Matthieu Delion

Long term motor function after neonatal stroke: Lesion localization above all

Motor outcome is variable following neonatal arterial ischemic stroke (NAIS). We analyzed the relationship between lesion characteristics on brain MRI and motor function in children who had suffered from NAIS. Thirty eight full term born children with unilateral NAIS were investigated at the age of seven. 3D T1‐ and 3D FLAIR‐weighted MR images were acquired on a 3T MRI scanner. Lesion characteristics were compared between patients with and without cerebral palsy (CP) using the following approaches: lesion localization either using a category‐based analysis, lesion mapping as well as voxel‐based lesion‐symptom mapping (VLSM). Using diffusion‐weighted imaging the microstructure of the cortico‐spinal tract (CST) was related to the status of CP by measuring DTI parameters. Whereas children with lesions sparing the primary motor system did not develop CP, CP was always present when extensive lesions damaged at least two brain structures involving the motor system. The VLSM approach provided a statistical map that confirmed the cortical lesions in the primary motor system and revealed that CP was highly correlated with lesions in close proximity to the CST. In children with CP, diffusion parameters indicated microstructural changes in the CST at the level of internal capsule and the centrum semiovale. White matter damage of the CST in centrum semiovale was a highly reproducible marker of CP. This is the first description of the implication of this latter region in motor impairment after NAIS. In conclusion, CP in childhood was closely linked to the location of the infarct in the motor system. Hum Brain Mapp 36:4793–4807, 2015..

Functional MRI comparison of passive and active movement: possible inhibitory role of supplementary motor area.

Recent studies have hypothesized that the supplementary motor area plays a role in motor inhibition. To study this possible role, we used functional MRI study to compare conditions, which require various level of inhibition of motor patterns. Seventeen healthy participants were scanned while executing – actively or passively – rhythmic opening/closing movements of their right hand, with and without congruent visual information. The contrast passive>active movement in the visual guidance condition which requires inhibition in order ‘not’ to perform the movement, yields to significant activation of areas commonly involved in the inhibitory brain circuitry among which, notably, controlateral supplementary motor area.

Mortality in Children with Optic Pathway Glioma Treated with Up-Front BB-SFOP Chemotherapy

Background In terms of overall survival (OS), limited data are available for the very long-term outcomes of children treated for optic pathway glioma (OPG) with up-front chemotherapy. Therefore, we undertook this study with the aim of clarifying long-term OS and causes of death in these patients. Methods We initiated and analyzed a historical cohort study of 180 children with OPG treated in France with BB-SFOP chemotherapy between 1990 and 2004. The survival distributions were estimated using Kaplan-Meier method. The effect of potential risk factors on the risk of death was described using Cox regression analysis. Results The OS was 95% [95% CI: 90.6-97.3] 5 years after diagnosis and significantly decreased over time without ever stabilizing: 91.6% at 10 years [95% CI: 86.5-94.8], 80.7% at 15 years [95% CI: 72.7-86.8] and 75.5% [95% CI: 65.6-83] at 18 years. Tumor progression was the most common cause of death (65%). Age and intracranial hypertension at diagnosis were significantly associated with a worse prognosis. Risk of death was increased by 3.1[95% CI: 1.5-6.2] (p=0.002) for patients less than 1 year old at diagnosis and by 5.2[95% CI: 1.5-17.6] (p=0.007) for patients with initial intracranial hypertension. Boys without diencephalic syndrome had a better prognosis (HR: 0.3 [95% CI: 0.1-0.8], p=0.007). Conclusions This study shows that i) in children with OPG, OS is not as favorable as previously described and ii) patients can be classified into 2 groups depending on risk factors (age, intracranial hypertension, sex and diencephalic syndrome) with an OS rate of 50.4% at 18 years [95% CI: 31.4-66.6] in children with the worst prognosis. These findings could justify, depending on the initial risk, a different therapeutic approach to this tumor with more aggressive treatment (especially chemotherapy) in patients with high risk factors.

Specificities of Awake Craniotomy and Brain Mapping in Children for Resection of Supratentorial Tumors in the Language Area.

