bluuebunny/crossref_metadata_2025_split huggingface dataset:
Internal Carotid Aplasia/Hypoplasia and Intracranial Saccular Aneurysms: Series of Three New Cases and Systematic Review of the Literature
Authors: Zink Walter E. , Komotar Ricardo J. , Meyers Phillip M. 
Published: October 2009

ABSTRACT Background and Purpose. Abnormal arterial flow dynamics and intracranial collateral pathways can be seen in patients with congenital internal carotid artery (ICA) aplasia or hypoplasia. Here we seek to evaluate whether ICA aplasia/hypoplasia is associated with an increased prevalence of intracranial saccular aneurysm relative to carotid rete mirabile. Methods. We combined our experience of three cases with 148 previous publications to form a retrospective series including 132 cases of ICA aplasia, 33 cases of ICA hypoplasia, and 34 cases of carotid rete mirabile. Results. After excluding cases lacking angiograms, ICA aplasia/hypoplasia was more commonly associated with aneurysm (45/158, 27.8%) compared with rete mirabile (2/34, 5.9%). A significantly greater overall aneurysm prevalence was seen among ICA aplasia/hypoplasia patients age 30 years or older (38/101, 36.6%) than in younger individuals (7/48, 14.6%). Conclusions. Intracranial saccular aneurysm is more strongly associated with ICA aplasia/hypoplasia than rete mirabile. An increased aneurysm prevalence among older individuals with ICA aplasia/hypoplasia suggests an acquired etiology. Magnetic resonance angiography (MRA) is recommended in the initial evaluation of ICA aplasia/hypoplasia to evaluate for intracranial saccular aneurysm, particularly after the third decade of life.
Meckel's Cave Tuberculoma with Unusual Infratemporal Extension
Authors: Kesavadas Chandrasekharan , Somasundaram S. , Rao Ravi M. , Radhakrishnan VV 
Published: October 2009

ABSTRACTThe authors describe a rare case of intracranial tuberculoma of the Meckel's cave and cavernous sinus with extension into the infratemporal fossa causing widening of the foramen ovale and adjacent bone destruction. The rarity of the lesion and the unusual extension of the lesion are presented with a brief review of literature.
Moyamoya Disease with Cerebral Arteriovenous Malformation Presenting as Primary Subarachnoid Hemorrhage
Authors: Somasundaram Sivaraman , Thamburaj Krishnamoorthy , Burathoki Sandeep , Gupta Arun K. 
Published: October 2009

ABSTRACTThe authors report a rare combination of definite moyamoya disease and brain arteriovenous malformation (AVM) presenting with primary subarachnoid hemorrhage (SAH) unheard of in the literature. The authors review the radiographic findings of this unique case with a brief review of literature.
Neuroimaging and Neurologic Complications after Organ Transplantation
Authors: Živković Saša 
Published: October 2009

ABSTRACTNeurologic complications are common after transplantation and affect 30‐60% of transplant recipients. The etiology of most of the posttransplant neurologic disorders is related to the opportunistic infections, both systemic and involving central nervous system (CNS), toxicity of immunosuppressive medications, and the metabolic insult created by the underlying primary disease and the transplant procedure. Neuroimaging studies are one of the key tools in the evaluation and enable early diagnosis of neurologic complications in transplant patients, especially posterior reversible leukoencephalopathy syndrome, central pontine myelinolysis, intracerebral hemorrhage, and fungal and bacterial abscesses. Magnetic resonance imaging (MRI) is the preferred technique, but each of the available neuroimaging techniques offers a unique insight into the pathophysiologic mechanisms underlying neurologic complications of transplantation. The role of neuroimaging in this population includes early detection of calcineurin inhibitor neurotoxicity, opportunistic infections, neoplasia, metabolic disorders, or cerebrovascular diseases. In addition, we can monitor longitudinal progression of disease and treatment response.
Mechanical Disruption of Thrombus Following Intravenous Tissue Plasminogen Activator for Ischemic Stroke
Authors: Qureshi Adnan I. , Janjua Nazli , Kirmani Jawad F. , Harris‐Lane Pansy , Suri M. Fareed K. , Zhou Jingying , Divani Afshin A. 
Published: October 2009

