bluuebunny/crossref_metadata_2025_split huggingface dataset:
Baseline Computed Tomography Changes and Clinical Outcome After Thrombolysis With Recombinant Tissue Plasminogen Activator in Acute Ischemic Stroke
Authors: Mendizabal Jorge E. , Lurie Douglas N. , Greiner Francis G. , Shah Arvind K. , Zweifler Richard M. 
Published: November 2009

ABSTRACT Objective. Intravenous recombinant tissue plasminogen activator (rt‐PA) is the only therapy of proven value for patients with acute ischemic stroke (AIS). Controversy exists with regard to the prognostic significance of early computed tomography (CT) changes in patients receiving rt‐PA for AIS. The authors retrospectively reviewed all cases of AIS who received intravenous rt‐PA for AIS in University of South Alabama hospitals between January 1996 and May 1999. A neuroradiologist, blinded to clinical outcomes, reviewed all baseline CT scans for the presence of the following signs: hyperdense middle cerebral artery (HMCA), loss of gray‐white differentiation (LGWD), insular ribbon sign (IRS), parenchymal hypodensity (PH), and sulcal effacement (SE). Modified Rankin Scale (mRS) score was recorded 90 days after thrombolysis, and clinical outcome was dichotomized as favorable (0–1) or unfavorable (2–6). The authors performed both univariate and multivariate analyses to investigate the relationship between early CT signs, baseline clinical variables, and functional outcome as measured by the 90‐day mRS scores. Any one early CT finding was detected in 23 (64%) patients. The frequency of specific findings were as follows: SE in 13 patients (36%), LGWD in 12 patients (33%), PH in 9 patients (25%), HMCA in 4 patients (11%), and IRS in 3 patients (8%) patients. There was no statistically significant association between the occurrence of these imaging findings and subsequent functional outcome after thrombolysis. The data suggest that the presence of subtle acute CT changes in AIS patients is not predictive of clinical outcome following administration of rt‐PA as per National Institute of Neurological Disorders and Stroke protocol.
Who Should Be Screened for Asymptomatic Carotid Artery Stenosis? Experience From the Western New York Stroke Screening Program
Authors: Qureshi Adnan I. , Janardhan Vallabh , Bennett Susan E. , Luft Andreas R. , Hopkins L. Nelson , Guterman Lee R. 
Published: November 2009

ABSTRACT Objective. Identification of significant asymptomatic carotid artery stenosis (ACAS) is important because of the stroke‐risk reduction observed with carotid endarterectomy. The authors developed and validated a simple scoring system based on routinely available information to identify persons at high risk for ACAS using data collected during a community health screening program at various sites in western New York. A total of 1331 unselected volunteers without previous stroke, transient ischemic attack, or carotid artery surgery were evaluated by personal interview and duplex ultrasound. The main outcome measure was carotid artery stenosis >60% by duplex ultrasound. In the derivation set (n= 887), 4 variables were significantly associated with ACAS >60%: age >65 years (odds ratio [OR] = 4.1, 95% confidence interval [CI] = 2.6–6.7), current smoking (OR = 2.0, 95% CI = 1.2–3.5), coronary artery disease (OR = 2.4, 95% CI = 1.5–3.9), and hypercholesterolemia (OR = 1.9, 95% CI = 1.2–2.9). Three risk groups (low, intermediate, and high) were defined on the basis of total risk score assigned on the basis of the strength of association. The scheme effectively stratified the validation set (n= 444); the likelihood ratio and posttest probability for ACAS in the high‐risk group were 3.0 and 35%, respectively, and in the intermediate and low‐risk groups were 1.4 and 20% and 0.4 and 7%, respectively. Routinely available information can be used to identify persons in the community at high risk for ACAS. Doppler ultrasound screening in this subgroup may prove to be cost‐effective and have an effect on stroke‐free survival.
Technetium‐99m ECD Single Photon Emission Computed Tomography in Brain Trauma: Comparison of Early Scintigraphic Findings With Long‐Term Neuropsychological Outcome
Authors: Baulieu Françoise , Fournier Patrice , Baulieu Jean‐Louis , Dalonneau Marinette , Chiaroni Patrick , Eder Véronique , Pottier Jean Marie , Legros Bernard 
Published: November 2009

