bluuebunny/crossref_metadata_2025_split huggingface dataset:
Massive Cerebral Edema After Recanalization Post‐Thrombolysis
Authors: Cruz‐Flores Salvador , Thompson Daryl W. , Boiser Joey R. 
Published: November 2009

ABSTRACT Background. Intravenous thrombolysis with tissue plasminogen activator is an approved and effective therapy for acute ischemic stroke within the first 3 hours from onset. In addition to the risk of hemorrhage, there is a risk of postrecanalization cerebral edema. The authors present the case of a patient with an ischemic stroke treated successfully with intra‐arterial thrombolysis who subsequently developed massive brain edema in the face of clinical improvement. Case. An 81‐year‐old man presented within 1 hour of developing a full right middle cerebral artery (MCA) syndrome. Computed tomography (CT) was normal. A cerebral angiogram demonstrated an occlusion of the M1 segment of the right MCA. The patient was treated with intra‐arterial urokinase 750,000 units. He recovered during the procedure. Serial CT scans demonstrated progressive edema with mass effect in the right MCA distribution. The patient remained asymptomatic except for a mild sensory deficit. Discussion. Postrecanalization cerebral edema is an uncommon but potentially lethal complication of thrombolysis. It is postulated that the edema is due to ischemic injury aggravated by reperfusion with vasogenic edema. The presence of this massive edema is usually associated with clinical worsening. The present case illustrates that this disorder can be associated with good outcome.
The Nature of Microemboli in Patients With Artificial Heart Valves
Authors: Telman G. , Kouperberg E. , Sprecher E. , Yarnitsky D. 
Published: November 2009

ABSTRACTCognitive decline has recently been found to be associated with microemboli in cerebral vessels in patients with artificial heart valves. The authors sought to determine the nature of such microemboli, that is, whether they are gaseous or solid, by comparing their characteristics to those of artificially generated air emboli in patients with patent foramen ovale (PFO). Three hundred and forty‐eight microemboli were recorded in 11 patients with artificial valves (all taking coumadin), and 86 microemboli were recorded in response to intravenous injection of saline agitated with air in 8 PFO patients. No difference in intensity, duration, or relative velocity of microemboli was found between groups. The authors conclude that microemboli generated from artificial heart valves are generally gaseous and not solid.
Intravenous Tissue Plasminogen Activator and Flow Improvement in Acute Ischemic Stroke Patients with Internal Carotid Artery Occlusion
Authors: Christou Ioannis , Felberg Robert A. , Demchuk Andrew M. , Burgin W. Scott , Malkoff Marc , Grotta James C. , Alexandrov Andrei V. 
Published: November 2009

ABSTRACT Background and Purpose. It has been suggested that intravenous tissue plasminogen activator (TPA) would not lyse the large thrombus associated with internal carotid artery (ICA) occlusion and, therefore, would be ineffective in this setting. Vascular imaging, safety, and outcome of TPA therapy for ICA occlusion is not well described. Our goal was to determine the site of occlusion, early recanalization after TPA infusion, and its relationship to outcome. Methods. We reviewed our database of all stroke patients treated with IV TPA between July 1997 and July 1999. We identified all cases with carotid occlusion suggested by transcranial Doppler (TCD) and angiography. Occlusion and recanalization were assessed by site including proximal ICA (prICA), terminal ICA (tICA), and middle cerebral artery (MCA). Baseline National Institutes of Health Stroke Scale (NIHSS) scores and follow‐up Rankin scores were obtained. Results. We treated 20 patients with carotid occlusion (age 63.9 ± 10.8 years, 11 males, 9 females). Time to TPA infusion after stroke onset was 128 ± 66 minutes. Baseline NIHSS scores were 16.4 ± 5.4. Time to follow‐up was 3.5 ± 4.9 months (2 patients were lost to follow‐up). Occlusion sites were prICA 40%, tICA 70%, and concurrent MCA 45%. Multiple sites were involved in 10/20 patients (50%). Among patients with pretreatment and posttreatment vascular imaging studies (n= 18), recanalization in the prICA and tICA was complete in 10%, partial in 16%, and none in 74%. MCA recanalization was complete in 35%, partial in 24%, and none in 41%. At follow‐up, Rankin 0–1 was found in 8 patients (44%), Rankin 2–3 in 3 (17%), and Rankin 4–5 in 3 (17%). Mortality was 22% (n= 4) including 1 fatal intracerebral hemorrhage. Improvement was closely related to resumption of MCA flow (P < .01). Conclusions. Most patients did not recanalize their ICA occlusion after intravenous TPA therapy. However, recanalization of associated proximal MCA clot, found in 45% of our patients, or improved MCA collateral flow was strongly associated with good outcome.
Integration and Added Value of the Modern Noninvasive Vascular Laboratory in Vascular Diseases Management
Authors: Boyajian Robert A. , Otis Shirley M. 
Published: November 2009

