bluuebunny/crossref_metadata_2025 huggingface dataset:
Prospective Study of Calcium, Potassium, and Magnesium Intake and Risk of Stroke in Women
Authors: Iso Hiroyasu , Stampfer Meir J. , Manson JoAnn E. , Rexrode Kathryn , Hennekens Charles H. , Colditz Graham A. , Speizer Frank E. , Willett Walter C.
Published: June 2011

Background and Purpose
—High intakes of calcium, potassium, and magnesium have been hypothesized to reduce risks of cardiovascular disease, but only a few prospective studies have examined intakes of these cations in relation to risk of stroke.

Methods
—In 1980, 85 764 women in the Nurses’ Health Study cohort, aged 34 to 59 years and free of diagnosed cardiovascular disease and cancer, completed dietary questionnaires from which we calculated intakes of calcium, potassium, and magnesium. By 1994, after 1.16 million person-years of follow-up, 690 incident strokes (129 subarachnoid hemorrhages, 74 intraparenchymal hemorrhages, 386 ischemic strokes, and 101 strokes of undetermined type) had been documented.

Results
—Intakes of calcium, potassium, and magnesium were each inversely associated with age- and smoking-adjusted relative risks of ischemic stroke, excluding embolic infarction of nonatherogenic origin (n=347). Adjustment for other cardiovascular risk factors, including history of hypertension, attenuated these associations, particularly for magnesium intake. In a multivariate analysis, women in the highest quintile of calcium intake had an adjusted relative risk of ischemic stroke of 0.69 (95% CI, 0.50 to 0.95;
P
for trend=0.03) compared with those in the lowest quintile; for potassium intake the corresponding relative risk was 0.72 (95% CI, 0.51 to 1.01;
P
for trend=0.10). Further simultaneous adjustment for calcium and potassium intake suggested an independent association for calcium intake. The association of risk with calcium intake did not appear to be log linear; the increase in risk was limited to the lowest quintile of intake, and intakes >≈600 mg/d did not appear to reduce risk of stroke further. The inverse association with calcium intake was stronger for dairy than for nondairy calcium intake. Intakes of calcium, potassium, and magnesium were not related to risk of other stroke subtypes.

Conclusions
—Low calcium intake, and perhaps low potassium intake, may contribute to increased risk of ischemic stroke in middle-aged American women. It remains possible that women in the lowest quintile of calcium intake had unknown characteristics that made them susceptible to ischemic stroke.
Non–Velocity-Related Effects of a Rigid Double-Stopped Ankle-Foot Orthosis on Gait and Lower Limb Muscle Activity of Hemiparetic Subjects With an Equinovarus Deformity
Authors: Hesse Stefan , Werner Cordula , Matthias Konrad , Stephen Kirker , Berteanu Michael
Published: June 2011

Background and Purpose
—This study investigated the non–velocity-related effects of a 1-bar rigid ankle-foot orthosis on the gait of hemiparetic subjects, with particular emphasis on the muscle activity of the paretic lower limb.

Methods
—Twenty-one hemiparetic subjects who had been using an ankle-foot orthosis for equinovarus deformity for <1 week participated. Patients walked cued by a metronome at a comparable speed with and without the orthosis. Dependent variables were basic, limb-dependent cycle parameters, gait symmetry, vertical ground reaction forces, sagittal ankle excursions, and kinesiological electromyogram of several lower limb muscles.

Results
—The use of the caliper was associated with more dynamic and balanced gait, characterized by longer relative single-stance duration of the paretic lower limb, better swing symmetry, better pivoting over the stationary paretic foot, and better ankle excursions (
P
<0.05). The functional activity of the paretic quadriceps muscles increased, while the activity of the paretic tibialis anterior muscle decreased (
P
<0.05).

Conclusions
—The orthosis led to a more dynamic and balanced gait, with enhanced functional activation of the hemiparetic vastus lateralis muscle. The study further supports the functional benefits of a rigid ankle-foot orthosis in hemiparetic subjects as an integral part of a comprehensive rehabilitation approach. However, the reduced activity in the tibialis muscle may lead to disuse atrophy and hence long-term dependence on the orthosis.
Neuropsychological Change and S-100 Protein Release in 130 Unselected Patients Undergoing Cardiac Surgery
Authors: Kilminster Shaun , Treasure Tom , McMillan Tom , Holt David W.
Published: June 2011

Background and Purpose
—S-100 protein promises to be a valuable surrogate end point for cerebral injury. This is of particular interest within the context of cardiac surgery. We sought to explore the relationship between change in neurospychological performance attributable to cardiopulmonary bypass and the release of brain-specific S-100 protein.

Methods
—In an observational comparative study in a University Hospital Cardiac Surgical Unit, S-100 protein release during and 5 hours after the onset of cardiopulmonary bypass was compared with change (from preoperative to 6 to 8 weeks postoperative) in neuropsychological tests in 130 patients undergoing the full range of cardiac surgical procedures.

Results
—Neuropsychological performance usually improved, being significantly so in 10 of 25 parameters. S-100 area under the curve (AUC) protein release correlated with age (
r
=0.24,
P
<0.008) and bypass time (
r
=0.17,
P
<0.02). S-100 Cmax correlated with bypass times (
r
=0.29,
P
<0.0001). Bypass times correlated with memory performance (Rey R5;
r
=−0.21,
P
<0.03). Less S-100 protein release was associated with better neuropsychological performance, as indexed by significant correlations with the Rey Auditory Verbal Learning memory test, descending Critical Flicker Fusion thresholds, and the Hospital Anxiety and Depression rating scales, typically around
r
=0.2. Multiple regression models showed that neuropsychological tests accounted for 23% of the variance associated with S-100 AUC release, after partialing out the effects of age and bypass time.

