Bars Emmanuelle Le

Dr. Bars Emmanuelle Le

orcid

Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 March 2023 in Neuropsychology
Verified
Journal Article
Closed access
ACAdrian I. Campos
Adrian I. Campos
LVLaura S. Van Velzen
Laura S. Van Velzen
DVDick J. Veltman
Dick J. Veltman
EPElena Pozzi
Elena Pozzi
SASonia Ambrogi
Sonia Ambrogi
MRMiguel E. Rentería
Miguel E. Rentería
A major limitation of current suicide research is the lack of power to identify robust correlates of suicidal thoughts or behavior. Variation in suicide risk assessment instruments used across cohorts may represent a limitation to pooling data in international consortia. Here, we examine this issue through two approaches: (a) an extensive literature search on the reliability and concurrent validity of the most commonly used instruments and (b) by pooling data (N ∼ 6,000 participants) from cohorts from the Enhancing NeuroImaging Genetics Through Meta-Analysis (ENIGMA) Major Depressive Disorder and ENIGMA-Suicidal Thoughts and Behaviour working groups, to assess the concurrent validity of instruments currently used for assessing suicidal thoughts or behavior. We observed moderate-to-high correlations between measures, consistent with the wide range (κ range: 0.15-0.97; r range: 0.21-0.94) reported in the literature. Two common multi-item instruments, the Columbia Suicide Severity Rating Scale and the Beck Scale for Suicidal Ideation were highly correlated with each other (r = 0.83). Sensitivity analyses identified sources of heterogeneity such as the time frame of the instrument and whether it relies on self-report or a clinical interview. Finally, construct-specific analyses suggest that suicide ideation items from common psychiatric questionnaires are most concordant with the suicide ideation construct of multi-item instruments. Our findings suggest that multi-item instruments provide valuable information on different aspects of suicidal thoughts or behavior but share a modest core factor with single suicidal ideation items. Retrospective, multisite collaborations including distinct instruments should be feasible provided they harmonize across instruments or focus on specific constructs of suicidality. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

21 January 2021 in American Journal of Neuroradiology
Verified
Journal Article
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ABA. Benali
A. Benali
MMM. Moynier
M. Moynier
CDC. Dargazanli
C. Dargazanli
JDJ. Deverdun
J. Deverdun
FCF. Cagnazzo
F. Cagnazzo
VCV. Costalat
V. Costalat
BACKGROUND AND PURPOSE: Few data are available regarding the influence of the timing of ischemic stroke management, such as daytime and nighttime hours, on the delay of mechanical thrombectomy, the effectiveness of revascularization, and clinical outcomes. We aimed to investigate whether admission during nighttime hours could impact the clinical outcome (mRS at 90 days) of patients with acute ischemic stroke treated by mechanical thrombectomy. MATERIALS AND METHODS: We retrospectively analyzed 169 patients (112 treated during daytime hours and 57 treated during nighttime hours) with acute ischemic stroke in the anterior cerebral circulation. The main outcome was the rate of patients achieving functional independence at 90 days (mRS ≤2), depending on admission time. RESULTS: In patients admitted during nighttime hours, the rate of mRS ≤ 2 at 90 days was significantly higher (51% versus 35%, P = .05) compared with those admitted in daytime hours. Patients in daytime and nighttime hours were comparable regarding admission and treatment characteristics. However, patients in nighttime hours tended to have a higher median NIHSS score at admission (P = .08) and to be younger (P = .08), especially among the mothership group (P = .09). The multivariate logistic regression analysis confirmed that patients in nighttime hours had better functional outcomes at 90 days than those in daytime hours (P = .018; 95% CI, 0.064–0.770; OR = 0.221). CONCLUSIONS: In a highly organized stroke care network, mechanical thrombectomy is quite effective in the nighttime hours among acute ischemic stroke presentations. Unexpectedly, we found that those patients achieved favorable clinical outcomes more frequently than those treated during daytime hours. Larger series are needed to confirm these results.

