bluuebunny/crossref_metadata_2025 huggingface dataset:
Motor and perceptual impairments in acute stroke patients: effects on self-care ability.
Authors: Bernspång B , Asplund K , Eriksson S , Fugl-Meyer A R
Published: June 2011

The relative importance of motor, perceptual, and some cognitive functions for self-care ability was analyzed in a representative sample of 109 subjects within 2 weeks of acute stroke. Forty-nine patients (45%) were dependent or partly dependent in self-care. Profound motor dysfunction was present in 39%, low-order perceptual deficits in 10%, high-order perceptual deficits in 60%, and disorientation in time and space in 13% of the patients. There was a significant covariation between motor function and self-care ability and between low-order perception and orientation function. Low-order and high-order perception covaried only weakly. Discriminant analyses showed that the actual level of self-care proficiency could be correctly predicted in 70% of the cases by the 4 indexes of motor function, low-order perception, high-order perception, and orientation. The dominating predictor was motor function, and the next highest was high-order perception. When a program for early training is designed with the aim to alleviate long-term self-care disability after stroke, correct assessment of motor and perceptual functions in the individual stroke patient is essential.
Silent cerebral infarction in chronic atrial fibrillation.
Authors: Petersen P , Madsen E B , Brun B , Pedersen F , Gyldensted C , Boysen G
Published: June 2011

Atrial fibrillation (AF) is associated with an increased risk of stroke. In AF patients with acute stroke, cerebral computed tomography (CT) often reveals old asymptomatic infarcts. To investigate the frequency of such lesions, 29 AF patients and 29 controls in sinus rhythm without history of cerebrovascular disease were CT scanned. Fourteen patients with AF (48%) had abnormal CT scans with areas of low density with sharp demarcation from surrounding tissue compared with 8 patients in sinus rhythm (28%) (p greater than 0.10). However, the number of abnormal areas with apparent tissue loss was significantly higher in the AF group (39 lesions) compared with the control group (16 lesions) (p = 0.033). The lesions were mainly located in the cortex with no significant difference in lesion size between AF patients and controls. The abnormal areas probably reflected small, clinically silent infarcts. We conclude that these lesions are present in AF patients without history of cerebrovascular events and occur more frequently than in controls without atrial fibrillation.
Hematocrit and clinical outcome in acute cerebral infarction.
Authors: Ozaita G , Calandre L , Peinado E , Rodríguez-Antigüedad A , Bermejo F
Published: June 2011

Hematocrits of 131 cerebral infarction cases were correlated with the outcome at 2 weeks. Bivariate analysis showed that cases with more intense admission deficit had lower admission hematocrit and that cases with poorer outcome had lower Day 2 and 4 hematocrits. However, multivariate analysis of several prognostic factors (including hematocrit, glycemia, blood pressure, age, and sex) showed that hematocrit was not independently related to outcome. Higher hematocrit thus is not indicative of less favorable short-term outcome.
Failure of heparin to prevent progression in progressing ischemic infarction.
Authors: Haley E C , Kassell N F , Torner J C
Published: June 2011

Anticoagulation with heparin is frequently recommended for patients with progressing ischemic cerebral infarction, yet little data is available detailing the acute results of treatment with this agent. We report the results of continuous intravenous heparin treatment in 36 consecutive patients admitted with progressing ischemic infarction, all of whom had computed tomography scans to exclude the diagnosis of hemorrhage prior to treatment. Overall, 18 of 36 (50%) had continued neurologic worsening despite treatment. The incidence of further worsening was greater in carotid territory infarctions (14 of 19, 74%) than in either vertebrobasilar (2 of 8, 25%) or lacunar (2 of 9, 22%) infarctions (p less than 0.05, Fisher's exact test). These observations suggest that additional controlled studies of the efficacy of heparin in progressing ischemic infarction are warranted.
Duplex scanning in extracranial vertebral artery dissection.
Authors: Touboul P J , Mas J L , Bousser M G , Laplane D
Published: June 2011

Ultrasonic (duplex scanning and continuous-wave Doppler) and angiographic findings in three patients with bilateral extracranial vertebral artery dissection are reported. A pattern of ultrasonic anomalies diagnostic of dissection is described, including association of a localized increase in diameter of the artery with hemodynamic signs of stenosis or occlusion at the same level and decreased pulsatility and presence of intravascular echoes in the enlarged segment.
Cerebral perfusion reserve indexes determined by fluoromethane positron emission scanning.
Authors: Levine R L , Sunderland J J , Lagreze H L , Nickles R J , Rowe B R , Turski P A
Published: June 2011

An index of cerebral perfusion reserve (RES%), defined as the percent change of regional cerebral blood flow over baseline per mm Hg of end-tidal CO2 tension, was determined for each middle cerebral artery (MCA) territory in patients with unilateral carotid distribution transient ischemic attacks or minor cerebrovascular accidents and was compared with that of age-matched, neurologically normal volunteers. Vasodilator responses to induced hypercapnia were tested during inhalation of 5% CO2 in 95% O2 while regional cerebral blood flow was measured by fluoromethane inhalation positron emission tomography. Mean RES% for 24 normal MCA territories was 5.2 +/- 0.8%. Mean RES% for 15 patient nonischemic MCA territories was 3.8 +/- 1.3% and for 15 ischemic MCA territories was 2.8 +/- 1.9% (both p less than 0.001). Individual RES% values and symmetry ratios between ischemic and nonischemic regions were also determined and compared with angiographic data. Areas of diminished, asymmetric, or paradoxical (two patients) CO2 reactivity appear to correspond to areas of compensatory vasodilation. We found this technique to be a safe and reproducible method for defining and recording localized areas of cerebral tissue at apparent risk for hemodynamically related damage.
Evolving focal cerebral ischemia in cats: spatial correlation of nuclear magnetic resonance imaging, cerebral blood flow, tetrazolium staining, and histopathology.
Authors: Bose B , Jones S C , Lorig R , Friel H T , Weinstein M , Little J R
Published: June 2011

