The Experts below are selected from a list of 40914 Experts worldwide ranked by ideXlab platform
Jean Isnard - One of the best experts on this subject based on the ideXlab platform.
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pain behavior without pain sensation an epileptic syndrome of symbolism for pain
Pain, 2020Co-Authors: Koichi Hagiwara, Sylvain Rheims, Hélène Catenoix, Alexandra Montavont, Marc Guenot, Luis Garcialarrea, Leon Tremblay, Jean IsnardAbstract:"Asymbolia for pain" has shown the potentiality of diseased Insular networks to dissociate sensory from affective-behavioral dimensions of pain, resulting in the lack of appropriate motor and affective responses despite preserved sensory aspect of pain. Here, we describe 4 patients with an inverse phenomenon of asymbolia for pain, namely an isolated "symbolism for pain" triggered by epileptic seizures, characterized by pain behavior without declarative pain sensation despite fully preserved contact and vigilance. Stereoelectroencephalography demonstrated in each case focal seizure discharges within the posterior insulo-opercular cortex, with little or no propagation to other cortical structures, especially those considered to drive subjective pain experiences. The pain behavior might reflect seizure propagation from the Insula to brain networks serving for behavioral responses associated with pain, including the cingulate motor region and possibly also the basal ganglia. We propose that the isolated symbolism for pain is a novel epileptic syndrome of dissociation between pain perception and behaviors associated with the Insular nociceptive-related networks.
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How the Insula speaks to the heart: Cardiac responses to Insular stimulation in humans.
Human brain mapping, 2019Co-Authors: Florian Chouchou, Sylvain Rheims, Hélène Catenoix, Alexandra Montavont, Jean Isnard, François Mauguière, Julien Jung, Ophélie Vallayer, Vincent Pichot, Laure MazzolaAbstract:Despite numerous studies suggesting the role of Insular cortex in the control of autonomic activity, the exact location of cardiac motor regions remains controversial. We provide here a functional mapping of autonomic cardiac responses to intracortical stimulations of the human Insula. The cardiac effects of 100 Insular electrical stimulations into 47 epileptic patients were divided into tachycardia, bradycardia, and no cardiac response according to the magnitude of RR interval (RRI) reactivity. Sympathetic (low frequency, LF, and low to high frequency powers ratio, LF/HF ratio) and parasympathetic (high frequency power, HF) reactivity were studied using RRI analysis. Bradycardia was induced by 26 stimulations (26%) and tachycardia by 21 stimulations (21%). Right and left Insular stimulations induced as often a bradycardia as a tachycardia. Tachycardia was accompanied by an increase in LF/HF ratio, suggesting an increase in sympathetic tone; while bradycardia seemed accompanied by an increase of parasympathetic tone reflected by an increase in HF. There was some left/right asymmetry in Insular subregions where increased or decreased heart rates were produced after stimulation. However, spatial distribution of tachycardia responses predominated in the posterior Insula, whereas bradycardia sites were more anterior in the median part of the Insula. These findings seemed to indicate a posterior predominance of sympathetic control in the Insula, whichever the side; whereas the parasympathetic control seemed more anterior. Dysfunction of these regions should be considered when modifications of cardiac activity occur during epileptic seizures and in cardiovascular diseases.
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semiology of Insular lobe seizures
Revue Neurologique, 2019Co-Authors: Jean Isnard, K Ostrowskycoste, Laure Mazzola, Hélène Catenoix, Alexandra Montavont, Marc Guenot, Koichi Hagiwara, Sylvain RheimsAbstract:Abstract After the early attempts of intra-operative electrocorticography and insulectomy in the 1950s, the notion of Insular lobe seizures was largely forgotten for decades. It is only since the late 1990s that the recent technique of stereo-electroencephalography (SEEG) enabled preoperative diagnosis of Insular origin seizures and thus gave rise to a renewed interest for this ill-defined electroclinical entity. Owing to the multiple functional roles of Insula and its extensive connectivity with adjacent as well as distant brain structures, Insular lobe seizures present with a combination or series of diverse subjective and objective symptoms. In this review, we summarize current knowledge on the semiology of Insular origin seizures. The following two distinct forms of clinical presentation have been recognized: 1) Seizures with predominant insulo-perisylvian symptoms, most notably paraesthesia and cervico-laryngeal discomfort. The former typically involves a large/bilateral cutaneous territory and can be perceived as cold, hot, or painful sensations. The latter ranges from slight dyspnea to strong sensation of strangulation. Other symptoms include epigastric discomfort/nausea, hypersalivation, auditory, vestibular, gustatory, and aphasic symptoms. 2) Nocturnal hyperkinetic seizures with/without tonic elevation of upper limbs, masquerading as fronto-mesial seizures. Patients are usually not fully aware of their symptoms despite preserved contact and organized behavior to others. Ipsilateral eye blinking can be observed. These two patterns often occur in succession or simultaneously. This characteristic combination and progression of ictal symptoms orients us strongly towards an Insular origin of seizure, a better understanding of which is a crucial key to further optimize modern SEEG strategy.
