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Del Vecchio M, Bontemps B, Lance F, Gannerie A, Sipp F, Albertini D, Cassani CM, Chatard B, Dupin M, Lachaux JP. Introducing HiBoP: a Unity-based visualization software for large iEEG datasets. J Neurosci Methods 2024; 409:110179. [PMID: 38823595 DOI: 10.1016/j.jneumeth.2024.110179] [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: 12/22/2023] [Revised: 05/02/2024] [Accepted: 05/22/2024] [Indexed: 06/03/2024]
Abstract
BACKGROUND Intracranial EEG data offer a unique spatio-temporal precision to investigate human brain functions. Large datasets have become recently accessible thanks to new iEEG data-sharing practices and tighter collaboration with clinicians. Yet, the complexity of such datasets poses new challenges, especially regarding the visualization and anatomical display of iEEG. NEW METHOD We introduce HiBoP, a multi-modal visualization software specifically designed for large groups of patients and multiple experiments. Its main features include the dynamic display of iEEG responses induced by tasks/stimulations, the definition of Regions and electrodes Of Interest, and the shift between group-level and individual-level 3D anatomo-functional data. RESULTS We provide a use-case with data from 36 patients to reveal the global cortical dynamics following tactile stimulation. We used HiBoP to visualize high-gamma responses [50-150 Hz], and define three major response components in primary somatosensory and premotor cortices and parietal operculum. COMPARISON WITH EXISTING METHODS(S) Several iEEG softwares are now publicly available with outstanding analysis features. Yet, most were developed in languages (Python/Matlab) chosen to facilitate the inclusion of new analysis by users, rather than the quality of the visualization. HiBoP represents a visualization tool developed with videogame standards (Unity/C#), and performs detailed anatomical analysis rapidly, across multiple conditions, patients, and modalities with an easy export toward third-party softwares. CONCLUSION HiBoP provides a user-friendly environment that greatly facilitates the exploration of large iEEG datasets, and helps users decipher subtle structure/function relationships.
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Affiliation(s)
- Maria Del Vecchio
- Istituto di Neuroscienze, Consiglio Nazionale delle Ricerche, Parma 43125, Italy
| | - Benjamin Bontemps
- Lyon Neuroscience Research Center, EDUWELL team, INSERM UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, Lyon F-69000, France
| | - Florian Lance
- Lyon Neuroscience Research Center, EDUWELL team, INSERM UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, Lyon F-69000, France
| | - Adrien Gannerie
- Lyon Neuroscience Research Center, EDUWELL team, INSERM UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, Lyon F-69000, France
| | - Florian Sipp
- Lyon Neuroscience Research Center, EDUWELL team, INSERM UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, Lyon F-69000, France
| | - Davide Albertini
- Dipartimento di Medicina e Chirurgia, Università di Parma, Via Volturno 39, Parma 43125, Italy
| | - Chiara Maria Cassani
- Istituto di Neuroscienze, Consiglio Nazionale delle Ricerche, Parma 43125, Italy; Department of School of Advanced Studies, University of Camerino, Italy
| | - Benoit Chatard
- Lyon Neuroscience Research Center, EDUWELL team, INSERM UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, Lyon F-69000, France
| | - Maryne Dupin
- Lyon Neuroscience Research Center, EDUWELL team, INSERM UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, Lyon F-69000, France
| | - Jean-Philippe Lachaux
- Lyon Neuroscience Research Center, EDUWELL team, INSERM UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, Lyon F-69000, France.
