bluuebunny/crossref_metadata_2025_split huggingface dataset:
When Touch Elicits Cold: Functional Imaging of an Abnormal Sensation
Authors: Maihöfner Christian , Seifert Frank 
Published: October 2009

ABSTRACTThe authors report a 58‐year‐old man who presented with touch‐induced cold sensations and loss of pain and normal temperature sensation in the left leg and trunk. He was found to have syringomyelia at the level of the third thoracic vertebrae. A functional magnetic resonance imaging (fMRI) study was performed to evaluate the underlying cortical processing of the touch‐induced cold sensations. Blood oxygen level‐dependent(BOLD) responses were measured in response to light tonic pressure stimuli and to cold stimuli applied to both the symptomatic area on the left leg and to the unaffected contralateral side. Tonic pressure applied on the unaffected right thigh and the left hand resulted in activations of contralateral primary (S1) and bilateral secondary somatosensory cortices (S2). In contrast, application of tonic pressure to the affected left thigh, ie, where touch stimuli elicited cold sensations, induced robust activations not only in contralateral S1 and bilateral S2, but also in bilateral insular cortices, which are cortical areas known to be pivotally involved in the central processing of cold. The fMRI data argue in favor of supraspinal cross‐submodal plastic changes within the somatosensory system.
Prospective Evaluation of the Role of Atherosclerosis on Cerebral Atrophy: Pilot Study
Authors: Erbay Sami H. , O'Callaghan Mark. , Shah Paraq , Kini Jonathan , Bassett Midle Jennifer , Polak Joseph F. 
Published: October 2009

ABSTRACTPURPOSE Our purpose was to study the association between atherosclerosis measured by arterial calcium on computed tomography (CT) and cerebral atrophy demonstrated by brain magnetic resonance imaging (MRI). MATERIALS AND METHODS IRB approved this prospective study. Twenty‐one consecutive patients with acute stroke‐like symptoms who are scheduled to have brain MRI were recruited on a voluntary basis. electrocardiogram (ECG)‐gated helical CT scans were used to determine the arterial calcium as a reliable index of underlying atherosclerosis. Extracranial arterial calcium content was measured quantitatively by special software available in our CT scanner. Intracranial calcium was graded qualitatively. Brain MRI was independently evaluated to identify cortical, central atrophy, and ischemic changes. Relationship between CT demonstrated atherosclerosis and cerebral ischemic changes, brain atrophy patterns were evaluated both without and with adjustment for age and hypertension. RESULTS Out of 21 patients 20 were included in final study group. There was no correlation between atherosclerotic calcium measures and cortical atrophy, ischemic findings. Both intracranial and extracranial atherosclerosis had partial correlation with central atrophy (R= 0.43 and 0.52, respectively). After adjustment for age, only intracranial atherosclerosis maintained a partial correlation with central atrophy (R= 0.41). However, this correlation did not reach a statistically significant level (P= .10). CONCLUSIONS Intracranial atherosclerosis demonstrated a possible correlation with central atrophy.
Diagnosis of Lacunar Infarcts within 6 Hours of Onset by Clinical and CT Criteria Versus MRI
Authors: Rajajee Venkatakrishna , Kidwell Chelsea , Starkman Sidney , Ovbiagele Bruce , Alger Jeffrey , Villablanca Pablo , Saver Jeffrey L. ,   for the UCLA MRI Acute Stroke Investigators
Published: October 2009

ABSTRACTBACKGROUND The diagnosis of small deep infarcts (SDIs) based on clinical and noncontrast CT findings is often employed to triage stroke patients for emergent endovascular interventions. Few studies have evaluated the accuracy of <6 hours presentation with lacunar clinical syndromes in predicting the presence of a SDI and the absence of large vessel occlusion. METHODS Consecutive patients were identified with symptoms suggestive of acute stroke, diffusion‐weighted magnetic resonance imaging (DW‐MRI) and CT performed within 6 hours of onset, and absence of hemorrhage on imaging. Patients were given a diagnosis of SDI if they met the defined clinical and CT criteria. Diagnoses of large vessel occlusion absent (LVOA) and final diagnoses of SDI versus non‐SDI incorporated hyperacute multimodal MRI data. RESULTS Of 64 patients, 15 were diagnosed as SDI at <6 hours based on clinical/CT criteria. Fourteen of 15 patients (93%) had a final diagnosis of LVOA. Ten of 15 (67%) had a final MR‐DWI‐confirmed diagnosis of SDI. Clinical/CT diagnosis of SDI showed sensitivity of 44%, specificity 97%, positive predictive value (PPV) 93%, and negative predictive value (NPV) of 61% in predicting LVOA and sensitivity 83%, specificity 90%, PPV 67%, and NPV 96% compared to the final diagnosis of SDI. Most patients incorrectly diagnosed with SDIs harbored small cortical branch infarcts. CONCLUSIONS Diagnoses of SDI <6 hours from symptom onset based on a classic lacunar syndrome and CT criteria show only modest predictive value in predicting the presence of a small‐vessel territory infarct but perform fairly well in identifying patients without large‐vessel occlusions amenable to endovascular therapy.
Functional Imaging of Working Memory in Parkinson's Disease: Compensations and Deficits
Authors: Marié Rose‐Marie , Lozza Catherine , Chavoix Chantal , Louis Defer Gilles , Baron Jean‐Claude 
Published: October 2009

