four cases. The true laterality was determined based on the relief of seizures by selective amygdalo-hippocampectomy. Thus, oxy-Hb amplitude could be a reliable measure for determining the epileptic focus side. Long-term simultaneous fNIRS/EEG measurement serves as an effective tool for recording spontaneous seizures. Cerebral hemodynamic measurement by fNIRS would serve as a valuable supplementary noninvasive measurement method for presurgical evaluation of MTLE.
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Affiliation(s)
- Edmi Edison Rizki
- Jichi Medical University, Department of Neurosurgery, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Minako Uga
- Jichi Medical University, Center for Development of Advanced Medical Technology, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
- Chuo University, Research and Development Initiatives/Faculty of Science and Engineering, 1-13-27 Kasuga, Bunkyo, Tokyo 112-8551, Japan
| | - Ippeita Dan
- Jichi Medical University, Center for Development of Advanced Medical Technology, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
- Chuo University, Research and Development Initiatives/Faculty of Science and Engineering, 1-13-27 Kasuga, Bunkyo, Tokyo 112-8551, Japan
| | - Haruka Dan
- Jichi Medical University, Department of Neurosurgery, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
- Chuo University, Research and Development Initiatives/Faculty of Science and Engineering, 1-13-27 Kasuga, Bunkyo, Tokyo 112-8551, Japan
| | - Daisuke Tsuzuki
- Jichi Medical University, Center for Development of Advanced Medical Technology, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
- Chuo University, Research and Development Initiatives/Faculty of Science and Engineering, 1-13-27 Kasuga, Bunkyo, Tokyo 112-8551, Japan
| | - Hidenori Yokota
- Jichi Medical University, Department of Neurosurgery, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Keiji Oguro
- Jichi Medical University, Department of Neurosurgery, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Eiju Watanabe
- Jichi Medical University, Department of Neurosurgery, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
- Jichi Medical University, Center for Development of Advanced Medical Technology, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
- Address all correspondence to: Eiju Watanabe, E-mail:
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Yamakawa T, Inoue T, He Y, Fujii M, Suzuki M, Niwayama M. Development of an implantable flexible probe for simultaneous near-infrared spectroscopy and electrocorticography. IEEE Trans Biomed Eng 2014; 61:388-95. [PMID: 23996535 DOI: 10.1109/tbme.2013.2279888] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A combination of near-infrared spectroscopy (NIRS) and electrocorticography (ECoG) provides beneficial information on cortical activity from different aspects. Integration of such multimodal measurement capability into a single apparatus and the direct measurement of cortical activity during chronic subdural implantation may be a powerful means for clinical diagnosis and neuroscience. However, an optical fiber-based NIRS probe cannot be miniaturized for implantation into the brain, and the light-scattering effect of ECoG electrodes in NIRS measurements is unknown. We describe here the development of a flexible probe, small enough for chronic subdural implantation, for simultaneous NIRS and ECoG. Two light-emitting diodes of different wavelengths and two photodiodes were mounted on a polyimide-based flexible substrate, and ECoG electrodes were formed with a design minimizing artifacts in NIRS recording. The fabricated probe measured ECoGs at sufficient spatial resolution and submicromolar changes in hemoglobin concentrations in in vivo experiments with acute implantation into a rat. Comparison of measured changes in hemoglobin concentrations for different source-detector distances reveals the reliability of the measured values and the practicality of the simulation model. The proposed intracranial multimodality probe may provide beneficial evidence for pre- and intrasurgical assessment of neurosurgery and reveal the interaction of electrophysiology and hemodynamics at high spatial resolution without artifacts due to scalp blood flow.