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Alouit A, Gavaret M, Ramdani C, Lindberg PG, Dupin L. Cortical activations associated with spatial remapping of finger touch using EEG. Cereb Cortex 2024; 34:bhae161. [PMID: 38642106 DOI: 10.1093/cercor/bhae161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 03/22/2024] [Accepted: 03/23/2024] [Indexed: 04/22/2024] Open
Abstract
The spatial coding of tactile information is functionally essential for touch-based shape perception and motor control. However, the spatiotemporal dynamics of how tactile information is remapped from the somatotopic reference frame in the primary somatosensory cortex to the spatiotopic reference frame remains unclear. This study investigated how hand position in space or posture influences cortical somatosensory processing. Twenty-two healthy subjects received electrical stimulation to the right thumb (D1) or little finger (D5) in three position conditions: palm down on right side of the body (baseline), hand crossing the body midline (effect of position), and palm up (effect of posture). Somatosensory-evoked potentials (SEPs) were recorded using electroencephalography. One early-, two mid-, and two late-latency neurophysiological components were identified for both fingers: P50, P1, N125, P200, and N250. D1 and D5 showed different cortical activation patterns: compared with baseline, the crossing condition showed significant clustering at P1 for D1, and at P50 and N125 for D5; the change in posture showed a significant cluster at N125 for D5. Clusters predominated at centro-parietal electrodes. These results suggest that tactile remapping of fingers after electrical stimulation occurs around 100-125 ms in the parietal cortex.
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Affiliation(s)
- Anaëlle Alouit
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, 102-108 Rue de la Santé, 75014 Paris, France
| | - Martine Gavaret
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, 102-108 Rue de la Santé, 75014 Paris, France
- GHU-Paris Psychiatrie et Neurosciences, Hôpital Sainte Anne, Service de neurophysiologie clinique, 1 Rue Cabanis, F-75014 Paris, France
| | - Céline Ramdani
- Service de Santé des Armées, Institut de Recherche Biomédicale des Armées, 1 Place du Général Valérie André, 91220 Brétigny-sur-Orge, France
| | - Påvel G Lindberg
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, 102-108 Rue de la Santé, 75014 Paris, France
| | - Lucile Dupin
- Université Paris Cité, INCC UMR 8002, CNRS, 45 Rue des Saints-Pères, F-75006 Paris, France
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Insola A, Mazzone P, Scarnati E, Restuccia D, Valeriani M. Contribution of different somatosensory afferent input to subcortical somatosensory evoked potentials in humans. Clin Neurophysiol 2021; 132:2357-2364. [PMID: 34454262 DOI: 10.1016/j.clinph.2021.06.033] [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: 03/04/2021] [Revised: 06/04/2021] [Accepted: 06/23/2021] [Indexed: 10/20/2022]
Abstract
OBJECTIVES To investigate the subcortical somatosensory evoked potentials (SEPs) to electrical stimulation of either muscle or cutaneous afferents. METHODS SEPs were recorded in 6 patients suffering from Parkinson's disease (PD) who underwent electrode implantation in the pedunculopontine (PPTg) nucleus area. We compared SEPs recorded from the scalp and from the intracranial electrode contacts to electrical stimuli applied to: 1) median nerve at the wrist, 2) abductor pollicis brevis motor point, and 3) distal phalanx of the thumb. Also the high-frequency oscillations (HFOs) were analysed. RESULTS After median nerve and pure cutaneous (distant phalanx of the thumb) stimulation, a P1-N1 complex was recorded by the intracranial lead, while the scalp electrodes recorded the short-latency far-field responses (P14 and N18). On the contrary, motor point stimulation did not evoke any low-frequency component in the PPTg traces, nor the N18 potential on the scalp. HFOs were recorded to stimulation of all modalities by the PPTg electrode contacts. CONCLUSIONS Stimulus processing within the cuneate nucleus depends on modality, since only the cutaneous input activates the complex intranuclear network possibly generating the scalp N18 potential. SIGNIFICANCE Our results shed light on the subcortical processing of the somatosensory input of different modalities.
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Affiliation(s)
- Angelo Insola
- Unità Operativa di Neurofisiopatologia, CTO, Rome, Italy
| | - Paolo Mazzone
- Unità Operativa di Neurochirurgia funzionale e stereotassica, CTO, Rome, Italy
| | - Eugenio Scarnati
- Dipartimento di Scienze Cliniche e Biotecnologiche Applicate, Università dell'Aquila, Italy
| | - Domenico Restuccia
- Istituto di Neurologia, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Massimiliano Valeriani
- Divisione di Neurologia, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy; Center for Sensory-Motor Interaction, Aalborg University, Aalborg, Denmark.
