bluuebunny/crossref_metadata_2025 huggingface dataset:
Carotid Doppler Ultrasound Criteria for Internal Carotid Artery Stenosis Based on Residual Lumen Diameter Calculated From En Bloc Carotid Endarterectomy Specimens
Authors: Suwanwela Nijasri , Can Ufuk , Furie Karen L. , Southern James F. , Macdonald Nancy R. , Ogilvy Christopher S. , Hansen Calvin J. , Buonanno Ferdinando S. , Abbott William M. , Koroshetz Walter J. , Kistler J. Philip
Published: June 2011

Background and Purpose
Carotid duplex ultrasound is widely used to screen patients for carotid endarterectomy and if combined with MR angiography and transcranial Doppler may be an alternative to conventional angiography in the preoperative assessment. We have examined the correlation between Doppler velocities and the residual lumen diameters of internal carotid arteries from surgical pathological specimens to establish Doppler criteria for residual lumen diameter independent of percent stenosis.

Methods
Ninety-one patients who underwent 99 carotid endarterectomies for internal carotid artery stenosis within 6 months of their carotid duplex ultrasound evaluation were studied. The endarterectomy specimens were removed en bloc, and the minimal residual lumen diameter was calculated by computer analysis. The sensitivity and specificity of the Doppler criteria for determining high-grade stenosis were calculated and receiver-operator curves generated.

Results
Peak systolic velocity (PSV), end-diastolic velocity (EDV), and carotid index (peak internal carotid artery velocity/common carotid artery velocity) correlated with the residual lumen diameter. PSV >440 cm/s, EDV >155 cm/s, or carotid index >10 indicated a residual lumen diameter of ≤1.5 mm (specificity of 100% and sensitivity of 58%, 63%, and 30%, respectively). When these criteria were combined, the sensitivity increased to 72%. A PSV >200 cm/s combined with either an EDV >140 cm/s or a carotid index >4.5 has a sensitivity of 96% and a specificity of 61%.

Conclusions
Doppler criteria can be both specific and sensitive for detecting a significant stenosis, defined as a ≤1.5 mm residual lumen diameter. By adjustment of the velocity criteria, it can be 100% specific or a highly sensitive test (96%).
Cerebral Infarction in Patients Aged 15 to 40 Years
Authors: Neto José Ibiapina Siqueira , Santos Antonio Carlos , Fabio Soraia Ramos Cabete , Sakamoto Americo C.
Published: June 2011

Background and Purpose
Cerebral infarction among young adults has been little studied in Brazil. Most studies adopt a variable upper age limit and often use the term “young” to designate different age ranges. The objective of the present study was to determine possible differences in etiology of cerebral infarction in specific age subpopulations.

Methods
We studied 106 patients aged 15 to 40 years and divided them into two subpopulations by age at time of ictus (ie, 15 to 29 years and 30 to 40 years). On the basis of Trial of ORG 10172 in Acute Stroke Treatment (TOAST) criteria, we classified the patients into the following five groups: (1) large-artery atherosclerosis, (2) small-vessel occlusion or lacunae, (3) cardioembolism, (4) other determined causes, and (5) undetermined causes. The proportions for each group were compared between the two age ranges to determine whether there was a significant difference in group distribution.

Results
The proportions were different between the two age ranges, with a predominance of women and TOAST-criterion group 4 in the 15- to 29-year age range. In the 30- to 40-year age range, there was a predominance of men and of TOAST-criterion group 3.

Conclusions
The proportions of the groups in the two age ranges were significantly different for lacunar infarctions and infarctions of other etiologies. This observation suggests that different age ranges present characteristically different distributions and therefore should be considered separately when investigated. The older age range already presents features that suggest a transition to the spectrum observed among the aged.
An Analysis of Perioperative Surgical Mortality and Morbidity in the Asymptomatic Carotid Atherosclerosis Study
Authors: Young Byron , Moore Wesley S. , Robertson James T. , Toole James F. , Ernst Calvin B. , Cohen Stanley N. , Broderick Joseph P. , Dempsey Robert J. , Hosking James D.
Published: June 2011

Background and Purpose
Our aim was to determine the perioperative morbidity and mortality rates of patients in the surgical arm of the multi-institutional, prospective, randomized Asymptomatic Carotid Atherosclerosis Study (ACAS).

Methods
Of 828 patients with carotid stenosis of 60% or more randomized to the surgical arm of ACAS, 721 underwent carotid endarterectomy (CEA). To qualify for participation, surgeons were required to have performed at least 12 CEAs per year with a combined neurological morbidity and mortality rate no greater than 3% for asymptomatic patients and 5% for symptomatic patients. Clinical centers had to demonstrate arteriographic morbidity less than 1% and mortality less than 0.1% per year. Primary events were stroke and death in the period between randomization and 30 days after surgery; secondary events were transient ischemic attack and myocardial infarction occurring in the same period.

Results
Of the 721 patients who underwent CEA, 1 died and 10 others had strokes within 30 days (1.5%). Of the 415 who underwent arteriography after randomization but before CEA, 5 (1.2%) suffered transient ischemic attack or stroke caused by arteriography. Thus, a nearly equal risk of stroke was associated with both CEA and carotid arteriography. In addition, 6 transient ischemic attacks and 3 myocardial infarctions could be directly linked to CEA, for a total CEA event rate of 2.6%.

