Dominique Hasboun - Profile on Academia.edu (original) (raw)
Papers by Dominique Hasboun
Supplementary material from "Is the cardiac monitoring function related to the self in both the default-network and right anterior insula?
The self has been proposed to be rooted in the neural monitoring of internal bodily signals and m... more The self has been proposed to be rooted in the neural monitoring of internal bodily signals and might thus involve interoceptive areas, notably the right anterior insula (rAI). However, studies on the self consistently showed the involvement of midline default network (DN) nodes, without referring to visceral monitoring. Here, we investigate this apparent discrepancy. We previously showed that neural responses to heartbeats in the DN encode two different self-dimensions, the agentive 'I' and the introspective 'Me', in a whole-brain analysis of magnetoencephalography (MEG) data. Here we confirm and anatomically refine this result with intracranial recordings (iEEG). In two patients, we show a parametric modulation of neural responses to heartbeats by the self-relatedness of thoughts, at the single trial level. A region-of-interest analysis of the insula reveals that MEG responses to heartbeats in the rAI encode the 'I' self-dimension. The effect in rAI was weaker than in the DN and was replicated in iEEG data in one patient out of two. We propose that a common mechanism, the neural monitoring of cardiac signals, underlies the self in both the DN and rAI. This might reconcile studies on the self highlighting the DN, with studies on interoception focusing on the insula.This article is part of the themed issue 'Interoception beyond homeostasis: affect, cognition and mental health'.
Philosophical Transactions of the Royal Society B, Nov 19, 2016
The self has been proposed to be rooted in the neural monitoring of internal bodily signals and m... more The self has been proposed to be rooted in the neural monitoring of internal bodily signals and might thus involve interoceptive areas, notably the right anterior insula (rAI). However, studies on the self consistently showed the involvement of midline default network (DN) nodes, without referring to visceral monitoring. Here, we investigate this apparent discrepancy. We previously showed that neural responses to heartbeats in the DN encode two different self-dimensions, the agentive 'I' and the introspective 'Me', in a whole-brain analysis of magnetoencephalography (MEG) data. Here, we confirm and anatomically refine this result with intracranial recordings (intracranial electroencephalography, iEEG). In two patients, we show a parametric modulation of neural responses to heartbeats by the selfrelatedness of thoughts, at the single trial level. A region-of-interest analysis of the insula reveals that MEG responses to heartbeats in the rAI encode the 'I' self-dimension. The effect in rAI was weaker than in the DN and was replicated in iEEG data in one patient out of two. We propose that a common mechanism, the neural monitoring of cardiac signals, underlies the self in both the DN and rAI. This might reconcile studies on the self highlighting the DN, with studies on interoception focusing on the insula. This article is part of the themed issue 'Interoception beyond homeostasis: affect, cognition and mental health'.
Biometrie de l'hippocampe en imagerie par resonance magnetique 3d chez l'homme. Applications a l'epilepsie de la face mediale du lobe temporal
Les structures amygdalo-hippocampiques constituent une cible privilegiee dans l'epilepsie de ... more Les structures amygdalo-hippocampiques constituent une cible privilegiee dans l'epilepsie de la face interne du lobe temporal. La quantification du volume hippocampique contribue a poser les indications chirurgicales des epilepsies du lobe temporal. L'objectif central de l'etude est de definir un seuil d'asymetrie hippocampique en irm 3d permettant d'effectuer le diagnostic d'atrophie hippocampique. Les volumes hippocampiques ont ete obtenus par une segmentation realisee sur les acquisitions i. R. M. Tridimensionnelles. La definition du plan de segmentation est fondamentale. Les volumes obtenus sont significativement differents selon que la segmentation est realisee sur une acquisition coronale non perpendiculaire a l'hippocampe, sur ce meme examen reformate dans le plan perpendiculaire a l'hippocampe ou sur un examen directement acquis dans le bon plan. Parmi les principaux parametres biologiques : age, sexe, volume cerebral, poids, taille d'un echantillon de sujets (18-35 ans), seul le sexe et le volume cerebral ont un effet significatif sur le volume hippocampique. Ces resultats indiquent l'utilite d'ajuster les volumes hippocampiques aux volumes cerebraux pour les comparer d'un sujet a l'autre. Malgre l'ajustement des volumes hippocampiques, la persistance de l'effet du sexe suggere que l'hippocampe est caracterise par un dimorphisme sexuel. Par ailleurs, l'hippocampe droit presente un volume superieur a celui de l'hippocampe gauche. Il est important de determiner un seuil pathologique. L'analyse discriminante pour une variable (volume hippocampique ou index d'asymetrie) est insuffisante. L'analyse discriminante pour trois variables (index d'asymetrie hippocampique lateral, volume hippocampique droit corrige, volume hippocampique gauche corrige) donne les meilleurs resultats. La regression logistique donne des resultats plus satisfaisants. Elle a permis de determiner un seuil pathologique pour l'index d'asymetrie hippocampique iahps (0,18) et iahlat (0,20).