ABSTRACT Background and Purpose. Today's vascular laboratory technology offers broad applications throughout vascular medicine. We explore the diagnostic work‐up and management of selected peripheral vascular diseases by benchmarking the institutional mix of invasive and noninvasive technology utilization and associated cost burdens. Methods. Specialized diagnostic studies for prevention of stroke and pulmonary embolism, and diagnosis and management of femoral pseudoaneurysm were reviewed for our 355‐physician clinic and hospital practice. The proportions and costs for invasive and noninvasive diagnostic procedures were tabulated for carotid stenosis, deep venous thrombosis (DVT), and iatrogenic femoral pseudoaneurysm. Current technology utilization mix cost burdens were compared to projected cost burdens for hypothetical equivalent medical value (ie, the same total test volume) in the theoretical absence of noninvasive laboratory services. Results. The technology utilization mix was dominated by noninvasive duplex ultra‐sonography for all 3 vascular disease workups. The technology utilization mix benchmarks were 92% noninvasive for carotid stenosis, 98% noninvasive for DVT, and 100% noninvasive for pseudoaneurysm. Under hypothetical constant test volume normalized to utilization level for the 2‐year period, the maximal range in cost burdens between current reliance on noninvasive diagnoses versus projected 100% reliance on invasive procedures for the 3 vascular applications is approximately $6 million. Conclusion. Benchmark indices reveal near total adoption of noninvasive technology for vascular diagnostic workups at our center. The benefits to institutions of benchmarking their technology utilization mix and costs are discussed in relation to identifying potential for cost‐containment from modifying technology utilization practices.
Vertebral Artery Dissection Presenting With Isolated Neck Pain
Authors: Krespi Yakup , Gurol Mahmut Edip , Coban Oguzhan , Tuncay Rezzan , Bahar Sara 
Published: November 2009

ABSTRACTUnilateral pain in the cervical region and limitation of neck movements are nonspecific symptoms frequently encountered in daily medical practice. Vertebral artery dissection is rarely considered as a diagnostic possibility unless brainstem or cerebellar ischemia follows the acute pain. Three cases of vertebral artery dissection (VAD) having the sole complaint of pain of acute onset in the posterior neck region are presented. None of the patients had ever reported a similar pain, and the neurological examination was unremarkable in all of them. Doppler ultrasonography suggested VAD in 2 cases, and the diagnosis was confirmed with T1 fat‐suppressed magnetic resonance imaging technique in all patients. Severe neck pain and/or occipital headache frequently accompanies ischemic symptoms in cases with VAD. The cases in this report emphasize that spontaneous and often unilateral posterior cervical pain of acute onset can be the only manifestation of a VAD. A high degree of suspicion especially in young patients with no past history of a similar pain can help to establish the diagnosis, thereby preventing erroneous and potentially hazardous therapeutic interventions such as physiotherapy or neck manipulation.
Optimal Values of Flow Velocity on Transcranial Doppler in Grading Middle Cerebral Artery Stenosis in Comparison With Magnetic Resonance Angiography
Authors: Gao Shan , Lam Wynnie W. M. , Chan Yu Leung , Yan Liu Jun , Wong Ka Sing 
Published: November 2009

ABSTRACT Background and purpose. To investigate the optimal values of flow velocity on transcranial Doppler (TCD) in grading the severity of middle cerebral artery (MCA) stenosis in comparison with magnetic resonance angiography (MRA). Methods. Both TCD and MRA examinations were performed on 148 asymptomatic patients. The peak flow velocities of each MCA were recorded. Severity of MCA stenosis on MRA was classified as normal‐mild (< 50% lumen diameter reduction), moderate (50%‐75%), and severe‐void (> 75% and void of flow signal). Results. Among 296 MCAs evaluated, normal‐mild stenosis was found in 75 (25%), moderate stenosis in 112 (38%), and severe stenosis in 109 (37%). The mean of systolic velocity (Vs) of MCA differed significantly among these three groups: mean Vs = 121.83 ± 22.52 cm/s in the normal‐mild group; 155.96 ± 21.62 cm/s for the moderate group; and 199.39 ± 43.86 cm/s for the severe group (P < .001). The optimal cutoff velocity for detection of MCA (> 50%) stenosis was found at Vs > 140 cm/s on TCD (area under the ROC curve is 0.87, P < 0.001). The best cutoff points for grading severity of on TCD were 140 cm/s and 180 cm/s. Conclusion. TCD enables grading of the severity of MCA stenosis according to the flow velocity. This method provides a noninvasive and reliable method for grading MCA stenosis and allows longitudinal monitoring of the relationship between clinical outcome and hemodynamic change.
Criteria for Normalcy of Cavities Observed Within the Adult Hippocampus: High‐Resolution Magnetic Resonance Imaging Study on a 3.0‐T System
Authors: Yoneoka Yuichiro , Kwee Ingrid L. , Fujii Yukihiko , Nakada Tsutomu 
Published: November 2009

