Franck-Emmanuel Roux

Unité Inserm U1077, Caen, Lower Normandy, France

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Publications (36)123.43 Total impact

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    ABSTRACT: Object Sparing optic radiations can be of paramount importance during epilepsy surgery of the temporal lobe. The anatomical heterogeneity of the Meyer’s loop of the optic radiations could be assessed by means of diffusion tensor tractography. We used temporal lobe surgery as a lesion model to validate this method. Material and methods We analyzed the distance between the temporal pole (TP) and Meyer’s loop (ML) and the correlation between visual impairment and the percentage of virtual fibers injured. MRI studies were performed in 18 patients and 13 controls. Diffusion tensor imaging (DTI) with fiber tracking was performed using four different algorithms and various gradient directions (15 or 32) and fractional anisotropy (FA) thresholds (0.18, 0.20, and 0.22). To find the best DTI model, we tested each gradient direction and FA threshold on 16 operated patients by pre- and post-operative visual field testing that analyzed the percentage of virtual fibers damaged on 3-month-post-operative MRIs. Results Marked individual differences were noted in the TP-ML distances (mean: 25.4 mm; range 18.2–38.3 mm; standard deviation: 4.7) but with no significant difference between patients and controls (P = 0.9). The percentage of virtual fibers reconstructed by tracking and damaged by surgery was correlated with visual impairment. Significant differences appeared between algorithm types. The tensor-line algorithm with 15-direction resolution and an anisotropy threshold of 0.18 seemed to be the most relevant. A threshold of 5.5% of injured virtual fiber could predict a visual defect with a sensitivity of 71.4% and a specificity of 87.5%. Conclusion Optic radiation tractography by DTI could be a useful method to assess an individual patient’s risk of postoperative visual deficit.
    Clinical Neurology and Neurosurgery. 01/2014;
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    ABSTRACT: Cortical electrical stimulation mapping was used to study neural substrates of the function of writing in the temporoparietal cortex. We identified the sites involved in oral language (sentence reading and naming) and writing from dictation, in order to spare these areas during removal of brain tumours in 30 patients (23 in the left, and 7 in the right hemisphere). Electrostimulation of the cortex impaired writing ability in 62 restricted cortical areas (.25 cm(2)). These were found in left temporoparietal lobes and were mostly located along the superior temporal gyrus (Brodmann's areas 22 and 42). Stimulation of right temporoparietal lobes in right-handed patients produced no writing impairments. However there was a high variability of location between individuals. Stimulation resulted in combined symptoms (affecting oral language and writing) in fourteen patients, whereas in eight other patients, stimulation-induced pure agraphia symptoms with no oral language disturbance in twelve of the identified areas. Each detected area affected writing in a different way. We detected the various different stages of the auditory-to-motor pathway of writing from dictation: either through comprehension of the dictated sentences (word deafness areas), lexico-semantic retrieval, or phonologic processing. In group analysis, barycentres of all different types of writing interferences reveal a hierarchical functional organization along the superior temporal gyrus from initial word recognition to lexico-semantic and phonologic processes along the ventral and the dorsal comprehension pathways, supporting the previously described auditory-to-motor process. The left posterior Sylvian region supports different aspects of writing function that are extremely specialized and localized, sometimes being segregated in a way that could account for the occurrence of pure agraphia that has long-been described in cases of damage to this region.
