bluuebunny/crossref_metadata_2025 huggingface dataset:
Circle of Willis Collateral Flow Investigated by Magnetic Resonance Angiography
Authors: Hartkamp Monique J. , van der Grond Jeroen , van Everdingen Kaspar J. , Hillen B. , Mali Willem P. T. M.
Published: June 2011

Background and Purpose
—The circle of Willis (CW) is considered an important collateral pathway in maintaining adequate cerebral blood flow in patients with internal carotid artery (ICA) obstruction. We aimed to investigate the anatomic variation of the CW in patients with severe symptomatic carotid obstructive disease and to analyze diameter changes of its components in relation to varying grades of ICA obstruction and in relation to the presence or absence of (retrograde) collateral flow.

Methods
—Seventy-five patients with minor disabling neurological deficits and with ICA stenoses or occlusions were categorized into 4 groups according to the severity of ICA obstruction. This patient population reflected a relatively favorable subgroup of cerebral infarction (considering their minor neurological deficits). All subjects underwent magnetic resonance angiography, including magnetic resonance angiography sensitive to flow direction. CW morphology and the size of its components were determined and compared with those values in control subjects (n=100).

Results
—Compared with control subjects, patients demonstrated a significantly higher percentage of entirely complete CW configurations (55% versus 36%,
P
=0.02), complete anterior configurations (88% versus 68%,
P
=0.002), and complete posterior CW configurations (63% versus 47%,
P
=0.04). Patients with severe ICA stenosis did not show significantly increased CW vessel diameters. Patients with ICA occlusion demonstrated a high prevalence of collateral flow through the anterior CW and significantly increased diameters of the communicating channels. Patients with bilateral ICA occlusion relied on collateral flow via the posterior CW and demonstrated a bilateral increase in posterior communicating artery diameters (
P
<0.05).

Conclusions
—The anatomic and functional configuration of the CW reflects the degree of ICA obstruction.
Transcranial Doppler Detection of Fat Emboli
Authors: Forteza Alejandro M. , Koch Sebastian , Romano Jose G. , Zych Gregory , Bustillo Iszet Campo , Duncan Robert C. , Babikian Viken L.
Published: June 2011

Background and Purpose
—The fat embolism syndrome (FES) is characterized by the simultaneous occurrence of pulmonary and neurological symptoms as well as skin and mucosal petechiae in the setting of long-bone fractures or their surgical repair. Its pathophysiology is poorly understood, and effective treatments are lacking. We present 5 patients with long-bone fractures in whom in vivo microembolism was detected by transcranial Doppler.

Methods
—Five patients with long-bone fractures were monitored with transcranial Doppler for microembolic signals (MESs) after trauma. Two patients also had intraoperative monitoring. A TC-2020 instrument equipped with MES detection software was used. Detected signals were saved for subsequent review. Selected signals satisfied criteria defined previously and were categorized as large or small.

Results
—Cerebral microembolism was detected in all 5 patients and was transient, resolving within 4 days of injury. Intraoperative monitoring revealed an increase in MESs during intramedullary nail insertion. The characteristics of MESs after injury varied among patients, with large signals being more frequent in the only patient with a patent foramen ovale.

Conclusions
—Cerebral microembolism after long-bone fractures can be detected in vivo and monitored over time. These findings may have potential diagnostic and therapeutic implications.
Role of the Cerebrovascular and Metabolic Responses in the Delayed Phases of Injury After Transient Cerebral Ischemia in Fetal Sheep
Authors: Raad Ronnie Abi , Tan William K. M. , Bennet Laura , Gunn Alistair J. , Davis Suzanne L. , Gluckman Peter D. , Johnston Barbara M. , Williams Christopher E.
Published: June 2011

Background and Purpose
—Perinatal hypoxic-ischemic injuries can trigger a cascade of events leading to delayed deterioration and cell death several hours later. The objective of this study was to characterize the cerebral blood flow responses and the changes in extracellular glucose and lactate during the delayed phases of injury and to determine their relationships with the pathophysiological events after hypoxic-ischemic injury.

Methods
—Two groups of near-term chronically instrumented fetal sheep were subjected to 30 minutes of cerebral hypoperfusion. In the first group, regional cerebral blood flow was measured over the next 24 hours with radiolabeled microspheres. In the second, cortical extracellular glucose and lactate were measured by microdialysis. Parietal electrocorticographic activity and cortical impedance were recorded continuously in both groups, and the extent of neuronal loss was determined histologically at 72 hours after injury.

Results
—Cerebral blood flow was transiently impaired in the cortex during reperfusion, whereas during the delayed phase, there was a marked increase in cerebral blood flow. The severity of cortical neuronal loss was related to the degree of hypoperfusion in the immediate reperfusion period and inversely related to the magnitude of the delayed hyperperfusion. Cortical extracellular lactate was elevated after injury, and both glucose and lactate secondarily increased during the delayed phase of injury.

Conclusions
—The delayed phase is accompanied by a period of hyperperfusion that may protect marginally viable tissue.
Importance of Intracranial Atherosclerotic Disease in Patients With Symptomatic Stenosis of the Internal Carotid Artery
Authors: Kappelle L. J. , Eliasziw M. , Fox A. J. , Sharpe B. L. , Barnett H. J. M.
Published: June 2011

Background and Purpose
—The estimated prevalence of intracranial atherosclerotic disease (IAD) in patients with stenosis of the extracranial internal carotid artery (ICA) varies between 20% and 50%. The benefits of carotid endarterectomy (CE) in patients with both IAD and symptomatic extracranial ICA stenosis are uncertain.