Conclusions
—The correlation between S-100 protein release and neuropsychological function supports the belief that it is a measure of brain injury, which may be useful in future studies of mechanisms and prevention.
Angiographically Defined Collateral Circulation and Risk of Stroke in Patients With Severe Carotid Artery Stenosis
Authors: Henderson Robert D. , Eliasziw Michael , Fox Allan J. , Rothwell Peter M. , Barnett Henry J. M.
Published: June 2011

Background and Purpose
—Blood supply through collateral pathways improves regional cerebral blood flow and may protect against ischemic events. The effect of collaterals on the risk of stroke and transient ischemic attack (TIA), in the presence of angiographic severe internal carotid artery (ICA) stenosis, was assessed.

Methods
—Angiographic collateral filling through anterior communicating and posterior communicating arteries and retrograde filling through ophthalmic arteries were determined in all patients at entry into the North American Symptomatic Carotid Endarterectomy Trial. Kaplan-Meier event-free survival analyses were performed on 339 medically treated and 342 surgically treated patients.

Results
—The presence of collaterals supplying the symptomatic ICA increased with severity of stenosis. Two-year risk of hemispheric stroke in medically treated patients with severe ICA stenosis was reduced in the presence of collaterals: 27.8% to 11.3% (
P
=0.005). Similar reductions were observed for hemispheric TIA (36.1% versus 19.1%;
P
=0.008) and disabling or fatal strokes (13.3% versus 6.3%;
P
=0.11). For surgically treated patients, the perioperative risk of hemispheric stroke was 1.1% in the presence of collaterals versus 4.9% when absent. The 2-year stroke risks for surgical patients with and without collaterals were 5.9% versus 8.4%, respectively. Neither comparison in the surgical group was statistically significant. The observed reductions were independent of the degree of ICA stenosis and other vascular risk factors.

Conclusions
—Collaterals are associated with a lower risk of hemispheric stroke and TIA, both long term and perioperatively. Angiographic identification of collaterals assists in identifying patients with severe ICA stenosis at lower risk of stroke and TIA.
Specific Transcranial Doppler Flow Findings Related to the Presence and Site of Arterial Occlusion
Authors: Demchuk Andrew M. , Christou Ioannis , Wein Theodore H. , Felberg Robert A. , Malkoff Marc , Grotta James C. , Alexandrov Andrei V.
Published: June 2011

Background and Purpose
—Transcranial Doppler (TCD) can localize arterial occlusion in stroke patients. Our aim was to evaluate the frequency of specific TCD flow findings with different sites of arterial occlusion.

Methods
—Using a standard insonation protocol, we prospectively evaluated the frequency of specific TCD findings in patients with or without proximal extracranial or intracranial occlusion determined by digital subtraction or MR angiography.

Results
—Of 190 consecutive patients studied, angiography showed occlusion in 48 patients. With proximal internal carotid artery (ICA) occlusion, TCD showed abnormal middle cerebral artery (MCA) waveforms (AMCAW) in 66.7%, reversed ophthalmic artery (OA) in 70.6%, anterior cross-filling via anterior communicating artery (ACoA) in 78.6%, posterior communicating artery (PCoA) in 71.4%, and contralateral compensatory velocity increase (CVI) in 84.6% of patients. With distal ICA occlusion, TCD showed AMCAW in 88.9%, OA in 16.7%, ACoA in 50%, PCoA in 60%, and CVI in 88.9% of patients. With MCA occlusion, TCD showed AMCAW in 100%, OA in 23.5%, ACoA in 31.3%, PCoA in 23.1%, and CVI in 62.5%. With no anterior circulation occlusion at angiography, TCD showed these parameters in 1.8% to 17.9%, χ
2
P
≤0.003. Parameters localizing anterior circulation occlusion were stenotic terminal ICA velocities 46% versus 10% in patent vessels; flow diversion to perforators 73% versus 1.8%; OA 70.6% versus 5.6%; ACoA 78.6% versus 8.2%; PCoA 71.4% versus 8.5%, all at
P
<0.05. In patients with basilar artery (BA) occlusion, ABAW were found in 80% versus 3% (patent BA); flow diversion to anterior vessels in 60% versus 5.7%; BA flow reversal in 20% versus 0%; and PCoA in 100% versus 13.7%, all at
P
<0.001. No individual parameters differentiated BA from the terminal vertebral occlusion.

Conclusions
—Specific TCD findings are common with major arterial occlusion and can be used to broaden diagnostic batteries and improve the predictive value of noninvasive screening in stroke patients. TCD findings useful to localize anterior circulation occlusion include collaterals, abnormal waveforms or velocities, and flow diversion to perforators.
Cyclin D1 and Cdk4 Protein Induction in Motor Neurons After Transient Spinal Cord Ischemia in Rabbits
Authors: Sakurai Masahiro , Hayashi Takeshi , Abe Koji , Itoyama Yasuto , Tabayashi Koichi
Published: June 2011

Background and Purpose
—The mechanism of spinal cord injury has been thought to be related to the vulnerability of spinal motor neuron cells against ischemia. However, the mechanisms of such vulnerability are not fully understood. We hypothesized that spinal motor neurons might be lost by programmed cell death and investigated a possible mechanism of neuronal death by detection of double-strand breaks in genomic DNA and immunohistochemical analysis for cyclin D1 and cyclin-dependent kinases (Cdk) 4.

Methods
—We used a rabbit spinal cord ischemia model with a balloon catheter. Spinal cord was removed at 8 hours and 1, 2, and 7 days after 15 minutes of transient ischemia, and histological changes were studied with hematoxylin-eosin staining. In situ terminal deoxynucleotidyl transferase (TdT)–mediated dUTP-biotin nick-end labeling (TUNEL), DNA fragment with gel electrophoresis, Western blot analysis for cyclin D1 and Cdk4, and temporal profiles of cyclin D1 and Cdk4 immunoreactivity were investigated.

