bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diffusion Tensor MRI in Multiple Sclerosis
Authors: Rovaris Marco , Filippi Massimo 
Published: October 2009

ABSTRACTDuring the last 10 years, thanks to the development of sophisticated acquisition schemes and the application of novel image analysis and postprocessing, diffusion tensor (DT) magnetic resonance imaging (MRI) has increasingly been applied to the study of multiple sclerosis (MS). DT MRI proved to be able to detect and quantify tissue damage within and outside T2‐visible MS lesions. In addition, DT MRI has been shown to be sensitive to the evolution of MS damage over short‐term periods of time, and therefore holds promise to provide us with in vivo correlates of MS clinical severity, as well as predictors of long‐term disease evolution. Recent developments of the technique, such as DT tractography, are likely to improve dramatically our understanding of the mechanisms associated to the accumulation of MS disability. Unresolved issues to be addressed include the definition of the actual features underlying diffusion changes in MS and the potential of DT MRI in the differential diagnosis between MS and other demyelinating conditions. The best acquisition and postprocessing strategies for DT MRI studies of MS also remain a matter of debate. Moreover, the precision and accuracy of DT MRI scans in detecting longitudinal, MS‐related changes need to be further investigated. This is a pivotal issue for a future application of DT MRI to the monitoring of MS evolution in large‐scale clinical trials and, possibly, in individual patients.
MR Spectroscopy in Multiple Sclerosis
Authors: De Stefano Nicola , Filippi Massimo 
Published: October 2009

ABSTRACTIn the last decade, the use of magnetic resonance imaging (MRI) has led to a reevaluation of the pathogenesis and the natural history of multiple sclerosis (MS). This has been driven to a significant degree by results of proton magnetic resonance spectroscopy (1H‐MRS) studies. By providing evidence of early neurodegeneration (based on levels of N‐acetylaspartate), results of 1H‐MRS studies have led to a reconsideration of the role of axonal damage in MS. By measuring brain changes of metabolites such as choline and myo‐inosol, 1H‐MRS has confirmed the importance of assessing myelin damage and repair. However, despite the pathological specificity of 1H‐MRS and the relatively large number of clinical 1H‐MRS studies on patients with MS, measures provided by this MR technique are not used routinely for assessing and monitoring MS patients. This is due to technical difficulties and limitations that are at present not entirely solved. We will review here the most relevant results in MS studies that have used 1H‐MRS measures, the clinical importance of these results and the pending issues that need to be solved for a larger and more reliable use of 1H‐MRS in clinical MS studies.
MRI of Spinal Cord in Multiple Sclerosis
Authors: Agosta Federica , Filippi Massimo 
Published: October 2009

ABSTRACTThe spinal cord is a clinically eloquent region, whose damage has the potential to affect dramatically the functional outcome of patients with multiple sclerosis (MS). During the last 10 years, thanks to the development of sophisticated magnetic resonance imaging (MRI) techniques, MRI of the spinal cord has been made feasible and contributed significantly to increase the confidence in the diagnostic work‐up of patients suspected of having MS and to grade the severity of overall central nervous system (CNS) damage associated to the disease. Technical development in acquisition and postprocessing of spinal cord MRI is likely to increase in the near future our understanding of disease pathobiology through an increased ability to define the nature and location of spinal cord damage as well as through an accurate functional mapping of its activity, which might have an adaptive role in limiting the consequences of structural CNS injury due to MS.
MRI to Monitor Treatment Efficacy in Multiple Sclerosis
Authors: Fazekas Franz , Soelberg‐Sorensen Per , Comi Giancarlo , Filippi Massimo 
Published: October 2009