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how can we explain the frontal presentation of Insular lobe epilepsy the impact of non linear analysis of Insular seizures
Clinical Neurophysiology, 2017Co-Authors: Koichi Hagiwara, Sylvain Rheims, Marc Guenot, François Mauguière, Julien Jung, Romain Bouet, Chifaou Abdallah, L Garcialarrea, Jean IsnardAbstract:Abstract Objective For a decade it has been known that the Insular lobe epilepsy can mimic frontal lobe epilepsy. We aimed to clarify the pattern of functional coupling occurring during the frontal presentation. Methods We analyzed five Insular lobe epilepsy patients. Frontal semiology was predominant for three of them, whereas Insular semiology was predominant for the two others. We applied the non-linear regression analysis to stereoelectroencephalography-recorded seizures. A directed functional coupling index was calculated during clonic discharge periods that were accompanied either with frontal or Insular semiology. Results We found significant functional coupling between the Insula and mesial frontal/cingulate regions, with the former being a leader region for seizures propagation. Extra-Insular regions showed significantly less or even no coupling with the mesial hemispheric regions. The three patients with frontal semiology showed strong couplings with the mesial frontal as well as cingulate regions, including the medial orbitofrontal cortex, pre-SMA/SMA, and the anterior to posterior cingulate. The two patients with the Insular semiology only showed couplings between the Insula and cingulate regions. Conclusions The frontal semiology was expressed by strong functional couplings between the Insula and mesial frontal regions. Significance The Insular origin of seizure should be considered in cryptogenic mesial frontal epilepsies.
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monetary reward suppresses anterior Insula activity during social pain
Social Cognitive and Affective Neuroscience, 2015Co-Authors: Irene Cristofori, Jean Isnard, François Mauguière, Sylvain Harquel, Angela SiriguAbstract:Social pain after exclusion by others activates brain regions also involved in physical pain. Here we evaluated whether monetary reward could compensate for the negative feeling of social pain in the brain. To address this question we used the unique technique of intracranial electroencephalography in subjects with drug resistant epilepsy. Specifically, we recorded theta activity from intracranial electrodes implanted in the Insular cortex while subjects experienced conditions of social inclusion and exclusion associated with monetary gain and loss. Our study confirmed that theta rhythm in the Insular cortex is the neural signature of social exclusion. We found that while monetary gain suppresses the effect of social pain in the anterior Insula, there is no such effect in the posterior Insula. These results imply that the anterior Insula can use secondary reward signals to compensate for the negative feeling of social pain. Hence, here we propose that the anterior Insula plays a pivotal role in integrating contingencies to update social pain feelings. Finally, the possibility to modulate the theta rhythm through the reward system might open new avenues of research for treating pathologies related to social exclusion.
François Mauguière - One of the best experts on this subject based on the ideXlab platform.
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How the Insula speaks to the heart: Cardiac responses to Insular stimulation in humans.