ABSTRACT Background and Purpose: We prospectively evaluated the safety of aggressive mechanical disruption of thrombus following full‐dose intravenous (IV) recombinant tissue plasminogen activator (rt‐PA) to treat ischemic stroke in 24 patients with an initial National Institutes of Health stroke scale (NIHSS) score of ≥10. Methods: Clinical evaluations were performed at presentation and 24 hours, 7 to 10 days, and 1 to 3 months (using modified Rankin scale) after treatment. These end points were compared to matched historical controls treated with IV rt‐PA alone. Results: Of the 24 patients, mechanical disruption was undertaken in 17 patients with persistent angiographic occlusion using microcatheter exploration (n= 3), angioplasty (n= 5), snare maneuvers (n= 7), and combination of both (n= 2). Partial or complete recanalization was observed in 10 of the 17 patients. Neurological improvement at 24 hours (≥4 point reduction in NIHSS score) was observed in 11 of 17 patients. Comparisons with matched controls suggest potential equivalence for symptomatic ICH (0% vs 12%), asymptomatic ICH (18% vs 15%), and early neurological improvement (65% vs 53%). Conclusion: The study shows that aggressive mechanical thrombus disruption in large artery occlusion in the setting of acute ischemic stroke is safe with acceptable rates of ICH and promotes angiographic recanalization.
Spatial Profiling of the Corticospinal Tract in Amyotrophic Lateral Sclerosis Using Diffusion Tensor Imaging
Authors: Wong John C.T. , Concha Luis , Beaulieu Christian , Johnston Wendy , Allen Peter S. , Kalra Sanjay 
Published: October 2009

ABSTRACT Background and Purpose: Diffusion tensor imaging (DTI) was used as a noninvasive method to evaluate the anatomy of the corticospinal tract (CST) and the pattern of its degeneration in amyotrophic lateral sclerosis (ALS). Methods. Fourteen patients with ALS and 15 healthy controls underwent DTI. Parameters reflecting coherence of diffusion (fractional anisotropy, FA), bulk diffusion (apparent diffusion coefficient, ADC), and directionality of diffusion (eigenvalues) parallel to (λ∥) or perpendicular to (λ⊥) fiber tracts were measured along the intracranial course of the CST. Results: FA and λ∥ increased, and ADC and λ⊥ decreased progressively from the corona radiata to the cerebral peduncle in all subjects. The most abnormal finding in patients with ALS was reduced FA in the cerebral peduncle contralateral to the side of the body with the most severe upper motor neuron signs. λ∥ was increased in the corona radiata. Internal capsule FA correlated positively with symptom duration, and cerebral peduncle ADC positively with the Ashworth spasticity score. Conclusion: There is a spatial dependency of diffusion parameters along the CST in healthy individuals. Evidence of intracranial CST degeneration in ALS was found with distinct diffusion changes in the rostral and caudal regions.
Pattern of Cortex and White Matter Involvement in Severe Middle Cerebral Artery Ischemia
Authors: Stoeckel Maria Cornelia , Wittsack Hans‐Jörg , Meisel Stephanie , Seitz Rüdiger J. 
Published: October 2009

ABSTRACT Background and Purpose. In middle cerebral artery (MCA) stroke, ischemia usually is unevenly distributed within the MCA territory. We sought to investigate which brain structures are critical for the acute neurological deficit in severe MCA stroke. Methods. We used magnetic resonance (MR) imaging and statistical parametric mapping in 64 consecutive stroke patients (64 ±13 years) to study the pattern of the initial perfusion abnormality. Results. Patients with lesion progression had more severe time‐to‐peak (TTP) abnormalities (P < .0001) in the inferior frontal gyrus, superior temporal gyrus, insula, and underlying hemispheric white matter than those with lesion regression. Also, patients with lesion progression had more severe T2 abnormalities on day 8 than those with lesion regression. In contrast, the changes of water diffusion were similar among the two groups resulting in a perfusion–diffusion mismatch in lesion progression. TTP‐lesions were related to the neurological deficit score (rs=−0.563, P < .0001), T2‐lesions (r= 0.686, P < .0001), and cerebral artery abnormalities assessed on MR‐angiography (rs= 0.399, P < .01). Conclusions. In major MCA, stroke ischemia was most severe in the central portion of the MCA territory. It is suggested that involvement of hemispheric white matter accentuated the neurological deficit probably by affecting cortico‐cortical and cortico‐subcortical fibers.
Distinguishing Air From Solid Emboli Using Ultrasound: In‐Vitro Study of the Effect of Doppler Carrier Frequency
Authors: Rodriguez Rosendo A. , Rodriguez Carlos D. , Mesana Thierry , Nathan Howard J. 
Published: October 2009