Neurology, Apr 1, 1997
Article abstractprogressive facial hemiatrophy (PFH), a rare disorder characterized by progressiv... more Article abstractprogressive facial hemiatrophy (PFH), a rare disorder characterized by progressive and self-limited atrophy of the skin and the subcutaneous tissues, is often associated with epilepsy but the link between these two conditions is poorly understood. The cause of PFH remains unclear. We report four patients with PFH associated with partial epilepsy in whom brain MRI showed cerebral dysgenesis. The four patients (two men, two women; age range: 24 to 73 years) developed parasagittal PFH in their second decade. Seizures started before the age of 20 years in three patients and were refractory simple, or complex partial seizures. All the patients had focal MRI showing cortical dysgenesis, ipsilateral to PFH, consisting of cortex thickening, gyral effacement, and blurring of the white-gray interface. The underlying white matter was hyperintense on T,-weighted sequences, with nodular areas in two patients. These areas were stable over time, without contrast enhancement, and were consistent with the MRI characteristics of cystic encephalomalacia. These neuroradiologic features suggest a localized cerebral hemispheric defect of congenital origin. Because cells participating in the formation of the fronto-nasal bud derive from common progenitors with the cells that give rise to the cerebral hemisphere, we suggest that an early malformative process affecting one side of the rostra1 neural tube could underlie both cerebral dysgenesis and facial hemiatrophy.
NeuroImage, Sep 1, 2003
We present an MEG/EEG framework to reveal statistically significant brain areas engaged in the sa... more We present an MEG/EEG framework to reveal statistically significant brain areas engaged in the same cognitive process across trials without resort to averaging procedures. The variability of neuronal responses is assumed to take place only in the reconstructed time series of cortical sources and not in their positions. This hypothesis allows the use of the surrogate data method to detect recurrently active brain areas across trials adjusted with any cortically constrained focal MEEG inverse solution. Results obtained from synthetic data show that considering several trials enhances the accuracy of the source localisation. We apply this approach on MEG data recorded during a simple visual stimulation. The considered stimulus is frequency tagged in order to reveal the neural network correlated to its perception using phase synchronisation analysis. The results show consistent patterns of distributed synchronous networks centred on occipital areas.
Segmentation of the amygdalo-hippocampal complex by competitive region growing [MRI analysis]
Semi-automatic segmentation of amygdala and hippocampus is of major interest to neurologists but ... more Semi-automatic segmentation of amygdala and hippocampus is of major interest to neurologists but it is a challenge to numerical image analysis techniques because of intrinsic complexity of those structures. We introduce a new method to approach this problem with Markovian region growing. As we are concerned by segmenting atrophic structures, we did not use shape priors, but constrained the growth with relational and weak geometric priors. The major relational constraint is given by the simultaneous segmentation of hippocampus and amygdala. The algorithm runs quickly on a basic workstation with satisfactory results on both structures.
Fixel‐Based Analysis Reveals Whole‐Brain White Matter Abnormalities in Cervical Dystonia
Movement Disorders, May 6, 2023
BackgroundCervical dystonia (CD) is a form of isolated focal dystonia typically associated to abn... more BackgroundCervical dystonia (CD) is a form of isolated focal dystonia typically associated to abnormal head, neck, and shoulder movements and postures. The complexity of the clinical presentation limits the investigation of its pathophysiological mechanisms, and the neural networks associated to specific motor manifestations are still the object of debate.ObjectivesWe investigated the morphometric properties of white matter fibers in CD and explored the networks associated with motor symptoms, while regressing out nonmotor scores.MethodsNineteen patients affected by CD and 21 healthy controls underwent diffusion‐weighted magnetic resonance imaging. We performed fixel‐based analysis, a novel method evaluating fiber orientation within specific fiber bundles, and compared fiber morphometric properties between groups. Moreover, we correlated fiber morphometry with the severity of motor symptoms in patients.ResultsCompared to controls, patients exhibited decreased white matter fibers in the right striatum. Motor symptom severity negatively correlated with white matter fibers passing through inferior parietal areas and the head representation area of the motor cortex.ConclusionsAbnormal white matter integrity at the basal ganglia level may affect several functional networks involved, for instance, in motor preparation and execution, visuomotor coordination, and multimodal integration. This may result in progressive maladaptive plasticity, culminating in overt symptoms of dystonia. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Clinical neuroradiology, Jun 21, 2021