    Cortex 10/2013; · 6.16 Impact Factor
  • Franck-Emmanuel Roux, Marion Reddy
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    ABSTRACT: Considered as the most famous French military surgeon, Dominique-Jean Larrey (1766-1842), who joined all the campaigns of Napoleon, wrote his memoirs and several medical articles. This paper discusses how in the Napoleonic times, Larrey dealt with neurosurgical diseases or injuries. We reviewed four main publications of Larrey published between 1812 and 1838 and analyzed the type of neurosurgical cases presented and their treatment. These works include his practice of what we call now "neurosurgery" since most injuries described concern the skull or spine. He seemed to treat patients with humanity, integrity and perseverance. Larrey dealt with many aspects of neurosurgery, such as cranial or spinal trauma surgery, and also infectious diseases. He saw many head injuries inflicted not only by muskets or artillery, but also with spears and sabers. Unlike some others, Larrey advocated the use of trepanation in many situations as practiced, for instance, in the treatment of depressed fractures or in presence of subdural collections. On the other hand, this surgeon who saw thousands of amputees during his career did not mention the phantom limb phenomenon in his memoirs. Similarly, the issue of cerebral localizations is only mentioned in his last work, published in 1838. In his work, Larrey (and all his contemporaries) dealt essentially with "cranial" surgery, as in skull fractures where the brain could potentially have been injured by bone fragments. The time for brain surgery had not come yet.
    Clinical neurology and neurosurgery 09/2013; · 1.30 Impact Factor
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    ABSTRACT: Handwriting is a modality of language production whose cerebral substrates remain poorly known although the existence of specific regions is postulated. The description of brain damaged patients with agraphia and, more recently, several neuroimaging studies suggest the involvement of different brain regions. However, results vary with the methodological choices made and may not always discriminate between "writing-specific" and motor or linguistic processes shared with other abilities. We used the "Activation Likelihood Estimate" (ALE) meta-analytical method to identify the cerebral network of areas commonly activated during handwriting in 18 neuroimaging studies published in the literature. Included contrasts were also classified according to the control tasks used, whether non-specific motor/output-control or linguistic/input-control. These data were included in two secondary meta-analyses in order to reveal the functional role of the different areas of this network. An extensive, mainly left-hemisphere network of 12 cortical and sub-cortical areas was obtained; three of which were considered as primarily writing-specific (left superior frontal sulcus/middle frontal gyrus area, left intraparietal sulcus/superior parietal area, right cerebellum) while others related rather to non-specific motor (primary motor and sensorimotor cortex, supplementary motor area, thalamus and putamen) or linguistic processes (ventral premotor cortex, posterior/inferior temporal cortex). This meta-analysis provides a description of the cerebral network of handwriting as revealed by various types of neuroimaging experiments and confirms the crucial involvement of the left frontal and superior parietal regions. These findings provide new insights into cognitive processes involved in handwriting and their cerebral substrates.
    Cortex 06/2013; · 6.16 Impact Factor
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    ABSTRACT: The production of object and action words can be dissociated in aphasics, yet their anatomical correlates have been difficult to distinguish in functional imaging studies. To investigate the extent to which the cortical neural networks underlying object- and action-naming processing overlap, we performed electrostimulation mapping (ESM), which is a neurosurgical mapping technique routinely used to examine language function during brain-tumor resections. Forty-one right-handed patients who had surgery for a brain tumor were asked to perform overt naming of object and action pictures under stimulation. Overall, 73 out of the 633 stimulated cortical sites (11.5%) were associated with stimulation-induced language interferences. These interference sites were very much localized (<1 cm(2) ), and showed substantial variability across individuals in their exact localization. Stimulation interfered with both object and action naming over 44 sites, whereas it specifically interfered with object naming over 19 sites and with action naming over 10 sites. Specific object-naming sites were mainly identified in Broca's area (Brodmann area 44/45) and the temporal cortex, whereas action-naming specific sites were mainly identified in the posterior midfrontal gyrus (Brodmann area 6/9) and Broca's area (P = 0.003 by the Fisher's exact test). The anatomical loci we emphasized are in line with a cortical distinction between objects and actions based on conceptual/semantic features, so the prefrontal/premotor cortex would preferentially support sensorimotor contingencies associated with actions, whereas the temporal cortex would preferentially underpin (functional) properties of objects. Hum Brain Mapp, 2012. © 2012 Wiley Periodicals, Inc.