BACKGROUND In the pediatric population, awake craniotomy began to be used for the resection of brain tumor located close to eloquent areas. Some specificities must be taken into account to adapt this method to children. OBJECTIVE The aim of this clinical study is to not only confirm the feasibility of awake craniotomy and language brain mapping in the pediatric population but also identify the specificities and necessary adaptations of the procedure. METHODS Six children aged 11 to 16 were operated on while awake under local anesthesia with language brain mapping for supratentorial brain lesions (tumor and cavernoma). The preoperative planning comprised functional magnetic resonance imaging (MRI) and neuropsychologic and psychologic assessment. The specific preoperative preparation is clearly explained including hypnosis conditioning and psychiatric evaluation. The success of the procedure was based on the ability to perform the language brain mapping and the tumor removal without putting the patient to sleep. We investigated the pediatric specificities, psychological experience, and neuropsychologic follow-up. RESULTS The children experienced little anxiety, probably in large part due to the use of hypnosis. We succeeded in doing the cortical-subcortical mapping and removing the tumor without putting the patient to sleep in all cases. The psychological experience was good, and the neuropsychologic follow-up showed a favorable evolution. CONCLUSIONS Preoperative preparation and hypnosis in children seemed important for performing awake craniotomy and contributing language brain mapping with the best possible psychological experience. The pediatrics specificities are discussed.

Microanatomical study of the insular perforating arteries

BackgroundThe insular perforating arteries originate from the middle cerebral artery. They have only been very partially described up to now. In the literature, they come from the M2 segment and three types are listed: the short, medium and long perforators. The first two types supply the claustrum as well as the external and extreme capsules.ObjectiveWe describe the anatomy of long perforating insular arteries and their arterial contribution to the main white matter bundles of the oval center of Vieussens.Materials and methodTwenty adult cadaveric hemispheres were studied after perfusion of the arteries and veins with colored latex. The arteries were dissected and photographed under an operating microscope.ResultsThe long insular perforating arteries come from the M2 segment or from the junction of the M2 and M3 segments and sometimes from the M3 segment. They often perforate the insular cortex on the top of the posterior short insular gyrus and the insular long gyri, or in the superior peri-insular sulcus, before coming together in the oval center. At this level, they give arterial contribution to the main white matter bundles such as corticospinal and corticonuclear tracts for motricity, and the arcuate fasciculus and the occipitofrontal tract for language in the dominant hemisphere.ConclusionThese perforating arteries have to be carefully respected during insular surgery to avoid neurologic weakness.

Does Contralesional Hand Function After Neonatal Stroke Only Depend on Lesion Characteristics

Background and Purpose— In children having suffered from neonatal arterial ischemic stroke, the relationship between contralesional hand performance and structural changes in brain areas remote from the infarct site was examined. Methods— Using voxel-based morphometry, we correlated contralesional gross manual dexterity assessed by the box and block test and whole-brain gray and white-matter volume changes on high-resolution magnetic resonance imaging in 37 7-year-old post–neonatal arterial ischemic stroke children. We also compared the volume of the identified structures with magnetic resonance imaging data of 10 typically developing age-matched children. Results— Areas showing the highest positive correlation with the box and block test scores were ipsilesional mediodorsal thalamus, contralesional cerebellar lobule VIIa Crus I, and ipsilesional corticospinal tract at the level of superior corona radiata, the posterior limb of the internal capsule, and the cerebral peduncle and the ipsilesional body of corpus callosum. When compared with typically developing age-matched children, post–neonatal arterial ischemic stroke children with severe contralesional hand motor deficit exhibited significant volume reductions in these structures (except the cerebellum), whereas no differences were found with those with good manual dexterity. No negative correlation was found between box and block test scores and brain areas. Conclusions— Contralesional hand performance after neonatal arterial ischemic stroke is correlated with atrophy in brain areas directly or functionally connected but anatomically remote from the infarct. Our study suggests a role of the cerebellar lobule VIIa Crus I and mediodorsal thalamus in manual dexterity. Clinical Trial Registration— URL: https://clinicaltrials.gov. Unique identifier: NCT02511249.

