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Introduction: This study aimed to assess skull contents, brain appearance, and density on postmortem computed tomography in naturally mummified corpses., Material and Methods: For this purpose, a retrospective multicentric study, including mummified corpses from two French centers (Brest and Nantes) and from the New Mexico Decedent Image Database (USA), was performed by analyzing postmortem computed tomography (PMCT) focused on the head and neck of partially or fully mummified corpses discovered between 2011 and 2022. The PMCT analysis provided data on the CT appearance of brains, allowing them to be classified into four different categories (desiccation, liquefaction, dura mater only (DMO), and absence), and to measure densities (HU) of the brain remains. In addition, data on postmortem intervals (PMI) from Nantes and Brest centers were collected and analyzed to test the link between brain densities and PMIs., Results: 54 cases of naturally mummified corpses were included. The brains were classified as liquefied (56%), desiccated (17 %), DMO (20 %), and absent (7 %) based on their CT appearance. Dehydrated brains were significantly (p < 0.004) denser (median 102 HU, interquartile range (IQR) 41) than either liquefied brains (median 39.5 HU, IQR 9) or brains with DMO (median -25 HU, IQR 57). However, the density of brain remains was not significantly affected by where the bodies were found (p = 0,41). Analysis of PMI and brain densities was performed on 22 cases. The results showed that brain remains were significantly (p = 0.039) denser when they were found after a PMI of more than six months., Conclusion: Brain desiccation was the aspect with the highest densities on PMCT, and for which we were able to highlight great preservation of anatomical structures observable in living organisms., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial or personal relationships that could be viewed as influencing the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Background: Despite the prevalence of psoriasis, the processing of itch in psoriasis and its impact on the central nervous system (CNS) remain unclear., Objective: We studied the influence of psoriasis on the CNS using magnetic resonance imaging techniques (fMRI and DTI, respectively) to investigate whether mentally induced itch can modify the functional connectivity or the white matter microstructure of the brain., Methods: Fourteen patients with chronic psoriasis and 15 healthy controls were recruited. Itch was mentally induced in subjects by videos showing others scratching themselves., Results: The observation of functional connectivity during the viewing the video revealed an interconnected network of brain regions that are more strongly coupled in psoriasis patients than in healthy controls. This network links the cerebellum, the thalami, the anteroposterior cingulum, the inferior parietal lobules, the middle temporal poles and the parahippocampal, hippocampal, lingual and supramarginal gyri. We also found connections with the right precuneus and both left insula and superior temporal gyrus. The DTI analysis showed that chronic itch affects the microstructure of white matter, including the anterior thalamic radiations, the superior and inferior longitudinal fasciculi, the corticospinal tracts, the cingulum, the external capsules, the inferior frontal-occipital fasciculi and both minor and major forceps., Conclusion: Our results indicate that there could exist a network which is more interconnected in psoriasis patients. Among two building blocks of this network, the subnetwork encoding the perception and control of itch sensation is more affected than the subnetwork representing mentalizing and empathy. With an approach consisting of measuring microstructural changes at a local level in the brain, we also contradict the findings obtained with global measures which stated that chronic psoriasis cannot alter the anatomy of the brain. This confirms that itchy pathophysiological conditions have similar effects on functional and structural connectivity as those observed in chronic pain., (© 2020 European Academy of Dermatology and Venereology.)

Background and Purpose: Assess the evolution of gadolinium consumption and magnetic resonance imaging (MRI) scanners in France and Western Brittany (France) and compare regional practices between public and private hospitals for each organ specialty., Material and Methods: We collected data from national and universal health registries, and Western Brittany's health care structures, between 2011 and 2018, about the number of MR imaging exams and machines, the number of delivered GBCAs (gadolinium-based contrast agents), prescriptions and administration protocols., Results: Over the last eight years, we observed an increase in the number of MRI machines implemented in France (62%), correlated with the increase of annual gadolinium consumption (amount of delivered GBCAs in kg, 64%), without modification of the annual quantity of gadolinium used per machine (2.7kg in 2018). In Western Brittany, gadolinium impact is assigned to neuroimaging exams (50% CI95% [45;56] of all the contrast-enhanced exams), followed by thorax and abdomen exams (23% CI95% [18;28]). The ratio of injected exams to all exams is greater in public than in private hospitals (respectively 48% CI95% [46;49] versus 29% CI95% [26;30])., Conclusion: Gadolinium consumption is increasing, correlated with the increase in the number of examinations carried out. Regionally, the main impact comes from neuroimaging exams. No change in practices has been observed in recent years despite some warnings about gadolinium deposits and environmental consequences., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