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Norioka R, Shimizu T, Bokuda K, Morishima R, Kawazoe T, Kimura H, Asano Y, Nakayama Y, Takahashi K. Enlarged high frequency oscillations of the median nerve somatosensory evoked potential and survival in amyotrophic lateral sclerosis. Clin Neurophysiol 2021; 132:2003-2011. [PMID: 34284234 DOI: 10.1016/j.clinph.2021.05.023] [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: 01/16/2021] [Revised: 04/26/2021] [Accepted: 05/21/2021] [Indexed: 10/21/2022]
Abstract
OBJECTIVE A large N20 and P25 of the median nerve somatosensory evoked potential (SEP) predicts short survival in amyotrophic lateral sclerosis (ALS). We investigated whether high frequency oscillations (HFOs) over N20 are enlarged and associated with survival in ALS. METHODS A total of 145 patients with ALS and 57 healthy subjects were studied. We recorded the median nerve SEP and measured the onset-to-peak amplitude of N20 (N20o-p), and peak-to-peak amplitude between N20 and P25 (N20p-P25p). We obtained early and late HFO potentials by filtering SEP between 500 and 1 kHz, and measured the peak-to-peak amplitude. We followed up patients until endpoints (death or tracheostomy) and analyzed the relationship between SEP or HFO amplitudes and survival using a Cox analysis. RESULTS Patients showed larger N20o-p, N20p-P25p, and early and late HFO amplitudes than the control values. N20p-P25p was associated with survival periods (p = 0.0004), while early and late HFO amplitudes showed no significant association with survival (p = 0.4307, and p = 0.6858, respectively). CONCLUSIONS The HFO amplitude in ALS is increased, but does not predict survival. SIGNIFICANCE The enlarged HFOs in ALS might be a compensatory phenomenon to the hyperexcitability of the sensory cortex pyramidal neurons.
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Affiliation(s)
- Ryohei Norioka
- Department of Neurology, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan
| | - Toshio Shimizu
- Department of Neurology, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan.
| | - Kota Bokuda
- Department of Neurology, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan
| | - Ryo Morishima
- Department of Neurology, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan
| | - Tomoya Kawazoe
- Department of Neurology, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan
| | - Hideki Kimura
- Department of Neurology, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan
| | - Yuri Asano
- Department of Neurology, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan
| | - Yuki Nakayama
- Unit for Intractable Disease Nursing Care, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Kazushi Takahashi
- Department of Neurology, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan
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Miller LE, Longo MR, Saygin AP. Tool Use Modulates Somatosensory Cortical Processing in Humans. J Cogn Neurosci 2019; 31:1782-1795. [PMID: 31368823 DOI: 10.1162/jocn_a_01452] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Tool use leads to plastic changes in sensorimotor body representations underlying tactile perception. The neural correlates of this tool-induced plasticity in humans have not been adequately characterized. This study used ERPs to investigate the stage of sensory processing modulated by tool use. Somatosensory evoked potentials, elicited by median nerve stimulation, were recorded before and after two forms of object interaction: tool use and hand use. Compared with baseline, tool use-but not use of the hand alone-modulated the amplitude of the P100. The P100 is a mid-latency component that indexes the construction of multisensory models of the body and has generators in secondary somatosensory and posterior parietal cortices. These results mark one of the first demonstrations of the neural correlates of tool-induced plasticity in humans and suggest that tool use modulates relatively late stages of somatosensory processing outside primary somatosensory cortex. This finding is consistent with what has been observed in tool-trained monkeys and suggests that the mechanisms underlying tool-induced plasticity have been preserved across primate evolution.
