ICM Partners

About: ICM Partners is a based out in . It is known for research contribution in the topics: Population & Breast cancer. The organization has 1311 authors who have published 1521 publications receiving 33745 citations. The organization is also known as: International Creative Management Partners.

Early alteration of the locus coeruleus in phenotypic variants of Alzheimer's disease.

Abstract: Neuropathological studies showed early locus coeruleus (LC) neuronal loss associated with tauopathy in Alzheimer's Disease (AD). We used the LC signal intensity (LC-I) on 3T MRI to assess the LC integrity in AD (n = 37) and controls (n = 17). The LC-I was decreased in AD regardless of typical (amnesic) and atypical presentation (logopenic aphasia/visuo-spatial deficit), from the prodromal stage, and independently of the amyloid load measured by PiB-PET. The LC-I was correlated with memory performance of typical AD. This supports the pathophysiological model in which the LC plays a critical role in AD and may thus be a potential therapeutic target.

A selective role for dopamine in learning to maximize reward but not to minimize effort: evidence from patients with Parkinson's disease

Abstract: Instrumental learning is a fundamental process through which agents optimize their choices, taking into account various dimensions of available options such as the possible reward or punishment outcomes and the costs associated with potential actions Although the implication of dopamine in learning from choice outcomes is well established, less is known about its role in learning the action costs such as effort Here, we tested the ability of patients with Parkinson's disease (PD) to maximize monetary rewards and minimize physical efforts in a probabilistic instrumental learning task The implication of dopamine was assessed by comparing performance ON and OFF prodopaminergic medication In a first sample of PD patients (n = 15), we observed that reward learning, but not effort learning, was selectively impaired in the absence of treatment, with a significant interaction between learning condition (reward vs effort) and medication status (OFF vs ON) These results were replicated in a second, independent sample of PD patients (n = 20) using a simplified version of the task According to Bayesian model selection, the best account for medication effects in both studies was a specific amplification of reward magnitude in a Q-learning algorithm These results suggest that learning to avoid physical effort is independent from dopaminergic circuits and strengthen the general idea that dopaminergic signaling amplifies the effects of reward expectation or obtainment on instrumental behaviorSIGNIFICANCE STATEMENT Theoretically, maximizing reward and minimizing effort could involve the same computations and therefore rely on the same brain circuits Here, we tested whether dopamine, a key component of reward-related circuitry, is also implicated in effort learning We found that patients suffering from dopamine depletion due to Parkinson's disease were selectively impaired in reward learning, but not effort learning Moreover, anti-parkinsonian medication restored the ability to maximize reward, but had no effect on effort minimization This dissociation suggests that the brain has evolved separate, domain-specific systems for instrumental learning These results help to disambiguate the motivational role of prodopaminergic medications: they amplify the impact of reward without affecting the integration of effort cost

IDH mutation and 1p19q codeletion distinguish two radiological patterns of diffuse low-grade gliomas.

Abstract: Diffuse low-grade gliomas (DLGG) prognosis is variable, depending on several factors, including the isocitrate dehydrogenase (IDH) mutation and the 1p19q codeletion. A few studies suggested associations between these parameters and tumor radiological characteristics including topography. Our aim was analyzing the correlations between the IDH and 1p19q statuses and the tumor intracerebral distribution (at the lobar and voxel levels), volume, and borders. We conducted a retrospective, monocentric study on a consecutive series of 198 DLGG patients. The IDH and 1p19q statuses were recorded. The pre-treatment magnetic resonance FLAIR imagings were reviewed for determination of lobar topography, tumor volume, and characterisation of tumor borders (sharp or indistinct). We conducted a voxel-based lesion-symptom mapping analysis to investigate the correlations between the IDH and 1p19q statuses and topography at the voxel level. The IDH mutation and 1p19q statuses were correlated with the tumor topography defined using lobar anatomy (p < 0.001 and p = 0.004, respectively). Frontal tumors were more frequently IDH-mutant (87.1 vs. 57.4%) and 1p19q codeleted (45.2 vs. 17.0%) than temporo-insular lesions. At the voxel level, these associations were not found. Tumors with sharp borders were more frequently IDH-mutant (p = 0.001) while tumors with indistinct borders were more frequently IDH wild-type and 1p19q non-codeleted (p < 0.001). Larger tumors at diagnosis (possibly linked to a slower growth rate) were more frequently IDH-mutant (p < 0.001). IDH wild-type, 1p19q non-codeleted temporo-insular tumors are distinct from IDH-mutant, 1p19q codeleted frontal tumors. Further studies are needed to determine whether the therapeutic strategy should be adapted to each pattern.

An attempt to conceptualize the individual onco-functional balance: Why a standardized treatment is an illusion for diffuse low-grade glioma patients.

Abstract: In the era of evidence-based medicine, clinicians aim to establish standards of care from randomized studies. Following, personalized medicine has emerged, as new individualized biomarkers could help to predict sensitivity to specific treatment. In this paper, we show that, for diffuse low-grade glioma, some specificities - dual goal of both survival and functional gain, long duration of the disease with multistep treatments, multiparametric evaluation of the onco-functional balance of each treatment modality - call for a change of paradigm. After summarizing how to weight the benefits and risks of surgery, chemotherapy and radiotherapy, we show that the overall efficacy of a treatment modality cannot be assessed per se, as it depends on its integration in the whole sequence. Then, we revisit the notion of personalized medicine: instead of decision-making based solely on molecular profile, we plead for a recursive algorithm, allowing a dynamic evaluation of the onco-functional balance, integrating many individual characteristics of the patient's tumor and brain function.