Conclusions
Patients with asymptomatic internal carotid artery stenosis exceeding 60% reduction in diameter who are acceptable candidates for elective operation may be considered for CEA if the combined arteriographic and surgical complication rates are 3% or less.
Cerebrovascular Disease, the Apolipoprotein e4 Allele, and Cognitive Decline in a Community-Based Study of Elderly Men
Authors: Kalmijn S. , Feskens E.J.M. , Launer L.J. , Kromhout D.
Published: June 2011

Background and Purpose
Cerebrovascular disease and the apolipoprotein e4 (
APOE
*
4
) allele are both important risk factors for cognitive decline. We investigated the combined effect of
APOE
*
4
and cerebrovascular disease on cognitive decline.

Methods
Data are from a cohort of 353 men, aged 69 to 89 years at baseline, living in Zutphen, Netherlands. The 30-point Mini-Mental State Examination (MMSE) was used to measure cognitive decline (drop of >2 points) from 1990 to 1993 (14% of the sample). Odds ratios (OR [95% confidence interval]) for cognitive decline were adjusted for age, education, and baseline MMSE score.

Results
Compared with those without
APOE
*
4
and without a history of cerebrovascular disease, the adjusted OR was 4.7 (1.7 to 12.7) for subjects without
APOE
*
4
but with cerebrovascular disease, 3.3 (1.6 to 6.8) for those with
APOE
*
4
and no cerebrovascular disease, and 17.2 (2.7 to 110.0) for those with both risk factors. The risk for cerebrovascular disease and
APOE
*
4
combined was more than expected from the separate effects. The combined risk of coronary heart disease and
APOE
*
4
was 6.1 (1.7 to 22.3). The analysis of cardiovascular risk factors showed that the risk of cognitive decline was highest in subjects with both
APOE
*
4
and a high cholesterol level, high fibrinogen level, normal blood pressure, or diabetes mellitus.

Conclusions
Cerebrovascular disease and
APOE
*
4
may have a synergistic effect on cognitive decline.
A Reappraisal of Reliability and Validity Studies in Stroke
Authors: D'Olhaberriague Luis , Litvan Irene , Mitsias Panayiotis , Mansbach Harry H.
Published: June 2011

Background
The emergence of prophylactic and therapeutic interventions in stroke has been accompanied by the widespread use of stroke classifications and scales that measure deficit (stroke scales) or resulting long-term handicap (handicap and disability scales). Although the accuracy of some scales and classifications has been studied, there is no updated systematic review appraising all of them.

Review
We reviewed the literature and selected 21 studies on classifications and scales. The International Classification of Diseases, 10th revision, achieved the highest interobserver agreement among seven stroke classifications. The National Institutes of Health Stroke Scale, the Canadian Neurological Scale, and the European Stroke Scale had the highest reliability across items among nine stroke scales. The Barthel Index was the most reliable disability scale.

Conclusions
The identification of the most reliable stroke classifications and scales should encourage their use in selection of homogeneous populations of patients for clinical research studies and to improve communication among scientists. Further research is needed to investigate neglected aspects of the neurological examination and the validity of stroke classifications.
Long-term Prognosis in Cerebral Venous Thrombosis
Authors: Preter Maurice , Tzourio Christophe , Ameri Alain , Bousser Marie-Germaine
Published: June 2011

Background and Purpose
Very little is known about the long-term outcome of patients with cerebral venous thrombosis (CVT), particularly regarding the risk of residual epilepsy and further thrombotic events. We retrospectively studied 77 patients with CVT diagnosed by angiography and/or MRI.

Methods
A cohort of 77 patients aged 18 to 77 (mean, 38.5) years with CVT, evaluated from 1975 through 1990, was followed up for a mean of 77.8 months (range, 14 to 204 months; median, 63 months). Information on death, neurological status, seizures, recurrent CVT, other thrombotic events, and subsequent pregnancies was obtained from direct observation, mail questionnaire, or telephone interviews.

Results
Sixty-six of 77 patients (85.7%) had no neurological sequelae during follow-up. Eleven patients (14.3%) remained neurologically impaired. Two who initially presented with isolated intracranial hypertension had blindness due to optic atrophy. The other 9 had focal signs at the time of CVT and were left with various cognitive or focal deficits. Four of 28 (14.3%) patients who had seizures at the acute stage had recurrent seizures. One of the 51 patients with lateral sinus thrombosis developed a dural arteriovenous fistula. Nine of the 77 patients (11.7%) suffered a second CVT, all but one in the first year. Noncerebral thrombotic events occurred in 11 patients (14.3%). No recurrence of CVT occurred during later pregnancies, but 1 patient had a postpartum deep vein thrombosis.

Conclusions
In the present series, CVT has an essentially good long-term prognosis. The frequency of long-standing epilepsy was low, suggesting that long-term anticonvulsant treatment is not necessary in the majority of cases. A second CVT or another thrombotic episode occurred in 20% of patients, stressing the need in a minority of cases for long-term anticoagulation.
A Systematic Review of the Risks of Stroke and Death Due to Endarterectomy for Symptomatic Carotid Stenosis
Authors: Rothwell P.M. , Slattery J. , Warlow C.P.
Published: June 2011

Background and Purpose
Carotid endarterectomy reduces the risk of carotid territory ischemic stroke ipsilateral to a recently symptomatic severe carotid stenosis. However, the benefit is limited by the risks of stroke and death associated with the operation. Although reported surgical risks vary enormously, there has been no systematic review of the published literature.

Methods
We performed a systematic review of mortality and the risk of stroke and/or death due to endarterectomy for symptomatic carotid stenosis in studies published since 1980.