ABSTRACTBACKGROUND AND PURPOSE Over and above typical motor alterations, executive and working memory (WM) impairment can also occur in early idiopathic Parkinson's disease (PD). We aimed to investigate the compensatory neural processes involved in WM performance, as well as the networks involved in the long‐term memory transfer from short‐term stores in PD. METHODS Relative cerebral blood flow (rCBF) was mapped with H2O15‐PET in eight treated nondemented PD patients while performing a WM verbal double‐task (Brown‐Peterson paradigm) using both short (6‐second) and long (18‐second) delays. RESULTS As compared to nine age‐matched healthy subjects, performance of the PD group was only slightly reduced on the short‐delay but markedly impaired on the long‐delay task. Underlying the relatively preserved short‐delay performance, the PD group exhibited overactivation of prefrontal and parietal areas involved in attention‐demanding processes, suggestive of efficient compensatory processes. Further supporting this, significant positive correlations were found between short‐delay performance and rCBF in the bilateral inferior parietal cortex. In contrast, the lack of overactivation with the long‐delay task together with posterior cingulate hypoactivation would support the idea of functional disconnection impairing transfer of information from prefrontal onto (para)limbic areas. These findings suggest novel areas of investigation into early cognitive impairments in PD.
Diffusion Tensor Tractography‐based Analysis of the Pyramidal Tract in Patients with Amyotrophic Lateral Sclerosis
Authors: Hong Yoon‐Ho , Sung Jung‐Joon , Kim Sung‐Min , Park Kyung‐Seok , Lee Kwang‐Woo , Chang Kee‐Hyun , Song In Chan 
Published: October 2009

ABSTRACTBACKGROUND AND PURPOSE We attempted to measure DTI parameters of the brainstem pyramidal tract using two approaches, ie, simple ROI and tract‐specific analyses. Results obtained for healthy subjects and ALS patients were compared. METHODS DTI was performed using a single shot SE‐EPI with 25 noncollinear diffusion gradient directions (b= 1000 second/mm2) and with no diffusion gradient on a 3.0‐T MR system in 10 ALS patients and in 8 age‐ and sex‐matched normal controls. To delineate the brainstem pyramidal tract, tractography was performed using two ROIs, ie, a seed ROI at the cerebral peduncle (ROI‐1) and a target ROI at the lower pons (ROI‐2). ROI‐1 was subsequently restricted to voxels that contained streamlines in the tract reconstruction, thus creating a sub‐ROI. RESULTS Mean fractional anisotropy (FA) and mean diffusivity values were highly reproducible by tract specific analysis, whereas simple ROI analysis yielded larger variabilities between operators. FA values were significantly lower in ALS patients than in normal controls in the tractography‐derived sub‐ROI (P= .01), but not in the seed or target ROIs. CONCLUSIONS These results suggest, compared with simple ROI analysis, that tract‐specific analysis using DTI fiber‐tracking is more reliable and sensitive for detecting upper motor neuron pathology in ALS.
Assessment of Metabolism and Microcirculation of Healthy Skeletal Muscles by Magnetic Resonance and Ultrasound Techniques
Authors: Weber Marc‐André , Krakowski‐Roosen Holger , Hildebrandt Wulf , Schröder Leif , Ionescu Ingrid , Krix Martin , Kinscherf Ralf , Bachert Peter , Kauczor Hans‐Ulrich , Essig Marco 
Published: October 2009