Results
—Most motor neurons were preserved until 2 days but were selectively lost at 7 days of reperfusion. Immunocytochemistry showed positive TUNEL selectively at 2 days of reperfusion in spinal motor neuron nuclei. Typical ladders of oligonucleosomal DNA fragments were detected at 2 days of reperfusion. Immunoreactivity of cyclin D1 and Cdk4 proteins was induced selectively at 8 hours in motor neuron nuclei, which eventually died.

Conclusions
—These results indicate that induction of cyclin D1 and Cdk4 may be implicated in programmed cell death change after transient spinal cord ischemia in rabbits.
Risk of Stroke in Relation to Level of Blood Pressure and Other Risk Factors in Treated Hypertensive Patients
Authors: Makino Yuriko , Kawano Yuhei , Minami Junichi , Yamaguchi Takenori , Takishita Shuichi
Published: June 2011

Background and Purpose
—Treatment of hypertension effectively reduces the risk of stroke. However, many treated patients still have high blood pressure (BP), other cardiovascular risk factors, and complications. The risk of stroke in treated hypertensive patients is not well understood.

Methods
—We analyzed the level of BP over 1 year before the onset of stroke and other cardiovascular risk factors in treated hypertensive patients in a case-control study. The study population included 126 hypertensive patients (74 men; mean age, 70.9 years) with first strokes during 1988–1993 who had been treated for >1 year before stroke onset (stroke group). As a control group, we selected 126 sex- and age-matched hypertensive patients who were treated during the same period and were free from stroke.

Results
—Mean 12-month BP was not significantly different between stroke and control groups, although systolic BP was 2.5 mm Hg higher in the stroke group (148.7 [95% CI, 146.1 to 151.3]/82.1 [95% CI, 80.5 to 83.7] versus 146.2 [95% CI, 143.8 to 148.6]/82.4 [95% CI, 81.0 to 83.8] mm Hg). In patients aged <70 years, mean systolic BP was significantly higher in the stroke group than the control group (150.5 [146.3 to 154.7] versus 144.0 (140.6 to 147.4) mm Hg). Mean pulse pressure was also significantly higher in the stroke group than the control group in patients aged <70 years but not in older patients. In the stroke group, the level of BP within 1 month before stroke onset did not differ from the mean value over the 12-month period. Patients with brain hemorrhage had higher diastolic BP than those with other subtypes. The stroke group had higher plasma glucose, lower HDL cholesterol, and higher frequencies of diabetes mellitus, proteinuria, atrial fibrillation (29.4% versus 4.0%), and use of antiplatelet (31.0% versus 11.1%) and anticoagulant (10.3% versus 1.6%) agents than the control group.

Conclusions
—The onset of stroke in treated hypertensive patients was related to a higher level of BP in subjects <70 years old, although this relationship was not obvious in older patients. The risk of stroke in these patients was associated with the presence of metabolic risk factors and cardiovascular complications. Office BP did not change significantly 1 month before the onset of stroke.
Identifying Stroke in the Field
Authors: Kidwell Chelsea S. , Starkman Sidney , Eckstein Marc , Weems Kimberly , Saver Jeffrey L.
Published: June 2011

Background and Purpose
—Reliable identification of stroke patients in the field by prehospital personnel could expedite delivery of acute stroke therapy. The Los Angeles Prehospital Stroke Screen (LAPSS) is a 1-page instrument designed to allow prehospital personnel to rapidly identify acute stroke patients in the field. We performed a prospective, in-the-field validation study of the LAPSS.

Methods
—Paramedics assigned to 3 University of California at Los Angeles–based advanced life support units were trained and certified in use of the LAPSS. Over 7 months, paramedics completed the LAPSS on noncomatose, nontrauma patients with complaints suggestive of neurological disease. LAPSS form stroke identification results were compared with emergency department and final hospital discharge diagnoses. Sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and likelihood ratios were calculated for LAPSS identification of ischemic stroke, currently symptomatic transient ischemic attack, and intracerebral hemorrhage.

Results
—Of a total of 1298 runs, 34% were for nontraumatic, noncomatose neurologically relevant complaints. Thirty-six of these patients (3% of all transports) had a final diagnosis of acute symptomatic cerebrovascular disease (21 ischemic strokes, 7 transient ischemic attacks, and 8 intracerebral hemorrhages). LAPSS forms were completed on 206 patients. Paramedic performance when completing the LAPSS demonstrated sensitivity of 91% (95% CI, 76% to 98%), specificity of 97% (95% CI, 93% to 99%), positive predictive value of 86% (95% CI, 70% to 95%), and negative predictive value of 98% (95% CI, 95% to 99%). With correction for the 4 documentation errors, positive predictive value increased to 97% (95% CI, 84% to 99%).

Conclusions
—The LAPSS allows prehospital personnel to identify patients with acute cerebral ischemia and intracerebral hemorrhage with a high degree of sensitivity and specificity.
Treating Acute Stroke Patients With Intravenous tPA
Authors: Wang David Z. , Rose Jean A. , Honings Debra S. , Garwacki Dennis J. , Milbrandt Joseph C.
Published: June 2011

Background and Purpose
—Since the FDA approved tissue plasminogen activator (tPA) in 1996 for acute ischemic stroke, few data have been obtained during the postmarketing phase, and applicability in rural hospitals does not exist. We attempt to examine the safety and outcome of intravenous tPA for acute ischemic stroke in the OSF Stroke Network.

Methods
—Fifty-seven consecutive patients treated with tPA were examined from June 1996 through December 1998. Admission and discharge National Institute of Health Stroke Scales (NIHSS), modified Rankin Scales (MRS), and discharge disposition, as well as intracerebral hemorrhage and mortality rates, were compared.