Human brain mapping, 2019Co-Authors: Florian Chouchou, Sylvain Rheims, Hélène Catenoix, Alexandra Montavont, Jean Isnard, François Mauguière, Julien Jung, Ophélie Vallayer, Vincent Pichot, Laure MazzolaAbstract:Despite numerous studies suggesting the role of Insular cortex in the control of autonomic activity, the exact location of cardiac motor regions remains controversial. We provide here a functional mapping of autonomic cardiac responses to intracortical stimulations of the human Insula. The cardiac effects of 100 Insular electrical stimulations into 47 epileptic patients were divided into tachycardia, bradycardia, and no cardiac response according to the magnitude of RR interval (RRI) reactivity. Sympathetic (low frequency, LF, and low to high frequency powers ratio, LF/HF ratio) and parasympathetic (high frequency power, HF) reactivity were studied using RRI analysis. Bradycardia was induced by 26 stimulations (26%) and tachycardia by 21 stimulations (21%). Right and left Insular stimulations induced as often a bradycardia as a tachycardia. Tachycardia was accompanied by an increase in LF/HF ratio, suggesting an increase in sympathetic tone; while bradycardia seemed accompanied by an increase of parasympathetic tone reflected by an increase in HF. There was some left/right asymmetry in Insular subregions where increased or decreased heart rates were produced after stimulation. However, spatial distribution of tachycardia responses predominated in the posterior Insula, whereas bradycardia sites were more anterior in the median part of the Insula. These findings seemed to indicate a posterior predominance of sympathetic control in the Insula, whichever the side; whereas the parasympathetic control seemed more anterior. Dysfunction of these regions should be considered when modifications of cardiac activity occur during epileptic seizures and in cardiovascular diseases.
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how can we explain the frontal presentation of Insular lobe epilepsy the impact of non linear analysis of Insular seizures
Clinical Neurophysiology, 2017Co-Authors: Koichi Hagiwara, Sylvain Rheims, Marc Guenot, François Mauguière, Julien Jung, Romain Bouet, Chifaou Abdallah, L Garcialarrea, Jean IsnardAbstract:Abstract Objective For a decade it has been known that the Insular lobe epilepsy can mimic frontal lobe epilepsy. We aimed to clarify the pattern of functional coupling occurring during the frontal presentation. Methods We analyzed five Insular lobe epilepsy patients. Frontal semiology was predominant for three of them, whereas Insular semiology was predominant for the two others. We applied the non-linear regression analysis to stereoelectroencephalography-recorded seizures. A directed functional coupling index was calculated during clonic discharge periods that were accompanied either with frontal or Insular semiology. Results We found significant functional coupling between the Insula and mesial frontal/cingulate regions, with the former being a leader region for seizures propagation. Extra-Insular regions showed significantly less or even no coupling with the mesial hemispheric regions. The three patients with frontal semiology showed strong couplings with the mesial frontal as well as cingulate regions, including the medial orbitofrontal cortex, pre-SMA/SMA, and the anterior to posterior cingulate. The two patients with the Insular semiology only showed couplings between the Insula and cingulate regions. Conclusions The frontal semiology was expressed by strong functional couplings between the Insula and mesial frontal regions. Significance The Insular origin of seizure should be considered in cryptogenic mesial frontal epilepsies.
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monetary reward suppresses anterior Insula activity during social pain
Social Cognitive and Affective Neuroscience, 2015Co-Authors: Irene Cristofori, Jean Isnard, François Mauguière, Sylvain Harquel, Angela SiriguAbstract:Social pain after exclusion by others activates brain regions also involved in physical pain. Here we evaluated whether monetary reward could compensate for the negative feeling of social pain in the brain. To address this question we used the unique technique of intracranial electroencephalography in subjects with drug resistant epilepsy. Specifically, we recorded theta activity from intracranial electrodes implanted in the Insular cortex while subjects experienced conditions of social inclusion and exclusion associated with monetary gain and loss. Our study confirmed that theta rhythm in the Insular cortex is the neural signature of social exclusion. We found that while monetary gain suppresses the effect of social pain in the anterior Insula, there is no such effect in the posterior Insula. These results imply that the anterior Insula can use secondary reward signals to compensate for the negative feeling of social pain. Hence, here we propose that the anterior Insula plays a pivotal role in integrating contingencies to update social pain feelings. Finally, the possibility to modulate the theta rhythm through the reward system might open new avenues of research for treating pathologies related to social exclusion.