ABSTRACTIt is the primary goal of disease modifying treatments in multiple sclerosis (MS) to prevent the occurrence of new clinical deficits and lessen or prevent accumulation of disability. As a consequence, clinical aspects constitute the major outcome variables in treatment trials and are also the leading factor for treatment decisions in individual patients. However, determining treatment efficacy by clinical evaluation suffers from limited objectivity, sensitivity, and specificity for the underlying pathophysiologic aspects, which may constitute the target of a given therapy. Magnetic resonance imaging (MRI) can partly overcome these limitations by showing morphologic aspects of the disease with clinical relevance and responsiveness to therapy. Within the past 10 years sufficient data have been collected to establish the accumulation of new/enlarging T2 lesions and gadolinium enhancing lesions, T2 lesion load, T1‐hypointense lesions, and brain volume changes as reasonably well‐defined markers of disease processes, which may serve to monitor treatment efficacy. Accordingly, these variables have been extensively used for probing the efficacy of disease modifying treatments. In part they are also suited to guide therapeutic decisions in the individual patient. Further options may come from the use of advanced techniques like magnetization transfer MRI, diffusion‐weighted MRI, and proton magnetic resonance spectroscopy, which detect more subtle MS related tissue abnormalities. Irrespective of the technique employed, great care has to be given to the standardization and reproducibility of both data acquisition and interpretation when using MRI to monitor treatment efficacy. For the individual patient therapeutic decisions based on MRI need experience and caution.
Statistical Issues Related to the Use of MRI Data in Multiple Sclerosis
Authors: Sormani Maria Pia , Filippi Massimo 
Published: October 2009

ABSTRACTSince magnetic resonance imaging (MRI) of the brain has proved to be the most important paraclinical tool for diagnosing multiple sclerosis (MS) and monitoring its evolution, methodological and statistical issues related to the use of MRI markers in MS have been the focus of several studies in the past 10 years. While many of these methodological issues have been addressed using standard procedures available from other areas of application of medical statistics, in some cases statistical procedures that are not standard have been developed specifically for MRI variables in MS. Two of the major achievements in the statistical methods applied to the use of MRI variables in MS in the past 10 years were the identification of a parametric model to describe the distribution of MRI lesion counts across patients and the study of the relationships between MRI markers and clinical variables, with the aim to validate MRI parameters as surrogates for clinical progression.
MRI Assessment Followed by Successful Mechanical Recanalization of a Complete Tandem (Internal Carotid/Middle Cerebral Artery) Occlusion and Reversal of a 10‐Hour Fixed Deficit
Authors: Ionita Catalina C. , Yamamoto Junichi , Tummala Ramachandra P. , Levy Elad I. 
Published: October 2009

ABSTRACTBACKGROUND Mechanical clot extraction up to 8 hours after stroke onset is an alternative strategy for opening large vessels, especially for patients ineligible for intravenous thrombolysis. Safety beyond this therapeutic window is untested. METHODS An 81‐year‐old woman presented 8 hours after she developed left‐sided weakness and dysarthria with a National Institutes of Health Stroke Scale (NIHSS) score fluctuating between 6 and 13. Neuroimaging revealed a large perfusion deficit with no diffusion abnormalities. An emergent cerebral angiogram revealed a complete internal carotid artery terminus occlusion. RESULTS Successful mechanical thrombectomy was performed without complication and resulted in almost complete reversal of the patient's deficit to an NIHSS score of 1, 10 hours after stroke onset. CONCLUSION Patients with large hypoperfused areas and minimal diffusion abnormalities on the MRI may benefit from mechanical thrombectomy beyond an 8‐hour window.
Early Dynamic SPECT Imaging in Acute Viral Encephalitis
Authors: Kataoka Hiroshi , Inoue Makoto , Shinkai Takayuki , Ueno Satoshi 
Published: October 2009

ABSTRACTBACKGROUND AND PURPOSE Several cases have reported that dynamic single‐photon emission computed tomography (SPECT) shows increased tracer uptake in acute herpes simplex viral encephalitis (HSVE). The purpose of this study was to evaluate the clinical usefulness of dynamic Tc‐ECD SPECT in patients with acute viral encephalitis. METHOD We performed the dynamic SPECT in 9 patients with acute viral encephalitis (4 women, 5 men, 49.5 ± 17.4 years of age at onset). SPECT and magnetic resonance imaging (MRI) were performed within 2 weeks after acute clinical onset and at the time of resolution of acute symptoms. RESULTS Cranial MRI showed high intensities in all patients (7 medial temporal and 2 lateral temporal lobes, 1 inferior temporal lobe, 2 insula and adjacent regions, 1 thalamus, 1 putamen). The initial dynamic SPECT showed increased accumulation of tracer, corresponding to the lesions on MRI in 3 patients with HSVE. Resolution of acute symptoms was associated with a reduction in increased tracer uptake. Six patients with non‐HSVE showed no increased accumulation of tracer. CONCLUSIONS Dynamic SPECT may be a new optional neuroradiologic technique that may help to establish a diagnosis in patients with suspected HSVE.
Reliability of fMRI during a Continuous Motor Task: Assessment of Analysis Techniques
Authors: Kimberley Teresa Jacobson , Birkholz Dana D. , Hancock Renee A. , VonBank Sarah M. , Werth Teresa N. 
Published: October 2009