Methods
—The association between IAD and other vascular risk factors and with the risk of stroke at 3 years were studied in patients with symptomatic extracranial ICA stenosis who participated in the North American Symptomatic Carotid Endarterectomy Trial (NASCET). Since the NASCET protocol excluded severe IAD, only a modest number of patients in this category could be studied.

Results
—IAD was observed in one third of the patients. In medically treated patients, the relative risk of stroke associated with IAD varied from 1.3 (95% CI, 0.9 to 1.9) with extracranial ICA stenosis of <50% to 1.8 (95% CI, 1.1 to 3.2) with 85% to 99% ICA stenosis. In contrast, IAD did not affect the risk of stroke among surgically treated patients. To prevent 1 stroke ipsilateral to the symptomatic ICA stenosis over 3 years in patients who have also IAD, 12 patients with 50% to 69%, 5 patients with 70% to 84%, and 3 patients with 85% to 99% ICA stenosis have to undergo CE. In patients without IAD these numbers are 26, 7, and 6, respectively.

Conclusions
—IAD is an independent risk factor for subsequent stroke in medically treated patients with symptomatic ICA stenosis. CE reduces this risk. The additional risk imposed by IAD in medically treated patients enhances the value of CE in patients with moderate symptomatic extracranial ICA stenosis. Detection of IAD, requiring angiography, is an important prelude to planning CE in symptomatic patients with moderate extracranial ICA stenosis.
Socioeconomic Differences in Stroke Among Dutch Elderly Women
Authors: van Rossum Caroline T. M. , van de Mheen Hendrike , Breteler Monique M. B. , Grobbee Diederick E. , Mackenbach Johan P.
Published: June 2011

Background and Purpose
—We sought to assess the association between socioeconomic status and the risk of stroke among elderly women.

Methods
—The association between socioeconomic status and stroke emerged in cross-sectional and longitudinal data on 4274 female participants of the Rotterdam Study, a prospective, population-based, follow-up study in the Netherlands among older subjects.

Results
—A history of stroke was more common among women in lower socioeconomic strata. The same trend was observed for the relationship between the lowest socioeconomic groups and the incidence of stroke. Risk factors for stroke were not related to socioeconomic status in a consistent manner. Smoking, history of cardiovascular diseases, and overweight were more common in lower socioeconomic groups. However, socioeconomic differences in hypertension, antihypertensive drug use, prevalence of atrial fibrillation, and prevalence of left ventricular hypertrophy were not observed. The complex of established risk factors could only partly explain the association between socioeconomic status and stroke.

Conclusions
—There is a strong association among elderly women between socioeconomic status and stroke. The association could only partly be explained by known risk factors. Our findings indicate that not only the actual risk profile but also risk factors earlier in life may be of importance.
“Telestroke”
Authors: Levine Steven R. , Gorman Mark
Published: June 2011

Background
—Time is of the essence for effective intervention in acute ischemic stroke. Efforts including stroke teams that are “on call” around-the-clock are emerging to reduce the time from emergency room arrival to evaluation and treatment.

Summary of Comment
—Based on the results of the NINDS rt-PA Stroke Trial, which demonstrated both clinical effectiveness in reducing neurological deficits and disability and cost savings to health care systems, many community hospitals and managed-care organizations are exploring methods to enhance and expedite acute stroke care in their local communities. Only a small fraction of acute stroke victims is currently treated with thrombolytics (<1.5% nationally), and few benefit from the expertise and experience of the stroke teams. It is essential to develop new paradigms to improve acute stroke care in all settings, rural and urban. Rapid linkages to expert stroke care can help the underserved areas. Telemedicine for stroke, “Telestroke,” uses state-of-the-art video telecommunications that may be a potential solution and may maximize the number of patients given effective acute stroke treatment across the country and across the world. Telestroke could facilitate remote cerebrovascular specialty consults from virtually any location within minutes of attempted contact, adding greater expertise to the care of any individual patient. This model also has the potential to enhance patient entry into clinical trials. Telestroke would enhance stroke education through the use of Internet-based interactives for health-care professionals and patients. Education would be facilitated through the creation of telecommunication-linked classes providing interactive information on stroke care and prevention to places where they are otherwise not available. Health-care professionals will gain experience and expertise through the interaction with a remote expert—telementoring. Telestroke provides an excellent medium for data collection and an unprecedented opportunity for quality assurance. Monitoring of an entire tele-interaction can offer real-time assessments, which can then be analyzed in-depth at a later date for unique insights into health-care delivery. Prehospital use of telemedicine for stroke is already being piloted, linking patients in the ambulance to the emergency department. Legal and economic parameters must be established for telemedicine in the areas of reimbursement, liability, malpractice insurance, licensing, and credentialing. Issues of protection of privacy and confidentiality, informed consent, product liability, and industry standards must be addressed to facilitate the use of this new and potentially useful technology.