    Human Brain Mapping 09/2012; · 6.88 Impact Factor
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    ABSTRACT: A fundamental issue in cognitive neuroscience is the existence of two major, sub-lexical and lexical, reading processes and their possible segregation in the left posterior perisylvian cortex. Using cortical electrostimulation mapping, we identified the cortical areas involved on reading either orthographically irregular words (lexical, "direct" process) or pronounceable pseudowords (sublexical, "indirect" process) in 14 right-handed neurosurgical patients while video-recording behavioral effects. Intraoperative neuronavigation system and Montreal Neurological Institute (MNI) stereotactic coordinates were used to identify the localization of stimulation sites. Fifty-one reading interference areas were found that affected either words (14 areas), or pseudo-words (11 areas), or both (26 areas). Forty-one (80%) corresponded to the impairment of the phonological level of reading processes. Reading processes involved discrete, highly localized perisylvian cortical areas with individual variability. MNI coordinates throughout the group exhibited a clear segregation according to the tested reading route; specific pseudo-word reading interferences were concentrated in a restricted inferior and anterior subpart of the left supramarginal gyrus (barycentre x = -68.1; y = -25.9; z = 30.2; Brodmann's area 40) while specific word reading areas were located almost exclusively alongside the left superior temporal gyrus. Although half of the reading interferences found were nonspecific, the finding of specific lexical or sublexical interferences is new evidence that lexical and sublexical processes of reading could be partially supported by distinct cortical sub-regions despite their anatomical proximity. These data are in line with many brain activation studies that showed that left superior temporal and inferior parietal regions had a crucial role respectively in word and pseudoword reading and were core regions for dyslexia.
    PLoS ONE 01/2012; 7(11):e50665. · 3.73 Impact Factor
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    ABSTRACT: Cortical and subcortical electrostimulation mapping during awake brain surgery for tumor removal is usually used to minimize deficits. To use electrostimulation to study neuronal substrates involved in spatial awareness in humans. Spatial neglect was studied using a line bisection task in combination with electrostimulation mapping of the right hemisphere in 50 cases. Stimulation sites were identified with Talairach coordinates. The behavioral effects induced by stimulation, especially eye movements and deviations from the median, were quantified and compared with preoperative data and a control group. Composite and highly individualized spatial neglect maps were generated. Both rightward and leftward deviations were induced, sometimes in the same patient but for different stimulation sites. Group analysis showed that specific and reproducible line deviations were induced by stimulation of discrete cortical areas located in the posterior part of the right superior and middle temporal gyri, inferior parietal lobe, and inferior postcentral and inferior frontal gyri (P < .05). Fiber tracking identified stimulated subcortical areas important to spare as sections of fronto-occipital and superior longitudinal II fascicles. According to preoperative and postoperative neglect battery tests, the specificity and sensitivity of intraoperative line bisection tests were 94% and 83%, respectively. In humans, discrete cortical areas that are variable in location between individuals but mainly located within the right posterior Sylvian fissure sustain visuospatial attention specifically toward the contralateral or ipsilateral space direction. Line bisection mapping was found to be a reliable method for minimizing spatial neglect caused by brain tumor surgery.
    Neurosurgery 12/2011; 69(6):1218-31. · 2.53 Impact Factor
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    ABSTRACT: Direct cortical electrostimulation was used to study cortical areas hypothetically involved in translation in bilinguals during brain tumour resections, with a view to sparing these functional areas. A series of seven proficient bilingual patients was studied: two left-handed and five right-handed individuals with no pre-existing language deficit. Hemispheric cortex (on the side contralateral to the patient's hand-dominance) was directly stimulated whilst the patient performed naming and reading tasks in both languages and a translation task (of a written text from their second 'learned' language to their first or 'native' language). Of the 147 different cortical sites studied, 26 'language functional sites' were detected, where electrostimulation affected reading and/or naming in the patient's native and/or second learned language. Of these, 8 sites (in 4 patients) were "task-specific" and "language-specific" i.e., affecting only naming or reading in only one of the patient's languages. Of the 26 "language sites", only 3 produced any interferences in translation. All of these were located in frontal regions. Electrostimulation at these sites caused the patient to stop translating abruptly, but no language switching or other translation-related phenomenon was observed. No site was found that was involved only in translation and not other language tasks. Overall, in contrast to other language tasks, cortical structures of the convexity were rarely involved in translation. We suggest that translation interference could be more readily detected by subcortical stimulations. This spatial dissociation within the brain of translation function versus other language functions could explain the cases of dissociated language impairments observed in some bilingual patients with brain lesions. On a practical level, because the cortical sites found by translation tasks are few and related with other cortical language sites, we think that translation tasks provide little additional helpful information for cortical brain mapping in bilingual neurosurgical patients.