Purpose Tectum mesencephali arteriovenous malformations (TM-AVMs) are rare lesions deeply located... more Purpose Tectum mesencephali arteriovenous malformations (TM-AVMs) are rare lesions deeply located close to eloquent structures making them challenging to treat. We aimed to present clinical presentation, angiographic features and treatment strategies of TM-AVMs through a single center retrospective case series. Methods A TM-AVMs is defined as a nidus located in the parenchyma or on the pia mater of the posterior midbrain. Records of consecutive patients admitted with TM-AVMs over a 21-year period were retrospectively analyzed. Vascular anatomy of the region is also reviewed. Results In this study 13 patients (1.63% of the complete cohort; 10 males), mean age 48 years, were included. All patients presented with intracranial hemorrhage and two patients (15%) died after an early recurrent bleeding. Mean size of the TM-AVMs was 10.1 ± 5 mm. Multiple arterial feeders were noted in every cases. Of the patients 11 underwent an exclusion treatment, 8 via embolization (6 via arterial access and 2 via venous access) and 4 via stereotactic radiosurgery (SRS) (1 patient received both). Overall success treatment rate was 7/11 patients (64% overall; 63% in the embolization group, 25% in the SRS group). Two hemorrhagic events led to a worsened outcome, one during embolization and one several years after SRS. All other patients remained clinically stable or improved. Conclusion The TM-AVMs are rare but stereotypic lesions found in a hemorrhagic context. Multiple arterial feeders are always present. Endovascular treatment seems to be an effective technique with relatively low morbidity; SRS had a low success rate but was only use in a limited number of patients.
HAL (Le Centre pour la Communication Scientifique Directe), Jun 14, 2015
[MRI of drug-resistant epilepsies: contribution of FLAIR sequence in a series of 150 patients]
PubMed, Sep 1, 2000
We studied the usefulness of the Fluid-Attenuated Inversion-Recovery (FLAIR) pulse sequence for p... more We studied the usefulness of the Fluid-Attenuated Inversion-Recovery (FLAIR) pulse sequence for patients with intractable seizures by reviewing the MR images of 150 consecutive patients including a standard imaging protocol and a FLAIR sequence. FLAIR images revealed a cortical lesion in 8 of the 81 patients with no lesion detected on the standard MR imaging protocol. In addition, FLAIR images provided additional informations for 13 patients of the 69 patients for whom a lesion was already detected on the standard MR imaging protocol. Therefore, our results indicated that FLAIR sequences were a useful imaging tool for patients with intractable seizures since it improved the MR diagnosis in 21 of 150 patients (14%).
Neuroradiology, Jul 7, 1999
American Journal of Neuroradiology, Aug 1, 1998
The role of genetic mechanisms and the influence of environmental events in human brain developme... more The role of genetic mechanisms and the influence of environmental events in human brain development have been difficult to evaluate. The purpose of this study was to compare the cerebral cortical morphology and midline structures of monozygotic twin pairs using MR imaging. METHODS: Six observers, blinded to twin pairings, evaluated the 3-D renderings of the cortical surface and midline structures from MR images of seven monozygotic twin pairs. A morphometric analysis of the corpus callosum and of the distance between the anterior and posterior commissures was also performed. RESULTS: Despite surprising anatomic differences, the brains of the twin pairs were similar enough to enable the observers to distinguish twin pairs from unrelated subjects. Five of six observers correctly identified the brains of all seven twin pairs; the remaining observer failed to make a correct match in only one of seven pairs. Three of six observers identified the midline sagittal images of the related twins in all seven pairs, and the other three identified the related midline sagittal images in five of seven pairs. The results were statistically significant. CONCLUSION: Although the observed differences in morphologic characteristics between twins necessarily reflect nongenetic influences, the cortical patterns and midline structures of monozygotic twins probably are genetically similar.
Journal of Neuropathology and Experimental Neurology, Apr 1, 2011
Sleep disorders are important manifestations of neurodegenerative diseases and sometimes are clin... more Sleep disorders are important manifestations of neurodegenerative diseases and sometimes are clinically evident well before the onset of other neurological manifestations. This review addresses the neuroanatomical basis and the mechanisms of sleep regulation in humans in relation to the neuropathology of entities associated with sleep disturbances in selected diseases, including Alzheimer disease, progressive supranuclear palsy, Lewy body disorders, multiple-system atrophy, and fatal familial insomnia. This includes abnormalities of circadian rhythm, insomnia, narcolepsy, rapid eye movements sleep behavior disorders, and excessive daytime sleepiness.
