4 results on '"Sandrone, Stefano"'
Search Results
2. Detecting axonal injury in individual patients after traumatic brain injury.
- Author
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Jolly, Amy E, Bălăeţ, Maria, Azor, Adriana, Friedland, Daniel, Sandrone, Stefano, Graham, Neil S N, Zimmerman, Karl, and Sharp, David J
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BRAIN injuries ,DIFFUSION tensor imaging ,DIFFUSION magnetic resonance imaging ,WOUNDS & injuries ,BIOMARKERS ,CENTRAL nervous system injuries ,CEREBRAL small vessel diseases ,BRAIN ,DIGITAL image processing ,RESEARCH ,NEURONS ,RESEARCH evaluation ,RESEARCH methodology ,MAGNETIC resonance imaging ,MEDICAL cooperation ,EVALUATION research ,COMPARATIVE studies ,IMPACT of Event Scale ,RESEARCH funding - Abstract
Poor outcomes after traumatic brain injury (TBI) are common yet remain difficult to predict. Diffuse axonal injury is important for outcomes, but its assessment remains limited in the clinical setting. Currently, axonal injury is diagnosed based on clinical presentation, visible damage to the white matter or via surrogate markers of axonal injury such as microbleeds. These do not accurately quantify axonal injury leading to misdiagnosis in a proportion of patients. Diffusion tensor imaging provides a quantitative measure of axonal injury in vivo, with fractional anisotropy often used as a proxy for white matter damage. Diffusion imaging has been widely used in TBI but is not routinely applied clinically. This is in part because robust analysis methods to diagnose axonal injury at the individual level have not yet been developed. Here, we present a pipeline for diffusion imaging analysis designed to accurately assess the presence of axonal injury in large white matter tracts in individuals. Average fractional anisotropy is calculated from tracts selected on the basis of high test-retest reliability, good anatomical coverage and their association to cognitive and clinical impairments after TBI. We test our pipeline for common methodological issues such as the impact of varying control sample sizes, focal lesions and age-related changes to demonstrate high specificity, sensitivity and test-retest reliability. We assess 92 patients with moderate-severe TBI in the chronic phase (≥6 months post-injury), 25 patients in the subacute phase (10 days to 6 weeks post-injury) with 6-month follow-up and a large control cohort (n = 103). Evidence of axonal injury is identified in 52% of chronic and 28% of subacute patients. Those classified with axonal injury had significantly poorer cognitive and functional outcomes than those without, a difference not seen for focal lesions or microbleeds. Almost a third of patients with unremarkable standard MRIs had evidence of axonal injury, whilst 40% of patients with visible microbleeds had no diffusion evidence of axonal injury. More diffusion abnormality was seen with greater time since injury, across individuals at various chronic injury times and within individuals between subacute and 6-month scans. We provide evidence that this pipeline can be used to diagnose axonal injury in individual patients at subacute and chronic time points, and that diffusion MRI provides a sensitive and complementary measure when compared to susceptibility weighted imaging, which measures diffuse vascular injury. Guidelines for the implementation of this pipeline in a clinical setting are discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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3. Frontal networks in adults with autism spectrum disorder.
- Author
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Catani, Marco, Dell'Acqua, Flavio, Budisavljevic, Sanja, Howells, Henrietta, de Schotten, Michel Thiebaut, Froudist-Walsh, Seán, D'Anna, Lucio, Thompson, Abigail, Sandrone, Stefano, Bullmore, Edward T., Suckling, John, Baron-Cohen, Simon, Lombardo, Michael V., Wheelwright, Sally J., Chakrabarti, Bhismadev, Meng-Chuan Lai, Ruigrok, Amber N. V., Leemans, Alexander, Ecker, Christine, and Craig, Michael C.