Conclusions
—Computer-based technology can now be used to integrate electronic medical information, clinical assessment tools, neuroradiology, laboratory data, and clinical pathways to bring state-of-the-art expert stroke care to underserved areas.
Increased Platelet Activation in the Chronic Phase After Cerebral Ischemia and Intracerebral Hemorrhage
Authors: van Kooten Fop , Ciabattoni Giovanni , Koudstaal Peter J. , Dippel Diederik W. J. , Patrono Carlo
Published: June 2011

Background and Purpose
—Enhanced thromboxane (TX) biosynthesis has previously been reported in the acute phase after ischemic stroke. We investigated whether enhanced urinary excretion of 11-dehydro-TXB
2
, a noninvasive index of platelet activation, was present in the chronic phase after a transient ischemic attack (TIA) or stroke, including intracerebral hemorrhage.

Methods
—We obtained a single urinary sample from 92 patients between 3 and 9 months after onset of stroke or TIA. The urinary excretion of the major enzymatic metabolite of TXA
2
, 11-dehydro-TXB
2
, was measured by a previously validated radioimmunoassay. The excretion rates were compared with those of 20 control patients with nonvascular neurological diseases.

Results
—Urinary 11-dehydro-TXB
2
averaged 294±139, 413±419, and 557±432 pmol/mmol creatinine for patients with TIA, ischemic stroke, and intracerebral hemorrhage, respectively; the values were higher in all subgroups (
P
<0.01) than that in control patients (119±66 pmol/mmol). Increased 11-dehydro-TXB
2
excretion was present in 59% of all patients, in 60% (
P
<0.001) of patients with TIA, in 56% (
P
<0.001) of patients with ischemic stroke, and in 73% (
P
<0.001) of patients with intracerebral hemorrhage. Atrial fibrillation, no aspirin use, and severity of symptoms at follow-up contributed independently to the level of 11-dehydro-TXB
2
excretion in a multiple linear regression analysis.

Conclusions
—Platelet activation is often present in patients in the chronic phase after stroke, including those with intracerebral hemorrhage. Persistent platelet activation, which is associated with atrial fibrillation and poor stroke outcome, can be substantially suppressed by aspirin treatment.
Nitric Oxide Production in the CA1 Field of the Gerbil Hippocampus After Transient Forebrain Ischemia
Authors: Lei Baiping , Adachi Naoto , Nagaro Takumi , Arai Tatsuru
Published: June 2011

Background and Purpose
—The present study was designed to examine the time course of nitric oxide (NO) production and the source of NO in the CA1 field of the gerbil hippocampus after transient forebrain ischemia.

Methods
—The production of NO in the CA1 field of the hippocampus after transient ischemia was monitored consecutively by measuring total NO metabolites (NO
x
−
, NO
2
−
plus NO
3
−
) with the use of brain microdialysis. 7-Nitroindazole (7-NI) and
N
G
-nitro-
l
-arginine methyl ester were used to dissect the relative contributions of neuronal NO synthase and endothelial NO synthase to the NO production. The histological outcomes of 7-NI in 5- and 10-minute global ischemia were also evaluated.

Results
—The production of NO in the CA1 field of the hippocampus after ischemia was dependent on the severity of ischemia. Ischemia for 2 or 5 minutes did not induce a significant increase in NO
x
−
levels in the CA1 field of the hippocampus after reperfusion, whereas the 10- and 15-minute ischemias produced significant and persistent increases in NO
x
−
levels. 7-NI did not inhibit the basal NO
x
−
levels and showed no effects on NO
x
−
levels after 5 minutes of ischemia. However, it completely inhibited the increased NO
x
−
levels after 10 or 15 minutes of ischemia. 7-NI provided minor neuroprotection in 5 minutes but not in 10 minutes of global ischemia.

Conclusions
—The increased NO level in the CA1 field of the hippocampus after ischemia is produced mostly by neuronal NO synthase, whereas the basal NO level mainly originates from endothelial NO synthase. The observed neuroprotective effect of 7-NI in 5-minute global ischemia in gerbils may not be due to neuronal NO synthase inhibition by this drug.
Stroke Incidence and Survival Among Middle-Aged Adults
Authors: Rosamond Wayne D. , Folsom Aaron R. , Chambless Lloyd E. , Wang Chin-Hua , McGovern Paul G. , Howard George , Copper Lawton S. , Shahar Eyal
Published: June 2011

Background and Purpose
—Although stroke mortality rates in the United States are well documented, assessment of incidence rates and case fatality are less well studied.

Methods
—A cohort of 15 792 men and women aged 45 to 64 years from a population sample of households in 4 US communities was followed from 1987 to 1995, an average of 7.2 years. Incident strokes were identified through annual phone contacts and hospital record searching and were then validated.

Results
—Of the 267 incident definite or probable strokes, 83% (n=221) were categorized as ischemic strokes, 10% (n=27) were intracerebral hemorrhages, and 7% (n=19) were subarachnoid hemorrhages. The age-adjusted incidence rate (per 1000 person-years) of total strokes was highest among black men (4.44), followed by black women (3.10), white men (1.78), and white women (1.24). The black versus white age-adjusted rate ratio (RR) for ischemic stroke was 2.41 (95% CI, 1.85 to 3.15), which was attenuated to 1.38 (95% CI, 1.01 to 1.89) after adjustment for baseline hypertension, diabetes, education level, smoking status, and prevalent coronary heart disease. There was a tendency for the adjusted case fatality rates to be higher among blacks and men, although none of the case fatality comparisons across sex or race was statistically significant.