Results
—Of 20 network hospitals, 12 had the experience of administering tPA. No statistically significant differences in the variables recorded were observed for patients treated at the community hospitals versus those who received tPA at the tertiary medical center. In 35% of patients, tPA was initiated by an emergency room or primary care physician in consultation with an OSF neurologist. At discharge, 47% of the patients had minimal or no disability (MRS, 0 to 1), 44% had an NIHSS score of 0 or 1, 54% went home, 25% were transferred to in-patient rehabilitation, 12% went to a nursing or skilled-care facility, and 9% died. Intracerebral hemorrhage rate was 9%; 5% were symptomatic.

Conclusions
—tPA can be administered safely with good outcome at community and rural hospitals. The OSF Stroke Network can serve as a model to assist small community hospitals to set up stroke programs and deliver up-to-date, acute stroke therapies.
DIAS I: Duplex-Sonographic Assessment of the Cerebrovascular Status in Acute Stroke
Authors: Gerriets T. , Postert T. , Goertler M. , Stolz E. , Schlachetzki F. , Sliwka U. , Seidel G. , Weber S. , Kaps M.
Published: June 2011

Background and Purpose
—A number of controlled trials have evaluated the benefit of intravenous thrombolysis in acute stroke with inconsistent results. None of these studies assessed the initial vascular status or provided information regarding the recanalization rate after therapy. Further trials need to clarify whether certain subgroups might possibly benefit more than others from intravenous thrombolysis. Therefore, a fast and valid method for assessment of cerebrovascular status is needed. In this multicenter study, we evaluated the potentials and limitations of color-coded duplex sonography (TCCS) for cerebrovascular status assessment in acute stroke patients before and after therapy. Furthermore, we compared the recanalization rate for patients referred to thrombolytic and conservative medical therapy.

Methods
—Fifty-eight patients suffering from hemispheric stroke were enrolled consecutively in 8 centers. Duplex sonography was performed on admission, 2 hours after start of therapy, and 24 hours after onset of symptoms. Therapy was started within 6 hours.

Results
—Intravenous thrombolysis was performed in 18 patients, conservative medical therapy in 39 patients, and early thromboendarterectomy in 1 patient. The middle cerebral artery (MCA) mainstem was patent in 29 patients (53.7%), occluded in 25 (46.3%), and was not assessable in 4 patients. Recanalization of the occluded MCA after 2 and 24 hours was diagnosed in 50% and 78% of the patients treated with rtPA and in 0% and 8% in the conservatively treated patients.

Conclusions
—Intravenous thrombolysis is highly effective in restoring blood flow after MCA occlusion. TCCS is suitable for assessment of the cerebrovascular status in acute stroke and therefore might define therapeutically relevant subgroups of patients in future stroke trials on the basis of their vascular pathology.
Cost and Outcome of Mechanical Ventilation for Life-Threatening Stroke
Authors: Mayer Stephan A. , Copeland Daphne , Bernardini Gary L. , Boden-Albala Bernadette , Lennihan Laura , Kossoff Sharon , Sacco Ralph L.
Published: June 2011

Background and Purpose
—Hospital mortality rates of 50% to 90% have been reported for stroke patients treated with mechanical ventilation. These data have raised serious questions about the cost-effectiveness of this intervention. We sought to determine how often stroke patients are mechanically ventilated, identify predictors of 30-day survival among ventilated patients, and evaluate the cost-effectiveness of this intervention.

Methods
—We identified mechanically ventilated patients in a population-based multiethnic cohort of 510 incidence stroke patients who were hospitalized between July 1993 and June 1996. Factors affecting 30-day survival were identified in a multiple logistic regression analysis. We calculated the cost per patient discharged alive, life-year saved, and quality-adjusted life-year saved using a zero-cost, zero-life assumption.

Results
—Ten percent of patients (n=52) were mechanically ventilated. Thirty-day mortality was 65% overall and did not differ significantly by stroke subtype. Glasgow Coma Scale score on the day of intubation (
P
<0.01) and subsequent neurological deterioration (
P
=0.02) were identified as predictors of 30-day mortality. The cost (1996 US dollars) of hospitalization per patient discharged alive was $89 400; the cost per year of life saved was $37 600; and the cost per quality-adjusted life-year saved was $174 200. Functional status of most survivors was poor; at 6 months, half were severely disabled and completely dependent. In a worst-case scenario of quality of life preferences, mechanical ventilation resulted in a net deficit of meaningful survival.

Conclusions
—Two thirds of mechanically ventilated stroke patients die during their hospitalization, and most survivors are severely disabled. Survival is particularly unlikely if patients are deeply comatose or clinically deteriorate after intubation. In our multiethnic urban population, mechanical ventilation for stroke was relatively cost-effective for extending life but not for preserving quality of life.
Outcomes of Early Endovascular Versus Surgical Treatment of Ruptured Cerebral Aneurysms
Authors: Koivisto Timo , Vanninen Ritva , Hurskainen Heleena , Saari Tapani , Hernesniemi Juha , Vapalahti Matti
Published: June 2011

Background and Purpose
—This prospective study was conducted to compare the outcomes of surgical clipping and endovascular treatment in acute (<72 hours) aneurysmal subarachnoid hemorrhage (SAH).

Methods
—One hundred nine consecutive patients were randomly assigned to either surgical (n=57) or endovascular (n=52) treatment. Clinical and neuropsychological outcome was assessed at 3 and 12 months after treatment; MRI of the brain was performed at 12 months. Follow-up angiography was scheduled after clipping and 3 and 12 months after endovascular treatment.

