bluuebunny/crossref_metadata_2025_split huggingface dataset:
Equivalence of measurements of carotid stenosis. A comparison of three methods on 1001 angiograms. European Carotid Surgery Trialists' Collaborative Group.
Authors: Rothwell P M , Gibson R J , Slattery J , Sellar R J , Warlow C P 
Published: June 2011

There is confusion about how carotid stenosis should be measured on angiograms. If the results of research based on different methods of measurement of stenosis are to be discussed and the results of clinical trials properly applied to routine clinical practice, measurements made by the different methods must be formally compared.
The method of measurement of stenosis used in the European Carotid Surgery Trial (ECST), that used in the North American Symptomatic Carotid Endarterectomy Trial (NASCET), and a method based on measurement of the common carotid (CC) artery lumen diameter were compared. Carotid stenosis was measured by two observers, working independently and using the three different methods of measurement, on the angiographic view of the symptomatic carotid stenosis that showed the most severe disease in 1001 patients from the ECST.
The results of using the ECST and CC methods differed from those of using the NASCET method in the classification of stenoses as mild (0% to 29%), moderate (30% to 69%), or severe (70% to 99%) in 51% of measurements. The ECST and CC methods indicated that twice as many stenoses were severe as did the NASCET method, and classified less than a third of the number of stenoses as mild. The results of the ECST and CC methods differed from each other in 15% of measurements. The relations between measurements made by each method to those made by the others were approximately linear, so a simple equation could be derived to convert measurements made by one method to measurements made by the others.
There were major and clinically important disparities between measurements of stenosis made using different methods of measurement on the same angiograms. However, it is possible to convert measurements made by one method to those of another using a simple arithmetic equation.
Association of occurrence of aneurysmal bleeding with meteorologic variations in the north of France.
Authors: Lejeune J P , Vinchon M , Amouyel P , Escartin T , Escartin D , Christiaens J L 
Published: June 2011

Previous reports have established that the incidence of stroke may be influenced by meteorologic variations. However, no significant correlation was clearly demonstrated concerning aneurysmal bleeding.
From January 1, 1989, to December 31, 1991, 238 patients with angiographically confirmed diagnoses of subarachnoid hemorrhage were registered in the North of France region. For each day, the weather variables were provided by the national meteorologic office (Meteo France). We compared the meteorologic variables of days when subarachnoid hemorrhage occurred with the variables of days without subarachnoid hemorrhage in a multivariate model.
We observed a seasonal pattern in the occurrence of subarachnoid hemorrhage, with a low frequency of rupture in June and July and maximum frequency in April and September (P < .05). The days of occurrence were associated with short duration of sunshine (P < .00006), low minimal level of hygrometry (P < .0002), low maximal temperature (P < .005), and low atmospheric pressure the day before the event (P < .05).
Aneurysmal bleeding was significantly associated with weather variables. Cold-induced hypertension may explain these fluctuations in the occurrence of aneurysmal bleeding.
Does age affect benefits of stroke unit rehabilitation?
Authors: Kalra L 
Published: June 2011

The influence of age on benefits of stroke unit rehabilitation is largely unknown.
A prospective controlled study was undertaken in 245 stroke survivors randomized to a stroke unit or to general wards 2 weeks after stroke. Patients were divided into older (75 years and over) and younger (under 75 years) age groups, and their characteristics, prognosis, duration, and type of therapy input and outcome were compared in different settings.
Younger (n = 101) and older (n = 144) stroke patients were comparable for neurological and functional deficits and were distributed equally between the stroke unit and general wards. The duration of therapy input was similar in younger patients in either setting. Older patients received more occupational therapy in both settings (10.7 +/- 2.4 versus 7.9 +/- 04.1) and more physiotherapy (18.4 +/- 9.6 versus 15.2 +/- 7.8) on general wards. Younger patients on the stroke unit showed better outcome compared with those on general wards (discharge home, 83% versus 60%; median Barthel score, 17 versus 13; median length of hospital stay, 27 versus 56 days) and with older patients on the stroke unit (discharge home, 83% versus 65%; median Barthel score, 17 versus 14). Outcome in older stroke patients was similar in both settings except for a shorter median length of hospital stay on the stroke unit (36 versus 84 days). Outcome in younger patients managed on general wards was worse than that in older patients with similar prognostic expectations (discharge home, 41% versus 61%; median Barthel score, 11 versus 13).
Younger stroke patients benefited more by stroke unit rehabilitation compared with older patients, not only because of their age but also because of differences in the multidisciplinary input available for elderly patients outside the stroke unit.
Serial assessment of acute stroke using the NIH Stroke Scale.
Authors: Wityk R J , Pessin M S , Kaplan R F , Caplan L R 
Published: June 2011