ABSTRACT Background and Purpose. Cavities occasionally found within the hippocampus during routine clinical magnetic resonance imaging (MRI) studies are believed to be a normal variant reflecting fluid collection within the vestigial hippocampal sulcus. However, the lack of systematic studies defining objective criteria for such cavities has hampered further assessment of potential abnormalities within the hippocampus. This study assessed the detailed characteristics of hippocampal cavities in normal subjects using a new high‐resolution MRI technique in an attempt to define objective criteria of normalcy. Methods. A new high‐resolution imaging technique, T2‐reversed MRI on a high‐field (3.0‐T) system was used to image the hippocampus in 74 normal volunteers in 3 age groups (28 young, 24 middle, and 22 senior). Results. Residual cavities in the vestigial hippocampal sulcus were resolved as single, crescent‐shaped structures along the deep aspect of the vestigial hippocampal sulcus. The size of the cavities did not vary with age and never exceeded 1 mm in width and 3 mm in length. The frequency of detection, however, increased with age (21.4% [5/28] in the young, 25.0% [6/24] in the middle, and 36.4 [8/22] in the senior age group). Conclusion. The study established clear objective criteria for normal cavities within the hippocampus. These cavities likely represent physiological fluid collection within the vestigial hippocampal sulcus. Any cavity that does not meet these defined criteria should be considered potentially abnormal.
Volumetric Assessment of Plaque Progression With 3‐Dimensional Ultrasonography Under Statin Therapy
Authors: Schminke U. , Hilker L. , Motsch L. , Griewing B. , Kessler C. 
Published: November 2009

ABSTRACT Background and Purpose. Lowering of serum cholesterol levels with HMG‐CoA reductase inhibitors (statins) slowed the progression of atherosclerosis in the carotid arteries in several clinical trials using carotid artery intima media thickness as primary outcome measure. Whereas conventional ultrasonography is limited to thin 2‐dimensional image planes, 3‐dimensional (3D) ultrasonography provides quantitative measurement of the entire carotid artery plaque volume. This study aims to assess the feasibility of 3D ultrasonography to monitor plaque progression in hypercholesterolemic patients. Methods. The authors prospectively assessed the progression of 31 carotid artery plaques over 15.1 ±4.5 months in a study of 23 patients (6 women, 17 men; mean age = 61.7 ±7.5 years) with hypercholesterolemia under therapy with HMG‐CoA reductase inhibitors. All patients were maintained on a lipid‐lowering diet. Sixteen patients were additionally treated with statins. Quantitative measurements of carotid artery plaque volumes were performed after 3D reconstruction of exactly parallel transverse duplex ultrasound scans (slice distance = 0.1 mm) into volumetric 3D data sets and segmentation of voxels representing the carotid artery plaque. Results. Within the treatment group, plaques were significantly less frequently progressive if they had a hypoechoic echogenicity (11%, n= 9 vs 64%, n= 14; P= .016) or if baseline serum cholesterol levels were above 8.0 mmol/L (9%, n= 11 vs 75%, n= 12; P= .002). Conclusion. Three‐dimensional ultrasonography extends the measurement of the arterial wall thickness to the 3D volume of an entire atherosclerotic plaque including analysis of its morphology and configuration. However, further clinical trials with an adequate sample size to achieve sufficient statistical power are necessary to assess the effect of statin therapy on plaque progression.
Transcranial Doppler Study of the Cerebral Hemodynamic Changes During Breath‐Holding and Hyperventilation Tests
Authors: Settakis Georgios , Lengyel András , Molnár Csilla , Bereczki Dániel , Csiba László , Fülesdi Béla 
Published: November 2009

