[Show abstract][Hide abstract] ABSTRACT: Background:
Repetitive transcranial magnetic stimulation (rTMS) appears as a useful tool to alleviate neuropathic pain but only few data are available for the long-term benefit of this treatment.
Here we report the effects of rTMS sessions, considered as a possible therapy for pain relief after a failure of different medications in patients with central (neuropathic) pain. We review here the prospectively collected data of the first forty patients treated as follow: 20 Hz stimulation delivered over the contralateral primary motor cortex (M1), each 3-4 weeks.
A total of 440 rTMS sessions was collected (mean sessions number: 11, range: 1-37, follow-up 312 days on average, maximum 2.8 years). After four sessions, nine patients (22.5%) discontinued rTMS because of a lack of efficiency (<10% pain-relief). The other 31 patients (77.5%) had a cumulative effect across sessions leading to a mean pain relief of 41% for a duration of 15.6 days. A correlation was observed between pain relief in the first session and long-term pain relief (R = 0.649. p = 5.6*10(-6) ). Both intensity and duration of pain relief were significantly better for patients with persistent laser evoked potentials (LEPs, p = 0.049 and 0.0018). We did not observe any adverse-effects.
These results suggest that repeated sessions of 20 Hz rTMS over M1 are interesting in clinical practice for the treatment of selected patients with central pain. Both the cumulative effects across the first sessions and the long duration of pain-relief should impact further randomized trials that are warranted to conclude formally on rTMS efficiency in central pain.
Full-text · Article · Jan 2016 · European journal of pain (London, England)
[Show abstract][Hide abstract] ABSTRACT: Confocal microscopy is a technique able to realize “optic sections” of a tissue with increasing applications. We wondered if we could apply an ex vivo confocal microscope designed for dermatological purpose in a routine use for the most frequent brain tumors. The aim of this work was to identify tumor tissue and its histopathological hallmarks, and to assess grading criteria used in neuropathological practice without tissue loss on freshly removed brain tissue. Seven infiltrating gliomas, nine meningiomas and three metastases of carcinomas were included. We compared imaging results obtained with the confocal microscope to frozen sections, smears and tissue sections of formalin-fixed tissue. Our results show that ex vivo confocal microscopy imaging can be applied to brain tumors in order to quickly identify tumor tissue without tissue loss. It can differentiate tumors and can assess most of grading criteria. Confocal microscopy could represent a new tool to identify tumor tissue on freshly removed sample and could help in selecting areas for biobanking of tumor tissue.
No preview · Article · Jun 2015 · Journal of Neuro-Oncology
[Show abstract][Hide abstract] ABSTRACT: Nous rapportons le cas d’une patiente âgée de 58 ans, consultant pour une détérioration rapide de l’acuité visuelle. L’imagerie par résonance magnétique nucléaire a révélé un aspect hypertrophique du chiasma optique, avec un rehaussement homogène après injection de gadolinium, évoquant un gliome des voies optiques ou une pathologie inflammatoire. Les investigations complémentaires n’ont pas retrouvé d’argument pour une étiologie spécifique. La biopsie d’un nerf optique a mis en évidence un lymphome malin non Hodgkinien de type B. En l’absence d’autre(s) localisation(s) intra-oculaire(s) ou systémique(s), nous avons conclu à un exceptionnel lymphome primitif du système nerveux central avec atteinte isolée des voies visuelles antérieures, chez une patiente immuno-compétente. Le traitement a comporté deux cycles de polychimiothérapie (rituximab, méthotrexate, carmustine, étoposide, méthylprednisolone) et une greffe autologue de cellules souches hématopoïétiques périphériques, secondairement consolidée par l’association de rituximab et cytarabine. Lors des derniers examens de surveillance un an après le traitement, la patiente était en rémission complète, avec une amélioration significative de la fonction visuelle. L’objectif de ce travail était d’illustrer en détail les caractéristiques cliniques et radiologiques de cette forme particulière de lymphome primitif du système nerveux central. Une meilleure connaissance des éléments diagnostiques est souhaitable pour améliorer la prise en charge de ces patients, dont le pronostic visuel et vital dépend de la rapidité de mise en œuvre du traitement.
[Show abstract][Hide abstract] ABSTRACT: We used the method of direct electrostimulation combined with navigated tractography to map the frontal "aslant" tract, enabling us to perform reliable anatomo-functional correlation in a patient undergoing awake surgery to remove a left frontal glioma. The findings enhanced our understanding of the organization of language within the human brain.