The spatial correlation of nuclear magnetic resonance imaging (NMRI) and cerebral blood flow (CBF) may improve our ability to identify ischemic brain lesions and may provide further insight into the pathophysiology of early cerebral ischemia. Eleven pentobarbital-anesthetized adult cats underwent exposure of the common carotid arteries bilaterally and the right middle cerebral artery through a transorbital approach. Baseline NMRI images were obtained with a single spin-echo, multislice technique using a 0.6-T field, 0.4-cm slice thickness, and a surface coil. Focal ischemia was produced with right middle cerebral artery occlusion and potentiated with bilateral common carotid artery ligation. Sequential NMRI studies were then performed at 1, 2, 4, 6, and 12 hours or until CBF was determined in the same cats using [14C]iodoantipyrine at either 2 (n = 2), 4 (n = 2), 6 (n = 2), or 12 (n = 1) hours after the time of occlusion. This protocol allowed temporal and spatial correlation of NMRI and CBF. Alternate 5-mm brain slices were incubated with 1% 2,3,5-triphenyltetrazolium chloride (TTC) for 45 minutes at 37-41 degrees C and frozen in liquid Freon for later autoradiographic CBF determination. Four cats were studied only with NMRI and TTC (not CBF). The correlation between areas of increased NMRI signal intensity observed in T2-weighted images (repetition time 2,000 msec, echo time 120 msec), vital staining with TTC, low CBF, and routine histology was evaluated. During the early phase (less than 6 hours), T2-weighted NMRI changes were localized to the central ischemic gray matter areas, as defined in the later CBF images, with no involvement of the white matter. By the twelfth hour the NMRI changes involved the entire ischemic area including gray and white matter. The initial visible changes seen on T2-weighted NMRI are suggestive of cellular edema, and the later changes are characteristic of vasogenic edema. The spread of NMRI changes compared with the ischemic area determined from autoradiographic CBF is consistent with the previously described biphasic evolution of ischemic injury. These data suggest that T2-weighted NMRI could be used clinically to delineate areas of acute ischemic stroke.
Stroke rehabilitation outcome: impact of coronary artery disease.
Authors: Roth E J , Mueller K , Green D
Published: June 2011

The frequency of clinically significant coronary artery disease (CAD) among stroke patients and the impact of CAD on stroke rehabilitation were studied in 132 patients with first thrombotic or embolic stroke who participated in comprehensive rehabilitation. Sixty-one patients (46%) had a history of CAD, and 16 of the 61 also had congestive heart failure (CAD-CHF). Patients with CAD, and especially those with CAD-CHF, had significantly longer intervals from stroke onset to rehabilitation admission (p less than 0.001), and once in rehabilitation they experienced three times as many cardiac complications (p less than 0.001). While all patient groups improved function during rehabilitation, those with CAD and CAD-CHF improved significantly less than did those without CAD (p less than 0.01). Patients with CAD did least well with rolling, moving in bed, transferring from a wheelchair to bed, and walking. CHF not only adversely influenced overall function and mobility task performance but also affected the potential for achieving functional gains. These data suggest that specific measures of function and rehabilitation are affected by CAD and that the levels of achievement for patients with CAD-CHF are limited.
Intracerebral hemorrhage in a Japanese community, Hisayama: incidence, changing pattern during long-term follow-up, and related factors.
Authors: Ueda K , Hasuo Y , Kiyohara Y , Wada J , Kawano H , Kato I , Fujii I , Yanai T , Omae T , Fujishima M
Published: June 2011

The incidence of intracerebral hemorrhage over 13 years is compared between two Hisayama cohorts. Among men aged 40 years or older, the annual incidence declined significantly from 3.1/1,000 in the early cohort (1961-1970) to 1.2/1,000 in the recent cohort (1974-1983). Massive ganglionic hemorrhage decreased, while small or medium-sized intracerebral hemorrhage increased in the recent cohort on pathologic or computed tomographic examination. These trends could be due to the reduced prevalence of hypertension in the Hisayama population. The association of serum total cholesterol with intracerebral hemorrhage is discussed based on the results during a 22-year follow-up period.
Erythrocytes are essential for development of cerebral vasculopathy resulting from subarachnoid hemorrhage in cats.
Authors: Duff T A , Louie J , Feilbach J A , Scott G
Published: June 2011