ABSTRACTThe purpose of this study was to determine which method of functional magnetic resonance image analysis had the highest reliability in cortical and cerebellar areas during a continuous motor task. Fourteen subjects underwent 4 testing trials during 2 testing sessions separated by 3 weeks. Subjects performed a joystick task. Methods of analysis evaluated included: percent signal intensity change, active voxel count, and percent contribution. Two types of activation thresholds were evaluated: P≤ .05 and false discovery rate = .05. Reliability was determined with intraclass correlation coefficients and a repeated measure ANOVA was used to determine whether there was a significant difference between trials. A group analysis was assessed with coefficient of variation. Results indicate within session reliability was higher than between session and that signal intensity is more reliable than voxel count analysis. The intraclass correlation coefficients across different regions of interest varied depending on analysis technique. The data did not support a clear difference between thresholds. The group analysis also found less variability with intensity measures than voxel count. A stabilization effect was seen after the first trial of the experiment, suggesting that in pretest/posttest designs, a more stable result may be obtained by performing a test trial prior to actual data collection.
Assessment of the Cerebral Vasomotor Reactivity in Internal Carotid Artery Occlusion Using a Transcranial Doppler Sonography and Functional MRI
Authors: Herzig Roman , Hluštík Petr , Školoudík David , Šaňák Daniel , Vlachová Ivanka , Heřman Miroslav , Kaňovský Petr 
Published: October 2009

ABSTRACTBACKGROUND AND PURPOSE Several methods are being used to assess cerebral vasomotor reactivity (CVR), including transcranial Doppler (TCD) sonography and blood oxygenation level‐dependent functional magnetic resonance imaging (fMRI). The aim was to assess the correlation of TCD and fMRI in the CVR assessment. METHODS Study group consisted of 28 patients (24 males, 4 females; aged 30–82, mean 63.1 ± 10.0 years), presenting with 29 occluded internal carotid arteries. The TCD examination, including breath‐holding/hyperventilation test (BH/HV) and breath‐holding index (BHI), and fMRI examination were used for the assessment of CVR. fMRI employed a bimanual motor task within both a block paradigm and an event‐related paradigm. Cohen's κ was applied when statistically assessing correlation of the methods. RESULTS The following correlations were found—between BH/HV and BHI 58.6%, κ= .205; BH/HV and fMRI 65.5%, κ= .322; BHI and fMRI 58.6%, κ= .151; TCD (consistent result of both BH/HV and BHI test) and fMRI 70.6%, κ= .414. CONCLUSIONS In the evaluation of CVR, there is only a minimal correlation between the particular TCD tests (both BH/HV and BHI), and fMRI examination. However, there is a moderate correlation between TCD and fMRI in the case of congruity of both TCD tests.
Adult Idiopathic Occlusion of the Foramina of Monro: Diagnostic Tools and Therapy
Authors: De Bonis Pasquale , Anile Carmelo , Tamburrini Gianpiero , Tartaglione Tommaso , Mangiola Annunziato 
Published: October 2009

ABSTRACTBACKGROUND AND PURPOSE The bilateral foramina of Monro occlusion is an extremely rare event in adults. To date, only six cases of adult hydrocephalus due to idiopatic obstruction of the bilateral foramina of Monro (including our patient) have been reported. METHODS The authors describe the case of a 41‐year‐old man with a recent onset of motor hindrance which occurred specially while jumping or playing basketball, together with recent memory impairment, deceleration of thought, and asthenia. The patient was studied with fast spin echo (FSE) and steady‐state free precession high‐resolution 3D sequences (SSFP) together with a ventricular infusion test, and subsequently treated with endoscopic foraminoplasty. RESULTS The presenting symptoms completely resolved. Follow‐up magnetic resonance imaging (MRI) showed the patency of right Monro foramen, with gradually decreasing ventricular size and increase of subarachnoid spaces. CONCLUSIONS These patients should be accurately studied before treatment. In fact, MRI has made it possible to know what a surgeon will exactly find on the operative field. In that way a correct surgical planning can be achieved.
Are Limb‐Shaking Transient Ischemic Attacks a Risk Factor for Postendarterectomy Hemorrhage? Case Report and Literature Review
Authors: Switzer Jeffrey A , Nichols Fenwick T 
Published: October 2009