ABSTRACTPURPOSE To assess metabolism and microcirculation of healthy skeletal muscle by magnetic resonance (MR) and ultrasound techniques and to compare these data with muscle histology, and anthropometric and blood parameters. METHODS Thirty‐four healthy volunteers were selected such that their measured aerobic capacity (VO2max) per body weight ranged between 23 and 66 mL/minute/kg to render a large variability of skeletal muscle capillarization as a result of their different physical activity. We analyzed body composition, blood parameters, and skeletal muscle fiber size and capillarization in biopsies of the vastus lateralis muscle. These data were compared with knee extensor cross‐sectional area (CSA) obtained by MR imaging, microcirculation of the vastus lateralis muscle by contrast‐enhanced ultrasound (CEUS), and its energy and lipid metabolism measured with 31P and 1H MR spectroscopy. Statistical analysis was performed using Pearson's correlation coefficient and significance was tested at a level of .5%. RESULTS The variable physical activity was reflected in a large variability of vastus lateralis muscle perfusion and metabolism at rest with highest histologic capillarization and CEUS‐perfusion values observed in the best‐trained volunteers. Levels of high‐energy phosphates, such as phosphocreatine, were positively correlated with CSA (r= .5) and histologic fiber size (r= .6 for type IIA and IIX fibers), while phosphocreatine concentration was significantly negatively correlated to myocellular lipids (r=−.6) and trimethyl ammonium containing compounds (r=−.8). Local blood volume measured in vivo with CEUS was positively correlated with several histologic capillarization parameters. CONCLUSIONS Dedicated MR‐ and CEUS‐methods deliver (patho‐)physiologic information about capillarization and fiber characteristics of skeletal muscles in vivo and hence establish a useful diagnostic tool for muscular diseases.
MR Imaging after Hip and Knee Replacement
Authors: Koch Sebastian , Forteza Alejandro , Lavernia Carlos , Romano Jose G. , Campo Nelly , Bhatia Rita , Campo‐Bustillo Iszet 
Published: October 2009

ABSTRACTBACKGROUND Diffusion‐weighted (DW) imaging abnormalities often develop in patients after invasive procedures associated with cerebral microembolism. Cerebral microembolism has recently been shown during orthopedic surgery. We here examine the effects of intraoperative microembolism on acute magnetic resonance(MR) imaging in patients undergoing hip and knee replacement. METHODS We enrolled 24 patients, at least 65 years old, requiring elective knee or hip replacement surgery. MR with DW and axial fluid‐attenuated inversion recovery (FLAIR) imaging was performed pre‐ and postoperatively. All patients were monitored intraoperatively for microemboli. RESULTS The mean age of patients was 74 years. All patients had intraoperative microemboli. The mean number of emboli detected was 9.9 ± 18 per surgery. MR imaging was obtained a mean of 3.5 days postoperatively. No DW imaging abnormalities were found after surgery. One patient had new findings on postoperative FLAIR imaging. CONCLUSION Intraoperative microembolism occurred universally, but did not lead to acute DW imaging abnormalities following knee and hip replacement. Acute imaging abnormalities on FLAIR imaging are rare but may occasionally occur after joint surgery.
Intracranial Artery Calcification: A Newly Identified Risk Factor of Ischemic Stroke
Authors: Chen Xiang‐yan , Lam Wynnie Wai Man , Ng Ho Keung , Fan Yu‐hua , Wong Ka Sing 
Published: October 2009

ABSTRACTBACKGROUND AND PURPOSE Calcification in cerebral arteries is understudied, although frequently observed on computed tomography of the brain (CT brain). We aimed to assess the incidence of intracranial artery calcification in ischemic stroke patients and to evaluate its correlation with ischemic stroke. METHODS Our study included ischemic stroke patients and age‐gender‐matched nonischemic stroke patients referred for CT brain. RESULTS One hundred and seventy‐five ischemic stroke patients and 182 controls were enrolled. The highest prevalence of calcification was seen in intracranial internal carotid artery (IICA) (80.4%), and less commonly in the vertebral artery (35.6%). There was a higher prevalence of intracranial artery calcification in ischemic stroke patients than controls (92.6% vs. 76.4%, P < .001). Hypertension (OR = 2.056, 95% CI: 1.129 ∼ 3.745), diabetes (OR = 2.483, 95% CI: 1.233 ∼ 5.001), smoking (OR = 2.844, 95% CI: 1.542 ∼ 5.243), intracranial artery calcification (OR = 3.172, 95% CI: 1.252 ∼ 8.036), hyperlipidemia (OR = 6.714, 95% CI: 3.302 ∼ 13.650), and atrial fibrillation (OR = 7.941, 95% CI: 2.790 ∼ 22.599) were found to be independently associated with ischemic stroke. CONCLUSIONS We demonstrated a higher incidence of intracranial artery calcification in ischemic stroke patients. Besides traditional risk factors, intracranial artery calcification was found to be an independent risk factor of ischemic stroke.
Computed Tomographic Angiography as the Primary Diagnostic Study in Spontaneous Subarachnoid Hemorrhage
Authors: Nijjar Satnam , Patel Bijal , McGinn Greg , West Michael 
Published: October 2009

