Catani M.,Kings College London |
Dell'Acqua F.,Kings College London |
Bizzi A.,Neuroradiology Unit |
Forkel S.J.,Kings College London |
And 5 more authors.
Cortex | Year: 2012
Last year was the 150th anniversary of Paul Broca's landmark case report on speech disorder that paved the way for subsequent studies of cortical localization of higher cognitive functions. However, many complex functions rely on the activity of distributed networks rather than single cortical areas. Hence, it is important to understand how brain regions are linked within large-scale networks and to map lesions onto connecting white matter tracts. To facilitate this network approach we provide a synopsis of classical neurological syndromes associated with frontal, parietal, occipital, temporal and limbic lesions. A review of tractography studies in a variety of neuropsychiatric disorders is also included. The synopsis is accompanied by a new atlas of the human white matter connections based on diffusion tensor tractography freely downloadable on http://www.natbrainlab.com. Clinicians can use the maps to accurately identify the tract affected by lesions visible on conventional CT or MRI. The atlas will also assist researchers to interpret their group analysis results. We hope that the synopsis and the atlas by allowing a precise localization of white matter lesions and associated symptoms will facilitate future work on the functional correlates of human neural networks as derived from the study of clinical populations. Our goal is to stimulate clinicians to develop a critical approach to clinico-anatomical correlative studies and broaden their view of clinical anatomy beyond the cortical surface in order to encompass the dysfunction related to connecting pathways. © 2012 Elsevier Srl.
Cosottini M.,Imago7 Foundation |
Frosini D.,University of Pisa |
Pesaresi I.,Neuroradiology Unit |
Costagli M.,Imago7 Foundation |
And 4 more authors.
Radiology | Year: 2014
Purpose: To evaluate the anatomy of the substantia nigra (SN) in healthy subjects by performing 7-T magnetic resonance (MR) imaging of the SN, and to prospectively define the accuracy of 7-T MR imaging in distinguishing Parkinson disease (PD) patients from healthy subjects on an individual basis. Materials and Methods: The 7-T MR imaging protocol was approved by the Italian Ministry of Health and by the local competent ethics committee. SN anatomy was described ex vivo on a gross brain specimen by using highly resolved proton-density (spin-echo proton density) and gradient-recalled-echo (GRE) images, and in vivo in eight healthy subjects (mean age, 40.1 years) by using GRE three-dimensional multiecho susceptibility-weighted images. After training on appearance of SN in eight healthy subjects, the SN anatomy was evaluated twice by two blinded observers in 13 healthy subjects (mean age, 54.7 years) and in 17 PD patients (mean age, 56.9 years). Deviations from normal SN appearance were described and indicated as abnormal, and both diagnostic accuracy and intra-and interobserver agreement for diagnosis of PD with 7-T MR imaging were calculated. Results: Three-dimensional multiecho susceptibility-weighted 7-T MR imaging reveals a three-layered organization of the SN allowing readers to distinguish pars compacta ventralis and dorsalis from pars reticulata. The abnormal architecture of the SN allowed a discrimination between PD patients and healthy subjects with sensitivity and specificity of 100% and 96.2% (range, 92.3%-100%), respectively. Intraobserver agreement (k = 1) and interobserver agreement (k = 0.932) were excellent. Conclusion: MR imaging at 7-T allows a precise characterization of the SN and visualization of its inner organization. Threedimensional multiecho susceptibility-weighted images can be used to accurately differentiate healthy subjects from PD patients, which provides a novel diagnostic opportunity. © 2014 RSNA.
Rizzo R.,University of Ferrara |
Bortolotti D.,University of Ferrara |
Baricordi O.R.,University of Ferrara |
Fainardi E.,Neuroradiology Unit
Inflammation and Allergy - Drug Targets | Year: 2012
Human leucocyte antigen-G (HLA-G) is a non-classical HLA class I molecule with an important role at the fetus-maternal interface, preventing fetus recognition and abortion. The role of HLA-G as an immune-modulatory and anti-inflammatory molecule has led to investigate its role in pathological conditions. In these years, HLA-G has been shown to have an important implication in inflammatory pathologies. The focus of this review is to up-date the scientific knowledge on the expression of HLA-G molecules in inflammatory conditions. © 2012 Bentham Science Publishers.
Bonetto N.,University of Padua |
Manara R.,Neuroradiology Unit |
Citton V.,University of Padua |
Cagnin A.,University of Padua
Neurology | Year: 2011
Objective: To explore the efficacy of spinal MRI study with subtraction analysis as a rapid, reliable, and noninvasive procedure to detect epidural CSF collection in spontaneous intracranial hypotension (SIH) syndrome. Methods: Seventeen patients (mean age 42 years, age range 17-65 years; 11 female) with SIH diagnosed using the International Classification of Headache Disorders criteria and 13 agematched control subjects underwent standard sagittal spinal MRI. Postprocessing image analysis with subtraction of T1-weighted from T2-weighted MRI scans was performed and tested for the detection of the CSF leak. Results: The CSF epidural collection was visible in all patients with SIH and was detected at the dorsal (16 of 17), cervical (13 of 17), lumbar (13 of 17), and sacral (12 of 17) levels. None of the control subjects showed a CSF leak. Diverticula were present in 23% of patients, whereas the actual site of the CSF leak was recognized in only one patient. Eight patients were treated conservatively, whereas 9 patients required an epidural blood patch, performed at a fixed L2-L3 or L3-L4 spinal level, with complete recovery. Conclusions: Spinal MRI with dedicated subtraction analysis could represent the first-line diagnostic tool in the management of patients with SIH, thus leaving invasive investigation for selected patients, such those requiring dural surgery. Copyright © 2011 by AAN Enterprises, Inc.
Vallesi A.,University of Padua |
Arbula S.,University of Padua |
Capizzi M.,University of Padua |
Causin F.,Neuroradiology Unit |
D'Avella D.,University of Padua
Cortex | Year: 2015
The ability to shift between different tasks according to internal or external demands, which is at the core of our behavioral flexibility, has been generally linked to the functionality of left fronto-parietal regions. Traditionally, the left and right hemispheres have also been associated with verbal and spatial processing, respectively. We therefore investigated with functional MRI whether the processes engaged during task-switching interact in the brain with the domain of the tasks to be switched, that is, verbal or spatial. Importantly, physical stimuli were exactly the same and participants' performance was matched between the two domains. The fMRI results showed a clearly left-lateralized involvement of fronto-parietal regions when contrasting task-switching versussingle task blocks in the context of verbal rules. A more bilateral pattern, especially in the prefrontal cortex, was instead observed for switching between spatial tasks. Moreover, while a conjunction analysis showed that the core regions involved in task-switching, independently of the switching context, were localized both in left inferior prefrontal and parietal cortices and in bilateral supplementary motor area, a direct analysis of functional lateralization revealed that hemispheric asymmetries in the frontal lobes were more biased toward the left side for the verbal domain than for the spatial one and vice versa. Overall, these findings highlight the role of left fronto-parietal regions in task-switching, above and beyond the specific task requirements, but also show that hemispheric asymmetries may be modulated by the more specific nature of the tasks to be performed during task-switching. © 2015 Elsevier Ltd.