Conclusions
—After accounting for established baseline risk factors, blacks still had a 38% greater risk of incident ischemic stroke compared with whites. Identification of new individual and community-level risk factors accounting for the elevated incidence of stroke requires further investigation and incorporation into intervention planning.
Cerebral Vasculopathy in HIV Infection Revealed by Transcranial Doppler
Authors: Brilla Roland , Nabavi Darius G. , Schulte-Altedorneburg Gernot , Kemény Vendel , Reichelt Doris , Evers Stefan , Schiemann Uwe , Husstedt Ingo-W.
Published: June 2011

Background and Purpose
—There is growing evidence for affection of cerebral vessels during human immunodeficiency virus (HIV) infection. We prospectively evaluated cerebrovascular reserve capacity (CRC) in HIV-seropositive patients by transcranial Doppler sonography (TCD) after systemic administration of acetazolamide. We hypothesized that a disturbed vasoreactivity would reflect the cerebral arteries’ involvement in HIV infection.

Methods
—We assessed the mean blood flow velocity (BFV) of the middle cerebral artery and its increase after intravenous administration of 1 g acetazolamide (CRC) in 31 HIV-infected individuals without symptoms of cerebrovascular disease (mean±SD age, 39±11 years). Stenotic or occlusive lesions of the large brain-supplying arteries were excluded by color-coded duplex and transcranial imaging. BFV and CRC were also measured in an age-matched group of 10 healthy control subjects. Patients were classified according to clinical, laboratory, and neurophysiological parameters. We also performed cerebral MRI (n=25) and rheumatological blood tests (n=26).

Results
—Baseline BFV and CRC both were significantly reduced in HIV-infected patients as compared with control subjects (
P
<0.05, Student’s
t
test). These findings did not correlate with duration of seropositivity, helper cell count, or other clinical, rheumatological, and neuroradiological findings.

Conclusions
—Our findings support the hypothesis of a cerebral vasculopathy etiologically associated with HIV infection.
Influence of Platelet-Activating Factor on Cerebral Microcirculation in Rats
Authors: Uhl Eberhard , Pickelmann Sven , Baethmann Alexander , Schürer Ludwig
Published: June 2011

Background and Purpose
—Platelet-activating factor (PAF) has been demonstrated to have a mediator function in shock, with some of its deleterious effects being attributed to its influence on microcirculation. Systemic PAF concentrations as found in shock could also compromise the cerebral microcirculation. Our purpose in the present study was to examine the influence of systemically applied PAF on microvascular perfusion and leukocyte-endothelium interactions in cerebral microvessels.

Methods
—A closed cranial window technique was used for intravital fluorescence microscopy of the brain surface. PAF was infused in concentrations of 10
−12
, 10
−9
, and 10
−6
mol/L into the carotid artery (5 mL/h for 20 min) of Sprague-Dawley rats (n=30). The selective PAF receptor antagonist WEB 2170BS (2 mg/kg body weight) was used to inhibit specific PAF effects.

Results
—The number of leukocytes (cells/100 μm · min) rolling along or adhering at the venular endothelium increased following infusion of PAF 10
−6
mol/L from 7.7±2.5 to 24.4±8.9 (
P
<0.05) and from 1.9±0.5 to 6.9±2.2 (
P
<0.05), respectively, within 2 hours. Mean arterial pressure decreased from 92±22 mm Hg to 49±17 mm Hg (
P
<0.05). The lower concentrations of PAF were less effective to decrease mean arterial pressure but also induced leukocyte-endothelium interactions. The intravenous administration of WEB 2170BS 15 min before the infusion of PAF 10
−6
mol/L prevented both systemic hypotension and activation of leukocyte-endothelium interactions.

Conclusions
—Increased systemic blood levels of PAF as found during shock can not only cause systemic arterial hypotension but also induce leukocyte-endothelium interactions in cerebral venules. The activation of leukocytes was found to be independent of PAF-induced arterial hypotension. The specificity of these results is confirmed by the findings that WEB 2170BS could inhibit the PAF-induced systemic hypotension as well as the activation of leukocytes.
Usefulness of Transcranial Color-Coded Sonography in the Diagnosis of Cerebral Vasospasm
Authors: Proust F. , Callonec F. , Clavier E. , Lestrat J. P. , Hannequin D. , Thiébot J. , Fréger P.
Published: June 2011

Background and Purpose
—The noninvasive diagnosis of cerebral vasospasm with the use of conventional transcranial Doppler ultrasonography (TCD) is based on a velocity study of the middle cerebral artery (MCA). The authors report a prospective comparative study between transcranial color-coded sonography (TCCS), conventional transcranial Doppler (TCD), and angiography in the diagnosis of cerebral vasospasm after surgical treatment for aneurysm.

Methods
—Thirty consecutive patients underwent routine angiography after surgical treatment for intracranial aneurysm. The distribution of vasospasm was determined after a prospective calculation of the angiographic diameter of the MCA, internal carotid artery (ICA), and anterior cerebral artery (ACA). The blood flow velocities (systolic and maximum) of the MCA, ICA, and ACA were evaluated by TCCS and TCD.

Results
—The correlation between mean maximum velocity and angiographic diameter was significant for the MCA (
r
=−0.637,
P
<0.0001), ICA (
r
=−0.676,
P
<0.0001), and ACA (
r
=−0.425,
P
<0.01). TCCS sensitivity and specificity were higher than those for TCD for MCA (100% and 93%, respectively) and ICA (100% and 96.6%, respectively). For ACA, the sensitivity and specificity were 71.4% and 84.8%, respectively.