    Cortex 03/2011; 48(5):614-22. · 6.16 Impact Factor
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    ABSTRACT: Selective naming categories impairments for living and non-living things are widely reported in brain damaged patients. Electrostimulation mapping was used to study the possible anatomical segregation of living/non-living categories in a prospective series of patients operated on for tumor removal. Fifty brain mappings (patients with no language impairment; range: 14-80 years; mean: 48 years; 26 males; 5 left handed) were performed in 46 left and 4 right hemispheres using two linguistically controlled tasks (naming for living and non-living things) during an awake surgery procedure. Fifteen regions and four macro cortical areas were designed to analyze the distribution of the interference sites. Over 761 sites stimulated in the lateral hemispheres, 130 naming interferences sites were detected in small cortical areas (<1cm(2)). High individual variability was observed for living/non-living word retrieval localization and organization with a majority (62%) of shared living/non-living interferences. Specific living (12%) or non-living (26%) interferences were found too. In group analysis, no statistical significant anatomical localization was observed for living items in left lateral hemispheric cortex. A statistical significant representation of interference sites for non-living objects was found (Generalized Estimating Equation methodology, z-test=2.28, p=0.027) in the left posterolateral temporoparietal cortex. No influence of histopathology, gender and age on anatomical localization of naming categories was detected. The existence of dedicated neural structures for naming non-living things in the left posterolateral temporoparietal cortex is supported by this study although high individual differences exist in the organization of word categories retrieval.
    NeuroImage 02/2011; 56(1):323-9. · 6.25 Impact Factor
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    ABSTRACT: The use of an awake craniotomy in the treatment of supratentorial lesions is a challenge for both patients and staff in the operation theater. To assess the safety and effectiveness of an awake craniotomy with brain mapping in comparison with a craniotomy performed under general anesthesia. We prospectively compared 2 groups of patients who underwent surgery for supratentorial lesions: those in whom an awake craniotomy with intraoperative brain mapping was used (AC group, n = 214) and those in whom surgery was performed under general anesthesia (GA group, n = 361, including 72 patients with lesions in eloquent areas). The AC group included lesions in close proximity to the eloquent cortex that were surgically treated on an elective basis. Globally, the 2 groups were comparable in terms of sex, age, American Society of Anesthesiologists score, pathology, size of lesions, quality of resection, duration of surgery, and neurological outcome, and different in tumor location and preoperative neurological deficits (higher in the AC group). However, specific data analysis of patients with lesions in eloquent areas revealed a significantly better neurological outcome and quality of resection (P < .001) in the AC group than the subgroup of GA patients with lesions in eloquent areas. Surgery was uneventful in AC patients and they were discharged home sooner. AC with brain mapping is safe and allows maximal removal of lesions close to functional areas with low neurological complication rates. It provides an excellent alternative to craniotomy under GA.
