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A better understanding of gait disorders that are associated with aging is crucial to prevent adverse outcomes. The functional study of gait remains a thorny issue due to technical constraints inherent to neuroimaging procedures, as most of them require to stay supine and motionless. Using an MRI‐compatible system of boots reproducing gait‐like plantar stimulation, we investigated the correlation between age and brain fMRI activation during simulated gait in healthy adults. Sixty‐seven right‐handed healthy volunteers aged between 20 and 77 years old (49.2 ± 18.0 years; 35 women) were recruited. Two paradigms were assessed consecutively: (a) gait‐like plantar stimulation and (b) chaotic and not gait‐related plantar stimulation. Resulting statistical parametric maps were analyzed with a multiple‐factor regression that included age and a threshold determined by Monte‐Carlo simulation to fulfill a family‐wise error rate correction of p < .05. In the first paradigm, there was an age‐correlated activation of the right pallidum, thalamus and putamen. The second paradigm showed an age‐correlated deactivation of both primary visual areas (V1). The subtraction between results of the first and second paradigms showed age‐correlated activation of the right presupplementary motor area (Brodmann Area [BA] 6) and right mid‐dorsolateral prefrontal cortex (BA9‐10). Our results show age‐correlated activity in areas that have been associated with the control of gait, highlighting the relevance of this simulation model for functional gait study. The specific progressive activation of top hierarchical control areas in simulated gait and advancing age corroborate a progressive loss of automation in healthy older adults. Gait decline during normal aging is a key public health concern. This fMRI study addresses the question of brain activation evolution with advance in age in healthy adults. We highlight a gradual and specific overactivation of top hierarchical cortical motor control areas in simulated gait during advance in age. Our results support the theory of a progressive loss of automation of gait in older healthy adults.

Introduction Preoperative language mapping using functional magnetic resonance imaging (fMRI) aims to identify eloquent areas in the vicinity of surgically resectable brain lesions. fMRI methodology relies on the blood‐oxygen‐level‐dependent (BOLD) analysis to identify brain language areas. Task‐based fMRI studies the BOLD signal increase in brain areas during a language task to identify brain language areas, which requires patients' cooperation, whereas resting‐state fMRI (rsfMRI) allows identification of functional networks without performing any explicit task through the analysis of the synchronicity of spontaneous BOLD signal oscillation between brain areas. The aim of this study was to compare preoperative language mapping using rsfMRI and task fMRI to cortical mapping (CM) during awake craniotomies. Methods Fifty adult patients surgically treated for a brain lesion were enrolled. All patients had a presurgical language mapping with both task fMRI and rsfMRI. Identified language networks were compared to perioperative language mapping using electric cortical stimulation. Results Resting‐state fMRI was able to detect brain language areas during CM with a sensitivity of 100% compared to 65.6% with task fMRI. However, we were not able to perform a specificity analysis and compare task‐based and rest fMRI with our perioperative setting in the current study. In second‐order analysis, task fMRI imaging included main nodes of the SN and main areas involved in semantics were identified in rsfMRI. Conclusion Resting‐state fMRI for presurgical language mapping is easy to implement, allowing the identification of functional brain language network with a greater sensitivity than task‐based fMRI, at the cost of some precautions and a lower specificity. Further study is required to compare both the sensitivity and the specificity of the two methods and to evaluate the clinical value of rsfMRI as an alternative tool for the presurgical identification of brain language areas. We compared task‐based and resting‐state fMRI for the identification of language network in patient surgically treated for a brain tumor. fMRI data were then compared to the standard, the electric cortical stimulation. Resting‐state fMRI was able to detect brain language areas during CM with a sensitivity of 100% compared to 64% with task fMRI.

Background Pre-surgical mapping of language using functional MRI aimed principally to determine the dominant hemisphere. This mapping is currently performed using covert linguistic task in way to avoid motion artefacts potentially biasing the results. However, overt task is closer to natural speaking, allows a control on the performance of the task, and may be easier to perform for stressed patients and children. However, overt task, by activating phonological areas on both hemispheres and areas involved in pitch prosody control in the non-dominant hemisphere, is expected to modify the determination of the dominant hemisphere by the calculation of the lateralization index (LI). Objective Here, we analyzed the modifications in the LI and the interactions between cognitive networks during covert and overt speech task. Methods Thirty-three volunteers participated in this study, all but four were right-handed. They performed three functional sessions consisting of (1) covert and (2) overt generation of a short sentence semantically linked with an audibly presented word, from which we estimated the “Covert” and “Overt” contrasts, and a (3) resting-state session. The resting-state session was submitted to spatial independent component analysis to identify language network at rest (LANG), cingulo-opercular network (CO), and ventral attention network (VAN). The LI was calculated using the bootstrapping method. Results The LI of the LANG was the most left-lateralized (0.66 ± 0.38). The LI shifted from a moderate leftward lateralization for the Covert contrast (0.32 ± 0.38) to a right lateralization for the Overt contrast (− 0.13 ± 0.30). The LI significantly differed from each other. This rightward shift was due to the recruitment of right hemispheric temporal areas together with the nodes of the CO. Conclusion Analyzing the overt speech by fMRI allowed improvement in the physiological knowledge regarding the coordinated activity of the intrinsic connectivity networks. However, the rightward shift of the LI in this condition did not provide the basic information on the hemispheric language dominance. Overt linguistic task cannot be recommended for clinical purpose when determining hemispheric dominance for language.