Results
—One year postoperatively, 43/41 (surgical/endovascular) patients had good or moderate recovery, 5/4 had severe disability or were in a vegetative state, and 9/7 had died (NS) according to intention to treat. Patients with good clinical recovery did not differ in their neuropsychological test scores. Symptomatic vasospasm (OR 2.47; 95% CI 1.45 to 4.19;
P
<0.001), poorer Hunt and Hess grade (OR 2.50; 95% CI 1.31 to 4.75;
P
=0.005), need for permanent shunt (OR 8.90; 95% CI 1.80 to 44.15;
P
=0.008), and larger size of the aneurysm (OR 1.22; 95% CI 1.02 to 1.45;
P
=0.032) independently predicted worsened clinical outcome regardless of the treatment modality. In MRI, superficial brain retraction deficits (
P
<0.001) and ischemic lesions in the territory of the ruptured aneurysm (
P
=0.025) were more frequent in the surgical group. Kaplan-Meier analysis (mean±SD follow-up 39±18 months) revealed equal survival in both treatment groups. No late rebleedings have occurred.

Conclusions
—One-year clinical and neuropsychological outcomes seem comparable after early surgical and endovascular treatment of ruptured intracranial aneurysms. The long-term efficacy of endovascular treatment in preventing rebleeding remains open.
Differences in Stroke Subtypes Among Natives and Caucasians in Boston and Buenos Aires
Authors: Saposnik Gustavo , Caplan Louis R. , Gonzalez Leonardo A. , Baird Alison , Dashe John , Luraschi Adriana , Llinas Rafael , Lepera Sandra , Linfante Italo , Chaves Claudia , Kanis Karla , Sica Roberto E. P. , Rey Raul C.
Published: June 2011

Background and Purpose
—Several issues regarding ethnic-cultural factors, sex-related variation, and risk factors for stroke have been described in the literature. However, there have been no prospective studies comparing ethnic differences and stroke subtypes between populations from South America and North America. It has been suggested that natives from Buenos Aires, Argentina, may have higher frequency of hemorrhagic strokes and penetrating artery disease than North American subjects. The aim of this study was to validate this hypothesis.

Methods
—We studied the database of all consecutive acute stroke patients admitted to the Ramos Mejia Hospital (RMH) in Buenos Aires and to the Beth Israel Deaconess Medical Center (BIMC) in Boston, Massachusetts, from July 1997 to March 1999. Stroke subtypes were classified according to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria. All information on patients (demographic, clinical, and radiographic) was recorded prospective to the assessment of the stroke subtype.

Results
—Three hundred sixty-one and 479 stroke patients were included at RMH and BIMC stroke data banks, respectively. Coronary artery disease was significantly more frequent in BIMC (
P
<0.001), whereas tobacco and alcohol intake were significantly more frequent in RMH (
P
<0.001). Intracerebral hemorrhage (
P
<0.001) and penetrating artery disease (
P
<0.001) were significantly more frequent in the RMH registry, whereas large-artery disease (
P
<0.02) and cardioembolism (
P
<0.001) were more common in the BIMC data bank.

Conclusions
—Penetrating artery disease and intracerebral hemorrhage were the most frequent stroke subtypes in natives from Buenos Aires. Lacunar strokes and intracerebral hemorrhage were more frequent among Caucasians from Buenos Aires than Caucasians from Boston. Poor risk factor control and dietary habits could explain these differences.
Cerebral Microembolism Detected by Transcranial Doppler During Cardiac Procedures
Authors: Stygall Jan , Kong Robert , Walker J. Malcolm , Hardman Suzanna M. C. , Harrison Michael J. G. , Newman Stanton P.
Published: June 2011

Background and Purpose
—Cerebral embolism with clinical sequelae may rarely complicate cardioversion and cardiac catheterization. Transcranial Doppler sonography has recently been introduced to monitor microemboli entering the middle cerebral artery in cardiac and carotid surgery. We therefore used this technique to evaluate the risk of asymptomatic embolism during common cardiac procedures.

Methods
—Patients were monitored by transcranial Doppler while undergoing direct current cardioversion (n=15) and cardiac catheterization (n=17).

Results
—Microemboli were detected in all patients having cardiac catheterization but in only 1 patient after cardioversion.

Conclusions
—Microembolism occurred frequently during cardiac catheterization and rarely during cardioversion. It is not yet known whether this has clinical relevance.
Combined Intravenous and Intra-Arterial Recombinant Tissue Plasminogen Activator in Acute Ischemic Stroke
Authors: Ernst Robert , Pancioli Arthur , Tomsick Thomas , Kissela Brett , Woo Daniel , Kanter Daniel , Jauch Edward , Carrozzella Janice , Spilker Judith , Broderick Joseph
Published: June 2011

Background and Purpose
—A retrospective analysis was performed on 20 consecutive patients who presented with severe acute ischemic stroke and were evaluated for a combined intravenous (IV) and local intra-arterial (IA) recombinant tissue plasminogen activator (rtPA) thrombolytic approach within 3 hours of onset.

Methods
—Twenty consecutive patients with carotid artery distribution strokes were evaluated and treated using a combined IV and IA rtPA approach over a 14-month period (September 1998 to October 1999). rtPA (0.6 mg/kg) was given intravenously (maximum dose 60 mg); 15% of the IV dose was given as bolus, followed by a continuous infusion over 30 minutes. A maximal IA dose, up to 0.3 mg/kg or 24 mg, whichever was less, was given over a maximum of 2 hours. IV treatment was initiated within 3 hours in 19 of 20 patients. All 20 patients underwent angiography, and 16 of 20 patients received local IA rtPA.