    Neurosurgery 01/2011; 68(5):1192-8; discussion 1198-9. · 2.53 Impact Factor
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    ABSTRACT: Frontoethmoidal mengingoencephaloceles (fMECs) are frequently observed in Cambodia, especially in poor families. The authors describe issues related to the surgical treatment of fMECs in Cambodia at the end of a humanitarian program that provided surgery free of charge to patients and their families. The authors reviewed 257 cases of fMEC involving patients who presented to their institution, the Children's Surgical Center in Phnom Penh, between 2004 and 2009. They treated 200 of these patients surgically (108 males, 92 females; 89% younger than 18 years) using a "low-cost" management plan with no routine pre- or postoperative investigations. Initially, surgery was performed by visiting foreign surgeons who taught the procedures to resident surgeons. Patients were not charged for consultations or treatment and received at least 1 follow-up examination 6 months postoperatively. The nasoethmoidal type was the most frequent fMEC encountered (69%). Many patients had associated ophthalmological issues (46% of cases). Only 1 familial case was detected. Combined neurosurgical and facial procedures were successfully standardized and learned by surgeons initially unfamiliar with fMEC management. A neurosurgical approach avoided the need for a facial incision in 42 cases, improving cosmetic results. The most common postoperative issues were a temporary CSF leak (24 cases [12%]) and/or infection (28 cases [14%]). There were 3 deaths directly related to the operations. Cosmetic results were good in 145 cases, average in 27, poor in 7, and worse than preoperative appearance in 6 patients. Fifteen patients were lost to follow-up. The parents of 87% of the children were rice farmers. Questionnaire results confirmed that fMEC has important social and educational consequences for the affected children and that these consequences can be partially improved by fMEC correction. This experience in fMEC management demonstrates that local surgeons can treat these malformations with limited surgical materials and in a nonspecialized infrastructure after principles of treatment have been learned and if they are carefully respected. Surgery for fMEC can thus be more accessible to a larger number of patients in developing countries. Moreover, local treatment facilitates better postoperative and follow-up care.
    Journal of Neurosurgery Pediatrics 12/2010; 6(6):541-9. · 1.63 Impact Factor
  • Vincent Lubrano, Louisa Draper, Franck-Emmanuel Roux
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    ABSTRACT: Surgical resection of mass lesions in Broca's area is controversial. To demonstrate that pathology may influence the localization of functional areas and language performance, we reviewed our experience of awake craniotomies in Broca's area. Sixteen consecutive patients who underwent awake craniotomy and direct brain mapping for resective surgery in Broca's area were analyzed. Six patients had well-circumscribed lesions, whereas 10 patients had infiltrative gliomas. A short version of the Boston Diagnostic Aphasia Examination test was used for language assessment. Inferior frontal language sites were found in all but 4 patients. In patients with cavernomas or well-circumscribed tumors, 9 of 9 (100%) of the positive sites were located in the classic Broca's area (BA 44/45). By contrast, in those patients with gliomas, only 5 of 20 (25%) of the positive sites were located in BA 44/45. Patients with infiltrative gliomas demonstrated more deficits in the pre and postoperative periods than those with well-circumscribed mass lesions. All patients returned to their baseline abilities within 6 months. Intraoperative language maps generated in cases with well-circumscribed lesions are different from those generated in cases with infiltrative gliomas. This supports the view that interindividual language variability and displacement of critical structures by mass effect should first be considered for circumscribed lesions, whereas reshaping should largely be attributed to brain plasticity in gliomas. Surgery in Broca's area can be safely conducted using awake craniotomy and brain mapping.
    Neurosurgery 05/2010; 66(5):868-75; discussion 875. · 2.53 Impact Factor
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    ABSTRACT: We have translated the most famous text of Sigmund Exner (1846-1926), which relates to the existence of a localised "writing centre" in the brain. We discuss its relevance to modern studies and understanding of writing and agraphia. In Exner's most famous text, he hypothesised about the eponymous "Exner's Area", a discrete area within the brain that was located in the left middle frontal gyrus, which was dedicated to the function of writing. This text in German, included in a book published in 1881 "Untersuchungen über die Lokalisation der Functionen in der Grosshirnrinde des Menschen" (Studies on the localisation of functions in the cerebral cortex of humans), lent itself to passionate debates during the following decades on the possibility of finding a specific writing centre in left middle frontal gyrus. Modern authors still refer back to the evidence cited in this seminal text. However, over the 281 pages of Exner's book, only a few chapters dealt with agraphia. Only four of the 167 case reports in the book explicitly mention agraphia. Although Exner describes the anatomical details of these lesions (from autopsies), no patient had pure agraphia, and only one case had an isolated lesion of the posterior part of the middle frontal gyrus. The small number of patients, the absence of pure agraphia symptoms, and the variation in the anatomy of these lesions are the main reasons why Exner's hypothesis of a writing centre in left middle frontal gyrus has been continually debated until now. More than the seminal publication of Sigmund Exner on agraphia, we think that the diffusion of his hypothesis was partly due to the influence that Exner and his family had within the scientific community at the turn of the 20th century.