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Vestibular responses to direct stimulation of the human Insular cortex
Annals of neurology, 2014Co-Authors: Laure Mazzola, Isabelle Faillenot, François Mauguière, Christophe Lopez, Florian Chouchou, Jean IsnardAbstract:Objective: The present study provides a functional mapping of vestibular responses in the human Insular cortex. Methods: A total of 642 electrical stimulations of the Insula were performed in 219 patients, using stereotactically implanted depth electrodes, during the presurgical evaluation of drug-refractory partial epilepsy. We retrospectively identified 41 contacts where stimulation elicited vestibular sensations (VSs) and analyzed their location with respect to (1) their stereotactic coordinates (for all contacts), (2) the anatomy of Insula gyri (for 20 vestibular sites), and (3) the probabilistic cytoarchitectonic maps of the Insula (for 9 vestibular sites). Results: VSs occurred in 7.6% of the 541 evoked sensations after electrical stimulations of the Insula. VSs were mostly obtained after stimulation of the posterior Insula, that is, in the granular Insular cortex and the postcentral Insular gyrus. The data also suggest a spatial segregation of the responses in the Insula, with the rotatory and translational VSs being evoked at more posterior stimulation sites than other less definable VSs. No left-right differences were observed. Interpretation: These results demonstrate vestibular sensory processing in the Insula that is centered on its posterior part. The present data add to the understanding of the multiple sensory functions of the Insular cortex and of the cortical processing of vestibular signals. The data also indicate that lesion or dysfunction in the posterior Insula should be considered during the evaluation of vestibular epileptic seizures.
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Processing of nociceptive input from posterior to anterior Insula in humans.
Human brain mapping, 2014Co-Authors: Maud Frot, Isabelle Faillenot, François MauguièreAbstract:Previous brain imaging studies have shown robust activations in the Insula during nociceptive stimulation. Most activations involve the posterior Insular cortex but they can cover all Insular gyri in some fMRI studies. However, little is known about the timing of activations across the different Insular sub-regions. We report on the distribution of intracerebrally recorded nociceptive laser evoked potentials (LEPs) acquired from the full extent of the Insula in 44 epileptic patients. Our study shows that both posterior and anterior subdivisions of the Insular cortex respond to a nociceptive heat stimulus within a 200-400 ms latency range. This nociceptive cortical potential occurs firstly, and is larger, in the posterior granular Insular cortex. The presence of phase reversals in LEP components in both posterior and anterior Insular regions suggests activation of distinct, presumably functionally separate, sources in the posterior and anterior parts of the Insula. Our results suggest that nociceptive input is first processed in the posterior Insula, where it is known to be coded in terms of intensity and anatomical location, and then conveyed to the anterior Insula, where the emotional reaction to pain is elaborated.
Marc Guenot - One of the best experts on this subject based on the ideXlab platform.
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pain behavior without pain sensation an epileptic syndrome of symbolism for pain
Pain, 2020Co-Authors: Koichi Hagiwara, Sylvain Rheims, Hélène Catenoix, Alexandra Montavont, Marc Guenot, Luis Garcialarrea, Leon Tremblay, Jean IsnardAbstract:"Asymbolia for pain" has shown the potentiality of diseased Insular networks to dissociate sensory from affective-behavioral dimensions of pain, resulting in the lack of appropriate motor and affective responses despite preserved sensory aspect of pain. Here, we describe 4 patients with an inverse phenomenon of asymbolia for pain, namely an isolated "symbolism for pain" triggered by epileptic seizures, characterized by pain behavior without declarative pain sensation despite fully preserved contact and vigilance. Stereoelectroencephalography demonstrated in each case focal seizure discharges within the posterior insulo-opercular cortex, with little or no propagation to other cortical structures, especially those considered to drive subjective pain experiences. The pain behavior might reflect seizure propagation from the Insula to brain networks serving for behavioral responses associated with pain, including the cingulate motor region and possibly also the basal ganglia. We propose that the isolated symbolism for pain is a novel epileptic syndrome of dissociation between pain perception and behaviors associated with the Insular nociceptive-related networks.