Results
Fifty-one studies fulfilled our criteria. Overall mortality was 1.62% (95% confidence interval [CI], 1.3 to 1.9), and the risk of stroke and/or death was 5.64% (95% CI, 4.4 to 6.9). However, there was significant heterogeneity of risk of stroke and/or death (
P
<.001). The risk varied systematically with the methods and the authorship of the study. The risk of stroke and/or death was highest in studies in which patients were assessed by a neurologist after surgery (7.7%; 95% CI, 5.0 to 10.2) and lowest in studies with a single author affiliated with a department of surgery (2.3%; 95% CI, 1.8 to 2.7). After correcting for study methodology, there was no temporal trend in the risk of stroke and/or death between 1980 and 1995.

Conclusions
The reported risks of endarterectomy for symptomatic carotid stenosis show significantly greater variability than would be expected by chance. However, much of this variability can be accounted for by differences in methodology and authorship. The 5.6% overall risk of stroke and/or death is consistent with present guidelines.
A Systematic Comparison of the Risks of Stroke and Death Due to Carotid Endarterectomy for Symptomatic and Asymptomatic Stenosis
Authors: Rothwell P.M. , Slattery J. , Warlow C.P.
Published: June 2011

Background and Purpose
There is some evidence that carotid endarterectomy reduces the risk of ipsilateral carotid territory ischemic stroke in patients with severe asymptomatic carotid stenosis. However, the benefit of endarterectomy is dependent on a low risk of stroke and/or death due to surgery. Whether the low operative risks reported in recent clinical trials and cited in recent guidelines are widely generalizable to clinical practice is unclear. Is endarterectomy for asymptomatic carotid stenosis really safer than surgery for recently symptomatic stenosis?

Methods
We performed a systematic review comparing the risks of stroke and death due to carotid endarterectomy, performed by the same surgeons or in the same institutions, for symptomatic and asymptomatic stenosis in studies published since 1980.

Results
Twenty-five studies fulfilled our criteria. Mortality within 30 days of endarterectomy was 1.31% for asymptomatic stenosis and 1.81% for symptomatic stenosis (odds ratio [OR], 0.69; 95% confidence interval [CI], 0.49 to 0.99). The risks of fatal stroke were 0.47% and 0.91%, respectively (OR, 0.57; 95% CI, 0.34 to 0.98). The overall risk of stroke and/or death was 3.35% for asymptomatic and 5.18% for symptomatic stenosis (OR, 0.61; 95% CI, 0.51 to 0.74).

Conclusions
Mortality and the risk of stroke and/or death due to carotid endarterectomy are significantly lower for asymptomatic than symptomatic stenosis. These findings are consistent across virtually all studies and are likely to be widely generalizable.
Mitochondrial Generation of Reactive Oxygen Species After Brain Ischemia in the Rat
Authors: Piantadosi Claude A. , Zhang Jing
Published: June 2011

Background and Purpose
Brain mitochondria have a substantial capacity to generate reactive oxygen species after ischemia when the components of the respiratory chain are reduced and molecular oxygen is present. We tested the hypothesis that brain mitochondria in vivo produce reactive oxygen species after ischemia/reperfusion (IR) in rats at a rate sufficient to escape endogenous antioxidant defenses.

Methods
Ischemia-dependent production of hydroxyl radical in the hippocampus of the anesthetized rat was monitored with the use of intracerebral microdialysis. Transient global ischemia was produced by bilateral carotid artery occlusion and hemorrhagic hypotension to a mean arterial pressure of 35 mm Hg for 15 minutes followed by reperfusion for 60 minutes. Salicylic acid was infused into the hippocampus during the experiments, and changes in the recovery of its hydroxylated product, 2,3-dihydroxybenzoic acid (2,3-DHBA), were used to assess the effects of inhibitors of mitochondrial complex I on formation of hydroxyl radical during IR. Hydroxylation data from control groups of animals were compared with data from animals undergoing IR during treatment with either a mitochondrial complex I inhibitor alone or the inhibitor plus succinic acid.

Results
Transient ischemia led to a fivefold increase in the recovery of 2,3-DHBA by microdialysis after 1 hour relative to control animals (
P
<.05). Inhibition of mitochondrial complex I prevented 2,3-DHBA formation after IR; this effect could be reversed by infusion of succinic acid by microdialysis during IR.

Conclusions
The data indicate that reactive oxygen species generated by mitochondrial electron transport escape cellular antioxidant defenses and promote highly damaging hydroxyl radical activity after transient brain ischemia in the rat.
Visually Evoked Cerebral Blood Flow Velocity Changes in Different States of Brain Dysfunction
Authors: Becker Veit U. , Hansen Hans C. , Brewitt Uta , Thie Andreas
Published: June 2011

Background and Purpose
By assessment of metabolically induced cerebral blood flow velocity changes, transcranial Doppler sonography offers the opportunity to evaluate vasoneuronal coupling in different states of brain activation and in critically ill patients.

Methods
With simultaneous transcranial Doppler monitoring of the posterior cerebral artery (PCA) and the middle cerebral artery (MCA), 27 control subjects, 11 patients under general anesthesia, 5 patients in the vegetative state, and 12 patients with aneurysmal subarachnoid hemorrhage were stimulated with a 10-Hz flashlight for 30 seconds. Ten cycles of stimulation were averaged, and a specific flow response (SFR) was computed as the normalized ratio of PCA/MCA mean flow velocity.