ABSTRACT Background and purpose. The aim of the present study was to assess the time course of hyperventilation (HV) and breath‐holding (BH) tests in healthy volunteers. Subjects and Methods. Young healthy volunteers (n= 29) underwent continuous registration of the middle cerebral artery mean blood flow velocity (MCAV) during and after 30 seconds of BH and 60 seconds of HV. Absolute values as well as percentage changes of the MCAV are reported. In 13 subjects, determination of capillary blood gas parameters (pH, pCO2, pO2, and O2 saturation) was performed before tests, after BH and after HV. Results. MCAV during 30 seconds of breath‐holding starts to increase after 10 seconds and reaches its highest level at 30 seconds. After breathing normally, MCAV normalizes within 30 seconds. Hyper‐ ventilation results in a decrease in MCAV, which reaches a plateau at 20 to 30 seconds after starting to hyperventilate, and blood flow velocity did not change significantly any further until the end of the procedure. The normalization of the MCAV is incomplete at 30 seconds after finishing hyperventilation. None of the capillary blood gases changed significantly after breathholding, whereas capillary pH, pO2, and oxygen saturation increased and pCO2 decreased after hyperventilation. No relationship was found between capillary blood gas parameters and MCAV values. Conclusions. The authors concluded that breathholding and hyperventilation tests seem to be a practical alternative to acetazolamide and the CO2 inhalation method in the assessment of cerebral hemodynamics.
Magnetic Resonance Imaging of Multiple Sclerosis
Authors: Filippi Massimo , Tortorella Carla , Rovaris Marco 
Published: November 2009

ABSTRACTAlthough conventional magnetic resonance imaging (cMRI) is widely used for diagnosing multiple sclerosis (MS) and monitoring disease activity and evolution, the correlation between cMRI and clinical findings is far from strict. Among the reasons for this “clinical‐MRI paradox,” a major role has been attributed to the limited specificity of cMRI to the heterogeneous pathological substrates of MS and to its inability to quantify the extent of damage in the normal‐appearing tissue. Modern quantitative MRI techniques have the potential to overcome some of the limitations of cMRI. Metrics derived from magnetization transfer and diffusion‐weighted MRI enable one to quantify the extent of structural changes occurring within and outside macroscopic MS lesions with increased pathological specificity over cMRI. Magnetic resonance spectroscopy can add information on the biochemical nature of such changes, with the potential to improve significantly our ability to monitor inflammatory demyelination and axonal injury. Finally, functional MRI might provide new insights into the role of cortical adaptive changes in limiting the clinical consequences of white‐matter structural damage. This review outlines the major contributions given by MRI‐based techniques to the diagnostic work‐up of MS patients, to the understanding of the pathobiology of the disease, and to the assessment of the effects of new experimental treatments.
Is Gadolinium Enhancement Predictive of the Development of Brain Atrophy in Multiple Sclerosis? A Review of the Literature
Authors: Zivadinov Robert , Zorzon Marino 
Published: November 2009

ABSTRACT Background and Purpose. Several studies have demonstrated that brain atrophy can be detected over relatively short intervals from the earliest stages of multiple sclerosis (MS). Reviewing the published data, the authors highlight some hypothetical pathological mechanisms proposed as determinants of brain atrophy. Methods. Using the terms multiple sclerosis, MRI (magnetic resonance imaging), and brain atrophy, 181 citations were identified. The authors considered only studies with prospective designs with natural‐course MS patients and/or placebo‐treated patients of therapeutic trials, in which patients under‐went baseline and follow‐up scans with a T1‐weighted gadolinium diethylenetriamine penta‐acetic acid sequence (0.1 mmol/kg body weight), and correlation analyses between Gd enhancement activity and brain atrophy progression. Results. Five hundred thirty‐two patients of 5 natural history studies and 5 therapeutic trial studies participated in the review process. The main observation was that in patients with a relapsing‐remitting (RR) disease course, there was a correlation between Gd enhancement activity and brain atrophy progression. This correlation was not influenced by any other demographic and clinical additional data considered in the review process. Conclusions. Examination of the pathological mechanisms pro‐posed in the reviewed studies led the authors to believe that inflammation is only in part responsible for the development of brain atrophy. This conclusion may have an implication for the strategies of tissue protection advocated in the early stages of the RR course and strengthen recent evidence indicating that anti‐inflammatory immunomodulatory agents and immunosuppressive treatments, which predominantly act against the inflammatory component of disease activity, may not have similar effects on progressive tissue loss, either in RR or progressive MS.
Blood Flow Velocities in the Basal Cerebral Vein After Head Trauma: A Prospective Study in 82 Patients
Authors: Mursch Kay , Müller Christian‐Andreas , Buhre Wolfgang , Lang Johannes K. , Vatter Hartmut , Behnke‐Mursch Julianne 
Published: November 2009