ABSTRACT Objective. The aim of this study was to assess the prognostic value of early brain scintigraphy in head injury in relation to long‐term neuropsychological behavior. Twenty‐four patients underwent technetium‐99m (Tc‐99m) ECD single photon emission computed tomography (SPECT) within 1 month of the trauma. Scintigraphic abnormalities were evaluated both visually and semiquantitatively using the brain‐to‐cerebellum ratio method. The clinical neuropsychological investigation was conducted to evaluate abnormalities related to motor deficit, frontal behavior, and memory and language disorders. All patients had abnormalities on SPECT scan. One year after trauma, 14 patients (58%) had neuropsychological sequelae. The brain‐to‐cerebellum ratios in the left basal ganglia and brain stem were significantly decreased in patients with memory disorders (P= .03 and P= .02, respectively). Moreover, SPECT visual analysis indicated that low uptake in the basal ganglia, thalamus, and brain stem was associated with subsequent motor deficit, frontal behavior, and language and memory disorders. The authors conclude that brain SPECT can be valuable in predicting the neuropsychological behavior of survivors of severe head injury.
Comparison Between Magnetic Resonance Phase Contrast Imaging and Transcranial Doppler Ultrasound With Regard to Blood Flow Velocity in Intracranial Arteries: Work in Progress
Authors: Seitz Johannes , Strotzer Michael , Schlaier Jürgen , Nitz Wolfgang R. , Völk Markus , Feuerbach Stefan 
Published: November 2009

ABSTRACT Objective. The authors evaluate blood flow velocities in the medial cerebral artery (MCA) and the basilar artery using magnetic resonance (MR) phase contrast technique in comparison with transcranial Doppler ultrasound (TCD). Eleven healthy male volunteers were studied. TCD of the MCA (n= 22) and basilar artery (n= 11) was performed. MR phase velocity mapping was done in each vessel at the same location where the TCD signal had been acquired. A 2‐dimensional FLASH sequence with retrospective cardiac gating and an average temporal resolution of 45 ms was used. Resistance indices (RIs) and pulsatility indices (PIs) were calculated for both modalities. The TCD insonation angle was measured retrospectively with MR, and TCD velocities were corrected based on these measurements. The comparison of flow velocities obtained with TCD and MR led to a low correlation coefficient with regard to the basilar artery and the MCA: maximum systolic velocity, r= 0.02 and r= 0.50, respectively; enddiastolic velocity, r= 0.47 and r= 0.65, respectively; mean velocity, r= 0.52 and r= 0.66, respectively. The average PIs in the basilar artery and the MCA were 0.80 and 0.81 with MR and 0.65 and 0.85 with TCD, respectively. The average RIs in the basilar artery and the MCA were 0.52 and 0.54 with MR and 0.52 and 0.55 with TCD, respectively. The TCD insonation angle differed significantly from the ideal value in the basliar artery (mean value = 32.6°) and the MCA (mean value = 26.5°). The authors find a low correlation between velocities measured with MRI and TCD but similar results with regard to the PIs and RIs. Several sources of error, such as a nonideal TCD insonation angle, were identified.
Visualization of the IXth to XIIth Cranial Nerves Using 3‐Dimensional Constructive Interference in Steady State, 3‐Dimensional Magnetization‐Prepared Rapid Gradient Echo and T2‐Weighted 2‐Dimensional Turbo Spin Echo Magnetic Resonance Imaging Sequences
Authors: Seitz Johannes , Held Paul , Fründ Rüdiger , Strotzer Michael , Nitz Wolfgang R. , Völk Markus , Haffke Thomas , Feuerbach Stefan 
Published: November 2009

ABSTRACT Objective. The purpose of this study was to evaluate the visibility of the IXth to XIIth cranial nerves using different magnetic resonance sequences. Thirty healthy volunteers underwent magnetic resonance imaging at 1.5 T using 3‐dimensional constructive interference in steady state (CISS) sequence (TR = 17 ms, TE = 8.08 ms, α= 70°), 3‐dimensional magnetization‐prepared rapid gradient echo (MP‐RAGE) sequence (TR = 11.08 ms, TE = 4.3 ms, α= 15°), and T2‐weighted (w) 2‐dimensional turbo spin echo (TSE) sequence (TR = 4000 ms, TE = 102 ms, α= 180°, slice thickness = 2 mm). Visibility of the IXth to XIIth cranial nerves in each sequence was evaluated by consensus of 2 radiologists using an evaluation scale from 1 (excellently visible) to 5 (not visible). A correlation with anatomic specimens was made. The 3‐dimensional CISS sequence provides best resolution of the IXth to XIIth cranial nerves and their relation to surrounding structures. Additional information is given by the 3‐dimensional MP‐RAGE when nerves are surrounded by soft tissues. Using the T2w 2‐dimensional TSE sequence, even whole nerves cannot be visualized due to intersection gap and partial volume effects. However, even in 3‐dimensional high‐resolution sequences, segments of nerves are not always visualized. A combination of 3‐dimensional CISS and 3‐dimensional MP‐RAGE proved to be useful to visualize the IXth to XIIth cranial nerves, whereas the 2‐dimensional technique failed. Further investigations using 3‐dimensional MP‐RAGE with contrast medium should be performed in the case of abnormality.
Differences in Functional Magnetic Resonance Imaging Activation by Category in a Visual Confrontation Naming Task
Authors: Smith C. D. , Andersen A. H. , Kryscio R. J. , Schmitt F. A. , Kindy M. S. , Blonder L. X. , Avison M. J. 
Published: November 2009