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Affiliation(s)
- Luke E Miller
- University of California, San Diego.,Lyon Neuroscience Research Center, INSERM U1028, CNRS U5292, Bron Cedex, France
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Porcaro C, Di Lorenzo G, Seri S, Pierelli F, Tecchio F, Coppola G. Impaired brainstem and thalamic high-frequency oscillatory EEG activity in migraine between attacks. Cephalalgia 2016; 37:915-926. [DOI: 10.1177/0333102416657146] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Introduction We investigated whether interictal thalamic dysfunction in migraine without aura (MO) patients is a primary determinant or the expression of its functional disconnection from proximal or distal areas along the somatosensory pathway. Methods Twenty MO patients and twenty healthy volunteers (HVs) underwent an electroencephalographic (EEG) recording during electrical stimulation of the median nerve at the wrist. We used the functional source separation algorithm to extract four functionally constrained nodes (brainstem, thalamus, primary sensory radial, and primary sensory motor tangential parietal sources) along the somatosensory pathway. Two digital filters (1–400 Hz and 450–750 Hz) were applied in order to extract low- (LFO) and high- frequency (HFO) oscillatory activity from the broadband signal. Results Compared to HVs, patients presented significantly lower brainstem (BS) and thalamic (Th) HFO activation bilaterally. No difference between the two cortical HFO as well as in LFO peak activations between the two groups was seen. The age of onset of the headache was positively correlated with HFO power in the right brainstem and thalamus. Conclusions This study provides evidence for complex dysfunction of brainstem and thalamocortical networks under the control of genetic factors that might act by modulating the severity of migraine phenotype.
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Affiliation(s)
- Camillo Porcaro
- LET’S-ISTC-CNR, Ospedale Fatebenefratelli, Isola Tiberina, Rome, Italy
- Movement Control and Neuroplasticity Research Group, Department of Kinesiology, KU Leuven, Leuven, Belgium
- Department of Information Engineering, Università Politecnica delle Marche, Ancona, Italy
| | - Giorgio Di Lorenzo
- Laboratory of Psychophysiology, Psychiatric Chair, Department of Systems Medicine, University of Rome ‘Tor Vergata’, Rome, Italy
- Psychiatry and Clinical Psychology Unit, Department of Neurosciences, Fondazione Policlinico ‘Tor Vergata’, Rome, Italy
| | - Stefano Seri
- The Wellcome Trust Laboratory for MEG Studies, School of Life and Health Sciences, Aston University, Birmingham, UK
| | - Francesco Pierelli
- Sapienza University of Rome Polo Pontino, Latina and IRCCS Neuromed, Pozzilli (IS), Italy
| | - Franca Tecchio
- LET’S-ISTC-CNR, Ospedale Fatebenefratelli, Isola Tiberina, Rome, Italy
| | - Gianluca Coppola
- G.B. Bietti Foundation IRCCS, Department of Neurophysiology of Vision and Neurophthalmology, Rome, Italy
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Insola A, Padua L, Mazzone P, Valeriani M. Low- and high-frequency subcortical SEP amplitude reduction during pure passive movement. Clin Neurophysiol 2015; 126:2366-75. [DOI: 10.1016/j.clinph.2015.03.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 03/01/2015] [Accepted: 03/04/2015] [Indexed: 12/15/2022]
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Insola A, Padua L, Mazzone P, Scarnati E, Valeriani M. Low and high-frequency somatosensory evoked potentials recorded from the human pedunculopontine nucleus. Clin Neurophysiol 2014; 125:1859-69. [DOI: 10.1016/j.clinph.2013.12.112] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 12/04/2013] [Accepted: 12/20/2013] [Indexed: 10/25/2022]
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Baumgärtner U, Vogel H, Ohara S, Treede RD, Lenz FA. Dipole source analyses of early median nerve SEP components obtained from subdural grid recordings. J Neurophysiol 2010; 104:3029-41. [PMID: 20861430 DOI: 10.1152/jn.00116.2010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The median nerve N20 and P22 SEP components constitute the initial response of the primary somatosensory cortex to somatosensory stimulation of the upper extremity. Knowledge of the underlying generators is important both for basic understanding of the initial sequence of cortical activation and to identify landmarks for eloquent areas to spare in resection planning of cortex in epilepsy surgery. We now set out to localize the N20 and P22 using subdural grid recording with special emphasis on the question of the origin of P22: Brodmann area 4 versus area 1. Electroencephalographic dipole source analysis of the N20 and P22 responses obtained from subdural grids over the primary somatosensory cortex after median nerve stimulation was performed in four patients undergoing epilepsy surgery. Based on anatomical landmarks, equivalent current dipoles of N20 and P22 were localized posterior to (n = 2) or on the central sulcus (n = 2). In three patients, the P22 dipole was located posterior to the N20 dipole, whereas in one patient, the P22 dipole was located on the same coordinate in anterior-posterior direction. On average, P22 sources were found to be 6.6 mm posterior [and 1 mm more superficial] compared with the N20 sources. These data strongly suggest a postcentral origin of the P22 SEP component in Brodmann area 1 and render a major precentral contribution to the earliest stages of processing from the primary motor cortex less likely.