ABSTRACT Postoperative intracerebral hemorrhage occurs in about 0.5% of all carotid endarterectomies. There are no recognized risk factors for this complication. We report on a 74‐year‐old woman with right sided limb‐shaking transient ischemic attacks and severe stenosis of the left internal carotid artery. She suffered a fatal intracerebral hemorrhage 11 days after endarterectomy. This case prompted a review of the literature to determine if limb‐shaking transient ischemic attacks might be a risk factor for postoperative intracerebral hemorrhage. We propose that patients with limb‐shaking transient ischemic attacks have loss of vasomotor reactivity placing them at high risk for carotid reperfusion syndrome and hemorrhage into the revascularized territory.
Prognostic Value of CT Angiography in Patients with Suspected Vertebrobasilar Ischemia
Authors: Sylaja P.N. , Puetz Volker , Dzialowski Imanuel , Krol Andrea , Hill Michael D. , Demchuk Andrew M. 
Published: October 2009

ABSTRACTBACKGROUND The outcome of vertebrobasilar ischemia depends on the clinical presentation and the presence or absence of vascular occlusion. The aim of our study was to analyze the CT angiography (CTA) predictors of outcome in patients with suspected vertebrobasilar ischemia. METHODS We studied patients with suspected acute vertebrobasilar ischemia between April 2002 and January 2006 and had CTA done within 24 hours of symptom onset. We reviewed the final diagnosis and 3‐month follow‐up and analyzed the clinical and CTA predictors of outcome. RESULTS Of the 133 patients, 21(15%), 18 (13%), and 16 (12%) had occlusion of basilar artery (BA), vertebral artery (VA), and posterior cerebral artery (PCA) respectively. The final diagnosis was stroke in 98 (73.6%), transient ischemic attack (TIA) in 10 (7.5%), and nonischemic in 25 (18.8%). No vascular occlusion was seen on CTA in patients with TIA and nonischemic diagnosis. At 3‐month follow‐up, we found a mortality rate of 10.6% and good functional outcome in 71.4%. The predictors of death in the multivariable analysis were the presence of BA occlusion (odds ratio[OR] 6.7, 95% CI, 1.4–30.6) and baseline National Institutes of Health Stroke Scale (NIHSS) (OR 1.14, 95% CI, 1.06–1.2). When patients with basilar occlusion were excluded, the presence of VA occlusion (OR 6.5, 95% CI, 1.34–31.4), age (OR 1.09, 95% CI, 1.03–1.14), and baseline NIHSS (OR 1.1, 95% CI, 1.03–1.18) predicted poorer outcome. CONCLUSIONS The presence or absence of a vascular occlusion is a critical factor for prognosis in suspected acute vertebrobasilar ischemia and is correlated with the location of occlusion.
In Vivo Visualization of Senile‐Plaque‐Like Pathology in Alzheimer's Disease Patients by MR Microscopy on a 7T System
Authors: Nakada Tsutomu , Matsuzawa Hitoshi , Igarashi Hironaka , Fujii Yukihiko , Kwee Ingrid L. 
Published: October 2009

ABSTRACTBACKGROUND Microscopic application of magnetic resonance imaging (MRI) has entered the era of clinical application. One of the most important targets is the visualization of pathological findings such as senile plaques (SP), in vivo, in patients with Alzheimer's disease (AD). Such an application provides not only the most accurate diagnostic tool for clinicians but also a solid basis for scientists for developing effective treatment and preventive strategies for AD. METHODS Focused microscopic studies were performed on parietal association cortex at the level of the centrum semiovale identified on conventional axial slices using a system constructed based on General Electric Signa LX (Waukesha, WI) equipped with a 900‐mm clear bore superconducting magnet operating at 7.0 T in 10 patients (67‐83‐year old, five males, five females) who fulfilled the NINCD and the SADRDA criteria for probable AD, 10 age‐matched controls (71‐85‐year old, five males, five females), and 20 young adults (22‐35‐year old, 10 males, 10 females) using a susceptibility weighted imaging (SWI) algorithm. RESULTS SWI microscopy consistently provided images with SP‐like pathology extending within the entire parietal cortex in all cases of AD and 2 out of 10 age‐matched volunteers. CONCLUSIONS Although the precise mechanisms leading to the higher susceptibility rendering SP‐like pathology observable within the cortical mantle are not totally understood, the study unambiguously demonstrated that MR microscopy is capable of directly visualizing cortical pathology in AD patients in vivo.
CSF Rhinorrhea from a Transclival Meningocele: A Case Report
Authors: Akyuz Mahmut , Arslan Gokhan , Gurkanlar Doga , Tuncer Recai 
Published: October 2009