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AUTISM in adults ,FRONTAL lobe diseases ,FASCICULINS ,CHOLINESTERASE inhibitors ,LIMBIC system ,THERAPEUTICS ,BRAIN metabolism ,BRAIN ,FRONTAL lobe ,MAGNETIC resonance imaging ,NERVOUS system ,RESEARCH funding ,CROSS-sectional method - Abstract
It has been postulated that autism spectrum disorder is underpinned by an 'atypical connectivity' involving higher-order association brain regions. To test this hypothesis in a large cohort of adults with autism spectrum disorder we compared the white matter networks of 61 adult males with autism spectrum disorder and 61 neurotypical controls, using two complementary approaches to diffusion tensor magnetic resonance imaging. First, we applied tract-based spatial statistics, a 'whole brain' non-hypothesis driven method, to identify differences in white matter networks in adults with autism spectrum disorder. Following this we used a tract-specific analysis, based on tractography, to carry out a more detailed analysis of individual tracts identified by tract-based spatial statistics. Finally, within the autism spectrum disorder group, we studied the relationship between diffusion measures and autistic symptom severity. Tract-based spatial statistics revealed that autism spectrum disorder was associated with significantly reduced fractional anisotropy in regions that included frontal lobe pathways. Tractography analysis of these specific pathways showed increased mean and perpendicular diffusivity, and reduced number of streamlines in the anterior and long segments of the arcuate fasciculus, cingulum and uncinate--predominantly in the left hemisphere. Abnormalities were also evident in the anterior portions of the corpus callosum connecting left and right frontal lobes. The degree of microstructural alteration of the arcuate and uncinate fasciculi was associated with severity of symptoms in language and social reciprocity in childhood. Our results indicated that autism spectrum disorder is a developmental condition associated with abnormal connectivity of the frontal lobes. Furthermore our findings showed that male adults with autism spectrum disorder have regional differences in brain anatomy, which correlate with specific aspects of autistic symptoms. Overall these results suggest that autism spectrum disorder is a condition linked to aberrant developmental trajectories of the frontal networks that persist in adult life. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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4. Weighing brain activity with the balance: Angelo Mosso’s original manuscripts come to light.
- Author
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Sandrone, Stefano, Bacigaluppi, Marco, Galloni, Marco R., Cappa, Stefano F., Moro, Andrea, Catani, Marco, Filippi, Massimo, Monti, Martin M., Perani, Daniela, and Martino, Gianvito
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PHYSIOLOGISTS , *BLOOD circulation , *MENTAL work , *FUNCTIONAL magnetic resonance imaging , *PATHOLOGICAL physiology , *MANUSCRIPTS - Abstract
In the 1880s, the Italian physiologist Angelo Mosso claimed to have invented a ‘human circulation balance’ that measured the redistribution of blood during intellectual activity. Sandrone et al. have now unearthed Mosso’s original manuscripts in a rediscovery that tilts the balance of the history of neuroimaging.Neuroimaging techniques, such as positron emission tomography and functional magnetic resonance imaging are essential tools for the analysis of organized neural systems in working and resting states, both in physiological and pathological conditions. They provide evidence of coupled metabolic and cerebral local blood flow changes that strictly depend upon cellular activity. In 1890, Charles Smart Roy and Charles Scott Sherrington suggested a link between brain circulation and metabolism. In the same year William James, in his introduction of the concept of brain blood flow variations during mental activities, briefly reported the studies of the Italian physiologist Angelo Mosso, a multifaceted researcher interested in the human circulatory system. James focused on Mosso’s recordings of brain pulsations in patients with skull breaches, and in the process only briefly referred to another invention of Mosso’s, the ‘human circulation balance’, which could non-invasively measure the redistribution of blood during emotional and intellectual activity. However, the details and precise workings of this instrument and the experiments Mosso performed with it have remained largely unknown. Having found Mosso’s original manuscripts in the archives, we remind the scientific community of his experiments with the ‘human circulation balance’ and of his establishment of the conceptual basis of non-invasive functional neuroimaging techniques. Mosso unearthed and investigated several critical variables that are still relevant in modern neuroimaging such as the ‘signal-to-noise ratio’, the appropriate choice of the experimental paradigm and the need for the simultaneous recording of differing physiological parameters. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
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