Publications by authors named "Jean Jacques Lemaire"

Article Synopsis
  • Understanding the deep brain's architecture is difficult due to its complex structure, which controls movement and behavior, and lacks dedicated exploration tools.
  • A new deep-brain MRI architecture atlas was created using advanced MRI-based mapping techniques, featuring a young male adult template and various MRI datasets.
  • This open-source tool includes high-resolution images of 118 labeled deep brain structures, enhancing existing 3D atlases and clinical resources for better analysis.
View Article and Find Full Text PDF

Background And Objective: The common structural interpretation of diffusion color-encoded (DCE) maps assumes that the brain is aligned with the gradients of the MRI machine. This is seldom achieved in the field, leading to incorrect red (R), green (G) and blue (B) DCE values for the expected orientation of fiber bundles. We studied the virtual reorientation of gradients according to the anterior commissure - posterior commissure (ACPC) system on the RGB derivatives.

View Article and Find Full Text PDF

Background: Robot-assisted gait training (RAGT) is promising to help walking rehabilitation in cerebral palsy, but training-induced neuroplastic effects have little been investigated.

Methods: Forty unilateral cerebral palsy children aged 4-18 years were randomly allocated in a monocentric study to ten 20-minute RAGT sessions with the G-EO system, five days a week (n = 20) or to a control group (who continued conventional care with six 30-minute physiotherapy sessions, three days a week) (n = 20), two weeks running, from September 2020 to December 2021. Clinical and MRI outcomes were compared before and one month after therapy.

View Article and Find Full Text PDF

Deep brain stimulation (DBS) is a therapy for Parkinson's disease (PD) and essential tremor (ET). The mechanism of action of DBS is still incompletely understood. Retrospective group analysis of intra-operative data recorded from ET patients implanted in the ventral intermediate nucleus of the thalamus (Vim) is rare.

View Article and Find Full Text PDF

Essential oil (EO) composition of was characterised by high proportion of furanosesquiterpenes (51.66-69.35%).

View Article and Find Full Text PDF
Article Synopsis
  • Subthalamic nucleus deep brain stimulation can improve motor symptoms in Parkinson's disease but may lead to speech and gait issues due to contact balance in electrode positioning.
  • A study involving 92 patients analyzed the effects of symmetric versus asymmetric electrode contact balance on speech and axial signs after one year of treatment.
  • Results indicate that symmetric settings significantly worsen speech and gait, suggesting a need to avoid such configurations to enhance patient outcomes.
View Article and Find Full Text PDF

Background: Intracranial solitary fibrous tumour (iSFT) is an exceptional mesenchymal tumour with high recurrence rates. We aimed to analyse the clinical outcomes of newly diagnosed and recurrent iSFTs.

Methods: We carried out a French retrospective multicentre ( = 16) study of histologically proven iSFT cases.

View Article and Find Full Text PDF

Background: The objective of our study was to report predictive factors of local control (LC) and radionecrosis (RN) of brain metastases (BM) of non-small cell lung carcinoma (NSCLC) treated by multifractionated stereotactic radiotherapy (MF-SRT) according to French recommendations.

Method: From 2012 to 2020, 87 patients with 101 BM were retrospectively included. The median age was 63 years (37-85).

View Article and Find Full Text PDF

(1) Background: Glioblastoma multiforme (GBM) shows complex mechanisms of spreading of the tumor cells, up to remote areas, and little is still known of these mechanisms, thus we focused on MRI abnormalities observable in the tumor and the brain adjacent to the lesion, up to the contralateral hemisphere, with a special interest on tensor diffusion imaging informing on white matter architecture; (2) Material and Methods: volumes, macroscopic volume (MV), brain-adjacent-tumor (BAT) volume and abnormal color-coded DTI volume (aCCV), and region-of-interest samples (probe volumes, ipsi, and contra lateral to the lesion), with their MRI characteristics, apparent diffusion coefficient (ADC), fractional anisotropy (FA) values, and number of fibers (DTI fiber tracking) were analyzed in patients suffering GBM ( = 15) and metastasis ( = 9), and healthy subjects ( = 15), using ad hoc statistical methods (type I error = 5%) (3) Results: GBM volumes were larger than metastasis volumes, aCCV being larger in GBM and BAT ADC was higher in metastasis, ADC decreased centripetally in metastasis, FA increased centripetally either in GBM or metastasis, MV and BAT FA values were higher in GBM, ipsi FA values of GBM ROIs were higher than those of metastasis, and the GBM ipsi number of fibers was higher than the GBM contra number of fibers; (4) Conclusions: The MV, BAT and especially the aCCV, as well as their related water diffusion characteristics, could be useful biomarkers in oncology and functional oncology.

View Article and Find Full Text PDF

There is a growing body of evidences that brain surrogates will be of great interest for researchers and physicians in the medical field. They are currently mainly used for education and training purposes or to verify the appropriate functionality of medical devices. Depending on the purpose, a variety of materials have been used with specific and accurate mechanical and biophysical properties, More recently they have been used to assess the biocompatibility of implantable devices, but they are still not validated to study the migration of leaching components from devices.