[Dementia and memory: morphologic imagery with MRI]
PubMed, 1998
Modern imaging techniques, and notably magnetic resonance imaging (MRI) enable an increasingly pr... more Modern imaging techniques, and notably magnetic resonance imaging (MRI) enable an increasingly precise exploration of primary degenerative dementias. The main contribution of imaging is to demonstrate lesion localizations which confirm the degenerative nature of the observed disorders, contributing to an understanding of the correlation between clinical signs and causal lesions. The development of techniques quantifying cerebral volume which can be applied to an analysis of small structures such as the hippocampus coupled with a better understanding of primary degenerative dementias allow more specific study of the atrophy than could be obtained with a global assessment of ventricular dilatation. More recently, the development of MRI methods studying brain perfusion open the way for noninvasive exploration of perfusion anomalies in these patients.
Automatic Segmentation of Depth Electrodes Implanted in Epileptic Patients: A Modular Tool Adaptable to Multicentric Protocols
HAL (Le Centre pour la Communication Scientifique Directe), Feb 1, 2015
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Irradiation en conditions stéréotaxiques des métastases cérébrales chez les patients âgés
Bulletin Du Cancer, Oct 1, 2003
... Auteur(s) : Georges NOËL 1 , Sophie NOËL 5 , Loïc FEUVRET 1 , Charles-Ambroise VALERY 2 , Phi... more ... Auteur(s) : Georges NOËL 1 , Sophie NOËL 5 , Loïc FEUVRET 1 , Charles-Ambroise VALERY 2 , Philippe CORNU 2 , Gilbert BOISSERIE 1 , Dominique HASBOUN 3 , Bernadette TEP 1 , Jean ... 42. Auchter RM, Lamond JP, Alexander E, Buatti JM, Chappell R, Friedman WA, et al. ...
Acta Neurologica Scandinavica, Jul 1, 1996
Variability of presentation in medial temporal lobe epilepsy: a study of 30 operated cases Acta N... more Variability of presentation in medial temporal lobe epilepsy: a study of 30 operated cases Acta Neurol Scand 1996: 9 4 1-11. 0 Munksgaard 1996.
Neuroscience Research, 2000
have shown an inverse association between asymmetry in perisylvian areas and the size of a specif... more have shown an inverse association between asymmetry in perisylvian areas and the size of a specific segment, the isthmus, of the corpus callosum (CC) in males. The purpose of this work was to study in vivo the association between hemispheric asymmetry and the total size of the CC in 35 right-handed subjects (16 males, 19 females; mean age 24.9 93.9). An MRI scan was performed for each subject. The area of the right (RH) and left (LH) hemispheres were measured from images in the sagittal plane and the area of the CC from images in the mid-sagittal plane. The index of hemispheric asymmetry was (LH− RH)/[(LH+ RH)/2]. There was a negative correlation between the absolute value of hemispheric asymmetry and the size of the CC in males (r= −0.55, P =0.03) but not in females (r= −0.20, P = 0.42). These findings, like those of Aboitiz et al.
Brain, Dec 9, 2005
Patients with refractory partial seizures may benefit from epilepsy surgery. However, invasive in... more Patients with refractory partial seizures may benefit from epilepsy surgery. However, invasive investigations are often needed to define the precise location and limits of the epileptogenic zone (EZ). In this study, we asked whether diffusion tensor imaging (DTI) might provide a non-invasive alternative to locate the EZ or at least provide insights to help place intracerebral electrodes for stereo-electroencephalography (SEEG). Whole brain DTI and voxel-based analysis (SPM99) was used to assess diffusion properties objectively in 16 epilepsy patients investigated with SEEG. Epilepsy was symptomatic in two patients and cryptogenic in the 14 remaining patients. The suspected onset of seizures was temporal in 10 patients, frontal in 2 and occipital in 4. Individual maps of apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were calculated and compared to a database of 40 healthy volunteers. Thirteen of 16 patients exhibited diffusion abnormalities. ADC abnormalities were better correlated with SEEG data than FA abnormalities which were usually located at a distance or in the white matter. A significant increase in ADC (P < 0.01) was found in 11 patients and was located in the regions explored with depth electrodes in 7 of them. Surgery outcome was available in 3 of these 7 patients (2 were seizure free and 1 not). DTI specificity was better in extratemporal lobe epilepsy (83%) than in temporal lobe epilepsy (20%). When abnormalities concurred with the SEEG data, the concordance was optimal between the localization of the diffusion abnormalities and the irritative zone defined by SEEG. These encouraging, preliminary results, suggest that DTI examinations may provide accurate spatial data on the location and extent of the epileptogenic network in extratemporal lobe epilepsies.