In an effort to determine which blood elements play a critical role in the development of cerebral vasospasm, adult cats were subjected to prepontine injection of either autogenous whole blood or erythrocyte-free blood containing latex beads as a substitute morphologic marker. Seven or 10 days later the cats were anesthetized and perfused with fixative, and the basilar arteries were prepared for light and electron microscopy. Successful clot deposition was confirmed by the presence of numerous erythrocytes or latex beads within the adventitia of vessels. In agreement with previous studies, instillation of whole blood produced luminal narrowing associated with profound ultrastructural changes in all layers of the vascular wall. No significant alterations, however, occurred in arteries bathed in erythrocyte-free blood. These findings suggest first, that erythrocytes are essential for the development of the vasculopathy associated with chronic cerebral vasospasm, and second, that the role, if any, of other blood elements is not autonomous.
The common carotid circulation in patients with essential hypertension.
Authors: Safar M E , Laurent S , Benetos A , London G M
Published: June 2011

We review carotid artery hemodynamics in hypertensive men, with particular reference to common carotid artery diameter and blood flow, and emphasize the changes in artery diameter and compliance implied by antihypertensive therapy.
Transient ischemic attacks and normal cerebral angiograms: a follow-up study.
Authors: Shuaib A , Hachinski V C , Oczkowski W J
Published: June 2011

To determine the outcome of patients with carotid transient ischemic attacks (TIAs) and normal cerebral angiograms, we assessed 68 patients (40 men, 28 women) aged 24-72 (mean 53.5) years for recurrent TIAs and strokes and for the development of cardiac disease over 2-6 (mean 4.4) years. All but one patient had a follow-up interview in early 1987; that patient had died of an unrelated cause (lung cancer) 18 months after the presenting TIA. The diagnosis was changed at the follow-up interview in three patients (multiple sclerosis, meningioma, migraine). Among the 64 remaining patients, at admission cranial computed tomography had shown cerebral infarction in 11 of 64, two-dimensional echocardiography had been abnormal in nine of 61, Holter monitoring had been abnormal in eight of 45, and twelve-lead electrocardiography had been abnormal in three of 64. Two patients had abnormalities on both echocardiography and Holter monitoring. At the follow-up interview of the 64 remaining patients, TIAs had recurred in nine and three had developed a completed stroke; cardiac disease (angina in seven, myocardial infarction in four) was noted in 11 patients. Findings from cardiac investigations on admission in the nine patients with recurrent TIAs had been abnormal in six and normal in three; all three patients who developed a stroke had had abnormal cardiac findings. Overall, further neurologic or cardiac events occurred in 12 of 46 patients (26%) with normal and in 10 of 18 patients (55.5%) with abnormal findings on admission (p less than 0.01). In the presence of normal angiograms, extensive cardiac investigations may help predict the outcome of patients with TIAs.
Prediction of delayed cerebral ischemia, rebleeding, and outcome after aneurysmal subarachnoid hemorrhage.
Authors: Hijdra A , van Gijn J , Nagelkerke N J , Vermeulen M , van Crevel H
Published: June 2011

Using logistic regression, we analyzed the predictive value of a number of entry variables with respect to the outcome variables delayed cerebral ischemia, rebleeding, and poor outcome (death or severe disability) in patients with aneurysmal subarachnoid hemorrhage. The entry variables were clinical condition on admission (grades on the Glasgow Coma Scale, Hunt and Hess system), the amount of subarachnoid and intraventricular blood and the presence of hydrocephalus on the admission computed tomogram, and antifibrinolytic treatment with tranexamic acid. We used data from a prospectively studied population of 176 patients admitted within 72 hours after subarachnoid hemorrhage. The risk of delayed cerebral ischemia was best predicted by the amount of subarachnoid blood, intraventricular blood, and antifibrinolytic treatment irrespective of clinical condition and hydrocephalus. The site of delayed cerebral ischemia was not related to the location of the subarachnoid hemorrhage. Antifibrinolytic treatment was the only entry variable (negatively) predicting the risk of rebleeding. Death or severe disability after 3 months was best predicted by the amount of subarachnoid blood and the initial clinical condition reflected by the grade on the Glasgow Coma Scale.
Calcium channel blockers correct acidosis in ischemic rat brain without altering cerebral blood flow.
Authors: Berger L , Hakim A M
Published: June 2011

We compared the effects of intravenous infusions of 40 micrograms/kg/min verapamil (n = 5), 0.5 microgram/kg/min nimodipine (n = 5), and 5 ng/kg/min prostacyclin (n = 6) and no treatment (n = 6) on local cerebral pH and local cerebral blood flow in middle cerebral artery-occluded rats 90 minutes after the ischemic insult. Local cerebral pH and local cerebral blood flow were determined simultaneously by a double-label autoradiographic technique. The infusions were started 15 minutes after completion of the occlusion and ended at decapitation 90 minutes after completion of the occlusion. Cortical pH for four regions in the ischemic middle cerebral artery territory of rats receiving verapamil or nimodipine was normalized (mean +/- SEM 6.90 +/- 0.02 and 7.01 +/- 0.01, respectively, for the parietal, sensorimotor, frontal, and auditory cortexes), while mean +/- SEM pH in rats receiving prostacyclin was 6.79 +/- 0.01; in untreated rats, mean +/- SEM pH in the same brain regions was 6.72 +/- 0.01. Local cerebral pH in the verapamil- or nimodipine-treated rats was thus significantly different from that in untreated rats (p less than 0.05). Local cerebral blood flow in treated rats was not different from that in untreated ones. Our findings suggest that calcium channel blockers correct ischemic cerebral acidosis by metabolic mechanisms rather than by changes in blood flow.
White matter signal abnormalities in normal individuals: correlation with carotid ultrasonography, cerebral blood flow measurements, and cerebrovascular risk factors.
Authors: Fazekas F , Niederkorn K , Schmidt R , Offenbacher H , Horner S , Bertha G , Lechner H
Published: June 2011

