1,721,020 research outputs found
Adult-onset migraine-related ophthalmoplegia and omolateral fetal-type posterior cerebral artery.
No full textA 33-year-old woman with a long history of typical migraine without aura developed a pupillary-involving right third nerve palsy, after a typical migraine attack. The right pupil was 5 mm and showed delayed direct and consensual photomotor responses; the left pupil was 3 mm and reactive. Pupillary reaction to convergence was slow on the right eye. Ptosis, impaired elevation of the eye and weakened adduction were noted in the right eye. CT scan of the brain showed no abnormalities, whereas a CT digital cerebral angiography revealed a fetal-type right posterior cerebral artery (PCA). MRI disclosed thickening and contrast-enhancement of the cisternal portion of the right oculomotor nerve. A lumbar puncture, performed 5 days after the onset of ocular symptoms, yielded acellular cerebrospinal fluid (CSF) with normal protein and glucose levels. Ptosis and diplopia recovered within a week, whereas blurred vision, anisocoria and accommodation deficit subsided after 10 weeks
Bionic Ear Imaging: A Dose Comparison Study between Cone Beam Computed Tomography and Multislice Computed Tomography
No full textMagnetic Resonance Imaging in Primary and Secondary Septorhinoplasty
No full textThe authors emphasize the importance of MRI as a means to functionally evaluate patients in primary (PR) and secondary (SR) rhinoseptoplasty. Forty-eight subjects were appraised who underwent various types of corrective nose surgery: 31 PR, 12 SR, 4 introgenic perforations, and 1 dermoid cyst of the nasal dorsum. MRI allows the nasal structures at the level of the valve to be visualized, as well as the medial and lateral walls of the nasal fossa in all of its components. MRI studies improve pre-surgical evaluation (alar cartilages, iaterdomal distance, and valvular configuration), and the exam of structures and anomalies which are hard to evaluate by the rhinoscopy (turbino-septal-synchias, perforations, losses of bone-cartilaginous substance). Moreover, through MRI the nasal respiratory surface (NRS) is determined and used by the authors to quantify the improvement of the postsurgical nasal respiratory function. All of these points gain importance during the planning of primary, secondary, and/or corrective surgery
EEG-fMRI Evaluation of Patients with Mesial Temporal Lobe Sclerosis
No full textThis preliminary study sought more information on blood oxygen level dependent (BOLD) activation, especially contralateral temporal/extratemporal spread, during continuous EEG-fMRI recordings in four patients with mesial temporal sclerosis (MTS). In two patients, EEG showed unilateral focal activity during the EEG-fMRI session concordant with the interictal focus previously identified with standard and video-poly EEG. In the other two patients EEG demonstrated a contralateral diffusion of the irritative focus. In the third patient (with the most drug-resistant form and also extratemporal clinical signs), there was an extratemporal diffusion over frontal regions, ipsilateral to the irritative focus. fMRI analysis confirmed a single activation in the mesial temporal region in two patients whose EEG showed unilateral focal activity, while it demonstrated a bilateral activation in the mesial temporal regions in the other two patients. In the third patient, fMRI demonstrated an activation in the supplementary motxor area. This study confirms the most significant activation with a high firing rate of the irritative focus, but also suggests the importance of using new techniques (such as EEG-fMRI to examine cerebral blood flow) to identify the controlateral limbic activation, and any other extratemporal activations, possible causes of drug resistance in MTS that may require a more precise pre-surgical evaluation with invasive techniques
Circoli collaterali da occlusione dell'arteria carotide comune. Apporto dell'angiografia a risonanza magnetica
No full textno availabl
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
fMRI in Resting State as a Radiological Tool in Pharmaceutic Research: An Experimental Clinical Trial with Alprazolam
No full textPURPOSE: The aim of the study was to highlight the presence of modifications in the Default Mode Network (DMN) detected by means of fMRI in Resting State after
the administration of a neurotropic drug, the Alprazolam, and therefore to suggest fMRI as an alternative and non invasive tool for future pharmacological
experimentations in vivo.
METHOD AND MATERIALS: 11 healthy subjects (5 males; mean age: 32 years) were enrolled in a double-blind randomized study. They received Alprazolam or
placebo and underwent two fMRI scans each. Data were acquired at 1.5 T (Magnetom Symphony, Siemens, Enlargen, Germany). Functional connectivity and
activation maps were obtained by means of independent component analysis using FSL (FMRIB software Library 4.1, Oxford, UK). A F-test (p<0.05) was applied in
order to detect statistical differences between groups and Dual-Regression (p<0.05) permitted to obtain spatial maps defining the between-subject
group-consistency.
RESULTS: The reproducibility of fMRI in Resting State was demonstrated with a consistent detection of DMN in all subjects and all conditions, furthermore a
statistically non-significant difference between baselines was found (p<0,11242). The Dual-Regression analysis showed a diffuse significant higher functional
connectivity in the brain after the administration of Alprazolam, mainly in the precuneus/posterior cingulate cortex within the DMN, and also between the DMN and
other cerebral areas, in particular the basal ganglia. No significant differences in DMN were detected after placebo administration.
CONCLUSION: fMRI in Resting State reproducibility was demonstrated and connectivity modifications in DMN and other cerebral areas occur after Alprazolam
administration.
CLINICAL RELEVANCE/APPLICATION: fMRI should be considered an applicable model in humans during future clinical trials
Radiation dose saving through the use of cone-beam CT in hearing-impaired patients
No full textPURPOSE: Bionic ear implants provide a solution for deafness. Patients treated with these hearing devices are often children who require close follow-up with frequent functional and radiological examinations; in particular, multislice computed tomography (MSCT). Dental volumetric cone-beam CT (CBCT) has been reported as a reliable technique for acquiring images of the temporal bone while delivering low radiation doses and containing costs. The aim of this study was to assess, in terms of radiation dose and image quality, the possibility of using CBCT as an alternative to MSCT in patients with bionic ear implants. MATERIALS AND METHODS: One hundred patients (mean age 26 years, range 7-43) with Vibrant SoundBridge implants on the round window underwent follow-up: 85 with CBCT and 15 with MSCT. We measured the average tissue-absorbed doses during both MSCT and CBCT scans. Each scan was focused on the temporal bone with the smallest field of view and a low-dose protocol. In order to estimate image quality, we obtained data about slice thickness, high- and low-contrast resolution, uniformity and noise by using an AAPM CT performance phantom. RESULTS: Although the CBCT images were qualitatively inferior to those of MSCT, they were sufficiently diagnostic to allow evaluation of the position of the implants. The effective dose of MSCT was almost three times higher than that of CBCT. CONCLUSIONS: Owing to low radiation dose and sufficient image quality, CBCT could be considered an adequate technique for postoperative imaging and follow-up of patients with bionic ear implants
Auditory Brainstem Implant: Computer Tomography assessment of Electrodes Dislocation
No full textScientific Paper Session 16-06 Neuroradiology/Head and Neck (Temporal Bones
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