Full-text · Article · Feb 2014 · British Journal of Neurosurgery
[Show abstract][Hide abstract] ABSTRACT: Le lipoblastome est une entité tumorale bénigne à croissance rapide. Extrêmement rare en pédiatrie avant 3 ans, les quelques cas publiés ont des topographies cervicales ou des extrémités.
Nous rapportons un cas féminin de 11 mois, présentant une lésion frontale médiane congénitale extra-crânienne hétérogène et rénitente. Le bilan d’imagerie néonatal fait évoquer un kyste dermoïde ou épidermoïde. Une progression tumorale de 25 % à 11 mois, l’absence d’envahissement osseux ou endocrânien et la localisation distante de la fontanelle antérieure incite à réaliser une exérèse chirurgicale en double équipe neurochirurgicale et maxillo-faciale. À 3 ans de l’exérèse, il n’y a aucun signe de récidive locale et une bonne cicatrisation.
Ce cas met en exergue la technique chirurgicale employée associant une exérèse complète à un bon résultat esthétique. Il s’agit d’un cas rare de lipoblastome, épicrânien, aucun cas similaire n’est retrouvé dans notre revue de littérature. On retrouve une prédominance masculine. Un taux de récidive à un an estimée à 25 % est relatif à la complexité anatomique de la région envahie. 40 % des récidives surviennent dans les dix années suivant la première exérèse. Un cas de maturation en lipome bénin est retrouvé à 4 ans d’évolution. Aucune preuve de transformation maligne n’existe à ce jour. Un suivi trimestriel, puis annuel a été préconisé dans ce cas.
Le diagnostic de lipoblastome comporte des enjeux majeurs de prise en charge. Une exérèse macroscopiquement complète est curative ; cependant, elle ne doit pas alourdir la morbidité opératoire, a fortiori en pédiatrie. Une stratégie pluridisciplinaire est fréquemment requise.
[Show abstract][Hide abstract] ABSTRACT: Introduction:
For gliomas, the goal of surgery is maximal tumour removal with the preservation of neurological function. We evaluated the contribution of the combination of diffusion tensor imaging-based fibre tracking (DTI-FT) of the pyramidal tract (PT) integrated to the navigation and subcortical direct electrical stimulations (DESs) to surgical outcomes.
Ten patients underwent surgery for gliomas located in close relationship with the subcortical course of the PT. Preoperative DTI was performed with a three-Tesla magnetic resonance scanner applying an echo-planar sequence with 20 diffusion directions. DTI-FT data were systematically loaded into the navigation for intraoperative guidance. When the resection closely approached the PT as illustrated on navigation images, subcortical DESs were used to confirm the proximity of the PT by observing motor responses. The location of all subcortically stimulated points with positive motor response was correlated with the illustrated PT. Motor deficits were evaluated pre- and postoperatively, and compared with the extent of tumour removal.
DTI-FT of the PT was successfully performed in all patients. A total of fifteen positive subcortical DESs were obtained in 8 of 10 patients; in these cases, the mean distance from the stimulated point to the PT was 6.2 ± 3.6 mm. The mean tumoural volumetric resection was 90.8 ± 10.4%, with a gross total resection in four patients. At one month after surgery, only one patient had a slight impairment of motor function (decreased fine motor hand skills).
DTI-FT is an accurate technique to map the PT in the vicinity of brain tumours. By combining anatomical (DTI-FT) and functional (subcortical DES) studies for intraoperative localization of the PT, the authors achieved a good volumetric resection of tumours located in eloquent motor areas, with low morbidity. Careful use of this protocol requires the knowledge of some pitfalls, mainly the occurrence of brain shift during removal of large tumours.
Full-text · Article · Mar 2013 · British Journal of Neurosurgery
[Show abstract][Hide abstract] ABSTRACT: Background:
For gliomas, the goal of surgery is to maximise the extent of resection (EOR) while minimising the postoperative morbidity. The purpose of this study was to evaluate the benefits of a protocol developed for the surgical management of gliomas located in language areas, where tractography-integrated navigation was used in conjunction with direct electrical stimulations (DES).