We studied 52 asymptomatic subjects using magnetic resonance imaging, and we compared age-matched groups (51-70 years old) with and without white matter lesions with respect to carotid ultrasonography, cerebral blood flow (xenon-133 injection), and cerebrovascular risk factors. In the group with white matter signal abnormalities, we noted a higher frequency of extracranial carotid artery disease, a lower mean gray matter blood flow (F1), and a significant reduction (p less than 0.05) in blood flow of the slow-flowing (F2) compartment. Hypertension, diabetes mellitus, and cardiac diseases (p less than 0.002) were found more often in this group. Our results indicate that a higher incidence of changes known to be associated with an increased risk for stroke exists in the presence of white matter lesions in normal elderly individuals.
Dramatic changes in the performance of endarterectomy for diseases of the extracranial arteries of the head.
Authors: Pokras R , Dyken M L
Published: June 2011

Data from the National Hospital Discharge Survey have been reviewed each year to estimate the number of endarterectomies of extracranial vessels of head and neck performed in nonfederal hospitals in the United States. The number dramatically increased from 15,000 in 1971 to 107,000 in 1985. Regression estimates using data from 1971-1985 indicate that 127,000 procedures were expected for 1986, but the observed estimate indicated a dramatic drop to 83,000. Data reviewed suggest that on balance this reduction may have a favorable effect on stroke mortality and morbidity.
Importance of cerebral collateral pathways during carotid endarterectomy.
Authors: Schneider P A , Ringelstein E B , Rossman M E , Dilley R B , Sobel D F , Otis S M , Bernstein E F
Published: June 2011

Before surgery, we evaluated major intracranial collateral pathways using transcranial Doppler ultrasonography (TCD) in 50 patients who then underwent carotid endarterectomy with concurrent multimodality cerebral monitoring. Patients were grouped with respect to collateral pathways demonstrated preoperatively by TCD: Group 1, good collateralization with an anterior and/or posterior communicating artery ipsilateral to the operative carotid lesion (29 patients, 58%); Group 2, collateral pathways present but impeded by other proximal stenoses (nine patients, 18%); and Group 3, no collateralization identified (nine patients, 18%). Three patients (6%) could not be classified. TCD identified major collateral pathways with a sensitivity of 89% and a specificity of 80% when compared with arteriography. During carotid endarterectomy mean middle cerebral artery velocity, pulsatility index, and stump pressure were higher and the decrease in middle cerebral artery velocity with extracranial carotid artery cross clamping was significantly less among Group 1 patients than among Group 2 and 3 patients (p less than 0.05 for both groups). Group 1 patients required fewer intraoperative carotid artery shunts and developed fewer ischemic electroencephalographic abnormalities than did patients in Groups 2 and 3 (p less than 0.05 for both groups). TCD assessment of cerebral collateralization helps predict hemodynamic consequences of cross clamping during carotid endarterectomy.
Three-dimensional transcranial Doppler blood flow mapping in patients with cerebrovascular disorders.
Authors: Niederkorn K , Myers L G , Nunn C L , Ball M R , McKinney W M
Published: June 2011

We investigated 60 patients with cerebrovascular disorders using a three-dimensional transcranial Doppler blood flow mapping system. A composite display of the circle of Willis is created with computer assistance, allowing accurate vessel identification and optimal data documentation of blood flow velocity and direction in the basal cerebral arteries. The basilar artery was insonated in every patient; the middle cerebral artery and the most distal internal carotid artery were found in 95% of the patients, the anterior cerebral artery in 85%, and the posterior cerebral artery in 84%. Insonation problems occurred predominantly in elderly women. Transcranial Doppler blood flow mapping showed an abnormal result in 23 of 60 patients (38%). An intracranial stenosis with greater than 50% diameter reduction or occlusion was found in 10 of 31 patients (32%) with completed stroke, reversible ischemic neurologic deficit, or transient ischemic attack. Collateral blood flow mechanisms could be demonstrated in patients with extracranial carotid artery occlusions. Intra-arterial cerebral angiography performed in 21 patients confirmed the transcranial Doppler blood flow mapping diagnosis in 19 (90.5%). In one patient an arteriovenous malformation diagnosed by transcranial Doppler blood flow mapping was confirmed by magnetic resonance imaging.
Management of coexistent carotid artery and coronary artery disease.
Authors: Graor R A , Hetzer N R
Published: June 2011

At the present time staged carotid reconstruction several days before elective coronary artery bypass surgery seems to be the safest and most logical approach for patients with neurological symptoms, stable cardiac symptoms, and acceptable coronary anatomy. Combined procedures may well be necessary for those who have active neurological symptoms or bilateral carotid lesions in conjunction with diffuse or unstable coronary artery disease, but the incidence of neurological complications at the time of simultaneous operations could exceed the stroke risk for either carotid endarterectomy or coronary bypass alone. The asymptomatic patient with unilateral carotid stenosis who presents for coronary artery bypass might be best managed by myocardial revascularization followed by medical or surgical management of the carotid disease. In order to obtain optimal long-term results, both coronary disease and associated carotid disease require appropriate evaluation and medical and surgical management.
Stroke mortality maps. United States whites aged 35-74 years, 1962-1982.
Authors: Wing S , Casper M , Davis W B , Pellom A , Riggan W , Tyroler H A
Published: June 2011