Results
Maximal SFR was 14.2% in control subjects. Eye closure significantly reduced maximal SFR (11.6% versus 15.4%,
P
<.01). In subarachnoid hemorrhage, SFR was markedly decreased in the early phase (4.8%,
P
<.01) but became normal later on. Four of 5 patients with abolished SFR suffered delayed ischemia due to vasospasm. Of 7 patients with preserved SFR, 5 had vasospasm but none had delayed ischemia. No SFR was observed in patients under general anesthesia or in the vegetative state.

Conclusions
Although reflecting fast and local neuronal activity patterns, metabolically induced blood flow response is highly dependent on stimulus-directed attention. In subarachnoid hemorrhage, decreased metabolic flow response suggests severe depression of vasoneuronal coupling, and abolished SFR might indicate increased vulnerability to vasospasm and a higher risk for delayed ischemia.
Helical CT for the Diagnosis of Extracranial Internal Carotid Artery Dissection
Authors: Leclerc X. , Godefroy O. , Salhi A. , Lucas C. , Leys D. , Pruvo J.P.
Published: June 2011

Background and Purpose
We attempted to evaluate the sensitivity of helical CT for the diagnosis of extracranial internal carotid artery (ICA) dissection.

Methods
Sixteen consecutive patients with 18 angiographically confirmed extracranial ICA dissections were studied with a helical CT protocol with large-volume acquisition and thin axial slice reconstructions. A control group including normal and atherosclerotic ICAs was formed for comparison, and a blind interpretation of CT images was made by two observers. We evaluated the presence of stenosis, eccentric lumen, mural thickening, aneurysm, occlusion, and annular contrast enhancement. When the artery seemed to be occluded, we measured the external diameter of the ICA (1) on the occluded side, at its upper portion and most enlarged level, (2) at its lower portion, beyond the bulb, and (3) on the contralateral side, at its upper portion.

Results
Interobserver agreement was good except for the presence of annular contrast enhancement. In the stenotic dissection group (n=12), the presence of a narrowed eccentric lumen at the upper portion of the ICA on axial CT images was classified correctly in all cases (sensitivity, 100%; specificity, 100%). An arterial wall thickening was seen in all cases of dissection but also in three cases of the control group. In the occlusive dissection group (n=6), the enlargement of the dissected artery was the best criterion (sensitivity, 100%, specificity, 100%) for occlusive dissection.

Conclusions
Helical CT seems to be a reliable method for evaluating extracranial ICA dissection. The analysis of the residual arterial lumen and the measurement of the external diameter of the carotid artery were the best criteria for the diagnosis. Further studies with larger groups are required to determine whether ICA dissections might be diagnosed using helical CT as a first procedure.
Hemodynamic Parameter Assessment With Dynamic Susceptibility Contrast Magnetic Resonance Imaging in Unilateral Symptomatic Internal Carotid Artery Occlusion
Authors: Nighoghossian N. , Berthezene Y. , Philippon B. , Adeleine P. , Froment J.C. , Trouillas P.
Published: June 2011

Background and Purpose
Hemodynamic parameters such as regional cerebral blood volume (rCBV), mean transit time (MTT), and regional cerebral blood flow (rCBF) can be assessed by dynamic susceptibility contrast MRI. The aim of the present study was to apply this method in patients who had symptomatic unilateral internal carotid artery occlusion.

Methods
Relative hemodynamic parameters (rCBV, MTT, and rCBF) were evaluated on the occluded side and thus compared with contralateral hemispheric values. We also attempted to detect any relationship between collateral flow and the hemodynamic parameters.

Results
Although rCBV was clearly increased in five patients over the whole hemisphere, we did not observe a statistically significant difference regarding the whole sample between sides (mean rCBV, 14.1±4.58 on the occluded side versus 11.8±2.99 on the contralateral side;
P
>.10). MTT was clearly increased on the occluded side (mean MTT, 4.29±0.83 on the lesion side versus 3.14±0.81 on the contralateral side;
P
<.010). A statistically significant decrease of rCBF on the occluded side was observed (mean rCBF, 3.27±0.73 versus 3.93±1.03 on the contralateral side;
P
<.01).

Conclusions
A significant hemodynamic compromise in patients who had unilateral symptomatic carotid occlusion was observed according to CBF and MTT values. This approach might be promising in the understanding of cerebral hemodynamics in patients with vascular disorders.
Reactive Glia Express Cytosolic Phospholipase A2 After Transient Global Forebrain Ischemia in the Rat
Authors: Clemens James A. , Stephenson Diane T. , Barry Smalstig E. , Roberts Edda F. , Johnstone Edward M. , Sharp John D. , Little Sheila P. , Kramer Ruth M.
Published: June 2011

Background and Purpose
Phospholipid breakdown has been reported to be an early event in the brain after global cerebral ischemia. Our earlier observations showing the localization of cytosolic phospholipase A
2
(cPLA
2
) to astrocytes in aged human brains and the intense glial activation observed after global forebrain ischemia prompted us to investigate the cellular localization of cPLA
2
in the rat brain subjected to global ischemia.

Methods
Immunohistochemistry was performed in sections through the dorsal hippocampus in rats subjected to 30 minutes of four-vessel occlusion. PLA
2
was localized with the use of a highly selective antiserum. Double immunofluorescent localization was performed to colocalize cPLA
2
with various glial cell types. cPLA
2
levels were also measured by enzymatic assay and Western blot analysis.

Results
A marked induction of cPLA
2
was observed in activated microglia and astrocytes in the CA1 hippocampal region at 72 hours after ischemia. Only a subset of astrocytes and microglia were immunoreactive for cPLA
2
. Twenty-four hours after ischemia, numerous cPLA
2
immunoreactive astrocytes were observed. Western blot analysis of hippocampal homogenates at 72 hours after ischemia showed induction of a 100-kD band that comigrated with purified human cPLA
2
, and a threefold induction in cPLA
2
activity was demonstrated by enzymatic assay.