Conclusions
—The authors suggest that TCCS is useful for accurate monitoring of cerebral vasospasm in the MCA and ICA. In the ACA, TCCS monitors the hemodynamic state of the anterior part of the circle of Willis, which could expose the patient to a delayed ischemic deficit.
Evidence of Anaphylaxy After Alteplase Infusion
Authors: Rudolf Jobst , Grond Martin , Prince William S. , Schmülling Susanne , Heiss Wolf-Dieter
Published: June 2011

Background and Purpose
—Although alteplase, a recombinant tissue plasminogen activator (tPA), is structurally identical to endogenous tPA and therefore should not induce allergy, single cases of acute hypersensitivity reactions have been reported. Until now, specific antibodies against alteplase were not detected in blood samples obtained in these patients.

Case Description
—We report an anaphylactic reaction in a 70-year-old white female who was treated with intravenous alteplase for thrombolysis of acute ischemic stroke 160 minutes after onset of a right-sided hemiparesis. Thirty minutes after infusion of alteplase had been started, the patient suffered acute severe sinus tachycardia and hypotension, followed by cyanosis and loss of consciousness. The alteplase infusion was stopped, and following antiallergic therapy, tachycardia and hypotension resolved within 1 hour. The hemiparesis remained unaltered, but additional harm resulting from the hemodynamic complication was not observed. Serum samples analyzed with a radioimmunoprecipitation assay were negative for total antibodies to alteplase, but in a subsequent ELISA, both samples were positive for IgE antibodies to alteplase.

Conclusions
—The detection of specific IgE antibodies reactive with alteplase in this patient could provide the first evidence of an anaphylactic-type reaction to alteplase in man. Because previous exposure to alteplase can be excluded, the results suggest that this patient had preexisting antibodies that were cross-reactive with one or more epitopes of alteplase and therefore precipitated the anaphylactic-type reaction.
Axonal Injury in the Internal Capsule Correlates With Motor Impairment After Stroke
Authors: Pendlebury S. T. , Blamire A. M. , Lee M. A. , Styles P. , Matthews P. M.
Published: June 2011

Background and Purpose
—Magnetic resonance spectroscopy (MRS) in ischemic stroke has shown a correlation between
N
-acetylaspartate (NAA) loss from the infarcted region and disability. We tested the hypothesis that NAA loss in the descending motor pathways, measured at the level of the posterior limb of the internal capsule, would determine motor deficit after a cortical, subcortical, or striatocapsular stroke.

Methods
—Eighteen patients with first ischemic stroke causing a motor deficit were examined between 1 month and 5 years after stroke. T2-weighted imaging of the brain and localized proton (voxel, 1.5×2×2 cm
3
) MRS from the posterior limb of each internal capsule were performed and correlated to a motor deficit score.

Results
—Mean internal capsule NAA was significantly lower in the patient group as a whole compared with the control group (
P
<0.001). Reductions in internal capsule NAA on the side of the lesion were seen in cases of cortical stroke in which there was no extension of the stroke into the voxel as well as in cases of striatocapsular stroke involving the voxel region. There was a strong relationship between reduction in capsule NAA and contralateral motor deficit (log curve,
r
2
=0.9,
P
<0.001).

Conclusions
—Axonal injury in the descending motor pathways at the level of the internal capsule correlated with motor deficit in patients after stroke. This was the case for strokes directly involving the internal capsule and for strokes in the motor cortex and subcortex in which there was presumed anterograde axonal injury.
Prevention of Shoulder Subluxation After Stroke With Electrical Stimulation
Authors: Linn Sandra L. , Granat Malcolm H. , Lees Kennedy R.
Published: June 2011

Background and Purpose
—Subluxation is a significant problem in poststroke hemiplegia, resulting in pain and loss of function. Current treatments are not proved and not considered effective. It has been demonstrated that cyclical electrical stimulation of the shoulder muscles can reduce existing subluxation. The purpose of this study was to determine whether electrical stimulation could prevent subluxation in both the short and long terms.

Methods
—A prospective, randomized controlled study was used to determine the efficacy of electrical stimulation in preventing shoulder subluxation in patients after cerebrovascular accidents. Forty patients were selected and randomly assigned to a control or treatment group. They had their first assessment within 48 hours of their stroke, and those in the treatment group were immediately put on a regimen of electrical stimulation for 4 weeks. All patients were assessed at 4 weeks after stroke and then again at 12 weeks after stroke. Assessments were made of shoulder subluxation, pain, and motor control.

Results
—The treatment group had significantly less subluxation and pain after the treatment period, but at the end of the follow-up period there were no significant differences between the 2 groups.

Conclusions
—Electrical stimulation can prevent shoulder subluxation, but this effect was not maintained after the withdrawal of treatment.
Prospective Randomized Trial of Bilateral Carotid Endarterectomies
Authors: AbuRahma Ali F. , Robinson Patrick A. , Saiedy Samer , Richmond Bryan K. , Khan Jamal
Published: June 2011

Background and Purpose
—Although several studies have compared the results of carotid endarterectomy (CEA) with primary closure (PC) versus patch closure, none have compared the outcome of bilateral CEAs with patch versus PC performed on the same patient. This prospective randomized study compares the clinical outcome and incidence of recurrent stenosis (≥80%) for CEA with PC versus patch closure in patients with bilateral CEAs.