We mapped average age-adjusted stroke mortality rates for white men and white women aged 35-74 years for state economic areas (counties or groups of counties) in the continental United States for three 7-year periods between 1962 and 1982. Despite the decline of national stroke mortality rates, rates in some areas failed to decline between 1962-1968 and 1969-1975. All areas experienced declines in 1976-1982, by which time some rates in the highest decile of the rate distribution were comparable to rates that had been in the lowest decile in 1962-1968. An east-west gradient of high-to-low stroke mortality rates was evident for both white men and white women in all three periods. Within the eastern part of the United States, high rates appeared more commonly in the South, and more so for white men than for white women. The "stroke belt" (area of very high stroke mortality rates in the coastal plain of the South) became less concentrated over the 2 decades, while a clustering of state economic areas with high rates along the Mississippi River and in the Ohio River valley became more pronounced.
Effect of mild hyperthermia on recovery of metabolic function after global cerebral ischemia in cats.
Authors: Chopp M , Welch K M , Tidwell C D , Knight R , Helpern J A
Published: June 2011

We investigated the effect of mild whole-body hyperthermia before and after 16 minutes of global cerebral ischemia on metabolic recovery during recirculation in cats using in vivo phosphorus-31 nuclear magnetic resonance spectroscopy. Hyperthermia (temperature 40.6 +/- 0.2 degrees C) was induced greater than or equal to 1 hour before ischemia and was maintained during 1.5-2 hours of recirculation in nine cats; four cats were subjected to hyperthermia without cerebral ischemia, six to hyperthermia during recirculation (after return of intracellular pH to preischemic values), and 14 to normothermic ischemia and recirculation. Our data indicate that preischemic hyperthermia results in an intracellular cerebral pH during recirculation significantly lower than that in normothermic cats. In hyperthermic cats beta-ATP and phosphocreatine (PCr) concentrations and the ratio of PCr to inorganic phosphate failed to return to preischemic levels during recirculation in contrast to normothermic cats. Hyperthermia without ischemia and hyperthermia during recirculation had no significant effect on intracellular pH. Thus, preischemic hyperthermia has a detrimental effect on metabolic recovery after transient global cerebral ischemia.
Protection against ischemic brain damage using propentofylline in gerbils.
Authors: DeLeo J , Schubert P , Kreutzberg G W
Published: June 2011

We studied the xanthine derivative propentofylline (HWA 285) to determine its protection against ischemic brain damage when administered before and after ischemia. Transient forebrain ischemia was produced in 81 Mongolian gerbils by occluding both carotid arteries. The necessary surgery was performed under anesthesia with intraperitoneal pentobarbital/chloral hydrate 2 days before occlusion. We tested the parameters delayed selective hippocampal nerve cell damage, generation of seizures, and survival. Determination of the dose-response relation revealed the optimal dose of HWA 285 to be 10 mg/kg i.p. The effect of the drug on delayed selective nerve cell damage in the hippocampus was assessed by measuring the intensity of Nissl staining in the CA1 area by means of densitometry 4 days after a 10-minute occlusion. Gerbils treated with HWA 285 revealed significant protection of the CA1 neurons even when the drug was applied 1 hour after the end of the occlusion. In contrast to HWA 285, pentobarbital provided no detectable protection of the CA1 neurons in our experimental model when administered 1 hour after occlusion, suggesting different mechanisms of action. After a 15-minute occlusion, all six untreated gerbils developed convulsions and died within 2 days. Chronic (daily) treatment of nine gerbils with HWA 285 prevented the generation of convulsions in eight and allowed seven to survive for greater than 12 days.
Cerebral lactate detected by regional proton magnetic resonance spectroscopy in a patient with cerebral infarction.
Authors: Berkelbach van der Sprenkel J W , Luyten P R , van Rijen P C , Tulleken C A , den Hollander J A
Published: June 2011

Water-suppressed image-guided localized proton magnetic resonance spectroscopy was performed in a 59-year-old woman with two major brain infarcts. Spectra were measured in the infarcts, in an area between the infarcts, and in the healthy hemisphere. The volumes of interest were selected on the basis of a fast T2-weighted image. A 1331-2662 Hahn spin-echo sequence was used to suppress the water in the 8-cm3 volume that was selected by means of spatially resolved spectroscopy or stimulated echoes. The spectra were obtained in 5 minutes' accumulation time. Spectral editing was applied to separate the resonance of lactate from that of other substances. Our results show no increase of lactate concentration within the infarcts after 6 months; however, a resonance was observed at 1.6 ppm, which is assigned to fatty acids. Peak intensities of brain-specific compounds were decreased. Six months after the onset of clinical symptoms (at the time of bypass surgery), a fivefold increase in lactate concentration compared with normal values was observed in the area between the two infarcts. Four months after bypass surgery, the lactate concentration in this area had decreased to only twice normal. We speculate that lactate is a marker of reversible or impending brain damage.
Admission glucose level in relation to mortality and morbidity outcome in 252 stroke patients.
Authors: Woo E , Chan Y W , Yu Y L , Huang C Y
Published: June 2011