ABSTRACTThe most common site of cerebrospinal fluid (CSF) leakage is through the floor of the anterior fossa, which communicates with the ethmoid or frontal sinuses or with the nasal fossa. The sphenoid sinus is rarely implicated as a source of spontaneous CSF fistula. Transclival meningocele is an extremely rare lesion. A 36‐year‐old woman with a 1‐year history of intermittent CSF rhinorrhea was found to have a transclival meningocele. The diagnosis of transclival meningocele was made by magnetic resonance (MR), 3‐dimension‐computerized tomography (CT). At operation, by a transsphenoidal approach, the transclival meningocele was packed with fasia lata graft, fat tissue, and bio‐glue. This is the third case of transsphenoidal transclival meningocele producing rhinorrhea in an adult. Transclival meningocele should be taken into consideration in patients with spontaneous CSF rhinorrhea.
Atypical Wernicke's Encephalopathy Showing Lesions In the Cranial Nerve Nuclei and Cerebellum
Authors: Zuccoli Giulio , Motti Luisa 
Published: October 2009

ABSTRACTWernicke's encephalopathy (WE) is a severe neurological disorder caused by a dietary deficiency of Vitamin  B1 and characterized by consciousness changes, ocular abnormalities, and ataxia. Wernicke's encephalopathy is considered a medical emergency and treatment consists of intravenous thiamine administration. Typically in alcoholic and nonalcoholic patients magnetic resonance shows alterations in the mamillary bodies, medial thalami, tectal plate, and periaqueductal regions. We report here on a nonalcoholic atypical case of WE which presented with reversible symmetrical lesions in the cranial nerves nuclei and in the cerebellum alongside the classic neuroradiological findings.
Validation of Two Different Grading Schemes to Identify Patients With Asymptomatic Carotid Artery Stenosis in General Population
Authors: Suri M. Fareed K. , Ezzeddine Mustapha A. , Lakshminarayan Kamakshi , Divani Afshin A. , Qureshi Adnan I. 
Published: October 2009

ABSTRACTBACKGROUND Identification of significant asymptomatic carotid artery stenosis (ACAS) is important because of potential stroke‐risk reduction offered by carotid endarterectomy. We present an external validation of two previously developed scoring schemes designed to identify patients with ACAS. METHODS We used the data from the Cardiovascular Health Study (CHS)—a cohort study of cardiovascular risk factors, for external validation. Carotid Doppler ultrasound was performed in study participants. Two grading schemes, which used age more than 65 years, current smoking, and history of coronary artery disease and hyperlipidemia as predictors for ACAS, were validated using this dataset. RESULTS A total of 5,449 persons (mean age 72 ± 5 years; 42% men; and 84% white) were screened. The overall prevalence of ACAS of ≥50% was 4.2%. The prevalence of ACAS in the highest risk category was 19% in both stratification schemes. The stratification remained effective in the white sub‐population (P < .001), but was not significant in the African American population (P > .05). CONCLUSION Both schemes were effective in identifying persons with ACAS among general population aged 65 years or greater. A subset with a prevalence of ACAS of greater than 20% can be identified using these schemes making screening cost‐effective among white population.
In Vivo Imaging of Neurotransmission and Brain Receptors in Dementia
Authors: Pappatà Sabina , Salvatore Elena , Postiglione Alfredo 
Published: October 2009

ABSTRACTPositron emission tomography (PET) and single photon emission tomography (SPECT) are the most sensitive techniques to study, in vivo, neurotransmitter systems in normal human brain and in diseases. These methods have been applied over the last years to explore the integrity of cholinergic, serotonergic, GABAergic, and dopaminergic systems in Alzheimer's disease (AD) and in other dementias. The results of these investigations have provided new insights into the neurotransmission involvement in these disorders. Moreover, these methods provide objective quantitative markers for monitoring the progression of disease and the effects of therapies. The pathophysiological and clinical relevance of results from these studies are reviewed and the potential role in early and differential diagnosis discussed. New emerging radiotracers/methods for future investigations of neurochemical processes are delineated.