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Zhang T, Zhou J, Jiang R, Yang H, Carney PR, Jiang H. Pre-seizure state identified by diffuse optical tomography. Sci Rep 2014; 4:3798. [PMID: 24445927 PMCID: PMC3896905 DOI: 10.1038/srep03798] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Accepted: 12/30/2013] [Indexed: 11/23/2022] Open
Abstract
In epilepsy it has been challenging to detect early changes in brain activity that occurs prior to seizure onset and to map their origin and evolution for possible intervention. Here we demonstrate using a rat model of generalized epilepsy that diffuse optical tomography (DOT) provides a unique functional neuroimaging modality for noninvasively and continuously tracking such brain activities with high spatiotemporal resolution. We detected early hemodynamic responses with heterogeneous patterns, along with intracranial electroencephalogram gamma power changes, several minutes preceding the electroencephalographic seizure onset, supporting the presence of a "pre-seizure" state. We also observed the decoupling between local hemodynamic and neural activities. We found widespread hemodynamic changes evolving from local regions of the bilateral cortex and thalamus to the entire brain, indicating that the onset of generalized seizures may originate locally rather than diffusely. Together, these findings suggest DOT represents a powerful tool for mapping early seizure onset and propagation pathways.
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Affiliation(s)
- Tao Zhang
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida Gainesville, FL 32611, USA
| | - Junli Zhou
- Department of Pediatrics, University of Florida Gainesville, FL 32611, USA
| | - Ruixin Jiang
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida Gainesville, FL 32611, USA
| | - Hao Yang
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida Gainesville, FL 32611, USA
| | - Paul R. Carney
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida Gainesville, FL 32611, USA
- Department of Pediatrics, University of Florida Gainesville, FL 32611, USA
- Department of Neurology, University of Florida Gainesville, FL 32611, USA
- Department of Neuroscience, University of Florida Gainesville, FL 32611, USA
| | - Huabei Jiang
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida Gainesville, FL 32611, USA
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27
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Uga M, Saito T, Sano T, Yokota H, Oguro K, Rizki EE, Mizutani T, Katura T, Dan I, Watanabe E. Direct cortical hemodynamic mapping of somatotopy of pig nostril sensation by functional near-infrared cortical imaging (fNCI). Neuroimage 2014; 91:138-45. [PMID: 24418508 DOI: 10.1016/j.neuroimage.2013.12.062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Revised: 12/10/2013] [Accepted: 12/30/2013] [Indexed: 10/25/2022] Open
Abstract
Functional near-infrared spectroscopy (fNIRS) is a neuroimaging technique for the noninvasive monitoring of human brain activation states utilizing the coupling between neural activity and regional cerebral hemodynamics. Illuminators and detectors, together constituting optodes, are placed on the scalp, but due to the presence of head tissues, an inter-optode distance of more than 2.5cm is necessary to detect cortical signals. Although direct cortical monitoring with fNIRS has been pursued, a high-resolution visualization of hemodynamic changes associated with sensory, motor and cognitive neural responses directly from the cortical surface has yet to be realized. To acquire robust information on the hemodynamics of the cortex, devoid of signal complications in transcranial measurement, we devised a functional near-infrared cortical imaging (fNCI) technique. Here we demonstrate the first direct functional measurement of temporal and spatial patterns of cortical hemodynamics using the fNCI technique. For fNCI, inter-optode distance was set at 5mm, and light leakage from illuminators was prevented by a special optode holder made of a light-shielding rubber sheet. fNCI successfully detected the somatotopy of pig nostril sensation, as assessed in comparison with concurrent and sequential somatosensory-evoked potential (SEP) measurements on the same stimulation sites. Accordingly, the fNCI system realized a direct cortical hemodynamic measurement with a spatial resolution comparable to that of SEP mapping on the rostral region of the pig brain. This study provides an important initial step toward realizing functional cortical hemodynamic monitoring during neurosurgery of human brains.