Although previous studies have found that cerebral white matter hyperintensities are associated with balance-gait disorders, no proton magnetic resonance spectroscopy data at the plane of the basal ganglia have been published. We investigated a possible relationship between balance performance and brain metabolite ratios or structural MRI measurements. We also included neuropsychological tests to determine whether such tests are related to structural or metabolic findings. All 80 participants were taken from the cohort of the Three-City study (Dijon-Bordeaux-Montpellier, France). The ratios of N-acetyl-aspartate to creatine (NAA/Cr) and choline to creatine (Cho/Cr) were calculated in the basal ganglia, thalami and insular cortex. We used univariate regression to identify which variables predicted changes in NAA/Cr and Cho/Cr, and completed the analysis with a multiple linear or logistic regression. After the multivariate analysis including hypertension, age, balance-gait, sex, white matter lesions, brain atrophy and body mass index, only balance-gait performance remained statistically significant for NAA/Cr (p=0.01) and for deep white-matter lesions (p=0.02). The Trail-Making Test is independently associated with brain atrophy and periventricular white-matter hyperintensities. Neuronal and axonal integrity at the plane of the basal ganglia is associated with balance and gait in the elderly, whereas brain flexibility is associated with structural MRI brain abnormalities.

Background and Purpose: This retrospective study investigated the dependence of N-acetyl aspartate (NAA) ratios on risk factors for cerebral vasculopathy such as sex, age, hypertension, diabetes mellitus, carotid stenosis, and dyslipidaemia, which may have affected brain vessels and induced metabolic brain abnormalities prior to stroke. We hypothesise that in stroke patients metabolic alterations in the apparently normal contralateral brain are dependent on the presence or not of such risk factors., Methods: Fifty nine patients (31 male, 28 female: 58.8+/-16.1 years old) with cortical middle cerebral artery (MCA) territory infarction were included. Long echo time chemical shift imaging spectroscopy was carried out on a Siemens 1.5 T Magnetom Vision scanner using a multi-voxel PRESS technique. Metabolite ratios (NAA/choline, NAA/creatine, lactate/choline, etc) were studied using uni- and multivariate analyses with respect to common risk factors. The influence of age, stroke lesion size, and time since stroke was studied using a linear regression approach., Results: Age, sex, and hypertension all appeared to individually influence metabolite ratios, although only hypertension was significant after multivariate analysis. In both basal ganglia and periventricular white matter regions in apparently normal contralateral brain, the NAA/choline ratio was significantly lower in hypertensive (1.37+/-0.16 and 1.50+/-0.19, respectively) than in normotensive patients (1.72+/-0.19 and 1.85+/-0.15, respectively)., Conclusions: Regarding MCA infarction, contralateral tissue remote from the lesion behaves abnormally in the presence of hypertension, the NAA ratios in hypertensive patients being significantly lower. These data suggest that hypertension may compromise the use of contralateral tissue data as a reference for comparison with ischaemic tissue.

Objectives: Analysis of dose-area product (DAP) in cerebral angiography, according to the type of pathology and technique used., Materials and Methods: Use of dosimetric and clinical data resulting from 84 diagnostic cerebral angiograms and 32 cerebral embolizations., Results: The diagnostic angiography data were divided into three categories: A/ When a secondarily embolized aneurysm was diagnosed: n=17. B/ When the final diagnosis was an arteriovenous malformation (AVM): n=10. C/ In the case where the diagnosis was neither AVM, nor aneurysm to embolize: n=57. The cerebral embolizations were classified in two sub-groups: K/ When the embolization immediately followed the diagnostic angiogram: n=15. L/ When the embolization of the aneurysm took place 24 to 48H after the angiography: n=17. The mean DAP of group B containing the AVM is higher than mean DAP values in groups A and C, because of the increased cinegraphic time. There is a strong correlation between the duration of the fluoroscopy and the DAP (n=116; r=0.931; p<0.0001). Addition of runs in the group L contributes to the augmentation of the exposure time (significant difference in time: p=0.0054) and thus with the fact that DAP L>DAPK., Conclusion: Radiation dose during diagnostic cerebral angiography is increased in the presence of AVM. DAP of embolizations are higher when diagnostic and therapeutic phases are separated in time.