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semiology of Insular lobe seizures
Revue Neurologique, 2019Co-Authors: Jean Isnard, K Ostrowskycoste, Laure Mazzola, Hélène Catenoix, Alexandra Montavont, Marc Guenot, Koichi Hagiwara, Sylvain RheimsAbstract:Abstract After the early attempts of intra-operative electrocorticography and insulectomy in the 1950s, the notion of Insular lobe seizures was largely forgotten for decades. It is only since the late 1990s that the recent technique of stereo-electroencephalography (SEEG) enabled preoperative diagnosis of Insular origin seizures and thus gave rise to a renewed interest for this ill-defined electroclinical entity. Owing to the multiple functional roles of Insula and its extensive connectivity with adjacent as well as distant brain structures, Insular lobe seizures present with a combination or series of diverse subjective and objective symptoms. In this review, we summarize current knowledge on the semiology of Insular origin seizures. The following two distinct forms of clinical presentation have been recognized: 1) Seizures with predominant insulo-perisylvian symptoms, most notably paraesthesia and cervico-laryngeal discomfort. The former typically involves a large/bilateral cutaneous territory and can be perceived as cold, hot, or painful sensations. The latter ranges from slight dyspnea to strong sensation of strangulation. Other symptoms include epigastric discomfort/nausea, hypersalivation, auditory, vestibular, gustatory, and aphasic symptoms. 2) Nocturnal hyperkinetic seizures with/without tonic elevation of upper limbs, masquerading as fronto-mesial seizures. Patients are usually not fully aware of their symptoms despite preserved contact and organized behavior to others. Ipsilateral eye blinking can be observed. These two patterns often occur in succession or simultaneously. This characteristic combination and progression of ictal symptoms orients us strongly towards an Insular origin of seizure, a better understanding of which is a crucial key to further optimize modern SEEG strategy.
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how can we explain the frontal presentation of Insular lobe epilepsy the impact of non linear analysis of Insular seizures
Clinical Neurophysiology, 2017Co-Authors: Koichi Hagiwara, Sylvain Rheims, Marc Guenot, François Mauguière, Julien Jung, Romain Bouet, Chifaou Abdallah, L Garcialarrea, Jean IsnardAbstract:Abstract Objective For a decade it has been known that the Insular lobe epilepsy can mimic frontal lobe epilepsy. We aimed to clarify the pattern of functional coupling occurring during the frontal presentation. Methods We analyzed five Insular lobe epilepsy patients. Frontal semiology was predominant for three of them, whereas Insular semiology was predominant for the two others. We applied the non-linear regression analysis to stereoelectroencephalography-recorded seizures. A directed functional coupling index was calculated during clonic discharge periods that were accompanied either with frontal or Insular semiology. Results We found significant functional coupling between the Insula and mesial frontal/cingulate regions, with the former being a leader region for seizures propagation. Extra-Insular regions showed significantly less or even no coupling with the mesial hemispheric regions. The three patients with frontal semiology showed strong couplings with the mesial frontal as well as cingulate regions, including the medial orbitofrontal cortex, pre-SMA/SMA, and the anterior to posterior cingulate. The two patients with the Insular semiology only showed couplings between the Insula and cingulate regions. Conclusions The frontal semiology was expressed by strong functional couplings between the Insula and mesial frontal regions. Significance The Insular origin of seizure should be considered in cryptogenic mesial frontal epilepsies.
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somatotopic organization of pain responses to direct electrical stimulation of the human Insular cortex
Pain, 2009Co-Authors: L Mazzola, Marc Guenot, Jean Isnard, R Peyron, François MauguièreAbstract:The question whether pain encoding in the human Insula shows some somatotopic organization is still pending. We studied 142 patients undergoing depth stereotactic EEG (SEEG) exploration of the Insular cortex for pre-surgical evaluation of epilepsy. 472 Insular electrical stimulations were delivered, of which only 49 (10.5%) elicited a painful sensation in 38 patients (27%). Most sites where low intensity electric stimulation produced pain, without after-discharge or concomitant visually detectable change in EEG activity outside the Insula, were located in the posterior two thirds of the Insula. Pain was located in a body area restricted to face, upper limb or lower limb for 27 stimulations (55%) and affected more than one of these regions for all others. The Insular cortex being oriented parallel to the medial sagittal plane we found no significant difference between body segment representations in the medio-lateral axis. Conversely a somatotopic organization of sites where stimulation produced pain was observed along the rostro-caudal and vertical axis of the Insula, showing a face representation rostral to those of upper and lower limbs, with an upper limb representation located above that of the lower limb. These data suggest that, in spite of large and often bilateral receptive fields, pain representation shows some degree of somatotopic organization in the human Insula.