    Cortex 03/2010; 46(9):1204-10. · 6.16 Impact Factor
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    ABSTRACT: Although endoscopic third ventriculostomy (ETV) has been accepted as a procedure of choice for the treatment of obstructive hydrocephalus, the outcome of this treatment remains controversial with regard to age, cause, and long-term follow-up results. The goal of this study was to assess the risk of failure associated with these factors in a retrospective cohort study. Between 1999 and 2007, 368 ETVs were performed in 350 patients (165 patients < 18 years of age) with hydrocephalus at the University Hospital of Toulouse. Failure of ETV was defined as cases requiring any subsequent surgical procedure for CSF diversion or death related to hydrocephalus management. Tumors (53%), primary aqueductal stenosis (18%), and intracranial hemorrhage (13%) were the most common causes of hydrocephalus. The median follow-up period was 47 months (range 6-106 months), and the overall success rate was 68.5% (252 of the 368 procedures). Patients < 6 months of age had a 5-fold increased risk of ETV failure than older patients (adjusted hazard ratio [HRa] 5.0; 95% CI 2.4-10.4; p < 0.001). Hemorrhage-related (HRa 4.0; 95% CI 1.9-8.5; p < 0.001) and idiopathic chronic hydrocephalus (HRa 6.3, 95% CI 2.5-15.0, p < 0.001) had a higher risk of failure than other causes. Most failures (97%) occurred within 2 months of the initial procedure. The overall morbidity rate was 10%, although most complications were minor. Finally, the introduction of ETV in the authors' department reduced the number of shunt insertions and hospital admissions for shunt failures by half and was a source of cost savings. Endoscopic third ventriculostomy is a safe procedure and an effective treatment option for hydrocephalus. Factors indicating potential poor ETV outcome seem to be very young children and hemorrhage-related and chronic hydrocephalus in adults.
    Journal of Neurosurgery Pediatrics 01/2010; 5(1):68-74. · 1.63 Impact Factor
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    ABSTRACT: Cervical spine injuries after diving into private swimming pools can lead to dramatic consequences. We reviewed 34 patients hospitalized in our center between 1996 and 2006. Data was collected from their initial admission and from follow-up appointments. The injuries were sustained by young men in 97% (mean age 27) and the majority happened during the summer (88%). Fractures were at C5-C7 in 70%. American Spinal Injury Association class (ASIA) on admission was A for 8 patients, B for 4, C for 4, D for 1, and E for 17. There were 23 surgical spine stabilizations. Final ASIA class was A for 6 patients, B for 1, C for 3, D for 5, and E for 18. The mean duration of hospitalization was 21.3 days in our neurosurgical center (mean overall cost: 36,000 Euros/patient) plus 10.6 months in rehabilitation center for the 15 patients admitted who had an ASIA class A to C. Mean overall direct cost for a patient with class A is almost 300,000 Euros, compared to around 10,000 Euros for patients with class D and E. In addition, a profound impact on personal and professional life was seen in many cases including 11 divorces and 7 job losses. Dangerous diving into swimming pools can result in spinal injuries with drastic consequences, including permanent physical disability and a profound impact on socio-professional status. Moreover, there are significant financial costs to society. Better prevention strategies should be implemented to reduce the impact of this public health problem.