ABSTRACTPURPOSE To evaluate the utility of computed tomographic angiography (CTA) as the primary diagnostic investigation in patients with spontaneous subarachnoid hemorrhage (SAH), and to correlate the results with intraoperative findings in those with ruptured aneurysms. MATERIALS AND METHODS A retrospective review of 243 patients with spontaneous SAH was performed. The patients selected were those with acute SAH confirmed by noncontrast head computed tomography or by cerebrospinal fluid findings from a lumbar puncture. Patients subsequently underwent preoperative three‐dimensional CTA as the sole or primary diagnostic study. The results of the CTA were correlated with the intraoperative findings in those patients undergoing emergent surgical clipping of acutely ruptured intracranial aneurysms. RESULTS CTA correctly detected the ruptured aneurysm in 170 of the 171 cases, which required surgical clipping. Our data demonstrates that CTA has a 99.4% detection rate in acutely ruptured aneurysms as compared to intraoperative findings [confidence interval 97.8‐99.9%]. CONCLUSION CTA can provide prompt and accurate diagnostic and anatomic information in the setting of SAH with an excellent detection rate in acute ruptured aneurysms. These findings suggest an increased role for CTA in the evaluation of cerebral aneurysms.
Neuroimaging in Stroke and Seizure As Neurological Emergencies (NISSAN) Study
Authors: Rodriguez Gustavo J. , Nasar Abu , Suri M. Fareed K. , Ezzeddine Mustapha A. , Qureshi Adnan I. 
Published: October 2009

ABSTRACTOBJECTIVE To report the current national utilization of neuroimaging in the emergency department for the two most common neurological emergencies; stroke and seizure. METHODS Patients were identified using primary International Classification of Diseases (ICD)‐9‐CM codes from the 2004 National Hospital Ambulatory Medical Care Survey (NHAMCS). NHAMCS is designed to collect data on the utilization and provision of care in emergency departments of hospitals in the United States. We analyzed the use of neuroimaging in patients presenting to the emergency department with seizure or stroke. RESULTS About 60% of 1,190,219 patients with the diagnosis of stroke or seizure had neuroimaging performed emergently. Patients with any type of stroke were more likely to undergo neuroimaging compared to patients with seizure (78% vs. 37%, P < .05). When stroke subtypes were analyzed separately, neuroimaging was performed in the emergency department among 100% of patients with subarachnoid hemorrhage, 79% with ischemic stroke, and 69% with intracerebral hemorrhage. CONCLUSIONS In a nationally representative study, emergent neuroimaging appeared to be underutilized among patients with ischemic stroke and intracerebral hemorrhage. There is a need to increase the utilization of neuroimaging in the emergency department in anticipation of new acute stroke treatments.
Intracranial Atherosclerotic Disease: Medical, Biomechanical, Imaging, and Flow Dynamics Perspective
Authors: Suri M. Fareed K. , Divani Afshin A. , Hoffmann Kenneth R. , Qureshi Adnan I. 
Published: October 2009

ABSTRACTINTRODUCTION Intracranial stenosis is one of the most common disease entities encountered by neurointerventionists. The physical and hemodynamic properties of the lesion are determined by the experience of the clinician. Computerized analysis may provide more accurate values of these parameters which can be used during the procedure for improving patient care. MATERIALS AND METHODS We present a case of a 55‐year‐old man who was having ischemic symptoms related to severe middle cerebral artery stenosis. Intralesional stent placement normalized the diameter of the vessel leading to cessation of the episodes of neurological events. DISCUSSION Discussants include a neurointerventionist, a neurovascular image analyst, and a neurovascular flow and hemodynamic analyst. Questions discussed included qualitative and quantitative analysis of stenosis; comparison of angiographic perfusion studies including analysis of delay in opacification, transit times and time density curves; role of automation in analysis of “emboli tolerance” and “no re‐flow” phenomenon; and relationship of compliance and recoil in normal and diseased segments of a vessel during angioplasty or stent placement.
Functional MRI in Malformations of Cortical Development: Activation of Dysplastic Tissue and Functional Reorganization
Authors: Vitali Paolo , Minati Ludovico , D'Incerti Ludovico , Maccagnano Elio , Mavilio Nicola , Capello Dario , Dylgjeri Suela , Rodriguez Guido , Franceschetti Silvana , Spreafico Roberto , Villani Flavio 
Published: October 2009