Conclusions
These results indicate that both reactive astrocytes and microglia contain elevated levels of cPLA
2
. Induction of cPLA
2
was confined to areas of neurodegeneration and likely precedes its onset. The results suggest that reactive glia may play a role in the pathophysiology of delayed neuronal death after transient global forebrain ischemia.
AIDS and Cerebrovascular Disease
Authors: Pinto Amélia Nogueira
Published: June 2011

Background
Although neurological complications of human immunodeficiency virus (HIV) infection are common, the presence of cerebrovascular disease (CVD) has been seldom reported. The purpose of this report is to review available data on the association between stroke and acquired immunodeficiency syndrome (AIDS).

Summary of Review
A review of all literature published between mid-1976 and December 1994 was performed through a MEDLINE search with the following key words: AIDS, CVD, human T-cell lymphotropic virus type III, and HIV-1. Only reports of clinical stroke in patients with AIDS or HIV infection and autopsy series with stroke findings were selected. The type of study, population, number of stroke patients, subtype and etiology of stroke, and associated AIDS conditions were described. Six clinical series and 11 autopsy series were found, with a total of 1885 cases with AIDS, AIDS-related complex, and HIV carriers. Forty percent had a neurological complication, but only 1.3% had a stroke syndrome. Ischemic infarcts were more common than intracerebral hemorrhages. Cerebral infarcts were generally due to nonbacterial thrombotic endocarditis or concomitant opportunistic central nervous system infection, and intracerebral hemorrhages were usually associated with thrombocytopenia, primary central nervous system lymphoma, and metastatic Kaposi’s sarcoma. Autopsy findings of CVD were generally not related with clinical stroke before death. Data are not available to determine the role of risk factors for AIDS in CVD.

Conclusions
Because of limitations of the available data, it is still not clear whether there is an association between AIDS and stroke. Further studies are needed to better define the epidemiology of CVD in association with AIDS.
Nimodipine Neuroprotection in Cardiac Valve Replacement
Authors: Legault Claudine , Furberg Curt D. , Wagenknecht Lynne E. , Rogers Anne T. , Stump David A. , Coker Laura , Troost B. Todd , Hammon John W.
Published: June 2011

Background
We conducted a double-blind, randomized clinical trial in patients undergoing cardiac valve replacement to determine whether nimodipine, a dihydropyridine calcium antagonist, reduced the risk of new neurological, neuro-ophthalmologic, or neuropsychological deficits—common complications associated with cardiac surgery—1 week after surgery.

Methods and Results
Enrollment for a total of 400 patients started in May 1992 and was stopped in September 1994, with 150 patients randomized to the study. Nimodipine was given to the patients during the perioperative period. Patients underwent examinations before surgery and at approximately 1 week, 1 month, and 6 months after surgery. Major adverse events, including deaths and strokes, were monitored monthly. The trial was terminated early because of both an unexpected disparity in death rates between groups and a lack of evidence of a beneficial effect of nimodipine. New deficits were observed in 72% of the placebo group versus 77% of the nimodipine group (
P
=.55). In the 6-month follow-up period, 8 deaths (10.7%) occurred in the nimodipine group (n=75) compared with 1 death (1.3%) in the placebo group (n=74) (
P
=.02). Major bleeding occurred in 10 patients in the nimodipine group versus 3 in the placebo group (13.3% versus 4.1%;
P
=.04). Six (46.2%) of the 13 patients with major bleeding died compared with 3 deaths (2.2%) among the 136 patients without major bleeding.

Conclusions
Our findings add to the growing evidence that calcium antagonists have a prohemorrhagic effect in some patients and suggest that nimodipine use should be restricted perioperatively in patients scheduled for cardiac valve replacement.
Results of a Computerized Screening of Stroke Patients for Unjustified Hospital Stay
Authors: Goldman Robert S. , Hartz Arthur J. , Lanska Douglas J. , Guse Clare E.
Published: June 2011

Background and Purpose
Effective methods to monitor length of stay can help reduce unnecessary hospital stay without adversely affecting the quality of care. In this study a clinical algorithm for assessing unjustified hospital stay in stroke patients was computerized and tested.

Methods
An algorithm was developed by the authors to estimate the number of medically justified and unjustified hospital days for patients admitted with a primary diagnosis of ischemic stroke. Data for the algorithm were obtained from 177 stroke patients from an acute-care teaching hospital. The performance of the algorithm was evaluated on a subset of 46 patients by comparing the number of medically unjustified hospital days determined by the algorithm with the consensus determination of two neurologists.

Results
The algorithm classified 68% of the 177 patients as having some unjustified hospital days and 41% of all hospital days as unjustified. With the neurologists as the gold standard, the sensitivity of the algorithm was .89 and the specificity was .91. The correlation between the number of unjustified days determined by the algorithm and the neurologists was .76.

Conclusions
There is considerable unjustified length of stay for stroke patients. Physicians can develop simple clinical algorithms for detecting unjustified hospital stay in stroke patients that provide a reasonable approximation of complex clinical judgment.
A Novel Technique for Identification of Doppler Microembolic Signals Based on the Coincidence Method
Authors: Georgiadis D. , Goeke J. , Hill M. , König M. , Nabavi D.G. , Stögbauer F. , Zunker P. , Ringelstein E.B.
Published: June 2011

Background and Purpose
The applicability of a novel differentiation technique in embolus detection based on the coincidence principle and using a multigate probe was evaluated in this study.