Supplementary material from "Is the cardiac monitoring function related to the self in both the default-network and right anterior insula?
The self has been proposed to be rooted in the neural monitoring of internal bodily signals and m... more The self has been proposed to be rooted in the neural monitoring of internal bodily signals and might thus involve interoceptive areas, notably the right anterior insula (rAI). However, studies on the self consistently showed the involvement of midline default network (DN) nodes, without referring to visceral monitoring. Here, we investigate this apparent discrepancy. We previously showed that neural responses to heartbeats in the DN encode two different self-dimensions, the agentive 'I' and the introspective 'Me', in a whole-brain analysis of magnetoencephalography (MEG) data. Here we confirm and anatomically refine this result with intracranial recordings (iEEG). In two patients, we show a parametric modulation of neural responses to heartbeats by the self-relatedness of thoughts, at the single trial level. A region-of-interest analysis of the insula reveals that MEG responses to heartbeats in the rAI encode the 'I' self-dimension. The effect in rAI was weaker than in the DN and was replicated in iEEG data in one patient out of two. We propose that a common mechanism, the neural monitoring of cardiac signals, underlies the self in both the DN and rAI. This might reconcile studies on the self highlighting the DN, with studies on interoception focusing on the insula.This article is part of the themed issue 'Interoception beyond homeostasis: affect, cognition and mental health'.
Philosophical Transactions of the Royal Society B, Nov 19, 2016
The self has been proposed to be rooted in the neural monitoring of internal bodily signals and m... more The self has been proposed to be rooted in the neural monitoring of internal bodily signals and might thus involve interoceptive areas, notably the right anterior insula (rAI). However, studies on the self consistently showed the involvement of midline default network (DN) nodes, without referring to visceral monitoring. Here, we investigate this apparent discrepancy. We previously showed that neural responses to heartbeats in the DN encode two different self-dimensions, the agentive 'I' and the introspective 'Me', in a whole-brain analysis of magnetoencephalography (MEG) data. Here, we confirm and anatomically refine this result with intracranial recordings (intracranial electroencephalography, iEEG). In two patients, we show a parametric modulation of neural responses to heartbeats by the selfrelatedness of thoughts, at the single trial level. A region-of-interest analysis of the insula reveals that MEG responses to heartbeats in the rAI encode the 'I' self-dimension. The effect in rAI was weaker than in the DN and was replicated in iEEG data in one patient out of two. We propose that a common mechanism, the neural monitoring of cardiac signals, underlies the self in both the DN and rAI. This might reconcile studies on the self highlighting the DN, with studies on interoception focusing on the insula. This article is part of the themed issue 'Interoception beyond homeostasis: affect, cognition and mental health'.
Biometrie de l'hippocampe en imagerie par resonance magnetique 3d chez l'homme. Applications a l'epilepsie de la face mediale du lobe temporal
Les structures amygdalo-hippocampiques constituent une cible privilegiee dans l'epilepsie de ... more Les structures amygdalo-hippocampiques constituent une cible privilegiee dans l'epilepsie de la face interne du lobe temporal. La quantification du volume hippocampique contribue a poser les indications chirurgicales des epilepsies du lobe temporal. L'objectif central de l'etude est de definir un seuil d'asymetrie hippocampique en irm 3d permettant d'effectuer le diagnostic d'atrophie hippocampique. Les volumes hippocampiques ont ete obtenus par une segmentation realisee sur les acquisitions i. R. M. Tridimensionnelles. La definition du plan de segmentation est fondamentale. Les volumes obtenus sont significativement differents selon que la segmentation est realisee sur une acquisition coronale non perpendiculaire a l'hippocampe, sur ce meme examen reformate dans le plan perpendiculaire a l'hippocampe ou sur un examen directement acquis dans le bon plan. Parmi les principaux parametres biologiques : age, sexe, volume cerebral, poids, taille d'un echantillon de sujets (18-35 ans), seul le sexe et le volume cerebral ont un effet significatif sur le volume hippocampique. Ces resultats indiquent l'utilite d'ajuster les volumes hippocampiques aux volumes cerebraux pour les comparer d'un sujet a l'autre. Malgre l'ajustement des volumes hippocampiques, la persistance de l'effet du sexe suggere que l'hippocampe est caracterise par un dimorphisme sexuel. Par ailleurs, l'hippocampe droit presente un volume superieur a celui de l'hippocampe gauche. Il est important de determiner un seuil pathologique. L'analyse discriminante pour une variable (volume hippocampique ou index d'asymetrie) est insuffisante. L'analyse discriminante pour trois variables (index d'asymetrie hippocampique lateral, volume hippocampique droit corrige, volume hippocampique gauche corrige) donne les meilleurs resultats. La regression logistique donne des resultats plus satisfaisants. Elle a permis de determiner un seuil pathologique pour l'index d'asymetrie hippocampique iahps (0,18) et iahlat (0,20).