In a prospective study to correlate admission glucose level with neurologic outcome in stroke, 252 acute stroke patients without prior disability and admitted within 24 hours of onset of ictus were assessed. The stroke was classified into one of three types--cortical infarct, lacunar infarct, or intracerebral hemorrhage--by clinical, computed tomographic, and necropsy findings. Fifty-one diabetic patients were excluded from the entire cohort to form a nondiabetic category for analysis. We found that admission glucose level showed a significantly higher degree of correlation with mortality and morbidity (measured as arm function, leg function, and activities of daily living) when cortical (n = 118) and lacunar (n = 58) infarcts were pooled compared with when they were assessed separately. For intracerebral hemorrhage (n = 76), admission glucose level correlated with mortality but not morbidity. This trend persisted despite exclusion of diabetic patients. These results are consistent with previous observations of a correlation between a high admission glucose level and the severity of stroke. The importance of segregating cortical from lacunar infarcts, two groups with a different natural history and prognosis, in any future analysis is emphasized.
Autopsy study of incidence and distribution of cerebral amyloid angiopathy in Hisayama, Japan.
Authors: Masuda J , Tanaka K , Ueda K , Omae T
Published: June 2011

The incidence of cerebral amyloid angiopathy in a general population was evaluated in brains of 400 consecutive autopsies of residents of Hisayama, Japan (November 1971-October 1983). Six samples taken from frontal lobe, parietal lobe, temporal lobe, occipital lobe, hippocampus, and basal ganglia of the same side of each brain were stained with both hematoxylin and eosin and Congo red. The specimens were surveyed microscopically with polarized light for deposition of amyloid in the vascular wall. In 26 cases with brain hemorrhage, the region surrounding the hemorrhagic sites was further examined to study the probable causal relation between cerebral amyloid angiopathy and brain hemorrhage. Cerebral amyloid angiopathy was found in 40 of 218 men (18.3%) and 51 of 182 women (28.0%). The incidence increased with age in both sexes. The frontal lobe was most frequently affected (66 cases), followed by parietal lobe (65), occipital lobe (49), temporal lobe (44), and hippocampus (32); the putamen was never affected. The incidence of cerebral amyloid angiopathy did not correlate with blood pressure or with the severity of cerebral atherosclerosis. Among the 26 cases in which there was brain hemorrhage, only one cerebellar hemorrhage, in an 85-year-old man, was attributed to cerebral amyloid angiopathy. This case showed four microaneurysms in vessels, with cerebral amyloid angiopathy surrounding the hemorrhagic site. Thirty similar lesions were observed in eight cases without brain hemorrhage. Cerebral amyloid angiopathy may play an etiologic role in the development of brain hemorrhage through formation of angionecrosis and microaneurysm.
Hemodilution with low-molecular-weight hydroxyethyl starch after experimental focal cerebral ischemia in rabbits.
Authors: Lyden P D , Alving L I , Zivin J A , Rothrock J F
Published: June 2011

Newly developed colloid volume-expanding agents with mean molecular weights lower than currently available agents may improve outcome after stroke with fewer allergic and coagulation system side effects. The smaller molecule, however, may exacerbate ischemic cerebral edema if it accumulates in areas where ischemia has damaged the blood-brain barrier. We administered low-molecular-weight hydroxyethyl starch to rabbits after embolic infarction and measured specific gravity and total water content. We found evidence of ischemic edema in the hemisphere ipsilateral to the embolic arterial occlusion, but the measures of edema were not different in treated and control groups. Of those rabbits suffering severe neurologic deficit, mortality was 2 of 13 in the treated compared with 7 of 12 in the control groups (p less than 0.01). Thus, hemodilution with low-molecular-weight hydroxyethyl starch did not exacerbate cerebral edema and may have improved survival in this model.
Stable xenon enhanced computed tomography in the study of clinical and pathologic correlates of focal ischemia in baboons.
Authors: Yonas H , Gur D , Claassen D , Wolfson S K , Moossy J
Published: June 2011

When the lateral striate arteries of baboons are occluded, an immediate cessation of blood flow followed by a transient, minimal restitution of flow occurs in that vascular distribution. These findings are evident from serial xenon/computed tomography cerebral blood flow imaging. In our study, infarction consistently accompanied arterial occlusion for 6 hours or more. The xenon/computed tomography method provides a sensitive, noninvasive technique for examining sequential alterations of cerebral blood flow in small regions deep within the brain. This methodology for recording cerebral blood flow permits correlative studies of cerebral infarction, clinically and experimentally, and allows reasonable inferences about the probabilities of neural tissue damage.
Response time of stroke patients to a visual stimulus.
Authors: Kaizer F , Korner-Bitensky N , Mayo N , Becker R , Coopersmith H
Published: June 2011

We used a computer program to test response time among stroke patients in a clinical setting. Visual stimuli were presented to 82 hospitalized stroke patients, to 21 hospitalized controls, and to 76 nonhospitalized controls. Stroke patients had longer mean response times than controls. Patients with right hemispheric lesions had longer response times than those with left hemispheric lesions when the stimuli were presented on the left. The corresponding phenomenon of longer response times in patients with left hemispheric lesions to stimuli presented on the right was not observed. Patients with right hemispheric lesions with visual hemineglect had a longer mean response time than those without visual hemineglect when the stimuli were presented on the left or centrally, whereas the patients with right hemispheric lesions without neglect had a mean response time similar to that of patients with left hemispheric lesions.
Attenuation of postischemic cerebral hypoperfusion by the 21-aminosteroid U74006F.
Authors: Hall E D , Yonkers P A
Published: June 2011