ABSTRACT Background and Purpose. The authors' aim was to evaluate the time course of the basal vein's (BVR) mean flow velocity (VBVR)in patients after traumatic brain injury and its relation to intracranial pressure (ICP), cerebral perfusion pressure (CPP), and the clinical outcome. Methods. In 82 head‐injured patients (13 women and 69 men, median age = 31 years, Glasgow Coma Score = 15 to 3), daily measurement of the basal cerebral vein's and the middle cerebral artery's (MCA) flow velocities and pulsatilities was performed during each patient's entire stay in the intensive care unit. No angle correction was performed. A computerized sonography system (SD 800, Philips, Irvine, CA) with a 2.0‐MHz to 2.5‐MHz transducer was used for all measurements. The Glasgow Outcome Score (GOS) was evaluated after 6 months. Results. During the study period, VBVR values on the side of trauma were higher in the patients with favorable outcomes (GOS = 4 and 5) compared to patients with unfavorable out‐comes (GOS = 2 and 3). This was statistically significant on days 4, 6, 7, and 11 and was not observed in the mean flow velocity of the MCA (VMCA). VBVR values among the good‐outcome group tended to exceed the normal mean flow velocity (9.1 cm/s), whereas the unfavorable‐outcome group was below this level. A correlation between venous flow velocity or pulsatility and ICP or CPP was not observed. Conclusions. Repetitive Doppler examination of the basal cerebral veins may add new aspects to the monitoring of head‐injured patients.
A Case Study of Hemispatial Neglect Using Finite Element Analysis and Positron Emission Tomography
Authors: Peña Alonso , Owler Brian K. , Fryer Tim D. , Minhas Pawan , Czosnyka Marek , Crawford Peter J. , Pickard John D. 
Published: November 2009

ABSTRACT Background. The authors present a patient who developed transient hemispatial neglect following surgical drainage of a large right frontotemporal arachnoid cyst. As symptoms evolved in parallel with brain shift over the subsequent months, the authors hypothesized that the disorder was associated with the appearance of mechanical stresses in the cerebral mantle. Methods. To map tissue stress at the various stages of deformation, a finite element computer simulation was conducted on the basis of computed tomography scans of the patient. Results. The authors' results demonstrate substantial shear and compressive stress concentrations in the parietal lobe, a region commonly associated with neglect, and where positron emission tomography confirmed hypoperfusion in this patient. Treatment with combined ventricular‐peritoneal and cystoperitoneal shunts was accompanied by clinical recovery and improvement of right parietal lobe cerebral blood flow. Conclusions. The authors conclude that brain deformation was a contributing factor in the reversible neglect syndrome by compromising the normal flow of blood and/or the deactivation of subcortical circuits of the parietal lobe.
Development of a Posterior Fossa Cavernous Malformation Associated With Bilateral Venous Anomalies: Case Report
Authors: Sheehan Jason , Lunsford L. Dade , Kondziolka Douglas , Flickinger John 
Published: November 2009

ABSTRACTVenous angiomas (VAs) and cavernous malformations (CMs) are common cerebrovascular malformations. Frequently, these lesions are found in close proximity. The interrelationship between VAs and CMs has not yet been adequately defined. The authors report a case of a 48‐year‐old man with progressive dysarthria, dysmetria, and ataxia. Eight years previously, magnetic resonance imaging (MRI) revealed a solitary CM and bilateral posterior fossa VAs. Later imaging after neurological progression revealed the presence of 2 rather than 1 CMadjacent to the VAs. The sequential imaging suggests a causal relationship between VAs and some CMs. Furthermore, the detailed MRI permitted radiosurgical treatment of these CMs. The occurrence of de novo CMs adjacent to VAs on future imaging studies in other patients may help confirm the etiology of at least a subset of CMs.
Approach to Imaging the Patient With Neck Pain
Authors: Tong Carrie , Barest Glenn 
Published: November 2009

ABSTRACTNeck pain is a common complaint of patients seeking care in the outpatient setting, and the cases seen vary widely in severity and cause. A careful history and physical exam, followed by appropriate imaging studies, are essential for the orderly workup and management of neck pain in the ambulatory patient. Available imaging studies include plain film radiography, computed tomography (CT), magnetic resonance, and CT myelography. The general considerations necessary to select the appropriate imaging study are discussed for a broad spectrum of common disorders.