Methods
According to the coincidence method, high-intensity transients should only be classified as microembolic signals if they appear sequentially in the two sample volumes monitored and within a defined time window calculated from the blood velocity and the spatial distance between the insonation depths. Part A: microbubbles were introduced in a continuous-flow bench model of the middle cerebral artery to evaluate the accuracy of the multigate probe in embolus detection. Part B: in the subjects and patients, the minimal and maximum time delays in the appearance of microembolic signals in the two middle cerebral artery sample volumes were calculated as 0.01 second and set at 0.1 second, respectively. The multigate probe was used to monitor (1) 5 normal volunteers in whom 1008 artifact signals were produced, (2) 2 patients undergoing aortic valve replacement surgery, and (3) 12 patients with potential cardiac or carotid embolic sources.

Results
In the bench model, 95.5% of microembolic signals produced by microbubbles appeared in the two sample volumes with a time delay between 0.02 and 0.05 second, while in the remaining 4.5% a shorter passage time of 0.01 second was measured. A total of 1968 high-intensity signals were recorded in subjects and patients. All but 20 of these (99%) appeared in both monitoring channels within the above time frame. To summarize, 996 (98.8%) of the 1004 artifact signals and 943 (98.1%) of the 961 microembolic signals were correctly classified.

Conclusions
Application of the coincidence theory to distinguish microembolic signals from artifacts provides a promising new technique with high sensitivity and specificity that could decisively improve the validity of embolus detection.
Role of Platelet-Endothelial Cell Adhesion Molecule (PECAM) in Platelet Adhesion/Aggregation Over Injured but Not Denuded Endothelium In Vivo and Ex Vivo
Authors: Rosenblum William I. , Nelson Guy H. , Wormley Brandon , Werner Pamela , Wang Jimin , Shih Charles C.-Y.
Published: June 2011

Background and Purpose
We previously demonstrated that a monoclonal antibody (MoAb) with anti-CD31, anti-platelet-endothelial cell adhesion molecule (PECAM)-like properties delayed platelet adhesion/aggregation at a site of minor endothelial injury. To our knowledge, this was the first in vivo demonstration of an effect of anti-CD31. There was no exposure of collagen or basal lamina at the injured site, and the modulation of adhesion/aggregation at such sites has not received much study. The present investigation attempted to replicate the first with the use of a different MoAb, definitely characterized as anti-PECAM. In addition, an ex vivo investigation was performed to see whether the in vivo action of anti-PECAM could have been caused by an effect of the MoAb on the platelets rather than on the endothelium.

Methods
A helium-neon laser, in the presence of intravascular Evans blue, was used to injure the endothelium of arterioles on the surface of the mouse brain. Intravital microscopy was used to determine the number of seconds required for the light to initiate the first recognizable platelet aggregate forming at the injured site. Mice injected with vehicle were compared with mice injected with 2 mg/kg anti-PECAM through the tail vein. The injection was 10 minutes before challenge with the laser. Additional studies were performed of aggregation produced in vitro by arachidonate and by ADP added to platelet-rich plasma (PRP) prepared from blood taken from MoAb-treated and vehicle-treated mice.

Results
Aggregation latency was significantly prolonged (
P
<.02) by anti-PECAM (121±59 versus 65±26 seconds in controls; n=10 each). Aggregation ex vivo was not affected.

Conclusions
PECAM is an important modulator of platelet adhesion/aggregation at sites of minor endothelial damage in brain arterioles. The data are consistent with the hypothesis that PECAM sites on the endothelium are involved and may be exposed by the injury to promote adhesion/aggregation. Since the endothelial cell layer is intact at these sites, mechanisms such as this offer important alternatives to the more commonly studied pathways of platelet activation, which require exposure of collagen and are not applicable in this model.
Patterns of Alcohol Intake and Risk of Stroke in Middle-aged British Men
Authors: Wannamethee S. Goya , Shaper A. Gerald
Published: June 2011

Background and Purpose
The relationship between the pattern of alcohol intake and the risk of stroke is unclear, in particular the increased risk observed in abstainers and the possible protective effect of light to moderate drinking. For that reason, we examined in a large prospective study the role of alcohol consumption in the risk of a first major cerebrovascular event (stroke).

Methods
We prospectively studied 7735 middle-aged men drawn from general practices in 24 British towns. With exclusion of those who had recall of physician diagnosis of ischemic heart disease or stroke, data were available for 7273 men all followed for 13.5 years, with 216 major stroke events (fatal and nonfatal).

Results
Compared with occasional drinkers, nondrinkers (lifelong abstainers plus ex-drinkers) had an increased risk of stroke even after adjustment for age, lifestyle factors, and preexisting cardiovascular disease (relative risk [RR]=1.6; 95% CI, 1.0 to 2.7). All regular weekend drinkers (1 to 2, 3 to 6, and >6 drinks/d) and daily 1 to 2 and 3 to 6 drinkers showed no significant difference in adjusted risk of stroke compared with occasional drinkers. Heavy drinkers (daily >6 drinks) showed significantly increased risk evident within the first 8 years of follow-up only (RR=1.9; 95% CI, 1.0 to 3.5); however, this finding was attenuated after additional adjustment for systolic blood pressure (RR=1.5; 95% CI, 0.8 to 2.7). Information obtained 5 years after screening was used to separate lifelong abstainers and ex-drinkers. On subsequent 8.5 years of follow-up, both groups showed similar increased risk (RR=1.5) compared with occasional drinkers, but the risk in ex-drinkers was reduced after adjustment for lifestyle factors and cardiovascular disease status (RR=1.2). Lifelong abstainers, however, showed an increase in risk after adjustment of 1.8 (95% CI, 0.7 to 4.6).