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an attention modulated response to disgust in human ventral anterior Insula
Annals of Neurology, 2003Co-Authors: Pierre Krolaksalmon, Marc Guenot, Jean Isnard, Marieanna Henaff, Catherine Tallonbaudry, Alain Vighetto, Olivier F Bertrand, F MauguiereAbstract:The human brain is expert in analyzing rapidly and precisely facial features, especially emotional expressions representing a powerful communication vector. The involvement of Insula in disgust recognition has been reported in behavioral and functional imaging studies. However, we do not know whether specific Insular fields are involved in disgust processing nor what the processing time course is. Using depth electrodes implanted during presurgical evaluation of patients with drug-refractory temporal lobe epilepsy, we recorded intracerebral event-related potentials to human facial emotional expressions, that is, fear, disgust, happiness, surprise, and neutral expression. We studied evoked responses in 13 patients with Insular contacts to specify the Insular fields involved in disgust processing and assess the timing of their activation. We showed that specific potentials to disgust beginning 300 milliseconds after stimulus onset and lasting 200 milliseconds were evoked in the ventral anterior Insula in four patients. The occurrence and latency of event-related potentials to disgust in the ventral anterior Insula were affected by selective attention. The analysis of spatial and temporal characteristics of Insular responses to disgust facial expression lead us to underline the crucial role of ventral anterior Insula in the categorization of facial emotional expressions, particularly the disgust.
Dang Khoa Nguyen - One of the best experts on this subject based on the ideXlab platform.
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expected value and sensitivity to punishment modulate Insular cortex activity during risky decision making
Scientific Reports, 2020Co-Authors: Zorina Von Siebenthal, Mathieu Roy, Pierre Rainville, Olivier Boucher, Latifa Lazzouni, Veronique A Taylor, Kristina Martinu, Franco Lepore, Dang Khoa NguyenAbstract:The exact contribution of the Insula to risky decision making remains unclear, as are the specific outcome parameters and inter-individual characteristics that modulate Insular activity prior to a risky choice. This fMRI study examines the contributions of outcome valence, magnitude, probability, and expected value (EV) to Insular activity during risky decision making, and explores the influence of sensitivity to reward and to punishment, and anxiety, to Insular activity. Participants (N = 31) performed a gambling task requiring choice between two roulettes with different outcome magnitude, probability and EV, under gain and loss conditions separately, and filled questionnaires assessing sensitivity to punishment/reward, and state/trait anxiety. Parametric analyses were conducted to examine the modulation of brain activity during decision making in relation to each task parameter. Correlations were examined between Insular activity and psychometric questionnaires. EV of the selected roulette was associated with right posterior Insula activation during decision making. Higher sensitivity to punishment was associated with lower bilateral Insular activation. These findings suggest that the right posterior Insula is involved in tracking the EV of a risky option during decision making. The involvement of the Insula when making risky decisions also appears to be influenced by inter-individual differences in sensitivity to punishment.
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Spatiotemporal dynamics of auditory information processing in the Insular cortex: an intracranial EEG study using an oddball paradigm
Brain Structure and Function, 2020Co-Authors: Daphné Citherlet, Olivier Boucher, Franco Lepore, Julie Tremblay, Manon Robert, Anne Gallagher, Alain Bouthillier, Dang Khoa NguyenAbstract:Functional neuroimaging studies using auditory stimuli consistently show activation of the Insular cortex. However, due to the limited temporal resolution of non-invasive neuroimaging techniques, the role(s) of the Insula in auditory processing remains unclear. As the anterior Insula (aI) and the posterior Insula (pI) have different connections and are thought to be functionally distinct, it is likely that these two areas contribute differently to auditory processing. Our study examines the spatiotemporal dynamics of auditory processing in the Insula using intracranial electroencephalography (EEG). Eight epileptic patients completed two passive listening tasks and one three-stimulus auditory oddball detection task during the intracranial EEG monitoring of their drug-resistant seizures. Recordings were obtained from depth electrodes implanted in 11 Insulae. Event-related potentials (ERPs) were analyzed using permutation analyses during the N100 and the P300 intervals, and modulations of alpha, theta, and gamma band responses were compared using Wilcoxon/Mann–Whitney analyses. N100 responses to auditory stimuli were mostly observed in the pI and were little affected by task conditions. Auditory target detection was associated with P300 ERPs, and alpha, theta, high- and low-gamma responses, preferentially at aI contacts. Results suggest that the aI is involved in voluntary attentional processing of task-relevant information, whereas the pI is involved in automatic auditory processing.