The ability of the nonglucocorticoid 21-aminosteroid U74006F, a potent inhibitor of iron-dependent lipid peroxidation, to antagonize progressive brain hypoperfusion after a 5-minute episode of global brain ischemia was examined in alpha-chloralose-anesthetized cats. Immediately after a 5-minute episode of near-total tourniquet-induced brain ischemia, cortical blood flow returned to normal or above normal. Thereafter, cortical blood flow fell progressively to a level 71.7% below normal by 3 hours after ischemia. In contrast, in cats that received 1 mg/kg i.v. U74006F 15 minutes after the ischemic episode, cortical blood flow remained significantly greater than that seen in vehicle-treated cats. At 3 hours, cortical blood flow had declined by only 45.7% (p less than 0.04 compared with vehicle). In addition, U74006F treatment significantly improved postischemic maintenance of blood pressure and recovery of somatosensory evoked potentials and reduced postischemic arterial blood acidosis. U74006F had no effect on cortical blood flow, somatosensory evoked potentials, or blood pressure in nonischemic cats. Our results suggest that U74006F may be useful in the early treatment of global cerebral ischemia.
Bioenergetics of different brain areas after experimental subarachnoid hemorrhage in rats.
Authors: Marzatico F , Gaetani P , Rodriguez y Baena R , Silvani V , Paoletti P , Benzi G
Published: June 2011

We studied energy metabolism after experimental subarachnoid hemorrhage in rats. Four different cerebral areas were tested: frontal cortex, occipital cortex, hippocampus, and brainstem. Vmax of the following enzymatic activities was evaluated: in the homogenate: hexokinase, phosphofructokinase, and lactate dehydrogenase for the glycolytic pathway, and glucose-6-phosphate dehydrogenase for the hexose monophosphate shunt; in the purified nonsynaptic mitochondria: NAD+-isocitrate dehydrogenase, citrate synthase, and succinate dehydrogenase for the Krebs cycle, and cytochrome oxidase for the electron transfer chain. We also evaluated some parameters related to the respiration of nonsynaptic mitochondria (State 3, State 4, uncoupled state, respiratory control ratio, and ADP:O ratio). Subarachnoid hemorrhage did not significantly affect Vmax of the enzymatic activities related to anaerobic and aerobic metabolism; however, mitochondrial respiration was affected, particularly in the presence of NADH-producing substrates (glutamate + malate).
Medical treatment of transient ischemic attacks: does it influence mortality?
Authors: Ramirez-Lassepas M , Cipolle R J
Published: June 2011

All randomized studies published on the medical treatment of transient ischemic attacks in which controls received no treatment or placebo and in which mortality was reported were reviewed. Using the odds ratio method, we analyzed the results to determine if treatment had an effect on expected mortality. Studies were analyzed separately according to the treatment modality used. Chronic anticoagulation was used in four studies and platelet inhibitors in 12 (14 trials). This meta-analysis showed that neither treatment modality significantly reduces mortality. Chronic anticoagulation may have an adverse effect, and even though platelet inhibitors appeared to reduce mortality, no significance can be demonstrated, and the 95% confidence intervals did not allow us to rule out the possibility, albeit small, of an adverse effect or no effect at all.
Relation between blood lipids, lipoproteins, and cerebrovascular atherosclerosis. A review.
Authors: Tell G S , Crouse J R , Furberg C D
Published: June 2011

Although blood lipids and lipoproteins are strongly related to coronary atherosclerosis, their association with cerebrovascular atherosclerosis is less clear. A review of more than 20 publications in which a relation was sought between plasma lipid and lipoprotein concentrations and cerebrovascular atherosclerosis leads to the general conclusion that such a relation exists and that it is stronger in older than in younger individuals. A relation was found between blood lipids and/or lipoproteins and the extent and/or severity of cerebrovascular atherosclerosis in all but three of 26 reviewed studies. However, the specific nature of the relation is obscure because the various studies cannot easily be compared with one another. Interstudy variations in lipoprotein fraction analyzed, methodology for the analysis of lipids and lipoproteins, arterial segment examined, population sampled, control selection in case-control studies, statistical analytic approach taken, and methodology for the assessment of arterial disease preclude pooled analyses. There is a clear need for further evaluation of this relation using standardized and up-to-date methodologies both for analyses of lipids and lipoproteins and for assessment of cerebrovascular disease in symptom-free volunteers as well as in symptomatic patients.
Hypertension management and stroke recurrence in a community (Rochester, Minnesota, 1950-1979).
Authors: Meissner I , Whisnant J P , Garraway W M
Published: June 2011

The purposes of this study were to determine the trend in stroke recurrence over time and the effect of the prestroke blood pressure and management of hypertension on stroke recurrence in 1,680 incidence cases of stroke in residents of Rochester, Minnesota. Recurrent, primarily ischemic, stroke occurred in 267 cases. Stroke recurrence rates did not change during the 30-year period 1950-1979, in contrast to the decline in initial stroke incidence rates during this time. The overall stroke recurrence rates were less than 5%/yr, with cumulative rates of 5.7%, 19.3%, and 28.8% at 1, 5, and 10 years, respectively. Neither level of blood pressure before the first stroke nor management of hypertension had any apparent effect on stroke recurrence rates throughout the follow-up.
The rat hippocampal slice preparation as an in vitro model of ischemia.
Authors: Dong W Q , Schurr A , Reid K H , Shields C B , West C A
Published: June 2011