    European Spine Journal 12/2009; 19(4):552-7. · 2.47 Impact Factor
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    ABSTRACT: Frontoethmoidal meningoencephalocele (fMEC) is relatively common in many Southeast Asian countries, with devastating aesthetic and social consequences for affected children. No cause has been detected to date. Among other factors, the authors of this paper attempt to identify a statistically significant difference in the spread of fMEC births throughout the year compared with other births. This seasonal variation in the incidence of fMEC births may provide clues to the causes of this condition. From a group of 175 children with fMEC who underwent surgery at the authors' humanitarian institution (Children's Surgical Centre) in Phnom Penh between 2004 and 2008, 86 children were studied. These children were born at full term and had an accurately recorded date of birth. The birth dates of this fMEC group were compared with a group of > 15,000 other live births at one of the main maternity units in Phnom Penh in 2005 and 2006. Seasonal variation in incidence of fMEC by month of birth was highly statistically significant (p < 0.001), with the peak of births occurring in the dry season (between March and May). This is in contrast to the control group, in which there was an equal distribution of births throughout the year. More than 85% of the parents of children with fMEC who the authors treated were farmers, but this figure reflects the composition of the Cambodian population. Uneven spread in the incidence of fMEC births throughout the year suggests that a seasonal factor during the wet season may be suspected in the pathogenesis of fMEC in Cambodia.
    Journal of Neurosurgery Pediatrics 12/2009; 4(6):553-6. · 1.63 Impact Factor
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    ABSTRACT: In 1881, Exner first described a "graphic motor image center" in the middle frontal gyrus. Current psycholinguistic models of handwriting involve the conversion of abstract, orthographic representations into motor representations before a sequence of appropriate hand movements is produced. Direct cortical stimulation and functional magnetic resonance imaging (fMRI) were used to study the human frontal areas involved in writing. Cortical electrical stimulation mapping was used intraoperatively in 12 patients during the removal of brain tumors to identify the areas involved in oral language (sentence reading and naming) and writing, and to spare them during surgery. The fMRI activation experiment involved 12 right-handed and 12 left-handed healthy volunteers using word dictation (without visual control) and 2 control tasks. Direct cortical electrical stimulation of restricted areas rostral to the primary motor hand area (Brodmann area [BA] 6) impaired handwriting in 6 patients, without disturbing hand movements or oral language tasks. In 6 other patients, stimulation of lower frontal regions showed deficits combining handwriting with other language tasks. fMRI also revealed selective activation during word handwriting in left versus right BA6 depending on handedness. This area was anatomically matched to those areas that affected handwriting on electrical stimulation. An area in middle frontal gyrus (BA6) that we have termed the graphemic/motor frontal area supports bridging between orthography and motor programs specific to handwriting.
    Annals of Neurology 10/2009; 66(4):537-45. · 11.19 Impact Factor
  • Carlo Giussani, David Pirillo, Franck-Emmanuel Roux
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    ABSTRACT: The capability of recognizing the expressions of facial emotions has been hypothesized to depend on a right hemispheric cortical-subcortical network. Its impairment deeply disturbs social relationships. To spare right hemispheric cortical areas involved in recognizing facial emotion, the authors used intraoperative cortical stimulation and the awake surgery technique in a consecutive series of patients. The feasibility and the interest to map them during brain mapping for neurosurgical procedures are discussed. After a preoperative neuropsychological evaluation, 18 consecutive patients with right hemispheric lesions (5 metastases, 6 high-grade gliomas, 4 low-grade gliomas, 2 arteriovenous malformations, and 1 malignant meningioma) were tested by intraoperative cortical stimulation while performing a facial emotion recognition task along with sensorimotor and visuospatial tasks. Three hundred eighty-six cortical sites were studied. Five (1.30%) reproducible interference sites for facial emotion recognition were identified in 5 patients: 1 site in the medial segment of T1; 1 site in the posterior segment of T1; 1 site in the posterior segment of T2; and 2 sites in the supramarginal gyrus. No selective impairment was found regarding the emotion category. All facial emotion recognition sites were spared during surgery, and none of the patients experienced postoperative deficits in recognition of facial emotions. The finding of interference sites in facial emotion recognition in the right posterior perisylvian area, independent to sensorimotor or visuospatial orientation processes, reinforces the theory about the role of anatomically and functionally segregated right hemisphere structures in this cognitive process. The authors advocate offering a brain mapping of facial emotion recognition to patients with right posterior perisylvian tumors.