Results
—The median baseline National Institutes of Health Stroke Scale (NIHSS) score for the 20 patients was 21 (range 11 to 31). The median time from stroke onset to IV treatment was 2 hours and 2 minutes, and median time to initiation of IA treatment was 3 hours and 30 minutes. Ten patients (50%) recovered to a modified Rankin Scale (mRS) of 0 or 1; 3 patients (15%), to an mRS of 2; and 5 patients (25%), to an mRS of 4 or 5. One patient (5%) developed a symptomatic intracerebral hemorrhage and eventually died. One other patient (5%) expired because of complications from the stroke.

Conclusions
—We believe that the greater-than-expected proportion of favorable outcomes in these patients with severe ischemic stroke reflects the short time to initiation of both IV and IA thrombolysis.
Determinants of Use of Emergency Medical Services in a Population With Stroke Symptoms
Authors: Schroeder Emily B. , Rosamond Wayne D. , Morris Dexter L. , Evenson Kelly R. , Hinn Albert R.
Published: June 2011

Background and Purpose
—With the advent of time-dependent thrombolytic therapy for ischemic stroke, it has become increasingly important for stroke patients to arrive at the hospital quickly. This study investigates the association between the use of emergency medical services (EMS) and delay time among individuals with stroke symptoms and examines the predictors of EMS use.

Methods
—The Second Delay in Accessing Stroke Healthcare Study (DASH II) was a prospective study of 617 individuals arriving at emergency departments in Denver, Colo, Chapel Hill, NC, and Greenville, SC, with stroke symptoms.

Results
—EMS use was associated with decreased prehospital and in-hospital delay. Those who used EMS had a median prehospital delay time of 2.85 hours compared with 4.03 hours for those who did not use EMS (
P
=0.002). Older individuals were more likely to use EMS (odds ratio [OR] 1.21 for each 5-year increase, 95% CI 1.14 to 1.29), as were individuals who expressed a high sense of urgency about their symptoms (OR 1.69, 95% CI 1.09 to 2.62). Knowledge of stroke symptoms was not associated with increased EMS use (OR 0.63, 95% CI 0.40 to 0.98). Patients were more likely to use EMS if someone other than the patient first identified that there was a problem (OR 2.35, 95% CI 1.61 to 3.44).

Conclusions
—Interventions aimed at increasing EMS use among stroke patients need to stress the urgency of stroke symptoms and the importance of calling 911 and need to be broad-based, encompassing not only those at high risk for stroke but also their friends and family.
Estrogen Decreases Infarct Size After Temporary Focal Ischemia in a Genetic Model of Type 1 Diabetes Mellitus
Authors: Toung Thomas K. , Hurn Patricia D. , Traystman Richard J. , Sieber Frederick E.
Published: June 2011

Background and Purpose
—It is unclear how genetic type 1 diabetes mellitus (DM) influences infarct size when blood glucose is tightly controlled. The aim of this study was to determine the effect of genetic type 1 DM, as occurs in BB rats, on infarct size after transient unilateral middle cerebral artery occlusion (MCAO) in male and female rats. In addition, studies suggest that male type 1 DM rats have a higher incidence of end-organ complications than do females. A second aim of this study was to determine the effect of chronic 17β-estradiol (E
2
) administration on infarct size in male BB rats.

Methods
—Diabetic male (MDiab, n=14) and female (FDiab, n=8) BB rats were studied and compared with background strain Wistar rats (MWist, n=16; FWist, n=14). Two additional male cohorts (MWist+E
2
, n=15; MDiab+E
2
, n=14) received subcutaneous 25 μg E
2
implants 7 to 10 days before MCAO. Rats underwent 1 hour of MCAO followed by 22 hours of reperfusion. Physiological variables were controlled among groups, and the intraischemic laser Doppler flow signal was reduced similarly in all animals. Infarction volume was evaluated by 2,3,5-triphenyltetrazolium chloride staining and image analysis.

Results
—Preischemic blood glucose was 94±5, 127±13, 90±15, 63±18, 122±8, and 81±14 mg/dL in MWist, FWist, MDiab, FDiab, MWist+E
2
, and MDiab+E
2
rats, respectively (mean±SE). Intraischemic laser Doppler flow was reduced to 20% to 25% of baseline in all groups. Striatal infarct size (percentage of ipsilateral caudate putamen) was increased in male diabetic rats relative to nondiabetic MWist rats (41±3% versus 28±3%). Striatal injury was not increased in FDiab rats, and infarction volume was smaller than that in FWist rats (23±4% in FWist versus 13±3% in FDiab). Chronic estrogen treatment reduced cortical and striatal infarction in MDiab+E
2
rats compared with untreated MDiab rats.

Conclusions
—Type 1 DM is associated with increased infarct size after temporary MCAO, despite tight control of blood glucose. The deleterious effect of DM is evident only in males rats; female diabetic BB rats sustain small infarcts. Chronic E
2
treatment reduced injury in the male BB rat, providing neuroprotection even in the presence of DM. These data suggest that genetic diabetes even with mild glucose elevation plays a role in determining neuropathology in experimental stroke. However, factors such as reproductive steroids also determine outcome in DM stroke.
Dynamic Cerebral Autoregulation Is Unaffected by Aging
Authors: Carey Brian J. , Eames Penelope J. , Blake Melanie J. , Panerai Ronney B. , Potter John F.
Published: June 2011

Background and Purpose
—Normal aging is associated with marked changes in the cardiovascular and cerebrovascular systems. Although cerebral autoregulation (CA) is impaired in certain disease states, the effect of age per se on dynamic CA in humans is unknown and the focus of this study.

Methods
—Twenty-seven young subjects (≤40 years) and 27 older subjects (≥55 years), matched for sex and systolic blood pressure (BP), underwent measurement of cerebral blood flow velocity by transcranial Doppler ultrasound and noninvasive beat-to-beat arterial BP measurement during induced and spontaneous dynamic BP stimuli. A standard dynamic autoregulatory index (ARI) was derived for each spontaneous and induced dynamic BP stimulus to include the step response, as well as cardiac baroreceptor sensitivity (BRS), for the 2 groups.