Human locomotion is a complex sensorimotor behavior whose central control remains difficult to explore using neuroimaging method due to technical constraints, notably the impossibility to walk with a scanner on the head and/or to walk for real inside current scanners. The aim of this functional Magnetic Resonance Imaging (fMRI) study was to analyze interactions between two paradigms to investigate the brain gait control network: (1) mental imagery of gait, and (2) passive mechanical stimulation of the plantar surface of the foot with the Korvit boots. The Korvit stimulator was used through two different modes, namely an organized (\"gait like\") sequence and a destructured (chaotic) pattern. Eighteen right-handed young healthy volunteers were recruited (mean age, 27 ± 4.7 years). Mental imagery activated a broad neuronal network including the supplementary motor area-proper (SMA-proper), pre-SMA, the dorsal premotor cortex, ventrolateral prefrontal cortex, anterior insula, and precuneus/superior parietal areas. The mechanical plantar stimulation activated the primary sensorimotor cortex and secondary somatosensory cortex bilaterally. The paradigms generated statistically common areas of activity, notably bilateral SMA-proper and right pre-SMA, highlighting the potential key role of SMA in gait control. There was no difference between the organized and chaotic Korvit sequences, highlighting the difficulty of developing a walking-specific plantar stimulation paradigm. In conclusion, this combined-fMRI paradigm combining mental imagery and gait-like plantar stimulation provides complementary information regarding gait-related brain activity and appears useful for the assessment of high-level gait control.

Background Pediatric magnetic resonance imaging (MRI) and computed tompgraphy (CT) require patient immobility and therefore often require sedation or general anesthesia of patients. Consensus on these procedures is lacking in France. Objective Thus, the aim of this study was to describe the current sedation practices for pediatric MRI and CT in France. Material and methods From January 2019 to December 2019, an online questionnaire was delivered by electronic mail to a representative radiologist in 60 pediatric radiology centers registered by the French-speaking pediatric and prenatal imaging society. Questions included protocols, drugs used, monitoring and side effects. Results Representatives of 40 of the 60 (67%) radiology centers responded to the survey. Among them, 31 performed sedation including 17 (55%) centers where radiologists performed sedation without anesthesiologists present during the procedure. The premedication drugs were hydroxyzine ( n  = 8, 80%) and melatonin ( n  = 2, 20%), Sedation drugs used for children ages 0 to 6 years old were pentobarbital ( n  = 9, 60%), midazolam ( n  = 2, 13%), chloral hydrate ( n  = 2, 13%), diazepam ( n  = 1, 6.5%) and chlorpromazine ( n  = 1, 6.5%). A written sedation protocol was available in 10/17 (59%) centers. In 6/17 (35%) centers, no monitoring was used during the procedures. Blood pressure monitoring and capnography were rarely used (< 10%) and post-sedation monitoring was heterogeneous. No life-threatening adverse effect was reported, but 6 centers reported at least one incident per year. Conclusion For half of the responding radiology centers, radiologists performed sedation alone in agreement with the local anesthesiology team. Sedation procedures and monitoring were heterogenous among centers. Adjustment and harmonization of the practices according to the capacity of each center may be useful.

Rationale and objectivesIntroduction of post-mortem imaging has helped improve sudden unexpected death in infancy (SUDI) management in Europe. French guidelines were issued in 2007 to homogenise SUDI investigations including imaging. The aim of this study was to evaluate current imaging management of SUDI in France.Material and methodsBetween January 2022 and July 2022, all 35 SUDI French referral centres were invited to answer an e-mailed online survey including 29 questions divided into four different sections covering imaging practices for SUDI including radiology department organisation, imaging modalities performed, methods of reading, and current training resources. Partial responses were secondarily completed by a personal call to the SUDI imaging consultant. The current implementation of the 2007 recommendations was compared with a previous evaluation from 2015 and with current North American practices.ResultsThe participation rate of centres performing SUDI imaging was 100% (35/35). Imaging was systematically performed in 94.3% (33/35) of the centres: 74.3% (26/35) using radiography; 5.7% (2/35) using ultrasound; 94.3% (33/35) using computed tomography (CT), including 89% (31/35) whole-body CT and 5.7% (2/35) brain CT; and 20% (7/35) using magnetic resonance imaging (MRI). Two centres (5.7%, 2/35) did not systematically perform brain imaging. One (2.9%, 1/35) used ultrasound-guided biopsy. In comparison with 2015, rates of brain imaging increased by 25.4% (P=0.008). There was no significant difference in the number of forensic MRIs performed between France and North America (P=0.663).ConclusionDespite improvements since 2015, full compliance with French guidelines for SUDI investigations remains incomplete. The use of imaging, particularly CT and brain imaging, has increased. Further efforts are needed to standardise imaging practices for optimal SUDI investigations.