Neurology, Apr 1, 1997
Article abstractprogressive facial hemiatrophy (PFH), a rare disorder characterized by progressiv... more Article abstractprogressive facial hemiatrophy (PFH), a rare disorder characterized by progressive and self-limited atrophy of the skin and the subcutaneous tissues, is often associated with epilepsy but the link between these two conditions is poorly understood. The cause of PFH remains unclear. We report four patients with PFH associated with partial epilepsy in whom brain MRI showed cerebral dysgenesis. The four patients (two men, two women; age range: 24 to 73 years) developed parasagittal PFH in their second decade. Seizures started before the age of 20 years in three patients and were refractory simple, or complex partial seizures. All the patients had focal MRI showing cortical dysgenesis, ipsilateral to PFH, consisting of cortex thickening, gyral effacement, and blurring of the white-gray interface. The underlying white matter was hyperintense on T,-weighted sequences, with nodular areas in two patients. These areas were stable over time, without contrast enhancement, and were consistent with the MRI characteristics of cystic encephalomalacia. These neuroradiologic features suggest a localized cerebral hemispheric defect of congenital origin. Because cells participating in the formation of the fronto-nasal bud derive from common progenitors with the cells that give rise to the cerebral hemisphere, we suggest that an early malformative process affecting one side of the rostra1 neural tube could underlie both cerebral dysgenesis and facial hemiatrophy.
NeuroImage, Sep 1, 2003
We present an MEG/EEG framework to reveal statistically significant brain areas engaged in the sa... more We present an MEG/EEG framework to reveal statistically significant brain areas engaged in the same cognitive process across trials without resort to averaging procedures. The variability of neuronal responses is assumed to take place only in the reconstructed time series of cortical sources and not in their positions. This hypothesis allows the use of the surrogate data method to detect recurrently active brain areas across trials adjusted with any cortically constrained focal MEEG inverse solution. Results obtained from synthetic data show that considering several trials enhances the accuracy of the source localisation. We apply this approach on MEG data recorded during a simple visual stimulation. The considered stimulus is frequency tagged in order to reveal the neural network correlated to its perception using phase synchronisation analysis. The results show consistent patterns of distributed synchronous networks centred on occipital areas.
Segmentation of the amygdalo-hippocampal complex by competitive region growing [MRI analysis]
Semi-automatic segmentation of amygdala and hippocampus is of major interest to neurologists but ... more Semi-automatic segmentation of amygdala and hippocampus is of major interest to neurologists but it is a challenge to numerical image analysis techniques because of intrinsic complexity of those structures. We introduce a new method to approach this problem with Markovian region growing. As we are concerned by segmenting atrophic structures, we did not use shape priors, but constrained the growth with relational and weak geometric priors. The major relational constraint is given by the simultaneous segmentation of hippocampus and amygdala. The algorithm runs quickly on a basic workstation with satisfactory results on both structures.
Fixel‐Based Analysis Reveals Whole‐Brain White Matter Abnormalities in Cervical Dystonia
Movement Disorders, May 6, 2023
BackgroundCervical dystonia (CD) is a form of isolated focal dystonia typically associated to abn... more BackgroundCervical dystonia (CD) is a form of isolated focal dystonia typically associated to abnormal head, neck, and shoulder movements and postures. The complexity of the clinical presentation limits the investigation of its pathophysiological mechanisms, and the neural networks associated to specific motor manifestations are still the object of debate.ObjectivesWe investigated the morphometric properties of white matter fibers in CD and explored the networks associated with motor symptoms, while regressing out nonmotor scores.MethodsNineteen patients affected by CD and 21 healthy controls underwent diffusion‐weighted magnetic resonance imaging. We performed fixel‐based analysis, a novel method evaluating fiber orientation within specific fiber bundles, and compared fiber morphometric properties between groups. Moreover, we correlated fiber morphometry with the severity of motor symptoms in patients.ResultsCompared to controls, patients exhibited decreased white matter fibers in the right striatum. Motor symptom severity negatively correlated with white matter fibers passing through inferior parietal areas and the head representation area of the motor cortex.ConclusionsAbnormal white matter integrity at the basal ganglia level may affect several functional networks involved, for instance, in motor preparation and execution, visuomotor coordination, and multimodal integration. This may result in progressive maladaptive plasticity, culminating in overt symptoms of dystonia. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Clinical neuroradiology, Jun 21, 2021