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Affiliation(s)
- Ulf Baumgärtner
- Center for Biomedicine and Medical Technology Mannheim, Medical Faculty Mannheim, Ruprecht-Karls-University Heidelberg, Ludolf-Krehl-Str. 13-17, 68167 Mannheim, Germany.
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Bai X, Towle VL, van Drongelen W, He B. Cortical potential imaging of somatosensory evoked potentials by means of the boundary element method in pediatric epilepsy patients. Brain Topogr 2010; 23:333-43. [PMID: 20652392 DOI: 10.1007/s10548-010-0155-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2010] [Accepted: 07/06/2010] [Indexed: 11/29/2022]
Abstract
The aim of the present study was to assess the feasibility of identifying the primary hand sensory area and central sulcus in pediatric patients using the cortical potential imaging (CPI) method from the scalp recorded somatosensory evoked potentials (SEPs). The CPI method was used to reconstruct the cortical potential distribution from the scalp potentials with the boundary element (3-layer: scalp, skull and brain) head model based on MR images of individual subjects. The cortical potentials estimated from the pre-operative scalp SEPs of four pediatric patients, were compared with the post-op subdural SEP recordings made in the same subjects. Estimated and directly recorded cortical SEP maps showed comparable spatial patterns on the cortical surface in four patients (spatial correlation coefficient >0.7 in the SEP spikes). For two of four patients, the estimated waveforms correlated significantly to the waveforms obtained by direct cortical recordings. The present results demonstrated the feasibility of the cortical potential imaging approach in noninvasive imaging spatial distribution and temporal waveforms of cortical potentials for pediatric patients. These also suggest that the CPI method may provide a promising means of estimating the cortical potential and noninvasive localizing the central sulcus to aid surgical planning for pediatric patients.
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Affiliation(s)
- Xiaoxiao Bai
- Department of Biomedical Engineering, University of Minnesota, 7-105 NHH, 312 Church Street, Minneapolis, MN 55455, USA
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11
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Effect of movement on SEPs generated by dorsal column nuclei. Clin Neurophysiol 2010; 121:921-9. [DOI: 10.1016/j.clinph.2010.01.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2009] [Revised: 01/07/2010] [Accepted: 01/08/2010] [Indexed: 02/07/2023]
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Porcaro C, Coppola G, Di Lorenzo G, Zappasodi F, Siracusano A, Pierelli F, Rossini PM, Tecchio F, Seri S. Hand somatosensory subcortical and cortical sources assessed by functional source separation: an EEG study. Hum Brain Mapp 2009; 30:660-74. [PMID: 18266219 DOI: 10.1002/hbm.20533] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We propose a novel electroencephalographic application of a recently developed cerebral source extraction method (Functional Source Separation, FSS), which starts from extracranial signals and adds a functional constraint to the cost function of a basic independent component analysis model without requiring solutions to be independent. Five ad-hoc functional constraints were used to extract the activity reflecting the temporal sequence of sensory information processing along the somatosensory pathway in response to the separate left and right median nerve galvanic stimulation. Constraints required only the maximization of the responsiveness at specific latencies following sensory stimulation, without taking into account that any frequency or spatial information. After source extraction, the reliability of identified FS was assessed based on the position of single dipoles fitted on its retroprojected signals and on a discrepancy measure. The FS positions were consistent with previously reported data (two early subcortical sources localized in the brain stem and thalamus, the three later sources in cortical areas), leaving negligible residual activity at the corresponding latencies. The high-frequency component of the oscillatory activity (HFO) of the extracted component was analyzed. The integrity of the low amplitude HFOs was preserved for each FS. On the basis of our data, we suggest that FSS can be an effective tool to investigate the HFO behavior of the different neuronal pools, recruited at successive times after median nerve galvanic stimulation. As FSs are reconstructed along the entire experimental session, directional and dynamic HFO synchronization phenomena can be studied.