Methods and materials:
The authors included ten patients suffering of gliomas located in language areas. The preoperative planning for multimodal navigation was done by integrating anatomical magnetic resonance images and subcortical pathway volumes generated by diffusion tensor imaging. Six white matter fascicles implicated in language functions were reconstructed in each patient, including fibres for phonological processing (i.e. the arcuate fasciculus), fibres for lexical-semantic processing (i.e. the inferior frontooccipital fasciculus, inferior longitudinal fasciculus and uncinate fasciculus), and two premotor fasciculi involved in the preparation of speech movements (the subcallosal medialis fasciculus and cortical fibres originating from the medial and lateral premotor areas). During surgery, language fascicles were identified by direct visualisation on tractography-integrated navigation images and by observing transient language inhibition after subcortical DES. Language deficits were evaluated preoperatively and postoperatively, and compared with the EOR.
Tractography was successfully performed in all patients, preoperatively demonstrating the relationships between the tumours to resect and the language fascicles to preserve from injury. With the use of the tractography-integrated navigation system and intraoperative DES, language functions were preserved in all patients. The mean volumetric resection was 93.0 ± 10.4 % of the preoperative tumour volume, with a gross total resection in 60 % of patients.
The intraoperative combination of tractography and DES contributed to maximum safe resection of gliomas located in language areas.
Full-text · Article · Dec 2012 · Acta Neurochirurgica
[Show abstract][Hide abstract] ABSTRACT: Objectives:
To demonstrate that motor cortex stimulation (MCS) could improve motor function in patients with neuropathic pain.
In this prospective clinical study of 38 patients referred for MCS as treatment for their neuropathic pain, we collected any declaration of improvement in motor performance that could be attributed to MCS.
Ten patients (26%) declared a benefit in their motor function. Eight presented objective evidence of recovered dexterity for rapid alternating movements. A minor proportion had improvement in dystonic posture (n = 2), but none had detectable increased motor strength or tonus changes. Overall, 73% of the patients with limb ataxia declared a benefit after MCS. In 6 out of 10 patients (60%), the anatomic lesion responsible for pain was restricted to the lateral aspect of the thalamus. All of them had either clinical or electrophysiological evidence of lemniscal dysfunction (proprioceptive ataxia). No correlation was found between the scores of pain relief and the modification of motor status. The correlation between thalamic lesions and benefits in motor performance was significant (Fisher's exact test, two-tailed, p = 0.0017).
Up to 26% of patients estimated that MCS improved their motor outcome through recovered dexterity and in cases of lateral thalamic lesions.
Full-text · Article · Aug 2012 · Stereotactic and Functional Neurosurgery
[Show abstract][Hide abstract] ABSTRACT: The purpose of this technical/case report is to demonstrate that the appropriate oncological principle of margin-free, tumour en bloc removal can be successfully achieved in a large multilevel chordoma with C-2 involvement, with limited morbidity. Although technically challenging, such an approach offers the patient's best chance for cure.
Full-text · Article · May 2012 · British Journal of Neurosurgery
[Show abstract][Hide abstract] ABSTRACT: The ventrointermediate nucleus (Vim) of the thalamus is still considered "invisible" on current magnetic resonance imaging (MRI), requiring indirect methods based on stereotactic atlases for estimation of its location. Direct visualization of Vim is desirable to improve targeting.
To evaluate the ability of Inversion-Recovery 1.5-T MR images to produce high-resolution, anatomical depiction of the thalamus suitable for direct Vim targeting.
Twenty patients with essential tremor or tremor associated with Parkinson's disease received Vim deep brain stimulation (DBS). Fahn-Tolosa-Marin and Unified Parkinson's Disease Rating Scale (UPDRS) tremor scores were assessed pre- and postoperatively. Preoperative stereotactic 1.5-T MR images of the thalamus were acquired using a White Matter Attenuated Inversion Recovery (WAIR) sequence. Thalamic nuclei were manually contoured on the basis of spontaneous MRI contrasts; labeling relied on 3D identification from stereotactic books and in-house ex vivo 4.7-T microscopic MRI atlas. Vim was then directly probed for electrophysiological confirmation and determination of the optimal site for electrode placement.
The shape, spatial orientation, and signal contrast of Vim as depicted on our WAIR images were similar to those observed on the Schaltenbrand and Bailey atlas, as well as in our high-field MRI atlas. These images were successfully used for pure direct Vim targeting: at the last follow-up (median = 46.3 months), the average tremor score improved from 3.80 preoperatively to 0.50 postoperatively (on stimulation; P < 0.01).
1.5-T MRI with WAIR sequence provides high-quality images of Vim suitable in DBS surgery, for accurate preoperative planning, direct targeting and anatomic analysis.
Full-text · Article · Feb 2012 · Brain Stimulation