View Article and Find Full Text PDF

Risk-taking behaviors of adult bedridden patients in neurosurgery are frequent, however little analyzed. We aimed to estimate from the literature and our clinical experience the incidence of the different clinical pictures. Risk-taking behaviors seem to be more frequent than reported.

View Article and Find Full Text PDF

Background: Surgery is an important therapeutic option for brain metastases. Currently, postoperative stereotactic radiosurgery (SRT) leads to 6-month and 1-year local control estimated at 70 and 62% respectively. However, there is an increased risk of radio-necrosis and leptomeningeal relapse.

View Article and Find Full Text PDF
Article Synopsis
  • The human hypothalamus consists of 10 different structures known as nuclei, which include areas like the preoptic and suprachiasmatic nuclei.
  • Modern MRI techniques, especially diffusion methods, are used to analyze the macroconnectivity of these hypothalamic structures.
  • The hypothalamus has various structural connections to other brain regions, including the olfactory system and cortex, as well as connections within itself and to the pituitary gland.
View Article and Find Full Text PDF

Introduction: Although deep brain stimulation is nowadays performed worldwide, the biomechanical aspects of electrode implantation received little attention, mainly as physicians focused on the medical aspects, such as the optimal indication of the surgical procedure, the positive and adverse effects, and the long-term follow-up. We aimed to describe electrode deformations and brain shift immediately after implantation, as it may highlight our comprehension of intracranial and intracerebral mechanics.

Materials And Methods: Sixty electrodes of 30 patients suffering from severe symptoms of Parkinson's disease and essential tremor were studied.

View Article and Find Full Text PDF

Chronic disorders of consciousness (DOC) encompass unresponsive wakefulness syndrome and minimally conscious state. Their anatomo-functional correlates are not clearly defined yet, although impairments of functional cortical networks have been reported, as well as the implication of the thalamus and deep brain structures. However, the pallidal functional connectivity with the thalamus and the cortical networks has not been studied so far.

View Article and Find Full Text PDF

Background: Stereotactic radiosurgery (SRS) is a common treatment option for vestibular schwannomas. Historically, a dose de-escalation of the marginal prescribed dose from 16 Gy to 12-13 Gy has been done to limit toxicity without reducing local control (LC). We aimed to retrospectively report outcomes of Linac-based SRS for vestibular schwannomas treated with different doses.

View Article and Find Full Text PDF

We report a case of a needlefish jaws retained near the C5-C6 joint that was associated with chronic pain and inflammation and seen confirmed by FDG-PET scan. Two unsuccessful surgeries using an anterior approach were complicated by vascular and nerve injuries. We used image-guided surgery with a posterior approach.

View Article and Find Full Text PDF
Article Synopsis
  • The brainstem is critical for various functions in mammals and is increasingly important in neuroscience, connecting the forebrain and spinal cord while influencing consciousness, emotions, and motivation.
  • Researchers created a detailed, high-resolution map of the human brainstem utilizing a T2-weighted MRI dataset of postmortem brains and validated it against traditional histological maps.
  • The resulting 3D representations of the brainstem's neural systems are intended for use by the neuroimaging community in multiple fields, including basic neuroscience, neurology, psychiatry, and neurosurgery.
View Article and Find Full Text PDF

Deep brain stimulation (DBS) therapy requires extensive patient-specific planning prior to implantation to achieve optimal clinical outcomes. Collective analysis of patient's brain images is promising in order to provide more systematic planning assistance. In this paper the design of a normalization pipeline using a group specific multi-modality iterative template creation process is presented.

View Article and Find Full Text PDF

Deep brain stimulation (DBS) is an established therapy for movement disorders such as essential tremor (ET). Positioning of the DBS lead in the patient's brain is crucial for effective treatment. Extensive evaluations of improvement and adverse effects of stimulation at different positions for various current amplitudes are performed intraoperatively.

View Article and Find Full Text PDF

Background: Numerous studies have assessed the predictive factors for the arteriovenous malformation (AVM) response to stereotactic radiosurgery (SRS). However, only a few have discussed the causes of failure. The aim of the present study was to evaluate the patterns of failure in patients with AVM who had undergone linear accelerator SRS.

View Article and Find Full Text PDF

Mastering detailed anatomy of the human deep brain in clinical neurosciences is challenging. Although numerous pioneering works have gathered a large dataset of structural and topographic information, it is still difficult to transfer this knowledge into practice, even with advanced magnetic resonance imaging techniques. Thus, classical histological atlases continue to be used to identify structures for stereotactic targeting in functional neurosurgery.

View Article and Find Full Text PDF

Background: Battery life of the most commonly used implantable pulse generators in deep brain stimulation is limited. Device replacement is costly and may expose patients to additional risks. Driven by the observation that in our experience newer generation devices seemed to need earlier replacement than the older generation, we aimed to retrospectively analyze the battery life of two generations of non-rechargeable devices, manufactured by a single company (Medtronic, USA).

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_sessionj4mukvuun39tlsdfi6c3brva0j3kruju): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once