ABSTRACT Objective. Cortical processing involved in seemingly similar tasks may differ in important ways. The authors mapped cortical regions engaged in a commonly performed picture naming task, seeking differences by semantic category. Functional magnetic resonance imaging was used during presentation of standardized line drawings in 18 healthy right‐handed female participants, comparing living versus nonliving entities. During visual naming, across categories there was strong activation of left frontal (BA45/47), bilateral temporo‐occipital junction (BA19), and inferior temporal regions (BA36/37). Activation of right inferior temporal cortex (BA19 & 37) was greater during naming of living versus nonliving category items. No category differences in activation strength in the left temporal lobe were observed. The authors conclude that visual semantic operations may involve visual association cortex in the right temporal lobe in women.
Cerebral Hemodynamics Changes During Retrograde Brain Perfusion in Dogs
Authors: Razumovsky Alexander Y. , Tseng Elaine E. , Hanley Daniel F. , Baumgartner William A. 
Published: November 2009

ABSTRACTThe objective of this study was to examine cerebral hemodynamics changes during hypothermic circulatory arrest (HCA) with and without retrograde cerebral perfusion (RCP). Thirteen colony‐bred hound dogs were placed on cardiopulmonary bypass (CPB) and cooled to 18°C. Five dogs underwent 2 hours of HCA without RCP and 8 with RCP. The animals were then rewarmed on CPB until normothermic and weaned. Cerebral blood flow velocity (CBFV) and Gosling Pulsatility Index (PI) in the middle cerebral artery (MCA) were studied using transcranial Doppler (TCD) ultrasound. At baseline and during pre‐ and postarrest CPB, there was anterograde direction of blood flow in the MCA. During HCA with RCP, there was retrograde direction of blood flow in the MCA. There was no difference in CBFV between pre‐, during, and postarrest CPB in the group with RCP; however, there was significantly increased CBFV during postarrest CPB in the group without RCP compared to the dogs with RCP. Later, at 3 hours after postarrest CPB, there was decreased CBFV in all animals accompanied by increased PI (2.4 ± 0.4 and 2.2 ± 0.6 for animals with RCP and without RCP, respectively) and abnormal TCD waveform changes including decreased diastolic compartment and sharp systolic peak. During hypothermic circulatory arrest, RCP provides CBFV in the MCA comparable to MCA CBFV during CPB. HCA dogs without RCP showed immediate hyperemia on reperfusion. The decreased CBFV and increased PI at 1 hour after postarrest CPB could be an indicator of progressive ischemic injury due to the increased intracranial pressure despite the implementation of RCP.
Effect of Hyperventilation on Cerebral Blood Flow Velocity in Preeclamptic Pregnancies: Is There Evidence for an Altered Cerebral Vasoreactivity?
Authors: Zatik J. , Aranyosi J. , Molnár C. , Páll D. , Borsos A. , Fülesdi B. 
Published: November 2009

ABSTRACTThe purpose of this study was to investigate cerebral arteriolar vasoreactivity function in preeclampsia. Preeclamptic (n= 26) and healthy pregnant (n= 22) women underwent transcranial Doppler sonography of the middle cerebral artery at rest and after 60 seconds of hyperventilation (HV). Systolic, diastolic, and mean blood flow velocities were recorded. The percentage change of the blood flow velocities after HV was calculated. Mean blood flow velocity of the middle cerebral artery was higher in preeclamptic women as compared with healthy pregnant women. No difference could be detected in percentage change of middle cerebral artery blood flow velocities after HV between the two groups. There is no evidence of a small‐vessel vasoconstriction among preeclamptic patients. The role of vasoconstriction of the large cerebral arteries and vasodilation of the resistance arterioles, as well as a combination of these 2 pathomechanisms, in determining cerebral blood flow in preeclampsia and eclampsia should be investigated in further studies.
Isolated Petrous Carotid Stenosis and Transient Ischemic Attack
Authors: Levine Ross L. , Hafeez Faizan , Khasru Muhammed A. , Dulli Douglas A. 
Published: November 2009