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Insular epilepsy semiology and noninvasive investigations
Journal of Clinical Neurophysiology, 2017Co-Authors: Sami Obaid, Younes Zerouali, Dang Khoa NguyenAbstract:Summary:In this review, authors discuss the semiology and noninvasive investigations of Insular epilepsy, an underrecognized type of epilepsy, which may mimic other focal epilepsies. In line with the various functions of the Insula and its widespread network of connections, Insular epilepsy may feat
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revisiting the role of the Insula in refractory partial epilepsy
Epilepsia, 2009Co-Authors: Dang Khoa Nguyen, Dong Bach Nguyen, Ramez Malak, Jeanmaxime Leroux, Lionel Carmant, Jeanmarc Sainthilaire, Normand Giard, Patrick Cossette, Alain BouthillierAbstract:Summary Purpose: Recent evidence suggesting that some epilepsy surgery failures could be related to unrecognized Insular epilepsy have led us to lower our threshold to sample the Insula with intracerebral electrodes. In this study, we report our experience resulting from this change in strategy. Methods: During the period extending from October 2004 to June 2007, 18 patients had an intracranial study including 10 with Insular coverage. The decision to sample the Insula with intracerebral electrodes was made in the context of (1) nonlesional parietal lobe-like epilepsy; (2) nonlesional frontal lobe-like epilepsy; (3) nonlesional temporal lobe-like epilepsy; and (4) atypical temporal lobe-like epilepsy. Results: Intracerebral recordings confirmed the presence of Insular lobe seizures in four patients. Cortical stimulation performed in 9 of 10 patients with Insular electrodes elicited, in decreasing order of frequency, somatosensory, viscerosensory, motor, auditory, vestibular, and speech symptoms. Discussion: Our results suggest that Insular cortex epilepsy may mimic temporal, frontal, and parietal lobe epilepsies and that a nonnegligeable proportion of surgical candidates with drug-resistant epilepsy have an epileptogenic zone that involves the Insula.
Sylvain Rheims - One of the best experts on this subject based on the ideXlab platform.
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pain behavior without pain sensation an epileptic syndrome of symbolism for pain
Pain, 2020Co-Authors: Koichi Hagiwara, Sylvain Rheims, Hélène Catenoix, Alexandra Montavont, Marc Guenot, Luis Garcialarrea, Leon Tremblay, Jean IsnardAbstract:"Asymbolia for pain" has shown the potentiality of diseased Insular networks to dissociate sensory from affective-behavioral dimensions of pain, resulting in the lack of appropriate motor and affective responses despite preserved sensory aspect of pain. Here, we describe 4 patients with an inverse phenomenon of asymbolia for pain, namely an isolated "symbolism for pain" triggered by epileptic seizures, characterized by pain behavior without declarative pain sensation despite fully preserved contact and vigilance. Stereoelectroencephalography demonstrated in each case focal seizure discharges within the posterior insulo-opercular cortex, with little or no propagation to other cortical structures, especially those considered to drive subjective pain experiences. The pain behavior might reflect seizure propagation from the Insula to brain networks serving for behavioral responses associated with pain, including the cingulate motor region and possibly also the basal ganglia. We propose that the isolated symbolism for pain is a novel epileptic syndrome of dissociation between pain perception and behaviors associated with the Insular nociceptive-related networks.
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How the Insula speaks to the heart: Cardiac responses to Insular stimulation in humans.