The National Institutes of Health (NIH) Stroke Scale has been used in clinical trials to assess neurological outcome after investigational therapy for acute stroke. We used the NIH Stroke Scale to study the degree and time course of recovery in patients with acute stroke who were treated with conventional therapy.
We serially assessed 50 patients with ischemic stroke who presented within 24 hours of onset of symptoms. Patients were grouped by stroke subtype. Major neurological improvement was defined as a decrease in the stroke score by 4 points or more.
The mean NIH stroke score for all patients improved significantly by 7 to 10 days and at last follow-up (average, 44 days). Major neurological improvement was seen in 5 of 41 patients (12%; 95% confidence interval [CI], 2% to 22%) by 24 hours, 11 of 40 patients (28%; 95% CI, 14% to 41%) by 48 hours, and 19 of 37 patients (51%; 95% CI, 35% to 67%) by follow-up. The subgroup of patients with middle cerebral artery territory embolism showed a similar pattern of improvement; in contrast, patients with lacunar infarcts did not show significant change in scores during the study period. The score on admission did not correlate with the degree of subsequent improvement or deterioration.
A significant percentage of patients with acute ischemic stroke treated with conventional therapy show early improvement as assessed by the NIH Stroke Scale. The degree and time course of recovery may be influenced by stroke type.
Feeding dependence and nutritional status after acute stroke.
Authors: Unosson M , Ek A C , Bjurulf P , von Schenck H , Larsson J 
Published: June 2011

We assessed the nutritional status of patients with acute stroke and evaluated it in relation to the patients' dependence on assistance with feeding.
Fifty patients aged 70 years or older, admitted from their homes, were included. Weight index, triceps skinfold thickness, arm muscle circumference, serum proteins, delayed hypersensitivity, body composition measured by bioelectric impedance, and functional condition were determined on admission and 2 and 9 weeks after admission. Food and fluid consumption were also recorded.
On admission, four patients were regarded as protein-energy malnourished. Those who required assistance with feeding after admission (n = 18, 36%) had lower serum albumin (P < .05), lower body cell mass (P < .01), and were more anergic than the independent patients (P < .01) on admission. The mean food consumption was 72% of the food served without significant difference between dependent and independent patients. Nine weeks after the onset of stroke symptoms, the patients who were dependent on assisted feeding showed a decrease in body cell mass. The loss of body cell mass was related to their activity and feeding dependence.
Low serum albumin and anergy commonly occur in elderly patients with acute stroke, and they occur more prevalently among those with a severely impaired functional condition. During the recovery period, the patients use body fat to compensate for energy needs, and immobility leads to loss of body cell mass.
Comparison of magnetic resonance volume flow rates, angiography, and carotid Dopplers. Preliminary results.
Authors: Levine R L , Turski P A , Holmes K A , Grist T M 
Published: June 2011