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Affiliation(s)
- Camillo Porcaro
- AFaR, Center of Medical Statistics and IT, Fatebenefratelli Hospital, Rome, Italy
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Insola A, Padua L, Mazzone P, Valeriani M. Unmasking of presynaptic and postsynaptic high-frequency oscillations in epidural cervical somatosensory evoked potentials during voluntary movement. Clin Neurophysiol 2007; 119:237-45. [PMID: 18054280 DOI: 10.1016/j.clinph.2007.09.132] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2007] [Revised: 08/18/2007] [Accepted: 09/23/2007] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To investigate the effect of the voluntary movement on the amplitude of the somatosensory evoked potentials (SEPs) recorded by an epidural electrode at level of the cervical spinal cord (CSC). METHODS Fourteen patients underwent an epidural electrode implant at CSC level for pain relief. After the median nerve stimulation, SEPs were recorded from the epidural electrode and from 4 surface electrodes (in frontal and parietal regions contralateral to the stimulated side, over the 6th cervical vertebra, and on the Erb's point). SEPs were recorded at rest and during a voluntary flexo-extension movement of the stimulated wrist. Beyond the low-frequency SEPs, also the high-frequency oscillations (HFOs) were analysed. RESULTS The epidural electrode contacts recorded a triphasic potential (P1-N1-P2), whose negative peak showed the same latency as the cervical N13 response. The epidural potential amplitude was significantly decreased during the voluntary movement, as compared to the rest. Two main HFOs were identifiable: (1) the 1200 Hz HFO which was significantly lower in amplitude during movement than at rest, and (2) the 500 Hz HFO which was not modified by the voluntary movement. CONCLUSIONS The low-frequency cervical SEP component is subtended by HFOs probably generated by: (1) postsynaptic potentials in the dorsal horn neurones (1200 Hz), and (2) presynaptic ascending somatosensory inputs (500 Hz). SIGNIFICANCE Our findings show that the voluntary movement may affect the somatosensory input processing also at CSC level.
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Affiliation(s)
- Angelo Insola
- Unità Operativa di Neurofisiopatologia, CTO, Via S. Nemesio 21, 00145 Rome, Italy
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Insola A, Mazzone P, Valeriani M. Somatosensory evoked potential and clinical changes after electrode implant in basal ganglia of parkinsonian patients. Muscle Nerve 2006; 32:791-7. [PMID: 16124001 DOI: 10.1002/mus.20430] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Median nerve somatosensory evoked potentials (SEPs) were recorded in three parkinsonian patients who underwent electrode implant in the subthalamic nucleus and/or globus pallidus for chronic deep brain stimulation (DBS). SEPs were evoked before surgery, in a medication-free condition, and after the functional stereotactic procedure, before beginning DBS. In order to evaluate the timing of the SEP changes after the electrode implant, in three further patients SEPs were recorded within the operating theater, before and immediately after the implantation. Patients' symptoms improved immediately after the electrode implant, and both N20 and N30 amplitudes increased in the postsurgical SEP recording. The clinical and neurophysiological effects observed after surgery, before commencing DBS, can be explained by microdamage in the target nucleus following the electrode implant. They occurred also in the patients studied in the operating theater, thus suggesting that they occur immediately after the stereotactic procedure. Our results suggest that the circuitries between the basal ganglia and the primary sensorimotor cortex may be modified not only by DBS but also by microdamage due to surgery and that they exert an important influence on SEP amplitude.