Arteries and Veins of the Sylvian Fissure and Insula: Microsurgical Anatomy

We present a vascular anatomical study of the arteries and veins of the sylvian fissure and insula.A good knowledge of the sylvian fissure, the insula, and their vascular relationship would seem mandatory before performing surgery in this area, whatever the type of surgery (aneurysms, arteriovenous malformations, insular tumors).We start with the sylvian fissure and insula morphology, followed by the MCA description and its perforators, with special attention paid to the insular perforators. We demonstrate that the long insular perforators penetrating in the superior part of the posterior short gyrus and long gyri vascularize, respectively, the corticonuclear and corticospinal fasciculi. We particularly insist too on three anatomical constants regarding the vascularization of the insula, already described in the literature: The superior periinsular sulcus is the only sulcus on the lateral surface of the brain without an artery along its axis; the superior branch of the MCA supplies the anterior insular pole and both the anterior and middle short gyri in 100 % of cases; in at least 90 % of cases, the artery that supplied the central insular sulcus continued on to become the central artery.We end with the anatomical study of the veins and cisterns.

Arteries and Veins of the Cerebellum.

Surgery of the posterior fossa represents a technical challenge because of the proximity of the vessels of the cerebellum. If the arterial vascularization of the cerebellum is well known, the main arterial variations and the whole venous vascularization are probably under recognized. We describe the vascular organization and the main variations through photographs of colored latex perfused brains, obtained with a surgical microscope. The arterial vascularization of the cerebellum is based on three arteries which all originate from the vertebrobasilar system: the superior cerebellar artery (SCA), the anterior and inferior cerebellar artery (AICA), and the posterior and inferior cerebellar artery (PICA). The main arterial variations involve essentially the origin of these vessels. Concerning the SCA, its origin depends on the embryology. The AICA can arise from a common trunk AICA-PICA. It can be sometimes doubled and rarely absent. The PICA also can arise from a common trunk AICA-PICA and sometimes from the extradural segment of the vertebral artery. Concerning the venous organization, we distinguish the superficial and deep veins. The superficial veins drain the cerebellar cortex and transit on the surface of the cerebellum. The deep veins refer to the veins transiting in the fissures between the cerebellum and the brainstem. All these veins terminate as bridging veins that we can divide in three groups: a superior group emptying into the great vein, a posterior group emptying into the transtentorial sinus, and a lateral group ending into the superior petrosal sinus. The surgical implications are discussed.

Comparison of injection/dissection and injection/corrosion methods: example of vertebral veins in the transverse canal

PurposeIn order to contribute some new elements to the discussion on the organization of the vertebral veins inside the transverse canal, we compared two dissection techniques: injection/dissection and injection/corrosion. The aim of this study was to compare these two techniques to study the vertebral veins, and also to emphasize the importance of preserving specimens in anatomical museums.MethodsUsing the injection/dissection technique, latex was injected into ten specimens, then the transverse canal was opened to expose the vertebral veins and their anastomoses. Using the injection/corrosion technique, altufix was injected into eight specimens that were afterwards plunged in sulfuric acid and washed daily until complete corrosion was obtained.ResultsBoth techniques showed concordant results. The vertebral veins were plexuous, located ventro-laterally to the artery and received constant metamerical branches at each level. The injection/dissection technique conserved the anatomical relationships allowing metamerical analysis of the vertebral veins. The injection/corrosion technique, however, failed to conserve these relationships but provided a precise visualization of smaller anastomosis.ConclusionsBy analyzing different aspects of the vertebral veins anatomy in the transverse canal, the two techniques complete each other. This study emphasizes the importance of preserving the anatomical preparations: in addition to the historical and cultural value of these preparations, they contain precious information that furthers our anatomical knowledge.

Psychiatric and Psychologic Impact of Surgery While Awake in Children for Resection of Brain Tumors

BACKGROUND Intraoperative direct stimulation during surgery while awake is considered to be the gold standard for identifying eloquent cortical sites. Only a few studies have referenced the psychologic impact of this event in the pediatric population. OBJECTIVE The aim of this clinical study is to present the psychologic aspects of surgery while awake in children. We question the psychiatric contraindications and age limits, as well as the impact on children, with particular attention to the psychologic conditioning and experience of these patients. METHODS Seven patients aged 8-16 years old with brain lesions were operated on while awake between 2008 and 2015. Data collected included perception and memories of surgery and diagnosis and also their real-life experience after surgery. Symptoms of posttraumatic stress disorder or acute stress were investigated. RESULTS None of the children had initial psychiatric problems. No psychiatric diagnosis was made before surgery. The child psychiatrist did not contraindicate any child for this procedure. Patients experienced little anticipatory anxiety. No child presented symptoms of posttraumatic stress disorder or acute stress. CONCLUSIONS The results are encouraging, allowing us to contemplate using brain surgery while awake for children without particular worries about the psychologic aspect.