ABSTRACT Objective. To compare the ability of the signal relative‐intensity and sample‐volume‐length (SVL) to discriminate air bubbles from solid spheres in an in‐vitro model using two different carrier frequencies of the Doppler transducer. Methods. A gel ultrasound phantom was connected to a circuit in which blood‐mimicking fluid circulated. Air bubbles (100‐140 μm) and latex spheres (125 ± 10 μm) were injected into the circuit and interrogated using 1‐ and 2‐MHz transducers. High‐intensity‐transient‐signals (HITS) were recorded with a dual‐gated transcranial Doppler (TCD) system. Receiver‐Operating‐Characteristic curves determined the best cut‐off points that would distinguish between embolic materials. Results. HITS from air bubbles had higher intensities and longer SVL than solid spheres with either transducer (P < .0001). Air bubbles (P < .0001) and microspheres (P= .049) showed higher intensities with the 1‐MHz relative to the 2‐MHz transducer. The intensity increase with the 1‐MHz transducer was greater for air bubbles than microspheres (P < .0001). The discriminating efficacy of both the relative‐intensity and SVL was similar between transducers (intensity, P= .201; SVL, P= .98). Conclusions. The relative‐intensity and SVL are equally effective to distinguish solid from air emboli using 1‐ and 2‐MHz transducers. Our study indicates that using a lower carrier frequency does not improve the discrimination of air from solid emboli.
Transcranial Doppler Microembolic Signal Monitoring is Useful in Diagnosis and Treatment of Carotid Artery Dissection: Two Case Reports
Authors: Roy Jayanta , Akhtar Naveed , Watson Timothy , Demchuk Andrew M. , Saqqur Maher 
Published: October 2009

ABSTRACT Arterial dissection is the underlying stroke mechanism in approximately 2.5% of all strokes and the second leading cause of stroke in patients younger than 45 years of age. Controversy exists regarding the medical management of carotid dissection. Both anticoagulants and antiplatelet agents have been used with no compelling data supporting one therapy over the other. Transcranial Doppler (TCD) emboli monitoring may help in establishing the diagnosis and guide the treatment by measuring the frequency of microembolic signals (MES). We present two cases of carotid dissection where TCD monitoring for MES helped in establishing the diagnosis and proved useful in identifying that standard anticoagulation treatment was not preventing emboli. Both cases were also monitored for emboli count reduction with subsequent antiplatelet therapy.
Verbal Working Memory and Atherosclerosis in Patients with Cardiovascular Disease: An fMRI study
Authors: Haley Andreana P. , Sweet Lawrence H. , Gunstad John , Forman Daniel E. , Poppas Athena , Paul Robert H. , Tate David F. , Cohen Ronald A. 
Published: October 2009

ABSTRACT Background and Purpose. Intimal–medial thickening (IMT) of the carotid wall is an accepted peripheral marker of atherosclerosis. It is associated with increased risk for myocardial infarction and stroke, and lower attention‐executive‐psychomotor functioning. The purpose of this study was to examine the relationship between IMT and brain activity during a verbal working memory (VWM) task in patients with cardiovascular disease (CVD). Methods. Thirteen CVD patients underwent functional magnetic resonance imaging (fMRI) during a 2‐Back VWM task, and B‐mode ultrasound of the carotid arteries. IMT was calculated using an automated algorithm based on a validated edge‐detection technique. The relationship between IMT and 2‐Back‐related brain activity was modeled using partial correlations controlling for age and small vessel disease as measured by white matter signal hyperintensities on MRI (WMH). Results. Higher IMT was associated with lower 2‐Back‐related signal intensity and in the right middle frontal gyrus, independent of age and WMH. Conclusions. IMT may be one mechanism contributing to brain dysfunction in CVD. The blood oxygenation level‐dependent (BOLD) contrast appears to be highly sensitive to peripheral vascular health as measured by IMT. Future studies should examine the sensitivity and specificity of the BOLD response for predicting cognitive decline in CVD.
Intracranial Hemorrhage Sparing Meningioma in an Anticoagulated Patient
Authors: Romero José Rafael , Sakai Osamu , Rice Mary Berlik , Babikian Viken L. 
Published: October 2009