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Affiliation(s)
- Angelo Insola
- Unità Operativa di Neurofisiopatologia, Centro Traumatologico Ortopedico, Rome, Italy
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Zainea OF, Kostopoulos GK, Ioannides AA. Clustering of early cortical responses to median nerve stimulation from average and single trial MEG and EEG signals. Brain Topogr 2005; 17:219-36. [PMID: 16110772 DOI: 10.1007/s10548-005-6031-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Median nerve electrical stimulation (MNES) produces early and strong averaged magnetoencephalography (MEG) or electroencephalography (EEG) signals, despite considerable single trial (ST) variability, demonstrated in separate MEG and EEG studies. Here, simultaneous MEG/EEG recordings are used to assess whether same or different aspects of ST variability are influencing EEG and MEG. Clustering techniques provided groupings for the ST timeseries for cortical responses to MNES derived from one modality. These groupings were applied to the corresponding ST timeseries derived from the other modality to quantify the similarity in variability captured by MEG and EEG signals. Estimates of early cortical activity elicited by MNES derived from MEG and EEG signals were very similar, provided ongoing mu rhythm was removed. Similarity between EEG and MEG estimates included both results based on average signals and measures of ST variability. Either MEG or EEG can provide a robust measure of the early cortical activity elicited by MNES as well as of its variability. Reliable indices of early cortical responses to MNES can be derived from either MEG or EEG data. These indices can be based on average signals, as is routinely done with clinical EEG, but it could also rely on hitherto little utilized measures of ST variability.
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Affiliation(s)
- Ovidiu F Zainea
- Department of Physiology, Medical School, University of Patras, Patras, Greece
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Kida T, Nishihira Y, Wasaka T, Sakajiri Y, Tazoe T. Differential modulation of the short- and long-latency somatosensory evoked potentials in a forewarned reaction time task. Clin Neurophysiol 2004; 115:2223-30. [PMID: 15351362 DOI: 10.1016/j.clinph.2004.04.017] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/22/2004] [Indexed: 11/16/2022]
Abstract
OBJECTIVE We investigated modulation of the short- and long-latency somatosensory evoked potentials (SEPs) in a forewarned reaction time task. METHODS A pair of warning (auditory) and imperative stimuli (somatosensory) was presented with a 2 s interstimulus interval. In movement condition, subjects responded by grip movement with the ipsilateral hand to the somatosensory stimulation when the imperative stimulus was presented. In counting condition, they silently counted the number of imperative stimuli. The SEPs in response to the imperative stimuli were recorded. RESULTS Frontal N30 and central N60 amplitudes were significantly smaller in the movement than in the counting or rest conditions. None of the short-latency components differed between the counting and rest conditions. In contrast to the short-latency components, P80 was significantly larger in the counting than in the rest condition, and showed a further increase from the counting to the movement condition. The N140 amplitude was significantly larger in the movement than the rest condition, but was not changed between the counting and the rest conditions. CONCLUSIONS The attenuation of the frontal N30 and central N60, and the enhancement of the P80 and possibly the N140 resulted from the centrifugal mechanism. The present findings may show the different effects of voluntary movement on the early and subsequent cortical processing of the relevant somatosensory information requiring a behavioral response. SIGNIFICANCE The present study demonstrated the differential modulation of short- and long-latency components of SEPs in a forewarned reaction time task.
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Affiliation(s)
- Tetsuo Kida
- Doctoral program in Health and Sports Sciences, University of Tsukuba, Tsukuba, Japan.
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