14 July 2016 in American Journal of Neuroradiology
Verified
Journal Article
Open access
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Vincent DunetVincent Dunet
Vincent Dunet
JDJ. Deverdun
J. Deverdun
CCC. Charroud
C. Charroud
BLBars Emmanuelle Le
Bars Emmanuelle Le
FMF. Molino
F. Molino
NCN. Menjot de Champfleur
N. Menjot de Champfleur
BACKGROUND AND PURPOSE: Patients with vascular parkinsonism have higher cognitive decline and more basal ganglia lesions. We aimed to evaluate the relationship of cognitive impairment with functional connectivity between the basal ganglia and cingulate cortex in vascular parkinsonism. MATERIALS AND METHODS: Thirty patients (8 with vascular parkinsonism and 22 with Parkinson disease) and 23 controls were enrolled. The Mattis Dementia Rating Scale and the Stroop Task were used to assess cognitive decline. MR imaging examinations included T1-MPRAGE, FLAIR, and resting-state fMRI sequences. MPRAGE was segmented to obtain basal ganglia and cingulate cortex volumes. FLAIR was segmented to obtain white matter hyperintensity lesion volume. Resting-state fMRI sequences were used to compare basal ganglia functional connectivity with the cingulate cortex between patients and controls. RESULTS: Patients with vascular parkinsonism exhibited impaired attention, resistance to interference, and inhibitory control and an increased number of errors on the Stroop Task. They also had higher caudate nucleus and white matter hyperintensity lesion volumes, which were positively correlated (ρ = 0.75, P < .0001). Caudate nucleus functional connectivity with the perigenual anterior cingulate cortex was increased in patients with vascular parkinsonism compared with controls and patients with Parkinson disease, and it was positively correlated with the caudate nucleus volume (ρ = 0.44, P = .016). Caudate nucleus functional connectivity with the posterior cingulate cortex was decreased in patients with vascular parkinsonism compared with controls and negatively correlated with the number of errors on the Stroop test (ρ = −0.51, P = .0003). CONCLUSIONS: In patients with vascular parkinsonism, cognitive decline could be related to changes of caudate nucleus functional connectivity with the cingulate cortex at resting-state, which may be induced by ischemia-related remodelling.

1 June 2023 in Journal of Neurosurgery
Verified
Journal Article
Closed access
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SNSam Ng
Sam Ng
JDJeremy Deverdun
Jeremy Deverdun
ALAnne-Laure Lemaitre
Anne-Laure Lemaitre
DGDavide Giampiccolo
Davide Giampiccolo
BLBars Emmanuelle Le
Bars Emmanuelle Le
GHGuillaume Herbet
Guillaume Herbet
OBJECTIVE: The precuneus hosts one of the most complex patterns of functional connectivity in the human brain. However, due to the extreme rarity of neurological lesions specifically targeting this structure, it remains unknown how focal damage to the precuneus may impact resting-state functional connectivity (rsFC) at the brainwide level. The aim of this study was to investigate glioma-induced rsFC modulations and to identify patterns of rsFC remodeling that accounted for the maintenance of cognitive performance after awake-guided surgical excision. METHODS: In a unique series of patients with IDH1-mutated low-grade gliomas (LGGs) infiltrating the precuneus who were treated at a single neurosurgical center (Montpellier University Medical Center, 2014–2021), the authors gauged the dynamic modulations induced by tumors on rsFC in comparison with healthy participants. All patients received a preoperative resting-state functional MRI and underwent operation guided by awake cognitive mapping. Connectome multivariate pattern analysis (MVPA), seed-network analysis, and graph theoretical analysis were conducted and correlated to executive neurocognitive scores (i.e., phonological and semantic fluencies, Trail-Making Test [TMT] parts A and B) obtained 3 months after surgery. RESULTS: Seventeen patients with focal precuneal infiltration were selected (mean age 38.1 ± 11.2 years) and matched to 17 healthy participants (mean age 40.5 ± 10.4 years) for rsFC analyses. All patients underwent awake cognitive mapping, allowing total resection (n = 3) or subtotal resection (n = 14), with a mean extent of resection of 90.6% ± 7.3%. Using MVPA (cluster threshold: p–false discovery rate corrected < 0.05, voxel threshold: p-uncorrected < 0.001), remote hotspots with significant rsFC changes were identified, including both insulas, the anterior cingulate cortex, superior sensorimotor cortices, and both frontal eye fields. Further seed-network analyses captured 2 patterns of between-network redistribution especially involving hyperconnectivity between the salience, visual, and dorsal attentional networks. Finally, the global efficiency of the salience-visual-dorsal attentional networks was strongly and positively correlated to 3-month postsurgical scores (n = 15) for phonological fluency (r15 = 0.74, p = 0.0027); TMT-A (r15 = 0.65, p = 0.012); TMT-B (r15 = 0.70, p = 0.005); and TMT-B-A (r15 = 0.62, p = 0.018). CONCLUSIONS: In patients with LGGs infiltrating the precuneus, remote and distributed functional connectivity modulations in the preoperative setting are associated with better maintenance of cognitive performance after surgery. These findings provide a new vision of the mechanistic principles underlying neural plasticity and cognitive compensation in patients with LGGs.