ABSTRACTBACKGROUND AND PURPOSEFunctional neuroimaging and electrophysiological studies suggest that dysplastic neural tissue in malformations of cortical development may participate in task performance, and that functional organization can be altered beyond visible lesion boundaries. The aim of this work was to investigate cortical function in a heterogeneous group of patients with malformations of cortical development.METHODSTwelve patients participated in the study, 2 for each of the following categories: subcortical, periventricular, and band heterotopia, unilateral and bilateral polymicrogyria, and focal cortical dysplasia. Functional magnetic resonance imaging was performed with finger tapping, somatosensory and visual stimulation, and language‐related tasks.RESULTSWe found activations within the dysplastic tissue in subcortical heterotopia, band heterotopia, and polymicrogyria, but not in periventricular heterotopic nodules. In one of the patients with focal cortical dysplasia, language‐related activation involved part of the lesion. Functional reorganization beyond visible lesion boundaries was seen, with different patterns, in 4 patients.CONCLUSIONSIn accordance with previous reports, our findings indicate that dysplastic neural tissue can be activated during task performance, and that in some patients, extensive functional reorganization occurs, highlighting the importance of functional magnetic resonance imaging in presurgical planning in those patients for whom epilepsy surgery is considered as an option.
Retrieval of a Displaced Detachable Coil and Intracranial Stent with an L5 Merci Retriever During Endovascular Embolization of an Intracranial Aneurysm
Authors: Vora Nirav , Thomas Ajith , Germanwala Anand , Jovin Tudor , Horowitz Michael 
Published: October 2009

ABSTRACTCoil displacement during endovascular embolization of an intracranial aneurysm can result in significant thromboembolic complications. To avoid this problem, microsnares and other techniques have been developed to retrieve a lost foreign body in the cerebral circulation. The Merci Retriever (Concentric Medical, Inc., Mountain View, CA) is an FDA‐approved device for clot removal in the intracranial vessels. Modifications to its original design have enhanced this device not only for embolectomy but also for intravascular foreign body retrieval. To our review, we report the first use of an L5 Merci Retriever to evacuate a displaced detachable endovascular coil and intracranial stent during aneurysm treatment.
Prenatal Thrombosis of Torcular Herophili with Spontaneous Resolution and Normal Outcome
Authors: Grigoriadis Savvas , Cohen Jose E. , Gomori John Moshe 
Published: October 2009

ABSTRACTBACKGROUNDPrenatal thrombosis of torcular Herophili is a rare condition. It may be suspected during the routine ultrasonographic follow‐up of the fetus, but MRI is necessary to establish the diagnosis. There are 7 reported cases with various results.METHODSWe report a case of prenatal torcular Herophili thrombosis. We present 2 series of fetal MRIs. The first one was performed at 21 and the second at 37 weeks' gestation.RESULTSThe second MRI revealed a total resolution of the thrombus. The product was a neurologically intact infant with normal development.CONCLUSIONSThis is the fourth reported case of fetal torcular Herophili thrombosis with normal outcome. There are no sufficient data regarding the best management of this rare condition; however, following up with fetal MRIs seems to be the most rational choice.
Neurogenic Bladder Due to Hypoxic‐Ischemic Demyelination
Authors: Ramchandren Sindhu , Liebeskind David S. 
Published: October 2009

ABSTRACTBACKGROUND AND PURPOSE Hypoxia is commonly known to target neuronal cell bodies. Although myelin is a non‐infrequent target, posthypoxic demyelination is a rarely described entity. We describe the case of a man who developed neurogenic bladder following a motor vehicle accident. CASE REPORT Following a severe motor‐vehicle accident involving massive blood loss, a 46‐year‐old man developed urinary urgency requiring catheterization, with hyperactive reflexes and bilateral Babinski signs on exam. RESULTS Magnetic resonance imaging of the brain and cervical cord revealed diffuse, isolated white matter signal abnormality in a symmetric, confluent distribution, extending inferiorly into the spinal cord, with changes consistent with bilateral Wallerian degeneration. Serologic and CSF evaluations were normal. CONCLUSIONS Unlike previous reports of hypoxic‐ischemic demyelination, our patient lacked any cortical abnormalities, presumably due to isolated white matter changes. This report alerts physicians to the possibility of hypoxic‐ischemic demyelination due to global hypoxia‐ischemia as an etiologic factor for neurogenic bladder.