ABSTRACTAlthough anterior circulation transient ischemic attacks (TIAs) tend to be more common in patients with extracranial carotid arterial disease than in those with intracranial carotid or middle cerebral arterial disease, the authors recently encountered 4 patients with both recurrent, stereotypical TIAs as well as isolated stenosis of their petrous internal carotid artery (ICA). While the gold standard for establishing the diagnosis of intracranial large‐artery disease has always been conventional angiography, magnetic resonance angiography changes, confirmed with intra‐arterial digital subtraction angiography in 2 of these patients, were quite sufficient to define the occlusive disease in each of the cases. Petrous ICA stenosis is not uncommon, but it has often been overshadowed by the search for extracranial ICA disease that might be amenable to surgical reconstruction.
Transcranial Color‐Coded Sonography of a Vein of Galen Arteriovenous Malformation in an Adult
Authors: Strowitzki Martin , Fox Thomas , Hamann Gerhard 
Published: November 2009

ABSTRACTThe case of an adult harboring a vein of Galen arteriovenous malformation (VGAM) is reported. Diagnosis was established by computed tomography (CT) and digital subtraction angiography and confirmed afterwards by transcranial color‐coded sonography (TCCS). The patient's course after endovascular treatment was then consecutively monitored by TCCS until complete occlusion was achieved. The results of TCCS were validated by angiography, with which they showed good correlation. Thus, it can be concluded that TCCS may be a useful adjunct to CT and angiography to noninvasively monitor adults with VGAM.
HIV‐2 Infection With Cerebral Toxoplasmosis and Lymphomatoid Granulomatosis
Authors: Issakhanian M. , Chang L. , Cornford M. , Witt M. , Speck O. , Goldberg M. , Ernst T. 
Published: November 2009

ABSTRACTA Nigerian man had acute onset of headache and vertigo due to a cerebellar mass. A brain biopsy of the mass revealed toxoplasmosis despite repeated negative HIV‐1 serology. The presence of an opportunistic infection and his country of origin raised the suspicion for HIV‐2; this was confirmed by positive HIV‐2 serology. Despite his preliminary pathological diagnosis, results of physiological magnetic resonance imaging (MRI) (perfusion MRI and proton magnetic resonance spectroscopy) were not typical for toxoplasmosis. The lesion showed a biochemical and perfusion pattern that was intermediate for infectious and neoplastic processes. Further neuropathology confirmed a secondary diagnosis of lymphomatoid granulomatosis.
Transcranial Doppler Pulsatility Indices as a Measure of Diffuse Small‐Vessel Disease
Authors: Kidwell Chelsea S. , El‐Saden Suzie , Livshits Zhanna , Martin Neil A. , Glenn Thomas C. , Saver Jeffrey L. 
Published: November 2009

ABSTRACT Background and Purpose. Elevation in pulsatility indices (PIs) as measured by transcranial Doppler (TCD) have been postulated to reflect downstream increased vascular resistance caused by small‐vessel ischemic disease. Methods. The authors retrospectively compared TCD PIs and magnetic resonance imaging (MRI) manifestations of small‐vessel disease in 55 consecutive patients who underwent TCD studies and brain MRI within 6 months of each other during a 2‐year period. Results. Correlations between TCD middle cerebral artery PIs and MRI measures were as follows: periventricular hyperintensity (PVH) = 0.52 (P < .0001), deep white matter hyperintensity (DWMH) = 0.54 (P < .0001), lacunar disease = 0.31 (P= .02), and combined PVH/DWMH/lacunes = 0.54 (P < .0001). Correlation between pontine ischemia and vertebrobasilar PIs was 0.46 (P= .0004). Univariate analysis showed that age, elevated PI, and hypertension strongly correlated with white matter disease measures. After adjusting for these factors in a multivariate Poisson regression analysis, PI remained an independent predictor of white matter disease. Receiver operator curve analyses identified PI cut points that allowed discrimination of PVH with 89% sensitivity and 86% specificity and discrimination of DWMH with 70% sensitivity and 73% specificity. Conclusions. Elevation in PIs as measured by TCD shows strong correlation with MRI evidence of small‐vessel disease. TCD may be a useful physiologic index of the presence and severity of diffuse small‐vessel disease.
Single Photon Emission Computed Tomography, Magnetic Resonance Imaging Hyperintensity, and Cognitive Impairments in Patients With Vascular Dementia
Authors: Cohen Ronald A. , Paul Robert H. , Zawacki Tricia M. , Sethi Manish , Ott Brian R. , Moser David J. , Stone William , Noto Richard , Gordon Norman 
Published: November 2009