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Affiliation(s)
- Minako Uga
- Center for Development of Advanced Medical Technology, Jichi Medical University, Tochigi 329-0498, Japan; Research and Development Initiatives/Faculty of Science and Engineering, Chuo University, Tokyo 112-8551, Japan
| | - Toshiyuki Saito
- Center for Development of Advanced Medical Technology, Jichi Medical University, Tochigi 329-0498, Japan; Department of Animal Medical Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan
| | - Toshifumi Sano
- Center for Development of Advanced Medical Technology, Jichi Medical University, Tochigi 329-0498, Japan
| | - Hidenori Yokota
- Department of Neurosurgery, Jichi Medical University, Tochigi 329-0498, Japan
| | - Keiji Oguro
- Department of Neurosurgery, Jichi Medical University, Tochigi 329-0498, Japan
| | - Edmi Edison Rizki
- Department of Neurosurgery, Jichi Medical University, Tochigi 329-0498, Japan
| | - Tsutomu Mizutani
- Center for Development of Advanced Medical Technology, Jichi Medical University, Tochigi 329-0498, Japan
| | - Takusige Katura
- Central Research Laboratory, Hitachi Ltd., Hatoyama, Saitama 350-0395, Japan
| | - Ippeita Dan
- Center for Development of Advanced Medical Technology, Jichi Medical University, Tochigi 329-0498, Japan; Research and Development Initiatives/Faculty of Science and Engineering, Chuo University, Tokyo 112-8551, Japan.
| | - Eiju Watanabe
- Center for Development of Advanced Medical Technology, Jichi Medical University, Tochigi 329-0498, Japan; Department of Neurosurgery, Jichi Medical University, Tochigi 329-0498, Japan
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28
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Safaie J, Grebe R, Moghaddam HA, Wallois F. Toward a fully integrated wireless wearable EEG-NIRS bimodal acquisition system. J Neural Eng 2013; 10:056001. [DOI: 10.1088/1741-2560/10/5/056001] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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29
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Tsytsarev V, Bernardelli C, Maslov KI. Living Brain Optical Imaging: Technology, Methods and Applications. ACTA ACUST UNITED AC 2012; 1:180-192. [PMID: 28251038 DOI: 10.1166/jnsne.2012.1020] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Within the last few decades, optical imaging methods have yielded revolutionary results when applied to all parts of the central nervous system. The purpose of this review is to analyze research possibilities and limitations of several novel imaging techniques and show some of the most interesting achievements obtained by these methods. Here we covered intrinsic optical imaging, voltage-sensitive dye, photoacoustic, optical coherence tomography, near-infrared spectroscopy and some other techniques. All of them are mainly applicable for experimental neuroscience but some of them also suitable for the clinical studies.
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Affiliation(s)
- Vassiliy Tsytsarev
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, HSF II Room S251, 20 Penn Street, Baltimore, MD 21201-1075, USA
| | - Chad Bernardelli
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, HSF II Room S251, 20 Penn Street, Baltimore, MD 21201-1075, USA
| | - Konstantin I Maslov
- Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, St. Louis, Missouri 63130, USA
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Lenkov DN, Volnova AB, Pope ARD, Tsytsarev V. Advantages and limitations of brain imaging methods in the research of absence epilepsy in humans and animal models. J Neurosci Methods 2012; 212:195-202. [PMID: 23137652 DOI: 10.1016/j.jneumeth.2012.10.018] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 10/24/2012] [Accepted: 10/25/2012] [Indexed: 12/18/2022]
Abstract
The purpose of this review is to analyze research possibilities and limitations of several methods, technical tools and their combinations for elucidation of absence epilepsy mechanisms, particularly the childhood absences. Despite the notable collection of simultaneous recording of clinical electroencephalography (EEG) and behavioral changes in relation to absence seizures, shortcomings of scalp EEG in both spatial resolution and precise detection of subcortical centers have limited the understanding of the fundamental mechanisms of altered brain function during and after recurrent epileptic paroxysms. Therefore, in the past decade, EEG recordings have often been combined with simultaneous imaging methods in epilepsy studies. Among imaging methods, the following ones are used regularly: functional magnetic resonance imaging (fMRI), positron-emission tomography (PET), low-resolution electromagnetic tomography (LORETA), single photon emission spectroscopy (SPECT), near-infrared spectroscopy (NIRS), and optical imaging of intrinsic signals (IOS). In addition, voltage-sensitive dye optical imaging method and even photoacoustic microscopy can be applied to animal models of epilepsy. Samplings of some of the most relevant data obtained by the above methods are presented. It appears that the elaboration of more adequate animal models of the patterns of absence seizures during the early postnatal period is necessary for better correspondence of human and animal absence phenomena.