Methods
—This study includes 74 patients with bilateral CEAs with PC on one side and patching on the other. Patients were randomized to sequential operative treatment of either patching/PC or PC/patching. Postoperative duplex ultrasounds and clinical follow-up were done at 1, 6, and 12 months and every year thereafter. A Kaplan-Meier analysis was used to estimate the risk of significant restenosis (≥80%).

Results
—Demographic characteristics and the mean operative diameter of the internal carotid artery were similar for both PC and patching. The mean follow-up was 29 months (range, 6 to 65 months). The incidence of ipsilateral stroke was 4% for PC versus 0% for patching. PC had a significantly higher incidence of neurological complications (transient ischemic attacks and stroke combined) than patching (12% versus 1%;
P
=0.02). Operative mortality was 0%. PC had a higher incidence of recurrent stenosis (22% versus 1%;
P
<0.003) and total internal carotid artery occlusion (8% versus 0%;
P
=0.04) than patching. Restenoses necessitating a repeated CEA were also higher for PC (14%) than for patching (1%;
P
=0.01). The Kaplan-Meier analysis showed that patching had a significantly better cumulative patency rate than PC (
P
<0.01). This analysis also showed that freedom from recurrent stenosis at 24 months was 75% for PC and 98% for patching.

Conclusions
—Patch closure is less likely than PC to cause ipsilateral stroke, transient ischemic attacks, and recurrent carotid stenosis. The higher rate of unilateral recurrent stenosis may suggest that local factors play a more significant role than systemic factors in the etiology of recurrent carotid stenosis.
Assessing the Laryngeal Cough Reflex and the Risk of Developing Pneumonia After Stroke
Authors: Addington W. Robert , Stephens Robert E. , Gilliland Katherine A.
Published: June 2011

Background and Purpose
—We sought to evaluate the efficacy of testing the laryngeal cough reflex in identifying pneumonia risk in acute stroke patients.

Methods
—We performed a prospective study of 400 consecutive acute stroke patients examined using the reflex cough test (RCT) compared with 204 consecutive acute stroke patients from a sister facility examined without using the RCT. The binary end point for the study outcome was the development of pneumonia.

Results
—Of the 400 patients examined with the RCT, 5 developed pneumonia. Of the 204 patients examined without the RCT, 27 developed pneumonia (
P
<0.001). Three of the 27 patients died in the rehabilitation hospital of respiratory failure secondary to pneumonia. Seven others were transferred to the emergency department with acute respiratory distress. Power analysis for this comparison was 0.99. There were no other significant differences between the 2 groups.

Conclusions
—A normal RCT after an acute stroke indicates a neurologically intact laryngeal cough reflex, a protected airway, and a low risk for developing aspiration pneumonia with oral feeding. An abnormal RCT indicates risk of an unprotected airway and an increased incidence of aspiration pneumonia. Alternate feeding strategies and preventive measures are necessary with an abnormal RCT. Clinical treatment algorithm and prescription of food, fluids, and medications are discussed on the basis of RCT results.
Progression in Acute Stroke
Authors: DeGraba Thomas J. , Hallenbeck John M. , Pettigrew Karen D. , Dutka Andrew J. , Kelly Brian J.
Published: June 2011

Background and Purpose
—The objective was to determine the occurrence of neurological changes during the first 48 hours after acute stroke as it relates to initial stroke severity.

Methods
—The National Institutes of Health Stroke Scale (NIHSS) was performed serially for the first 48 hours on 127 consecutive ischemic stroke patients (129 strokes) admitted to the neuroscience intensive care unit. Incidence of stroke progression (a ≥3-point increase on the NIHSS) was recorded and analysis performed to determine its association with initial stroke severity and other demographic and physiological variables. Deficit resolution by 48 hours, defined as an NIHSS score of 0 or 1, measured the frequency of functional recovery predicted by the initial deficit.

Results
—Overall progression was noted in 31% of events (40/129). Applying Bayes’ solution to the observed frequency of worsening, the greatest likelihood of predicting future patient progression occurs with stratification at NIHSS scores of ≤7 and >7. Patients with an initial NIHSS of ≤7 experienced a 14.8% (13/88) worsening rate versus a those with a score of >7 with a 65.9% (27/41) worsening rate (
P
<0.000005). Forty-five percent (40/88) of those with an initial score of ≤7 were functionally normal at 48 hours, whereas only 2.4% (1/41) of those with scores of >7 returned to a normal examination within this period (χ
2
,
P
<0.000005).

Conclusions
—This study suggests that the early clinical course of the neurological deficit after acute stroke is dependent on the initial stroke severity and that a dichotomy in early outcome exists surrounding an initial NIHSS score of 7. These findings may have significant implications for the design and patient stratification in treatment protocols with respect to primary clinical outcome.
Replicability of SF-36 Summary Scores by the SF-12 in Stroke Patients
Authors: Pickard A. Simon , Johnson Jeffrey A. , Penn Andrew , Lau Francis , Noseworthy Tom
Published: June 2011

Background and Purpose
—The replicability of the physical and mental component summary scores of the Short Form (SF)-36 has been established using the SF-12 in selected patient populations but has yet to be assessed in stroke patients. If the summary scores of the SF-12 are highly correlated with those of the SF-36, the benefits of using a shorter health-status measure may be realized without substantial loss of information or precision. Both self-reported and proxy assessments were evaluated for replicability.