In vivo models of cerebral ischemia do not fully control for the interacting effects of many variables (e.g., anesthesia, temperature, cerebrovascular changes) and often do not clearly define the region affected. Numerous in vivo studies have indicated that hyperglycemia augments ischemic brain damage; this effect is often attributed to lactic acidosis. To separate the effects on neuronal tissue of ischemia from those due to actions on the cerebrovascular system, we used an in vitro blood-free system as an ischemic model. In our study we evaluated the effects of various combinations of oxygen and glucose levels on evoked synaptic activity in the CA1 region of the rat hippocampal slice preparation. A 50% inhibitory dose for both oxygen and glucose on neuronal synaptic function was determined. It is our intention to use this model for preliminary screening of antihypoxic/anti-ischemic drugs.
Detection of cerebral vasculopathy in sickle cell disease using transcranial Doppler ultrasonography and magnetic resonance imaging. Case report.
Authors: Adams R J , Aaslid R , el Gammal T , Nichols F T , McKie V
Published: June 2011

We describe a case of homozygous sickle cell anemia in which noninvasive transcranial Doppler ultrasonography and magnetic resonance imaging were used to detect angiographically documented occlusive lesions of intracranial arteries.
Spinal cord infarction.
Authors: Satran R
Published: June 2011

Spinal cord infarction occurs infrequently and may have diverse causes. It is necessary to establish whether an intrinsic or extrinsic lesion is responsible for the impaired cord function. Although therapy is limited at this time, the long-term prognosis is not necessarily unfavorable.
Protein C in acute stroke.
Authors: D'Angelo A , Landi G , Vigano'D'Angelo S , Nobile Orazio E , Boccardi E , Candelise L , Mannucci P M
Published: June 2011

The plasma concentrations of protein C, an anticoagulant protein, and fibrinopeptide A were measured in 37 patients with acute hemispheric stroke and in age-matched controls with nonvascular neurologic diseases. In 11 stroke patients who died within 15 days after the onset (nonsurvivors) protein C antigen concentration on admission was lower than in the control group (p less than 0.005), with a mean value of 63% of the concentrations found in the 26 survivors (p less than 0.001). The difference in protein C concentrations was not associated with different prothrombin time ratios and serum albumin concentration in survivors and nonsurvivors of stroke and was independent of the size of the cerebral lesion. Increased fibrinopeptide A concentration on admission was found in all stroke patients (p less than 0.001), but it was higher in nonsurvivors than in survivors (p less than 0.01), suggesting that lower protein C concentrations in nonsurvivors might be due to increased thrombin-dependent protein C activation. In survivors, protein C concentration was slightly but significantly higher than in controls (p less than 0.05) and was unchanged 2 months after stroke, a time when fibrinopeptide A concentrations had returned to normal. These results show that protein C is involved in the hemostatic derangement caused by stroke and provide a rationale for clinical trials evaluating the therapeutic supplementation with protein C of patients with acute ischemic stroke.
Interobserver agreement for the assessment of handicap in stroke patients.
Authors: van Swieten J C , Koudstaal P J , Visser M C , Schouten H J , van Gijn J
Published: June 2011

Interobserver agreement for the assessment of handicap in stroke patients was investigated in a group of 10 senior neurologists and 24 residents from two centers. One hundred patients were separately interviewed by two physicians in different combinations. The degree of handicap was recorded by each observer on the modified Rankin scale, which has six grades (0-5). The agreement rates were corrected for chance (kappa statistics). Both physicians agreed on the degree of handicap in 65 patients; they differed by one grade in 32 patients and by two grades in 3 patients. Kappa for all pairwise observations was 0.56; the value for weighted kappa (with quadratic disagreement weights) was 0.91. Our results confirm the value of the modified Rankin scale in the assessment of handicap in stroke patients; nevertheless, further improvements are possible.
Altered leukocyte rheology in patients with chronic cerebrovascular disease.
Authors: Vermes I , Strik F
Published: June 2011

Erythrocyte and leukocyte suspensions were prepared from 28 patients with chronic cerebrovascular disease and 30 age- and concomitant disease-matched control subjects. Cell filterability was studied with the new St. George's filtrometer, which can discriminate between initial filtration rate as an erythrocyte parameter and filter clogging as a leukocyte parameter. Compared with control subjects, a significant increase of filter clogging was found in the patients, suggesting decreased deformability or increased adhesiveness of leukocytes or both in chronic cerebrovascular disease.
Predicting survival after stroke: a three-year follow-up.
Authors: Bonita R , Ford M A , Stewart A W
Published: June 2011

We examined characteristics associated with a high risk of mortality within 3 years after a stroke. Analyses are based on data from a population-based register of stroke events that occurred in Auckland (total population 829,545), New Zealand during a 1-year period in 1981-1982 and a 3-year follow-up study of all survivors (97% complete). Statistical techniques that allow for the simultaneous evaluation of multiple factors indicated that retention of consciousness, decreasing age, and place of residence at the onset of the stroke were the strongest predictors of survival over 3 years. The survival rate for those living at home at the onset of the stroke who did not lose consciousness was 58% compared with 5% for people in institutional care who lost consciousness. Marital status, history of stroke, and ethnic group also predicted survival. Most of the important prognostic factors we identified in our study cannot be modified, testifying to the importance of the prevention of stroke in the first place.