ABSTRACT Background and Purpose. The risk of intracerebral hemorrhage (ICH) in patients receiving antithrombotic therapy is well known. However, there is sparse literature regarding the risk of intracerebral hemorrhage in patients receiving warfarin, who have an intracranial meningioma. Methods and Results. We report a case of a 66‐year‐old man who developed multifocal ICHs in the context of supratherapeutic anticoagulation. There was sparing of the intracranial meningioma despite the development and growth of multiple intraparenchymal hemorrhages that resulted in death. We also review the literature evaluating the risk of ICH in anticoagulated patients with an intracranial meningioma. Conclusions. The findings of this case lend further support to the gradually developing notion of relative safety of anticoagulation in patients with meningioma. They also underscore the importance of close monitoring of the INR.
Neuroimaging Characteristics in Subgroup of GBMs with p53 Overexpression
Authors: Mut Melike , Turba Ulku C. , Botella Anali Conesa , Baskurt Erol , Lopes M. Beatriz S. , Shaffrey Mark E. 
Published: October 2009

ABSTRACTGlioblastoma multiforme (GBM) is a heterogeneous group of tumors, and neuroimaging characteristics have not been well‐defined in molecular subgroups. Eighty‐five patients with GBM were analyzed regarding imaging characteristics and correlation to p53 expression. The p53 positivity was graded according to percentage of positive cells (Grade 0, for < 10%; Grade 1, for <25%; Grade 2, for 26–50%; Grade 3, for >50% labeled cells). Imaging characteristics evaluated in the preoperative MRI were location and number of lesions, dimensions of enhancing lesion and of surrounding edema, mass effect, tumor borders, enhancement pattern after intravenous contrast administration, and tumor necrosis. Eighteen tumors had p53 expression >50% in immunohistochemical staining. Preoperative MRI of patients harboring those tumors with high p53 positivity revealed typical lesions with ring enhancement pattern and well‐defined borders in T1‐weighted images with contrast, and they were significantly different from other groups of p53 expression. There was no difference in terms of location and number of the lesions, dimensions of enhancing lesion and surrounding edema, mass effect, and the tumor necrosis between four different groups of p53 expression. A special subgroup of GBMs with p53 overexpression has ring enhancement pattern and well‐defined border on MRI that may be influential in preoperative planning and postoperative management of adjunct therapy.
Hyperechogenicity of the Substantia Nigra in Parkinson's Disease
Authors: Ressner Pavel , Školoudík David , Hluštík Petr , Kaňovský Petr 
Published: October 2009

ABSTRACTSubstantia nigra (SN) was assessed by transcranial sonography (TCS) in 47 Parkinson's disease (PD) patients and in 39 healthy volunteers. A semiquantitative echogenicity scale was created with arbitrary values ranging from 1 to 5, zones with grade ≥3 and larger than 0.19 cm2 were recorded as hyperechogenic SN. TCS examination of SN as a diagnostic test for PD in our study showed 87.2% sensitivity and 94.9% specificity.
Paradoxical Brain Embolism as a Cause of Central Retinal Artery Occlusion: A Case Report
Authors: Hayashi Koji , Iguchi Yasuyuki , Kimura Kazumi , Shibazaki Kensaku , Kobayashi Kazuto , Inoue Takeshi 
Published: October 2009

ABSTRACTA 79‐year‐old right‐handed woman was admitted to hospital following sudden onset of severe visual loss in the left eye. Left central retinal artery occlusion (CRAO) was diagnosed. Diffusion‐weighted imaging showed an asymptomatic hyperintensity in left middle cerebral artery territory. Transcranial Doppler and transesophageal echocardiography revealed patent foramen ovale. No other embolic sources were identified in the carotid artery, aortic arch, or heart. We report herein a case of CRAO caused by paradoxical brain embolism.
Clinical and MRI Predictors of Outcome After Surgical Intervention for Cervical Spondylotic Myelopathy
Authors: Alafifi T. , Kern R. , Fehlings M. 
Published: October 2009