Methods
—Intraclass correlation coefficients (ICCs) and linear regression were used to assess the ability of the SF-12 physical component summary (PCS-12) scores to predict PCS-36 scores and the SF-12 mental component summary (MCS-12) scores to predict MCS-36 scores. Multivariate regression was used to explore the relationship between SF-12 and SF-36 scores.

Results
—The MCS-12 and PCS-12 scores were strongly correlated with the corresponding SF-36 summary scores for surveys completed by proxy or self-report (ICCs ranged from 0.954 to 0.973). Regression analysis of the proxy assessments indicated that patient age was an important effect modifier in the relationship between MCS-12 and MCS-36 scores.

Conclusions
—The SF-12 reproduced SF-36 summary scores without substantial loss of information in stroke patients. Accordingly, the SF-12 can be used at the summary score level as a substitute for the SF-36 in stroke survivors capable of self-report. However, the mental health summary scores of proxy assessments are influenced by patient age, thereby limiting the replicability of the SF-36 by the SF-12 under these conditions.
A Systematic Review of Cost-Effectiveness Research of Stroke Evaluation and Treatment
Authors: Holloway Robert G. , Benesch Curtis G. , Rahilly Catherine R. , Courtright Caryn E.
Published: June 2011

Background and Purpose
—This work was undertaken to review research addressing the cost-effectiveness of stroke-related diagnostic, preventive, or therapeutic interventions.

Methods
—We performed searches of MEDLINE, Excerpta Medica online, HealthSTAR, and Sciences Citation Index Expanded and examined the reference lists of the studies and reviews obtained. From these, we selected studies that reported an incremental analysis of cost per effect, in which the effect measure was life-years or quality-adjusted life-years. We abstracted data from each study using a standardized reporting form. Twenty-six articles met the eligibility criteria and were included in the review.

Results
—The methodological quality of the articles reviewed has improved compared with previously reported. Many stroke evaluation and treatment policies may result in benefits to health that are considered worth their cost. Some interventions were considered cost-ineffective (anticoagulation in low-risk nonvalvular atrial fibrillation and surveillance with duplex ultrasound after endarterectomy). Different studies addressing the cost-effectiveness of screening asymptomatic carotid stenosis resulted in strikingly divergent conclusions, from being cost-effective to being detrimental. Other studies omitted important costs that, if included, would likely have had profound impact on their cost-effectiveness estimates.

Conclusions
—Given the divergent conclusions drawn from studies addressing similar questions, it may be premature to use the results of cost-effectiveness research in developing stroke policy and practice guidelines. Successful implementation of such evaluations in the care of patients with stroke will depend on further standardization of methodology and critical appraisal of reported findings.
Can Stroke Patients Use Visual Analogue Scales?
Authors: Price C. I. M. , Curless R. H. , Rodgers H.
Published: June 2011

Background and Purpose
—Visual analogue scales (VAS) have been used for the subjective measurement of mood, pain, and health status after stroke. In this study we investigated how stroke-related impairments could alter the ability of subjects to answer accurately.

Methods
—Consent was obtained from 96 subjects with a clinical stroke (mean age, 72.5 years; 50 men) and 48 control subjects without cerebrovascular disease (mean age, 71.5 years; 29 men). Patients with reduced conscious level or severe dysphasia were excluded. Subjects were asked to rate the tightness that they could feel on the (unaffected) upper arm after 3 low-pressure inflations with a standard sphygmomanometer cuff, which followed a predetermined sequence (20 mm Hg, 40 mm Hg, 0 mm Hg). Immediately after each change, they rated the perceived tightness on 5 scales presented in a random order: 4-point rating scale (none, mild, moderate, severe), 0 to 10 numerical rating scale, mechanical VAS, horizontal VAS, and vertical VAS. Standard tests recorded deficits in language, cognition, and visuospatial awareness.

Results
—Inability to complete scales with the correct pattern was associated with any stroke (
P
<0.001). There was a significant association between success using scales and milder clinical stroke subtype (
P
<0.01). Within the stroke group, logistic regression analysis identified significant associations (
P
<0.05) between impairments (cognitive and visuospatial) and inability to complete individual scales correctly.

Conclusions
—Many patients after a stroke are unable to successfully complete self-report measurement scales, including VAS.
Family Caregiving for Patients With Stroke
Authors: Han Beth , Haley William E.
Published: June 2011

Background
—The literature on family caregiving for stroke patients is reviewed with the goals of (1) evaluating the effects of stroke caregiving on caregivers’ well-being, (2) outlining deficiencies and methodological limitations of current research, and (3) outlining policy and practice implications of current studies.

Summary of Review
—A total of 20 published stroke caregiving research articles were included in this review. Across studies, the effects of stroke caregiving on caregivers’ well-being and the significant predictors of caregivers’ depression were analyzed. Current evidence suggests that stroke caregivers have elevated levels of depression at both the acute stroke phase and the chronic stroke phase. However, major gaps are apparent in this literature, with few studies addressing such areas as caregiver physical health, ethnicity, and caregiver interventions.