Results
—The mean age of the young group was 29±5 years, and that of the older group was 68±5 years. Cardiac BRS was reduced in the older group (8.6±4.5 versus 16.9±8.8 ms/mm Hg;
P
<0.0001). However, no age-related differences were demonstrated in step response plots or in ARI values for any pressor or depressor dynamic BP stimulus (
P
=0.62), with mean ARI values for all stimuli combined being 4.9±1.8 for the young group and 5.0±2.3 for the older group.

Conclusions
—Although increasing age is associated with a decrease in cardiac BRS, dynamic CA, as assessed by step response analysis as well as cerebral blood flow responses to transient and induced BP stimuli, is unaffected by aging.
Benefit of an Extended Stroke Unit Service With Early Supported Discharge
Authors: Indredavik Bent , Fjærtoft Hild , Ekeberg Gun , Løge Anne D. , Mørch Birgitte
Published: June 2011

Background and Purpose
—Several trials have shown that stroke unit care improves outcome for stroke patients. The aim of the present trial was to evaluate the effects of an extended stroke unit service (ESUS), with early supported discharge, cooperation with the primary healthcare system, and more emphasis on rehabilitation at home as essential elements.

Methods
—In a randomized, controlled trial, 160 patients with acute stroke were allocated to the ESUS and 160 to the ordinary stroke unit service (OSUS). The primary outcome was the proportion of patients who were independent as assessed by the modified Rankin Scale (RS) (RS ≤2=global independence) and independent in activities of daily living (ADL) as assessed by Barthel Index (BI) (BI ≥95=independent in ADL) after 26 weeks. Secondary outcomes were RS and BI scores after 6 weeks; the proportion of patients at home, in institutions, and deceased after 6 and 26 weeks; and the length of stay in institutions.

Results
—After 26 weeks, 65.0% in the ESUS versus 51.9% in the OSUS group showed global independence (RS ≤2) (
P=
0.017)
,
while 60.0% in the ESUS versus 49.4% in the OSUS group were independent in ADL (BI ≥95) (
P
=0.056). The odds ratios for independence (ESUS versus OSUS) were as follows: RS, 1.72 (95% CI, 1.10 to 2.70); BI, 1.54 (95% CI, 0.99 to 2.39). At 6 weeks, 54.4% of the ESUS group and 45.6% of the OSUS group were independent according to RS (
P
=0.118), and 56.3% versus 48.8% were independent according to BI (
P
=0.179). The proportion of patients at home after 6 weeks was 74.4% for ESUS and 55.6% for OSUS (
P
=0.0004), and the proportion in institutions was 23.1% versus 40.0%, respectively (
P
=0.001). After 26 weeks, 78.8% in the ESUS group versus 73.1% in the OSUS were at home (
P
=0.239), while 13.1% versus 17.5% were in institutions (
P
=0.277). The mortality in the 2 groups did not differ. Average lengths of stay in an institution were 18.6 days in the ESUS and 31.1 days in the OSUS group (
P
=0.0324).

Conclusions
—An ESUS with early supported discharge seems to improve functional outcome and to reduce the length of stay in institutions compared with traditional stroke unit care.
Early [
11
C]Flumazenil/H
2
O Positron Emission Tomography Predicts Irreversible Ischemic Cortical Damage in Stroke Patients Receiving Acute Thrombolytic Therapy
Authors: Heiss Wolf-Dieter , Kracht Lutz , Grond Martin , Rudolf Jobst , Bauer Bernd , Wienhard Klaus , Pawlik Gunter
Published: June 2011

Background and Purpose
—Central benzodiazepine receptor ligands, such as [
11
C]flumazenil (FMZ), are markers of neuronal integrity and therefore might be useful in the differentiation of functionally and morphologically damaged tissue early in ischemic stroke. We sought to assess the value of a benzodiazepine receptor ligand for the early identification of irreversible ischemic damage to cortical areas that cannot benefit from reperfusion.

Methods
—Eleven patients (7 male, 4 female, aged 52 to 75 years) with acute, hemispheric ischemic stroke were treated with alteplase (recombinant tissue plasminogen activator; 0.9 mg/kg according to National Institute of Neurological Disorders and Stroke protocol) within 3 hours of onset of symptoms. At the beginning of thrombolysis, cortical cerebral blood flow ([
15
O]H
2
O) and FMZ binding were assessed by positron emission tomography (PET). Those early PET findings were related to the change in neurological deficit (National Institutes of Health Stroke Scale) and to the extent of cortical damage on MRI or CT 3 weeks after the stroke.

Results
—Hypoperfusion was observed in all cases, and in 8 patients the values were below critical thresholds estimated at 12 mL/100 g per minute, comprising 1 to 174 cm
3
of cortical tissue. Substantial reperfusion was seen in most of these regions 24 hours after thrombolysis. In 4 cases, distinct areas of decreased FMZ binding were detected. Those patients suffered permanent lesions in cortical areas corresponding to their FMZ defects (112 versus 146, 3 versus 3, 2 versus 1, and 128 versus 136 cm
3
). In the other patients no morphological defects were detected on MRI or CT, although blood flow was critically decreased in areas ranging in size up to 78 cm
3
before thrombolysis.

Conclusions
—These findings suggest that imaging of benzodiazepine receptors by FMZ PET distinguishes between irreversibly damaged and viable penumbra tissue early after acute stroke.
Identification of Patients at Risk for Periprocedural Neurological Deficits Associated With Carotid Angioplasty and Stenting
Authors: Qureshi Adnan I. , Luft Andreas R. , Janardhan Vallabh , Suri M. Fareed K. , Sharma Mudit , Lanzino Giuseppe , Wakhloo Ajay K. , Guterman Lee R. , Hopkins L. Nelson
Published: June 2011

Background and Purpose
—Transient or permanent neurological deficits can occur in the periprocedural period following carotid angioplasty and stenting (CAS), presumably due to distal embolization and/or hemodynamic compromise. We performed this study to identify predictors of neurological deficits associated with carotid angioplasty and stent placement.