ABSTRACTBACKGROUND Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord dysfunction in older individuals. Controversy remains in terms of the optimal timing and indications for surgical intervention. In this context, it would be of benefit to define clinical and magnetic resonance imaging (MRI) predictors of outcome after intervention for CSM. OBJECTIVE We studied subjects with clinically documented cervical myelopathy to evaluate the relationship among preoperative MRI signal change, clinical findings, and outcome after surgical intervention. METHODS We performed a retrospective case study of 76 CSM patients who underwent cervical decompressive surgery and who had pre‐ and postoperative MRI studies available for review. Preoperative clinical findings and MRI abnormalities on T1‐ (T1WI) and T2‐weighted (T2WI) images were correlated with outcomes (Nurick scores; Odom's criteria) following surgical intervention. Postoperative MRIs were performed 2‐4 months postsurgery to assess for adequacy of decompression and resolution of preoperative signal changes. The pattern of spinal cord signal intensity was classified as: Group A (MRI N/N), no intramedullary signal intensity abnormality on T1WI or T2WI; Group B (MRI N/Hi), no intramedullary signal intensity abnormality on T1WI and high intramedullary signal intensity on T2WI; Group C (MRI Lo/Hi), low intensity intramedullary signal abnormality on T1WI and high intensity intramedullary signal abnormality on T2WI. Statistical analyses were performed using SAS (version 8.2). RESULTS We evaluated 76 patients (57% males, mean age 62 years, range 30‐89) who experienced preoperative symptoms for an average of 6.5 months (range 1 month to 9 years). Preoperative MRI studies demonstrated the following: Group A (MRI N/N) = 45; Group B (MRI N/Hi) = 23; and Group C (MRI Lo/Hi) = 8. The mean postoperative follow‐up period was 2.5 years (range 2 months to 8.5 years). A positive Babinski sign and the presence of intrinsic hand muscle atrophy showed the greatest association with abnormal preoperative MRI signal change. High preoperative Nurick score, clonus, and leg spasticity were associated with a less favorable postoperative outcome. In Group B (MRI N/Hi), 11/23 (52.17%) patients had recovery to MRI N/N (P < .0001) at their follow‐up scan. CONCLUSIONS Patients with high intramedullary signal change on T2WI who do not have clonus or spasticity may experience a good surgical outcome and may have reversal of the MRI abnormality. A less favorable surgical outcome is predicted by the presence of low intramedullary signal on T1WI, clonus, or spasticity. These data suggest that there may be a window of opportunity to obtain optimal surgical outcomes in patients with CSM.
Intra‐Arterial Thrombolysis for Central Retinal Artery Occlusion in United States: Nationwide In‐Patient Survey 2001‐2003
Authors: Suri M. Fareed K. , Nasar Abu , Hussein Haitham M. , Divani Afshin A. , Qureshi Adnan I. 
Published: October 2009

ABSTRACTBACKGROUND Intra‐arterial thrombolysis (IAT) has been used as a treatment modality for central retinal artery occlusion (CRAO). However, national estimates of such practice and associated outcomes are not available. We performed this study to determine the frequency and outcomes of thrombolysis among adult patients hospitalized in United States (US) for CRAO. METHODS We determined the rates, hospital outcomes, and hospital charges incurred for patients with CRAO treated with thrombolysis using Nationwide Inpatient Survey (NIS) and compared them with patients treated without thrombolysis. NIS is the largest all‐payer inpatient care database in the US approximating a 20‐percent stratified sample of US community hospitals. RESULTS There were 1379 admissions for primary diagnosis of CRAO in 2001‐2003. IAT was used in 27(1.9%) of the patients with CRAO. There was no in‐hospital mortality or intracranial hemorrhage reported among any patient with CRAO treated with thrombolysis. All patients treated with IAT were discharged home. IAT was exclusively used in urbanteaching hospitals. CONCLUSIONS There is potential of benefit from IAT in CRAO, which is only offered in certain centers. Clinical trials are needed to demonstrate this beneficial effect.
Magnetization Transfer MRI in Multiple Sclerosis
Authors: Filippi Massimo , Agosta Federica 
Published: October 2009

ABSTRACTIn multiple sclerosis (MS), conventional magnetic resonance imaging (cMRI) has proved to be sensitive for detecting lesions and their changes over time. However, cMRI is not able to characterize and quantify the tissue damage within and outside such lesions. Magnetization transfer (MT) MRI is a quantitative technique with the potential to overcome this limitation and, as a consequence, to provide additional information about the nature and the extent of tissue damage associated to this disease.During the last 10 years, MT MRI indeed has allowed us to quantify the structural changes occurring within and outside lesions visible on cMRI scans, thus providing a more accurate in vivo picture of the heterogeneity of MS and, as a consequence, improving our ability to monitor the evolution of the disease. The application of MT MRI to the study of MS has contributed to change our understanding of how MS causes irreversible disability by showing that MS is more than an inflammatory‐demyelinating condition of the white matter of the central nervous system.