Purpose Tectum mesencephali arteriovenous malformations (TM-AVMs) are rare lesions deeply located... more Purpose Tectum mesencephali arteriovenous malformations (TM-AVMs) are rare lesions deeply located close to eloquent structures making them challenging to treat. We aimed to present clinical presentation, angiographic features and treatment strategies of TM-AVMs through a single center retrospective case series. Methods A TM-AVMs is defined as a nidus located in the parenchyma or on the pia mater of the posterior midbrain. Records of consecutive patients admitted with TM-AVMs over a 21-year period were retrospectively analyzed. Vascular anatomy of the region is also reviewed. Results In this study 13 patients (1.63% of the complete cohort; 10 males), mean age 48 years, were included. All patients presented with intracranial hemorrhage and two patients (15%) died after an early recurrent bleeding. Mean size of the TM-AVMs was 10.1 ± 5 mm. Multiple arterial feeders were noted in every cases. Of the patients 11 underwent an exclusion treatment, 8 via embolization (6 via arterial access and 2 via venous access) and 4 via stereotactic radiosurgery (SRS) (1 patient received both). Overall success treatment rate was 7/11 patients (64% overall; 63% in the embolization group, 25% in the SRS group). Two hemorrhagic events led to a worsened outcome, one during embolization and one several years after SRS. All other patients remained clinically stable or improved. Conclusion The TM-AVMs are rare but stereotypic lesions found in a hemorrhagic context. Multiple arterial feeders are always present. Endovascular treatment seems to be an effective technique with relatively low morbidity; SRS had a low success rate but was only use in a limited number of patients.
HAL (Le Centre pour la Communication Scientifique Directe), Jun 14, 2015
[MRI of drug-resistant epilepsies: contribution of FLAIR sequence in a series of 150 patients]
PubMed, Sep 1, 2000
We studied the usefulness of the Fluid-Attenuated Inversion-Recovery (FLAIR) pulse sequence for p... more We studied the usefulness of the Fluid-Attenuated Inversion-Recovery (FLAIR) pulse sequence for patients with intractable seizures by reviewing the MR images of 150 consecutive patients including a standard imaging protocol and a FLAIR sequence. FLAIR images revealed a cortical lesion in 8 of the 81 patients with no lesion detected on the standard MR imaging protocol. In addition, FLAIR images provided additional informations for 13 patients of the 69 patients for whom a lesion was already detected on the standard MR imaging protocol. Therefore, our results indicated that FLAIR sequences were a useful imaging tool for patients with intractable seizures since it improved the MR diagnosis in 21 of 150 patients (14%).
Neuroradiology, Jul 7, 1999
American Journal of Neuroradiology, Aug 1, 1998
The role of genetic mechanisms and the influence of environmental events in human brain developme... more The role of genetic mechanisms and the influence of environmental events in human brain development have been difficult to evaluate. The purpose of this study was to compare the cerebral cortical morphology and midline structures of monozygotic twin pairs using MR imaging. METHODS: Six observers, blinded to twin pairings, evaluated the 3-D renderings of the cortical surface and midline structures from MR images of seven monozygotic twin pairs. A morphometric analysis of the corpus callosum and of the distance between the anterior and posterior commissures was also performed. RESULTS: Despite surprising anatomic differences, the brains of the twin pairs were similar enough to enable the observers to distinguish twin pairs from unrelated subjects. Five of six observers correctly identified the brains of all seven twin pairs; the remaining observer failed to make a correct match in only one of seven pairs. Three of six observers identified the midline sagittal images of the related twins in all seven pairs, and the other three identified the related midline sagittal images in five of seven pairs. The results were statistically significant. CONCLUSION: Although the observed differences in morphologic characteristics between twins necessarily reflect nongenetic influences, the cortical patterns and midline structures of monozygotic twins probably are genetically similar.
Journal of Neuropathology and Experimental Neurology, Apr 1, 2011
Sleep disorders are important manifestations of neurodegenerative diseases and sometimes are clin... more Sleep disorders are important manifestations of neurodegenerative diseases and sometimes are clinically evident well before the onset of other neurological manifestations. This review addresses the neuroanatomical basis and the mechanisms of sleep regulation in humans in relation to the neuropathology of entities associated with sleep disturbances in selected diseases, including Alzheimer disease, progressive supranuclear palsy, Lewy body disorders, multiple-system atrophy, and fatal familial insomnia. This includes abnormalities of circadian rhythm, insomnia, narcolepsy, rapid eye movements sleep behavior disorders, and excessive daytime sleepiness.
