Neuroimaging Investigations (neuroimaging + investigation)

Distribution by Scientific Domains

Selected Abstracts

Headache characteristics and brain metastases prediction in cancer patients

The aim of this study was to evaluate the headache and other neurological symptoms and signs as guide predictors for the occurrence of brain metastases in cancer patients. We prospectively studied 54 cancer patients with newly appeared headache or with a change in the pattern of an existing headache during the recent months. All patients completed a questionnaire regarding headache's clinical characteristics and existence of accompanying symptoms. They also underwent a detailed neurological, ophthalmologic examination and brain neuroimaging investigation. Brain metastases were diagnosed in 29 patients. Univariate regression analysis showed an association between occurrence of brain metastases and nine clinical symptoms or signs. Multivariate regression analyses emerged only four of them as significant independent predictors. These were: bilateral frontal-temporal headache, more pronounced on the side of metastasis in cases of single metastases, with duration ,8 weeks, pulsating quality and moderate to severe intensity (OR: 11.9; 95% CI. 2.52,56.1), emesis (OR: 10.2; 95% CI. 2.1,55.8), gait instability (OR: 7.4; 95% CI. 1.75,33.9) and extensor plantar response (OR: 12.1; 95% CI. 2.2,120.7). In conclusion, all cancer patients who manifest the above independent clinical predictors should be highly suspected for appearance of brain metastases and therefore should be thoroughly investigated. [source]

Adult-Onset Rasmussen's Encephalitis: Anatomical-Electrographic-Clinical Features of 7 Italian Cases

EPILEPSIA, Issue 2006
Flavio Villani
Summary:,Purpose: A limited number of cases of adult-onset Rasmussen's encephalitis (A-RE) have been reported, but the features of the syndrome are still unclear. The aim of this study was to verify the clinical features of A-RE, and outline a noninvasive approach that may allow its early diagnosis and treatment. Methods: Retrospective evaluation of extensive noninvasive work-up of seven patients with A-RE, including repeat clinical, neurophysiological, and neuroimaging investigations. Results: The study identified two distinct patterns of disease presentation, one characterized by focal motor epilepsy (the "epileptic" phenotype), and the other by focal cortical myoclonus (the "myoclonic" phenotype). Unilateral neurological deficits and brain atrophy were progressive in both phenotypes, but they were more prominent and were detected earlier in the "epileptic" phenotype. Conclusions: The anatomo-electroclinical features of these patients allowed a noninvasive diagnosis of A-RE and identification of two distinct disease phenotypes. Early noninvasive diagnosis can allow faster initiation of treatment. [source]

Isotropic resolution diffusion tensor imaging with whole brain acquisition in a clinically acceptable time

Derek Kenton Jones
Abstract Our objective was to develop a diffusion tensor MR imaging pulse sequence that allows whole brain coverage with isotropic resolution within a clinically acceptable time. A single-shot, cardiac-gated MR pulse sequence, optimized for measuring the diffusion tensor in human brain, was developed to provide whole-brain coverage with isotropic (2.5 2.5 2.5 mm) spatial resolution, within a total imaging time of approximately 15 min. The diffusion tensor was computed for each voxel in the whole volume and the data processed for visualization in three orthogonal planes. Anisotropy data were further visualized using a maximum-intensity projection algorithm. Finally, reconstruction of fiber-tract trajectories i.e., ,tractography' was performed. Images obtained with this pulse sequence provide clear delineation of individual white matter tracts, from the most superior cortical regions down to the cerebellum and brain stem. Because the data are acquired with isotropic resolution, they can be reformatted in any plane and the sequence can therefore be used, in general, for macroscopic neurological or psychiatric neuroimaging investigations. The 3D visualization afforded by maximum intensity projection imaging and tractography provided easy visualization of individual white matter fasciculi, which may be important sites of neuropathological degeneration or abnormal brain development. This study has shown that it is possible to obtain robust, high quality diffusion tensor MR data at 1.5 Tesla with isotropic resolution (2.5 2.5 2.5 mm) from the whole brain within a sufficiently short imaging time that it may be incorporated into clinical imaging protocols. Hum. Brain Mapping 15:216,230, 2002. 2002 Wiley-Liss, Inc. [source]

The way of our errors: Theme and variations

Robert F. Simons
Abstract Negative feedback, either internal or external, is a fundamental guide to human learning and performance. The neural system that underlies the monitoring of performance and the adjustment of behavior has been subject to multiple neuroimaging investigations that uniformly implicate the anterior cingulate cortex and other prefrontal structures as crucial to these executive functions. The present article describes a series of experiments that employed event-related potentials to study a variety of processes associated with internal or external feedback. Three medial-frontal negativities (error-related negativity, correct-response negativity, feedback-related negativity) are highlighted, each of which plays an important role in the monitoring and dynamic adjustment of behavior. Extensions of basic research on these ERPs to questions relevant to clinical-science are also provided. [source]