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Affiliation(s)
- Dmitry N Lenkov
- Nevsky Center of Scientific Collaboration-Saint Petersburg, Razjezshaya 43/1 Liter A, Suite 8N, Saint Petersburg 192119, Russia
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31
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Matos G, Scorza FA, Cavalheiro EA, Tufik S, Andersen ML. PDEI‐5 for Erectile Dysfunction: A Potential Role in Seizure Susceptibility. J Sex Med 2012; 9:2111-21. [DOI: 10.1111/j.1743-6109.2012.02780.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Wallois F, Mahmoudzadeh M, Patil A, Grebe R. Usefulness of simultaneous EEG-NIRS recording in language studies. BRAIN AND LANGUAGE 2012; 121:110-23. [PMID: 21546072 DOI: 10.1016/j.bandl.2011.03.010] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Revised: 03/08/2011] [Accepted: 03/21/2011] [Indexed: 05/11/2023]
Abstract
One of the most challenging tasks in neuroscience in language studies, is investigation of the brain's ability to integrate and process information. This task can only be successfully addressed by applying various assessment techniques integrated into a multimodal approach. Each of these techniques has its advantages and disadvantages, but help to elucidate certain aspects of the capacity of neural networks to process information. These methods provide information about changes in electrical, hemodynamic and metabolic activities. Ideally, they should be noninvasive in order to facilitate their use particularly in children. In the present review, we describe the advantages of simultaneous electroencephalographic (EEG) acquisition with near infrared spectroscopy (NIRS) to provide a better understanding of the mechanisms involved in cerebral activation. This coregistration is also useful to avoid misleading interpretation of NIRS, notably during the various phases of sleep. Development and implementation of the various tools required and assessment strategies are also discussed.
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Affiliation(s)
- F Wallois
- GRAMFC, EA4293, Research Group on Functional Cerebral Multimodal Analysis, Faculty of Medecine, 3 rue des Louvels, 80036 Amiens, France.
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Nonlinear hemodynamic responses in human epilepsy: a multimodal analysis with fNIRS-EEG and fMRI-EEG. J Neurosci Methods 2011; 204:326-40. [PMID: 22138633 DOI: 10.1016/j.jneumeth.2011.11.016] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 11/02/2011] [Accepted: 11/09/2011] [Indexed: 11/20/2022]
Abstract
Functional magnetic resonance imaging (fMRI) combined with electroencephalography (fMRI-EEG) is a neuroimaging technique based on the blood oxygenation level dependent (BOLD) signal which has been shown to be useful in the study of epilepsy for the localization of the epileptogenic focus. Functional near-infrared spectroscopy (fNIRS) combined with EEG (fNIRS-EEG) is another imaging technique based on the measurement of oxygenated and deoxygenated hemoglobin with complementary clinical potential in epilepsy, for continuous patient monitoring, language lateralization, and focus localization. In this work fMRI-EEG and fNIRS-EEG are used to quantify nonlinear hemodynamic responses in three cases of human refractory focal epilepsy, by using the Volterra kernel expansion up to second order. Prior to analyzing real data, extensive simulations are carried out to show that nonlinearities are estimable. The Volterra methodology is then applied to multimodal data recorded from 3 epileptic patients selected for their frequent spiking activity. Care is taken to account for variability of hemodynamic responses due to other causes than Volterra nonlinearities. Statistically significant nonlinearities are observed for all patients and all modalities. Good concordance between fNIRS and fMRI is found for both the amplitude of the Volterra responses, and, with limitations, in the localization of the epileptic focus and regions of inverted responses (negative BOLD signals). In one patient, Volterra nonlinearities allowed epileptic focus identification with fMRI, while analyses without nonlinearities failed to see it. In simulations when nonlinearities were included, analysis without Volterra nonlinearities performed poorly. These two observations suggest routinely checking for nonlinearities in functional imaging of patients presenting with frequent spikes.