    Journal of Neurosurgery 07/2009; 112(3):520-7. · 3.15 Impact Factor
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    ABSTRACT: In a multicenter study, 102 patients aged 70 years or older with paraplegia or severe paraparesis, and who underwent operation for spinal meningiomas, are presented to correlate surgery and outcome and to determine the most influential factors that affected this outcome. Five French neurosurgical centers participated in this retrospective study between 1990 and 2007. Pre- and postoperative neurological status were assessed using a grading system. All patients underwent operation, and neurological evaluations were conducted 3 months and 1 year after surgery. The median follow-up period was 49.5 months (range, 12-169 months). Data were analyzed using a multiple logistic regression model. Twenty-six patients were paraplegic (Grade 4). Complete tumor removal was obtained in 93 patients. There was no surgical mortality, and morbidity was 9%. Three months after surgery, 7 of the patients were unchanged, 87 patients had improved, and 8 were not evaluated. One year after surgery, 7 of the 100 surviving patients were clinically unchanged and 93 had improved. Of those who had improved, 49 patients experienced complete recovery. Advanced age did not seem to contraindicate surgery, even in patients with severe preoperative neurological deficits and/or an American Society of Anesthesiologists class of III. Quality of life can be improved in most cases.
    Neurosurgery 04/2009; 64(3):503-9; discussion 509-10. · 2.53 Impact Factor
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    ABSTRACT: The treatment of symptomatic cranio-vertebral junction (CVJ) instability in children affected by CVJ abnormalities is a challenge. A series of severely symptomatic children has been reviewed to understand the controversial long-term effectiveness of the aggressive management of CVJ abnormalities, in terms of clinical improvement, spinal stability and growth. Three Down syndrome patients, 1 with mucopolysaccharidosis and 1 with os odontoideum (range 3-6 years old) with a CVJ instability determining spinal cord compression with severe neurological deficits (the patients presented at admission a Ranawat III A/III B neurological condition), were consecutively treated at our institution. Medical records, imaging studies, adopted surgical techniques and long-term results were reviewed. Details of the presenting symptoms, clinical and radiological signs were compared to the signs and symptoms at follow-up. The perioperative use of an halo-orthosis, the operative techniques and the timing of rehabilitation were always tailored to the patient's anatomical features. All the patients showed remarkable neurological improvements, along with construct stability and bone fusion without abnormalities of the developing spine. Considering the effective long-term results, we recommend, even in severely symptomatic children with CVJ abnormalities, a multidisciplinary aggressive tailored treatment of instability with rigid internal fixation.
    Pediatric Neurosurgery 03/2009; 45(1):29-36. · 0.42 Impact Factor

Publication Stats

590 Citations
123.43 Total Impact Points

Institutions

  • 2013–2014
    • Unité Inserm U1077
      Caen, Lower Normandy, France
    • University of Toulouse II - Le Mirail
      Tolosa de Llenguadoc, Midi-Pyrénées, France
  • 2009–2013
    • Paul Sabatier University - Toulouse III
      Tolosa de Llenguadoc, Midi-Pyrénées, France
    • University of Toulouse
      Tolosa de Llenguadoc, Midi-Pyrénées, France
  • 2002–2009
    • French Institute of Health and Medical Research
      Lutetia Parisorum, Île-de-France, France
  • 2008
    • Centre Hospitalier Universitaire de Toulouse
      Tolosa de Llenguadoc, Midi-Pyrénées, France