ABSTRACT Background. The relationship between subcortical hyperintensity (SH) on magnetic resonance imaging (MRI), cortical perfusion on single photon emission computed tomography (SPECT), and cognitive function is not well understood. The authors examined these relationships in individuals with vascular dementia (VaD), paying particular attention to frontal lobe function to determine whether the presence of SH on MRI was associated with frontal hypoperfusion on SPECT, which in turn would be associated with impairments of executive‐attention function. Methods. Patients with vascular dementia (n= 26) were assessed on neurocognitive tests and brain MRI and SPECT. SH volume was quantified from the axial T2‐weighted fluid attenuated inversion recovery MRI. Total counts of activation across voxels for 12 cortical regions of interest were determined from SPECT. Perfusion ratios of both total cortical and frontal activation relative to cerebellum activation were derived, and regression analyses were performed to determine the relationships between cognitive, MRI, and SPECT indices. Results. SH volume on MRI was significantly associated with frontal lobe perfusion, but not with global cortical perfusion as measured by SPECT. Frontal lobe perfusion did not consistently correlate with performance on measures of executive function, although both total and frontal perfusion ratios were significantly associated with other cognitive functions. Conclusions. These results suggest that a functional “disconnection” between the frontal lobes and subcortical structures does not fully account for the magnitude of global cognitive impairment in VaD. Cortical perfusion as measured by SPECT appears to be associated with cognitive performance, but not specifically executive‐attention dysfunction. Additional studies are needed to further examine the relationship between subcortical and cortical function in VaD.
A Computed Tomography Score for Assessment of Mass Effect in Space‐Occupying Cerebellar Infarction
Authors: Jauss M. , Müffelmann B. , Krieger D. , Zeumer H. , Busse O. 
Published: November 2009

ABSTRACT Background and Purpose. Patients with cerebellar infarction are threatened by infratentorial herniation and impaired circulation of cerebrospinal fluid if mass effect in posterior fossa develops. Clinical assessment is often impaired in patients with disturbances of consciousness. Therefore, computed tomography (CT) examination is essential in the diagnosis of complication and decision for operative treatment. Methods. Mass effect of cerebellar infarction was quantitatively assessed using a three‐item CT score: width of fourth ventricle, compression of quadrigeminal cistern, and width of lateral ventricle. Retest and interrater reliability was determined. Validity of assessment of mass effect was examined using 185 CT scans from a cerebellar infarction study, and the effect of operative treatment on CT score was determined. Results. The correlation coefficients for retest and interrater reliability were .94 and .75, respectively. The authors found a significant difference for the CT sum score and all CT items except “compression of the fourth ventricle” between patients with different levels of consciousness. Effect of operative treatment was documented by improvement of CT score. Conclusions. The proposed CT score is of high interrater and retest reliability, supplements the clinical assessment of the patient, and is able to monitor the efficacy of decompressive treatment.
1H Spectroscopy in Patients With Amyotrophic Lateral Sclerosis
Authors: Kenn Werner , Ochs Guenther , Pabst Thomas Alois , Hahn Dietbert 
Published: November 2009

ABSTRACT Background and Purpose. The authors investigate changes in brain metabolites among patients with amyotrophic lateral sclerosis (ALS). Twelve patients diagnosed with definite ALS (and 2 subgroups with either pronounced upper motoneuron signs or less obvious, probable upper motoneuron involvement) and 10 controls were examined.1H studies were performed on a 1.5‐T Siemens Magnetom Vision with single voxel (SV). A voxel (TR = 1500 ms, TE = 270 ms, 512 acquisitions, VOI = 8 cm3) was placed bilaterally in the precentral gyrus. In addition, chemical shift imaging (CSI) (VOI = 1 × 1 × 1.5 cm, TR = 1500 ms, TE = 135 ms) was performed. Ratios of peak integrals (N‐acetyl‐aspartate/choline, N‐acetyl‐aspartate/creatine, and creatine/choline) were determined. A Mann‐Whitney U Test and a Wilcoxon Matched Pairs Test were applied. Methods. The statistical analysis failed to demonstrate any significant differences between the ALS patients and the controls with respect to ratio measures. Using CSI, it was found that patients with clinically pronounced upper motoneuron signs had significantly lower (P= .037) N‐acetyl‐aspartate/choline ratios in the more affected hemisphere. Conclusions. The authors conclude that CSI is more effective at detecting lower N‐acetyl‐aspartate/choline levels among ALS patients than is SV.