[Dementia and memory: morphologic imagery with MRI]
PubMed, 1998
Modern imaging techniques, and notably magnetic resonance imaging (MRI) enable an increasingly pr... more Modern imaging techniques, and notably magnetic resonance imaging (MRI) enable an increasingly precise exploration of primary degenerative dementias. The main contribution of imaging is to demonstrate lesion localizations which confirm the degenerative nature of the observed disorders, contributing to an understanding of the correlation between clinical signs and causal lesions. The development of techniques quantifying cerebral volume which can be applied to an analysis of small structures such as the hippocampus coupled with a better understanding of primary degenerative dementias allow more specific study of the atrophy than could be obtained with a global assessment of ventricular dilatation. More recently, the development of MRI methods studying brain perfusion open the way for noninvasive exploration of perfusion anomalies in these patients.
Automatic Segmentation of Depth Electrodes Implanted in Epileptic Patients: A Modular Tool Adaptable to Multicentric Protocols
HAL (Le Centre pour la Communication Scientifique Directe), Feb 1, 2015
International audienceno abstrac
Irradiation en conditions stéréotaxiques des métastases cérébrales chez les patients âgés
Bulletin Du Cancer, Oct 1, 2003
... Auteur(s) : Georges NOËL 1 , Sophie NOËL 5 , Loïc FEUVRET 1 , Charles-Ambroise VALERY 2 , Phi... more ... Auteur(s) : Georges NOËL 1 , Sophie NOËL 5 , Loïc FEUVRET 1 , Charles-Ambroise VALERY 2 , Philippe CORNU 2 , Gilbert BOISSERIE 1 , Dominique HASBOUN 3 , Bernadette TEP 1 , Jean ... 42. Auchter RM, Lamond JP, Alexander E, Buatti JM, Chappell R, Friedman WA, et al. ...
Acta Neurologica Scandinavica, Jul 1, 1996
Variability of presentation in medial temporal lobe epilepsy: a study of 30 operated cases Acta N... more Variability of presentation in medial temporal lobe epilepsy: a study of 30 operated cases Acta Neurol Scand 1996: 9 4 1-11. 0 Munksgaard 1996.
Neuroscience Research, 2000
have shown an inverse association between asymmetry in perisylvian areas and the size of a specif... more have shown an inverse association between asymmetry in perisylvian areas and the size of a specific segment, the isthmus, of the corpus callosum (CC) in males. The purpose of this work was to study in vivo the association between hemispheric asymmetry and the total size of the CC in 35 right-handed subjects (16 males, 19 females; mean age 24.9 93.9). An MRI scan was performed for each subject. The area of the right (RH) and left (LH) hemispheres were measured from images in the sagittal plane and the area of the CC from images in the mid-sagittal plane. The index of hemispheric asymmetry was (LH− RH)/[(LH+ RH)/2]. There was a negative correlation between the absolute value of hemispheric asymmetry and the size of the CC in males (r= −0.55, P =0.03) but not in females (r= −0.20, P = 0.42). These findings, like those of Aboitiz et al.
Brain, Dec 9, 2005
Patients with refractory partial seizures may benefit from epilepsy surgery. However, invasive in... more Patients with refractory partial seizures may benefit from epilepsy surgery. However, invasive investigations are often needed to define the precise location and limits of the epileptogenic zone (EZ). In this study, we asked whether diffusion tensor imaging (DTI) might provide a non-invasive alternative to locate the EZ or at least provide insights to help place intracerebral electrodes for stereo-electroencephalography (SEEG). Whole brain DTI and voxel-based analysis (SPM99) was used to assess diffusion properties objectively in 16 epilepsy patients investigated with SEEG. Epilepsy was symptomatic in two patients and cryptogenic in the 14 remaining patients. The suspected onset of seizures was temporal in 10 patients, frontal in 2 and occipital in 4. Individual maps of apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were calculated and compared to a database of 40 healthy volunteers. Thirteen of 16 patients exhibited diffusion abnormalities. ADC abnormalities were better correlated with SEEG data than FA abnormalities which were usually located at a distance or in the white matter. A significant increase in ADC (P < 0.01) was found in 11 patients and was located in the regions explored with depth electrodes in 7 of them. Surgery outcome was available in 3 of these 7 patients (2 were seizure free and 1 not). DTI specificity was better in extratemporal lobe epilepsy (83%) than in temporal lobe epilepsy (20%). When abnormalities concurred with the SEEG data, the concordance was optimal between the localization of the diffusion abnormalities and the irritative zone defined by SEEG. These encouraging, preliminary results, suggest that DTI examinations may provide accurate spatial data on the location and extent of the epileptogenic network in extratemporal lobe epilepsies.