Conclusions
Heavy drinking is associated with an increased risk of total stroke that is largely mediated through blood pressure. The apparent increased risk seen in lifelong abstainers but not in ex-drinkers or occasional drinkers is unexplained but is unlikely to be attributed to abstinence from alcohol. There is no convincing evidence that light or moderate drinking is beneficial for stroke risk compared with occasional drinking.
Dementia After First Stroke
Authors: Censori Bruno , Manara Ornella , Agostinis Cristina , Camerlingo Massimo , Casto Luciano , Galavotti Bruna , Partziguian Tania , Servalli Maria Cristina , Cesana Bruno , Belloni Giorgio , Mamoli Angelo
Published: June 2011

Background and Purpose
Cognitive deficits may significantly worsen the quality of life after stroke. Our aim was to determine the frequency of dementia in a consecutive series of previously nondemented patients between the ages of 40 and 79 years at 3 months after a first ischemic stroke.

Methods
All patients admitted to our department during an 18-month period who met the above criteria were visited and tested and underwent a CT scan 3 months after their stroke. Dementia was diagnosed according to criteria of the National Institute of Neurological Disorders and Stroke and AIREN, but cases with aphasia were not excluded.

Results
Of 304 patients admitted for stroke, 146 were eligible for study. Eleven refused to participate, 25 were dead at 3 months, and 110 were tested. Fifteen patients were demented (13.6%; 95% confidence interval [CI], 7.8% to 21.5%), and six had severe isolated aphasia, neglect, or memory deficit (5.4%). Excluding patients with aphasia, 5.0% of cases showed dementia (95% CI, 1.6% to 11.3%). The frequency of dementia was 24.6% (95% CI, 14.5% to 37.3%), considering only patients with supratentorial lesions and with residual deficits of elementary functions (paresis, sensory deficits) at the time of examination. Demented patients had significantly more diabetes (
P
=.029), atrial fibrillation (
P
=.032), aphasia at entry (
P
<.001), large middle cerebral artery infarctions (
P
<.001), and a more severe neurological deficit at entry (
P
=.003) and at 3 months (
P
<.001). At CT scan, demented patients had a larger mean volume of the recent lesion (
P
<.001) and more lesions in the frontal lobe (
P
=.041). An exploratory multivariate analysis selected age between 60 and 69 years (odds ratio [OR], 45.8; 95% CI, 2.9 to 726.0), diabetes (OR, 59.4; 95% CI, 4.3 to 821.0), aphasia (OR, 14.8; 95% CI, 2.0 to 111.0), a large middle cerebral artery infarction (OR, 30.0; 95% CI, 2.7 to 334.0), and lesions of the frontal lobe (OR, 9.8; 95% CI, 1.3 to 72.8) as significant independent correlates of poststroke dementia.

Conclusions
Dementia is relatively frequent after a clinical first stroke in persons younger than 80 years, and aphasia is very often associated with poststroke dementia. If aphasic patients are not considered, it may be necessary to screen a very large number of subjects to collect an adequate sample of demented cases.
The ABCs of Measuring Intracerebral Hemorrhage Volumes
Authors: Kothari Rashmi U. , Brott Thomas , Broderick Joseph P. , Barsan William G. , Sauerbeck Laura R. , Zuccarello Mario , Khoury Jane
Published: June 2011

Background and Purpose
Hemorrhage volume is a powerful predictor of 30-day mortality after spontaneous intracerebral hemorrhage (ICH). We compared a bedside method of measuring CT ICH volume with measurements made by computer-assisted planimetric image analysis.

Methods
The formula
ABC
/2 was used, where
A
is the greatest hemorrhage diameter by CT,
B
is the diameter 90° to
A
, and
C
is the approximate number of CT slices with hemorrhage multiplied by the slice thickness.

Results
The ICH volumes for 118 patients were evaluated in a mean of 38 seconds and correlated with planimetric measurements (
R
2
=.96). Interrater and intrarater reliability were excellent, with an intraclass correlation of .99 for both.

Conclusions
We conclude that ICH volume can be accurately estimated in less than 1 minute with the simple formula
ABC
/2.
Effects of Defibrination on Hemorheology, Cerebral Blood Flow Velocity, and CO
2
Reactivity During Hypocapnia in Normal Subjects
Authors: Izumi Yoshinari , Tsuda Yoshiyasu , Ichihara Shin-Ichiro , Takahashi Tsutomu , Matsuo Hirohide
Published: June 2011

Background and Purpose
Plasma fibrinogen is reported to be an independent risk factor for stroke and cardiovascular diseases. The effects of defibrination on hemorheology, middle cerebral artery (MCA) blood flow velocity, and CO
2
reactivity during hypocapnia were evaluated in normal subjects.

Methods
Twenty-five healthy subjects (mean age, 31.8±5.7 years) were included in the study. Measurements were done at rest and repeated 24 hours after administration of 10 batroxobin units. Plasma fibrinogen, plasma viscosity, and whole blood viscosity were measured as hemorheological factors. MCA blood flow velocity was measured with a transcranial Doppler flowmeter. Blood flow velocity was corrected to 40 mm Hg of end-tidal CO
2
partial pressure (P
etco
2
), and expressed as CV
40
. CO
2
reactivity was measured as percent change in mean blood flow velocity per millimeter of mercury P
etco
2
.