Human brain mapping, 2019Co-Authors: Florian Chouchou, Sylvain Rheims, Hélène Catenoix, Alexandra Montavont, Jean Isnard, François Mauguière, Julien Jung, Ophélie Vallayer, Vincent Pichot, Laure MazzolaAbstract:Despite numerous studies suggesting the role of Insular cortex in the control of autonomic activity, the exact location of cardiac motor regions remains controversial. We provide here a functional mapping of autonomic cardiac responses to intracortical stimulations of the human Insula. The cardiac effects of 100 Insular electrical stimulations into 47 epileptic patients were divided into tachycardia, bradycardia, and no cardiac response according to the magnitude of RR interval (RRI) reactivity. Sympathetic (low frequency, LF, and low to high frequency powers ratio, LF/HF ratio) and parasympathetic (high frequency power, HF) reactivity were studied using RRI analysis. Bradycardia was induced by 26 stimulations (26%) and tachycardia by 21 stimulations (21%). Right and left Insular stimulations induced as often a bradycardia as a tachycardia. Tachycardia was accompanied by an increase in LF/HF ratio, suggesting an increase in sympathetic tone; while bradycardia seemed accompanied by an increase of parasympathetic tone reflected by an increase in HF. There was some left/right asymmetry in Insular subregions where increased or decreased heart rates were produced after stimulation. However, spatial distribution of tachycardia responses predominated in the posterior Insula, whereas bradycardia sites were more anterior in the median part of the Insula. These findings seemed to indicate a posterior predominance of sympathetic control in the Insula, whichever the side; whereas the parasympathetic control seemed more anterior. Dysfunction of these regions should be considered when modifications of cardiac activity occur during epileptic seizures and in cardiovascular diseases.
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semiology of Insular lobe seizures
Revue Neurologique, 2019Co-Authors: Jean Isnard, K Ostrowskycoste, Laure Mazzola, Hélène Catenoix, Alexandra Montavont, Marc Guenot, Koichi Hagiwara, Sylvain RheimsAbstract:Abstract After the early attempts of intra-operative electrocorticography and insulectomy in the 1950s, the notion of Insular lobe seizures was largely forgotten for decades. It is only since the late 1990s that the recent technique of stereo-electroencephalography (SEEG) enabled preoperative diagnosis of Insular origin seizures and thus gave rise to a renewed interest for this ill-defined electroclinical entity. Owing to the multiple functional roles of Insula and its extensive connectivity with adjacent as well as distant brain structures, Insular lobe seizures present with a combination or series of diverse subjective and objective symptoms. In this review, we summarize current knowledge on the semiology of Insular origin seizures. The following two distinct forms of clinical presentation have been recognized: 1) Seizures with predominant insulo-perisylvian symptoms, most notably paraesthesia and cervico-laryngeal discomfort. The former typically involves a large/bilateral cutaneous territory and can be perceived as cold, hot, or painful sensations. The latter ranges from slight dyspnea to strong sensation of strangulation. Other symptoms include epigastric discomfort/nausea, hypersalivation, auditory, vestibular, gustatory, and aphasic symptoms. 2) Nocturnal hyperkinetic seizures with/without tonic elevation of upper limbs, masquerading as fronto-mesial seizures. Patients are usually not fully aware of their symptoms despite preserved contact and organized behavior to others. Ipsilateral eye blinking can be observed. These two patterns often occur in succession or simultaneously. This characteristic combination and progression of ictal symptoms orients us strongly towards an Insular origin of seizure, a better understanding of which is a crucial key to further optimize modern SEEG strategy.
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how can we explain the frontal presentation of Insular lobe epilepsy the impact of non linear analysis of Insular seizures
Clinical Neurophysiology, 2017Co-Authors: Koichi Hagiwara, Sylvain Rheims, Marc Guenot, François Mauguière, Julien Jung, Romain Bouet, Chifaou Abdallah, L Garcialarrea, Jean IsnardAbstract:Abstract Objective For a decade it has been known that the Insular lobe epilepsy can mimic frontal lobe epilepsy. We aimed to clarify the pattern of functional coupling occurring during the frontal presentation. Methods We analyzed five Insular lobe epilepsy patients. Frontal semiology was predominant for three of them, whereas Insular semiology was predominant for the two others. We applied the non-linear regression analysis to stereoelectroencephalography-recorded seizures. A directed functional coupling index was calculated during clonic discharge periods that were accompanied either with frontal or Insular semiology. Results We found significant functional coupling between the Insula and mesial frontal/cingulate regions, with the former being a leader region for seizures propagation. Extra-Insular regions showed significantly less or even no coupling with the mesial hemispheric regions. The three patients with frontal semiology showed strong couplings with the mesial frontal as well as cingulate regions, including the medial orbitofrontal cortex, pre-SMA/SMA, and the anterior to posterior cingulate. The two patients with the Insular semiology only showed couplings between the Insula and cingulate regions. Conclusions The frontal semiology was expressed by strong functional couplings between the Insula and mesial frontal regions. Significance The Insular origin of seizure should be considered in cryptogenic mesial frontal epilepsies.