Methods
—We reviewed medical records and angiograms in a consecutive series of patients who underwent CAS for symptomatic or asymptomatic cervical internal carotid artery stenosis from June 1996 through December 1998. Using logistic regression analysis, we evaluated the effect of demographic, clinical, intraprocedural, and angiographic risk factors on subsequent development of periprocedural neurological deficits. Periprocedural neurological deficits were defined as new or worsening transient or permanent neurological deficits that occurred during or within 48 hours of the procedure.

Results
—A total of 111 patients (mean age 68.2±9.1 years) who underwent CAS for asymptomatic (n=54) or symptomatic (n=57) stenoses were included in this study. A total of 14 periprocedural neurological deficits (13%) were observed either during (n=4) or after (n=10) the procedure. Three identified variables were independently associated with periprocedural neurological deficits: symptomatic lesion (OR 8.3, 95% CI 1.6 to 42.6), length of stenotic segment ≥11.2 mm (OR 5.2, 95% CI 1.2 to 22.5), and absence of hypercholesterolemia (OR 5.4, 95% CI 1.4 to 20.9). Other variables, including age and degree of stenosis (defined by NASCET criteria), were not associated with periprocedural neurological deficits.

Conclusions
—A combination of clinical and angiographic variables can be used to identify patients at risk for periprocedural neurological deficits after CAS. Such identification may help in selection of patients who may benefit from novel pharmacological and mechanical preventive approaches.
Blood Pressure Exceeding National Guidelines Among Women After Stroke
Authors: Kernan Walter N. , Viscoli Catherine M. , Brass Lawrence M. , Makuch Robert W. , Sarrel Philip M. , Horwitz Ralph I.
Published: June 2011

Background and Purpose
—After a transient ischemic attack or stroke, the risk for recurrence may be reduced by treatment of hypertension. The purpose of this study was to determine how commonly blood pressure exceeds national guidelines among patients who have had one of these events.

Methods
—Subjects were 644 women participating in a randomized trial of estrogen for secondary stroke prevention. We measured blood pressure 1 month after the stroke or TIA while patients were under the care of their personal physicians. Among 536 patients, a second measure was made at an average of 2.9 years after the first.

Results
—The mean age of participants was 71 years, and 73% reported a history of hypertension. At baseline, only 44% (280/644) of the women had blood pressure values within national guidelines (<140/90 mm Hg). With separate guidelines used for diabetics (<130/85 mm Hg) and nondiabetics (<140/90 mm Hg), the proportions of women within the guidelines were 27% and 44%, respectively. Overall, 39% of patients were within the diabetes-adjusted guidelines. Among patients whose blood pressure exceeded 140/90 mm Hg at first examination, 55% were still in excess at follow-up. Features associated with severe hypertension at first examination (>160/100 mm Hg) were history of hypertension, education less than college, and higher cognitive functioning.

Conclusions
—Blood pressure values in excess of national guidelines are common after stroke and TIA, especially among diabetic patients. Efforts to lower blood pressure control may enhance secondary prevention.
Control of Blood Pressure and Risk of Stroke Among Pharmacologically Treated Hypertensive Patients
Authors: Klungel Olaf H. , Kaplan Robert C. , Heckbert Susan R. , Smith Nicholas L. , Lemaitre Rozenn N. , Longstreth W. T. , Leufkens Hubert G. M. , de Boer Anthonius , Psaty Bruce M.
Published: June 2011

Background and Purpose
—Despite improved control of blood pressure during the last decades in the United States, a considerable proportion of treated hypertensives have not achieved target blood pressure levels. We estimated the proportion of strokes occurring among treated hypertensive patients that may be attributable to uncontrolled blood pressure.

Methods
—A population-based case-control study was conducted among treated hypertensive members of Group Health Cooperative of Puget Sound. Cases were treated hypertensive patients who sustained a first fatal or nonfatal, ischemic (n=460) or hemorrhagic (n=95) stroke during 1989–1996. Controls were a random sample of stroke-free, treated hypertensive Group Health Cooperative enrollees (n=2966), similar in age to the stroke cases. Multiple measurements of blood pressure and other cardiovascular risk factors were collected from medical records. Logistic regression was used to estimate the risk of ischemic stroke and hemorrhagic stroke associated with uncontrolled blood pressure, defined as diastolic blood pressure >90 mm Hg or systolic blood pressure >140 mm Hg. The fraction of strokes attributable to uncontrolled blood pressure among treated hypertensives was calculated.

Results
—Blood pressure was uncontrolled in 78% of ischemic stroke cases, 85% of hemorrhagic stroke cases, and 65% of controls. After adjustment for potential confounders, uncontrolled blood pressure among treated hypertensive patients was moderately associated with ischemic stroke (risk ratio=1.5 [95% CI, 1.2 to 1.9]) and strongly related to hemorrhagic stroke (risk ratio=3.0 [95% CI, 1.7 to 5.4]). We estimated that 27% (95% CI, 11% to 39%) of the ischemic strokes and 57% (95% CI, 26% to 75%) of the hemorrhagic strokes among treated hypertensive patients were attributable to uncontrolled blood pressure. Overall, 32% (95% CI, 14% to 45%) of all strokes were attributable to uncontrolled blood pressure.

Conclusions
—A considerable proportion of incident strokes among treated hypertensive patients may be prevented by achieving control of blood pressure.