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Lareau E, Lesage F, Pouliot P, Nguyen D, Le Lan J, Sawan M. Multichannel wearable system dedicated for simultaneous electroencephalography∕near-infrared spectroscopy real-time data acquisitions. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:096014. [PMID: 21950928 DOI: 10.1117/1.3625575] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Functional neuroimaging is becoming a valuable tool in cognitive research and clinical applications. The clinical context brings specific constraints that include the requirement of a high channel count to cover the whole head, high sensitivity for single event detection, and portability for long-term bedside monitoring. For epilepsy and stroke monitoring, the combination of electroencephalography (EEG) and functional near-infrared spectroscopy (NIRS) is expected to provide useful clinical information, and efforts have been deployed to create prototypes able to simultaneously acquire both measurement modalities. However, to the best of our knowledge, existing systems lack portability, NIRS sensitivity, or have low channel count. We present a battery-powered, portable system with potentially up to 32 EEG channels, 32 NIRS light sources, and 32 detectors. Avalanche photodiodes allow for high NIRS sensitivity and the autonomy of the system is over 24 h. A reduced channel count prototype with 8 EEG channels, 8 sources, and 8 detectors was tested on phantoms. Further validation was done on five healthy adults using a visual stimulation protocol to detect local hemodynamic changes and visually evoked potentials. Results show good concordance with literature regarding functional activations and suggest sufficient performance for clinical use, provided some minor adjustments were made.
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Affiliation(s)
- Etienne Lareau
- Ecole Polytechnique de Montreal, Department of Electrical Engineering, Montreal, Quebec, H3C-3A7 Canada
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35
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Pittau F, Levan P, Moeller F, Gholipour T, Haegelen C, Zelmann R, Dubeau F, Gotman J. Changes preceding interictal epileptic EEG abnormalities: comparison between EEG/fMRI and intracerebral EEG. Epilepsia 2011; 52:1120-9. [PMID: 21671923 DOI: 10.1111/j.1528-1167.2011.03072.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE In simultaneous scalp electroencephalography (EEG) and functional magnetic resonance imaging (fMRI), blood oxygen level dependent (BOLD) changes occurring before the spike have been sometimes described but could not be explained. To characterize the origin of this prespike BOLD signal change, we looked for electrographic changes in stereo-EEG (SEEG) possibly preceding the scalp spike in patients that showed early BOLD response in EEG/fMRI. METHODS We studied four patients with drug-resistant focal epilepsy who underwent EEG/fMRI, showed a prespike BOLD response, and were then studied with depth electrodes for presurgical localization of the epileptic generator. Early BOLD responses in the region of the spike field were analyzed using models with hemodynamic response functions (HRFs) peaking from -9 to +9 s around the spike. SEEG recordings in the period and location corresponding to the early HRF responses were analyzed to detect if electrographic changes were present in the SEEG before the scalp abnormality. KEY FINDINGS One of the four patients presented a SEEG interictal discharge in the period corresponding to the early BOLD response. In the other three, no electrographic changes were detected in the SEEG in the period corresponding to early BOLD changes. SIGNIFICANCE Although the early BOLD activity may sometimes be explained by a synchronized neural discharge detectable with SEEG but not visible on the scalp EEG, in most cases the early BOLD response reflects a metabolic phenomenon that does not appear to result from a synchronized neuronal discharge. Prespike metabolic responses can result from synchronized or nonsynchronized neuronal activity, or from nonneuronal mechanisms including glia.
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Affiliation(s)
- Francesca Pittau
- Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada.
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36
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EEG-NIRS in epilepsy in children and neonates. Neurophysiol Clin 2010; 40:281-92. [DOI: 10.1016/j.neucli.2010.08.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Revised: 08/29/2010] [Accepted: 08/29/2010] [Indexed: 11/15/2022] Open
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Roche-Labarbe N, Zaaimi B, Mahmoudzadeh M, Osharina V, Wallois A, Nehlig A, Grebe R, Wallois F. NIRS-measured oxy- and deoxyhemoglobin changes associated with EEG spike-and-wave discharges in a genetic model of absence epilepsy: The GAERS. Epilepsia 2010; 51:1374-84. [DOI: 10.1111/j.1528-1167.2010.02574.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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