Results
Plasma fibrinogen (from 7.04 to 2.29 μmol/L;
P
<.001), whole blood viscosity, and plasma viscosity decreased after administration of batroxobin. Mean MCA blood flow velocity at rest, CV
40
, and CO
2
reactivity during hypocapnia increased significantly (from 67.4 to 73.6 cm/s, from 71.7 to 77.7 cm/s, and from 2.9%/mm Hg to 3.2%/mm Hg, respectively;
P
<.01) after defibrination. Mean arterial blood pressure and P
etco
2
at rest were constant before and 24 hours after administration of batroxobin. There was a significant positive correlation between CV
40
and CO
2
reactivity (
r
=.623,
P
<.0001).

Conclusions
The increase in MCA blood flow velocity was associated with improved CO
2
reactivity and reduced blood viscosity after defibrination. The data may suggest that defibrination increases cerebral blood flow by reducing blood viscosity.
Lifetime Cost of Stroke in the United States
Authors: Taylor Thomas N. , Davis Patricia H. , Torner James C. , Holmes Julia , Meyer Jay W. , Jacobson Mark F.
Published: June 2011

Background and Purpose
Stroke imposes a substantial economic burden on individuals and society. This study estimates the lifetime direct and indirect costs associated with the three major types of stroke: subarachnoid hemorrhage (SAH), intracerebral hemorrhage (ICH), and ischemic stroke (ISC).

Methods
We developed a model of the lifetime cost of incident strokes occurring in 1990. An epidemiological model of stroke incidence, survival, and recurrence was developed based on a review of the literature. Data on direct cost of treating stroke were obtained from Medicare claims data, the 1987 National Medical Expenditure Survey (NMES), and insurance claims data representing a group of large, self-insured employers. Indirect costs (the value of foregone market and nonmarket production) associated with premature morbidity and mortality were estimated based on data from the US Bureau of Economic Analysis and the 1987 NMES.

Results
The lifetime cost per person of first strokes occurring in 1990 is estimated to be $228 030 for SAH, $123 565 for ICH, $90 981 for ISC, and $103 576 averaged across all stroke subtypes. Indirect costs accounted for 58.0% of lifetime costs. Aggregate lifetime cost associated with an estimated 392 344 first strokes in 1990 was $40.6 billion: $5.6 billion for SAH, $6.0 billion for ICH, and $29.0 billion for ISC. Acute-care costs incurred in the 2 years following a first stroke accounted for 45.0%, long-term ambulatory care accounted for 35.0%, and nursing home costs accounted for 17.5% of aggregate lifetime costs of stroke.

Conclusions
The lifetime cost of stroke varies considerably by type of stroke and entails considerable costs beyond the first 2 years after a stroke.
Declining Incidence and Mortality Rates of Stroke in Finland From 1972 to 1991
Authors: Numminen Heikki , Kotila Mervi , Waltimo Olli , Aho Kari , Kaste Markku
Published: June 2011

Background and Purpose
We aimed to determine trends in stroke incidence, mortality rates, case-fatality rates, and their relation in Finland.

Methods
We compared the results of three population-based stroke registers that included first-ever strokes in people aged ≥15 years. Two registers were kept in Espoo-Kauniainen, the first in 1972 to 1973 (EK 72-73) and the second in 1978 to 1980 (EK 78-80). The present register of the Finnish Heart Association (FHA 89-91) was kept in four districts in Finland in 1989 to 1991.

Results
The age-adjusted incidence rates were 240.9, 174.4, and 191.6, and the 1-year mortality rates were 121.9, 77.0, and 65.3 in the EK 72-73, EK 78-80, and FHA 89-91 registers, respectively. The overall decline from 1972 to 1991 was 20% in the stroke incidence rate and 46% in the stroke mortality rate. One-month case-fatality rates decreased from 34.8% to 29.4% in the EK 72-73 and EK 78-80 registers and to 23.3% in the present register.

Conclusions
The decline in the stroke incidence rate during the 1970s stabilized during the late 1980s and early 1990s; however, the case-fatality rate is still decreasing. Their combined effects may explain the continuing decline in stroke mortality.
Prevalence of Stroke in the General Population
Authors: Bots Michiel L. , Looman Sophia J. , Koudstaal Peter J. , Hofman Albert , Hoes Arno W. , Grobbee Diederick E.
Published: June 2011

Background and Purpose
We assessed the prevalence of self-reported and medically confirmed stroke and the degree to which the event had led to hospitalization.

Methods
From all participants of the Rotterdam Study, a population-based cohort study of 7983 subjects aged 55 years and older living in a suburb of Ommoord in Rotterdam, information on stroke history was obtained by the question, “Did you ever suffer from a stroke, diagnosed by a physician?” Supplementary medical information was obtained from general practitioner or hospital discharge records.

Results
Prevalence of self-reported stroke was 2.5% in men aged 55 to 64 years, 5.0% in men aged 65 to 74 years, 8.9% in men aged 75 to 84 years, and 11.6% in men aged 85 years or older. Corresponding figures for women were 1.6%, 3.3%, 6.7%, and 10.5%, respectively. Of the self-reported strokes, 67% could be confirmed by medical information. In 53% (95% confidence interval, 47% to 60%) of subjects with a confirmed stroke, the event had led to hospital admission. The proportion of hospitalized patients decreased with age.

Conclusions
The present study provides valid age- and sex-specific estimates of prevalence of stroke. A substantial proportion of patients with stroke is not hospitalized.