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To purchase or authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1552-6569.2006.00052.x Byline: K. Berkouk (1), M. Quarantelli (1), A. Prinster (1), B. Landeau (1), B. Alfano (1), J.C. Baron (1) Keywords: Positron emission tomography; magnetic resonance imaging; FDG; partial volume effect; segmentation Abstract: ABSTRACT Interpretation of brain positron emission tomography (PET) in terms of function vs. structure is ambiguous owing to the partial volume effect (PVE). Therefore, observed differences in tracer distribution could reflect differences in either activity or volume, a problem that applies principally to gray matter (GM) since white matter (WM) virtually always has uniform activity. To assess the contribution of GM volume vs. activity, we implemented a method to directly compare PET images with underlying structure, and applied it to resting-state 18Fluoro-deoxy-glucose-PET (FDG) of healthy subjects. Methods. Average GM and WM PVE-corrected mean FDG uptake values were applied onto co-registered segmented magnetic resonance imaging data sets to generate a 'virtual PET' in which activity is proportional to GM volume and resolution set to that of PET. The raw PET and virtual PET values were then compared across the sample of subjects, first voxel-wise to detect clusters with significant activity-volume mismatch, and second within regions-of-interest (ROI) to quantify mismatches between unsmoothed voxel values. Results. Relative to volume, there was significant hyperactivity of most GM structures of the dorsal brain-except the thalamus-and significant hypoactivity of the temporal lobe, hippocampal region, and cerebellum, consistent across the voxel- and ROI-based analyses. Conclusion. As applied to normals, our method documented the expected contribution of functional activity independently of local differences in GM volume in the normal pattern of FDG uptake, and disclosed marked heterogeneities in functional activity per unit GM volume among structures. This generic method should find applications in pathological states as well as for other PET and SPECT radiotracers. Author Affiliation: (1)From the Inserm U.320 and E0218, Cyceron, Caen, France (KB, BL); Biostructure and Bioimaging Institute, National Council for Research, Naples, Italy (MQ, AP, BA); Department of Clinical Neurosciences, University of Cambridge, UK (JCB). Article History: Received February 08, 2006, and in revised form April 21, 2006. Accepted for publication April 26, 2006. Article note: Address correspondence to J.C. Baron, MD, Department of Clinical Neurosciences, Addenbrookes Hospital, Box 83, Cambridge CB2 2QQ, United Kingdom. E-mail: jcb54@cam.ac.uk.

Background and purpose: Changes of brain structure and function have been described in peripheral neuropathies. The aim of our study was to systematically investigate possible modifications of major large‐scale brain networks using resting‐state functional magnetic resonance imaging (RS‐fMRI) in Charcot–Marie–Tooth disease type 1A (CMT1A) patients. Methods: In this cross‐sectional study, 3‐T MRI brain scans were acquired of right‐handed genetically confirmed CMT1A patients and age‐ and sex‐comparable healthy controls. Patients also underwent clinical and electrophysiological examinations assessing neurological impairment. RS‐fMRI data were analysed using a seed‐based approach, with 32 different seeds sampling the main hubs of default mode, sensorimotor, visual, salience (SN), dorsal attention, frontoparietal, language and cerebellar networks. Between‐group differences in terms of functional connectivity (FC) with the explored seeds were tested voxelwise, correcting for local grey matter density to account for possible structural abnormalities, whilst the relationship between FC modifications and neurological impairment was investigated using robust correlation analyses. Results: Eighteen CMT1A patients (34.0 ± 11.4 years; M/F 11/7) were enrolled, along with 20 healthy controls (30.1 ± 10.2 years; M/F 11/9). In the CMT group compared to controls, clusters of increased FC with the visual cortex (P = 0.001), SN (P < 6 × 10−4), dorsal attention network (P < 8 × 10−5) and language network (P < 7 × 10–4) were found, along with a single cluster of reduced FC with the visual cortex in the left lentiform nucleus (P = 10–6). A significant correlation emerged between neurophysiological impairment and increased FC with right temporal language areas (r = 0.655, P = 0.006), along with an association between walking ability and increased FC with the left supramarginal gyrus (SN) (r = 0.620, P = 0.006). Conclusions: Our data show evidence of diffuse functional reorganization involving multiple large‐scale networks in the CMT1A brain, independent of structural modifications and partially correlating with peripheral nerve damage and functional impairment. [ABSTRACT FROM AUTHOR]

The study in question aims to analyze and describe the performative model of the kettlebell sport. The kettlebell sport is a weight lifting discipline in which the goal is to carry out as many repetitions as possible in the exercises of clean and jerk, biathlon (jerk and snatch) in the 10 minutes provided by the regulation. Four athletes of the agonist Umbria Kettlebell Training Center Team (3 men and 1 woman) were analyzed, respectively in the male biathlon (jerk 70+70 lbs and snatch 70 lbs), male biathlon under 18 (jerk 53+53 lbs and snatch 53 lbs), male clean and jerk (62+62 lbs) and female snatch (53 and 35 lbs). The investigation area is made up of three parts: anthropometric analysis, physiological analysis, electromyography analysis. The main results of the tests are the following: it is a form of weight lifting on aerobic regime (Vo2 max 40,4 ± 5,9 ml/kg/min, Average Heart Rate 162 ± 14 bpm, Max Ventilation 111,6 ± 29,6 l/min, End of test Ematic Lactate 3,3 ± 0,29 mmol/l) at which, in order to excelle and being able to perform, effective and efficient, an optimal technique is needed to make the best use of the available energy and organic reserves avoiding any over-use injuries due to the loads lifted. The analysis of the macrocycles' training in fact, tell us the kettlebell is a sport that requires high load volumes, at which the tonnage average per training is 19K pounds circa in the elite biathlon, 17K pounds in the under 18, 12K pounds in clean and jerk and 10K pounds in the female snatch (excluding auxiliary exercises in all cases). The electromyographic analysis show that the exercise which requires the greatest muscular recruitment of both the anterior and posterior muscular kinetic chain is the clean and jerk, while the snatching exercise, being unilateral, involves the crossed muscular kinetic chains. Further tests on a larger sample of athletes are needed to verify and eventually correct the assessments made of the study in question. [ABSTRACT FROM AUTHOR]