19 October 2017 in American Journal of Neuroradiology
Verified
Journal Article
Open access
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OEOmer F. EKER
Omer F. EKER
PPP. Panni
P. Panni
CDC. Dargazanli
C. Dargazanli
GMG. Marnat
G. Marnat
CAC. Arquizan
C. Arquizan
ABA. Bonafé
A. Bonafé
BACKGROUND AND PURPOSE: Mechanical thrombectomy for patients with acute ischemic stroke with tandem occlusions has been shown to present varying reperfusion successes and clinical outcomes. However, the heterogeneity of tandem occlusion etiology has been strongly neglected in previous studies. We retrospectively investigated patients with acute ischemic stroke atherothrombotic tandem occlusion. MATERIALS AND METHODS: All consecutive patients with acute ischemic stroke with atherothrombotic tandem occlusions treated with mechanical thrombectomy in our center between September 2009 and April 2015 were analyzed. They were compared with patients with acute ischemic stroke with dissection-related tandem occlusion and isolated intracranial occlusion treated during the same period. Comparative univariate and multivariate analyses were conducted, including demographic data, safety, and rates of successful recanalization and good clinical outcome. RESULTS: Despite comparable baseline severity of neurologic deficits and infarct core extension, patients with atherothrombotic tandem occlusions were older (P < .001), were more frequently smokers (P < .001), and had globally more cardiovascular risk factors (P < .001) than the other 2 groups of patients. The patients with atherothrombotic tandem occlusions had significantly longer procedural times (P < .001), lower recanalization rates (P = .004), and higher global burden of procedural complications (P < .001). In this group, procedural complications (OR = 0.15, P = .02) and the TICI 2b/3 reperfusion scores (OR = 17.76, P = .002) were independently predictive factors of favorable clinical outcome. CONCLUSIONS: Our study suggests that atherothrombotic tandem occlusions represent a peculiar and different nosologic entity compared with dissection-related tandem occlusions. This challenging cause of acute ischemic stroke should be differentiated from other etiologies in patient management in future prospective studies.

10 June 2023 in Diagnostics
Verified
Journal Article
Open access
PDF file
TPTom PAUNET
Tom PAUNET
DMDenis Mariano-Goulart
Denis Mariano-Goulart
JDJeremy Deverdun
Jeremy Deverdun
BLBars Emmanuelle Le
Bars Emmanuelle Le
MFMarjolaine Fourcade
Marjolaine Fourcade
FKFlorentin Kucharczak
Florentin Kucharczak
Ensuring a robust and reliable evaluation of coma deepness and prognostication of neurological outcome is challenging. We propose to develop PET neuroimaging as a new diagnostic and prognosis tool for comatose patients using a recently published methodology to perform functional PET (fPET). This exam permits the quantification of task-specific changes in neuronal metabolism in a single session. The aim of this protocol is to determine whether task-specific changes in glucose metabolism during the acute phase of coma are able to predict recovery at 18 months. Participation will be proposed for all patients coming for a standard PET-CT in our center in order to evaluate global cerebral metabolism during the comatose state. Legally appointed representative consent will be obtained to slightly modify the exam protocol: (1) 18F-fluorodeoxyglucose (18F-FDG) bolus plus continuous infusion instead of a simple bolus and (2) more time under camera to perform dynamic acquisition. Participants will undergo a 55-min fPET session with a 20% bolus + 80% infusion protocol. Two occurrences of three block (5-min rest, 10-min auditory stimulation and 10-min emotional auditory stimulation) will be performed after reaching equilibrium of FDG arterial concentration. We will compare the regional brain metabolism at rest and during the sessions of auditory and emotional auditory stimulation to search for a determinant of coma recovery (18 months of follow-up after the exam). Emotional auditory stimulation should induce an activation of: the auditory cortex, the consciousness areas and the neural circuitry for emotion (function to coma deepness). An activation analysis will be carried out to highlight regional brain activation using dedicated custom-made software based on Python statistical and image processing toolboxes. The association between activation levels and the Coma Recovery Scale-Revisited (CRS-R) will be assessed using multivariate analysis. If successful, the results from this study will help improve coma prognosis evaluation based on the pattern of neuronal metabolism at the onset of the pathology. The study protocol, rationale and methods are described in this paper.