Conclusions
—Given the increasing prevalence of stroke as well as the increasing pressures on families to provide care, more research is needed to guide policy and practice in this understudied topic.
Mechanisms of Retinal Arterial Occlusive Disease in African American and Caucasian Patients
Authors: Ahuja Richard M. , Chaturvedi Seemant , Eliott Dean , Joshi Nishith , Puklin James E. , Abrams Gary W.
Published: June 2011

Background and Purpose
—The aim of our study was to evaluate the causes of retinal arterial occlusive disease in African American patients and to compare these etiologies with those observed in Caucasian patients with retinal ischemic symptoms.

Methods
—We performed a retrospective analysis of a series of consecutive patients evaluated by both the ophthalmology department and the neurology/stroke clinic. Patients had a diagnosis of amaurosis fugax, branch retinal artery occlusion, central retinal artery occlusion, or intra-arterial retinal plaques.

Results
—Twenty-nine African American patients and 17 Caucasian patients were evaluated. African American patients had a mean age of 61 years (range, 30 to 77 years) and Caucasian patients a mean age of 73 years (range, 56 to 94 years) (
P
=0.003). There was no statistically significant difference between the 2 groups with respect to visible emboli on funduscopy (
P
=0.462). After adjusting for age, there was also no difference between the 2 groups with regards to risk factors for arterial occlusive disease such as hypertension, coronary artery disease, hypercholesterolemia, tobacco use, and history of stroke or transient ischemic attacks. Caucasian patients had a 41% incidence (7/17) of high-grade ipsilateral internal carotid artery stenosis, measured by carotid duplex, compared with 3.4% incidence (1/29) in African American patients (
P
=0.002).

Conclusions
—There are racial differences in the causes of retinal arterial occlusion. African American patients have a low prevalence of moderate to severe extracranial carotid stenosis, and a high proportion of African American patients have cryptogenic retinal ischemia. In Caucasian patients there is a stronger association between extracranial carotid artery disease and retinal arterial occlusion.
Therapeutic Benefit
Authors: Gorelick Philip B. , Born Gustav V. R. , D’Agostino Ralph B. , Hanley Daniel F. , Moye Lemuel , Pepine Carl J.
Published: June 2011

Background
—Antiplatelet agents are widely recognized for their efficacy in reducing the occurrence of vascular events in patients with atherothrombotic disease. Aspirin is currently considered to be the “reference standard” antiplatelet agent and is recommended by the American Heart Association for use in patients with a wide range of manifestations of cardiovascular disease on the basis of its high benefit-to-risk and benefit-to-cost ratios. Recently, clopidogrel (Plavix, Bristol-Myers Squibb Co), another antiplatelet agent, was approved by the Food and Drug Administration for many of the same indications as aspirin.

Summary of Review
—Because physicians will be faced with deciding whether to switch from the well-established practice of recommending aspirin for use in patients with atherothrombotic disease, both aspirin and clopidogrel are compared with respect to the primary factors that influence such decisions (ie, their relative efficacy, safety, cost, and convenience of use).

Conclusions
—Based on the available evidence, aspirin is preferred for the majority of stroke or myocardial infarction patients at risk of recurrent atherothrombotic events. Clopidogrel may, however, provide valuable therapeutic benefit over aspirin in patients with peripheral arterial disease and in stroke or myocardial infarction patients for whom aspirin treatment is contraindicated or for whom aspirin fails to achieve the desired therapeutic effect.
The North American Symptomatic Carotid Endarterectomy Trial
Authors: Ferguson Gary G. , Eliasziw Michael , Barr Hugh W. K. , Clagett G. Patrick , Barnes Robert W. , Wallace M. Christopher , Taylor D. Wayne , Haynes R. Brian , Finan Jane W. , Hachinski Vladimir C. , Barnett Henry J. M.
Published: June 2011

Background and Purpose
—This study reports the surgical results in those patients who underwent carotid endarterectomy in the North American Symptomatic Carotid Endarterectomy Trial (NASCET).

Methods
—The rates of perioperative stroke and death at 30 days and the final assessment of stroke severity at 90 days were calculated. Regression modeling was used to identify variables that increased or decreased perioperative risk. Nonoutcome surgical complications were summarized. The durability of carotid endarterectomy was examined.

Results
—In 1415 patients there were 92 perioperative outcome events, for an overall rate of 6.5%. At 30 days the results were as follows: death, 1.1%; disabling stroke, 1.8%; and nondisabling stroke, 3.7%. At 90 days, because of improvement in the neurological status of patients judged to have been disabled at 30 days, the results were as follows: death, 1.1%; disabling stroke, 0.9%; and nondisabling stroke, 4.5%. Thirty events occurred intraoperatively; 62 were delayed. Most strokes resulted from thromboembolism. Five baseline variables were predictive of increased surgical risk: hemispheric versus retinal transient ischemic attack as the qualifying event, left-sided procedure, contralateral carotid occlusion, ipsilateral ischemic lesion on CT scan, and irregular or ulcerated ipsilateral plaque. History of coronary artery disease with prior cardiac procedure was associated with reduced risk. The risk of perioperative wound complications was 9.3%, and that of cranial nerve injuries was 8.6%; most were of mild severity. At 8 years, the risk of disabling ipsilateral stroke was 5.7%, and that of any ipsilateral stroke was 17.1%.

Conclusions
—The overall rate of perioperative stroke and death was 6.5%, but the rate of permanently disabling stroke and death was only 2.0%. Other surgical complications were rarely clinically important. Carotid endarterectomy is a durable procedure.