We compared the results of conventional angiography, carotid Doppler, and magnetic resonance angiography volume flow rates to determine the clinical utility of volume flow rate assessment of blood flow to the anterior circulation in patients with carotid occlusive disease.
From 11 symptomatic patients, a total of 22 extracranial carotid arteries were studied with all three techniques. The studies were independently read, and regression analysis was used to compare the measurements.
Carotid Doppler measurements of the distal extracranial carotid arteries were proportional to the inverse of the extracranial carotid volume flow rate (r = .53, R2 = 29%, P < .01), volume flow rates were proportional to the inverse of measured percent stenosis on angiography (r = .84, R2 = 71%, P < .01), and Dopplers were proportional to angiography (r = .94, R2 = 90%, P < .01). Symptomatic Doppler systolic velocity was significantly higher (P < .002), symptomatic measured stenosis was significantly higher (P < .002), and symptomatic volume flow rate was significantly lower (P < .01) than their respective asymptomatic-side values. These preliminary observations, however, may well change once a large data set, especially one in which more patients with high-grade carotid stenosis are included, is studied.
Assessment of carotid volume flow rates by magnetic resonance angiography quantifies flow reduction secondary to atherosclerotic occlusive disease. The easily obtained flow data add both documentation of arterial flow characteristics related to internal carotid stenosis and information regarding the adequacy of collateral pathways.
Delayed protection by MK-801 and tetrodotoxin in a rat organotypic hippocampal culture model of ischemia.
Authors: Vornov J J , Tasker R C , Coyle J T 
Published: June 2011

The hippocampus demonstrates a regional pattern of vulnerability to ischemic injury that depends on its characteristic differentiation and intrinsic connections. We now describe a model of ischemic injury using organotypic hippocampal culture, which preserves the anatomic differentiation of the hippocampus in long-term tissue culture.
Ischemic conditions were modeled by metabolic inhibition. Cultures were briefly exposed to potassium cyanide to block oxidative phosphorylation and 2-deoxyglucose to block glycolysis. The fluorescent dye propidium iodide was used to observe membrane damage in living cultures during recovery.
2-Deoxyglucose/potassium cyanide incubation resulted in dose-dependent, regionally selective neuronal injury in CA1 and the dentate hilus, which began slowly after 2 to 6 hours of recovery. Subsequent histological examination of cultures after 1 to 7 days of recovery demonstrated neuronal pyknosis that was correlated with the early, direct observation of membrane damage with propidium. Both propidium staining and histological degeneration were prevented by the noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist MK-801 when administered 30 minutes after the end of the exposure to 2-deoxyglucose and potassium cyanide. Tetrodotoxin, which blocks voltage-dependent sodium channels, had protective effects that were greatest during the period of 2-deoxyglucose and potassium cyanide incubation but also produced protection against the mildest conditions of metabolic inhibition when administered after 30 minutes of recovery.
This in vitro model reproduced elements of the time course, regional vulnerability, and pharmacologic sensitivities of in vivo ischemic hippocampal injury. Inhibition of metabolism in organotypic culture provides a rapid, easily controlled injury and reproduces the in vitro pattern of hippocampal regional vulnerability to ischemia. It is the first in vitro model of ischemia to exhibit complete protection by delayed administration of an NMDA receptor antagonist during recovery from a brief insult. The protective effects of tetrodotoxin suggest that an early period of sodium entry into cells during and after ATP depletion may be responsible for the more prolonged period of toxic NMDA receptor activation.
Calcium/calmodulin-dependent protein kinase II activity in focal ischemia with reperfusion in rats.
Authors: Hanson S K , Grotta J C , Waxham M N , Aronowski J , Ostrow P 
Published: June 2011

Evidence linking changes in calcium/calmodulin-dependent protein kinase II activity with ischemic cell death has been reported in animal models of global ischemia. The purpose of this study was to delineate the course of these changes after focal ischemia and to clarify the relation of changes in activity of calcium/calmodulin-dependent protein kinase II to the process of ischemic cell death.
Change in calcium/calmodulin-dependent protein kinase II activity was evaluated in a rat model of focal ischemia after 5 minutes, 30 minutes, and 1 hour of tandem middle cerebral artery and common carotid artery occlusion both with and without reperfusion.
Calcium/calmodulin-dependent protein kinase II activity was significantly decreased after all three durations of ischemia followed by immediate decapitation compared with sham-operated animals, in both ischemic core and border-zone regions (P < .05 for all groups). Depression of activity occurred in a regionally graded fashion, with the most severe decrease in infarct core and progressively smaller decreases in samples moving out from the center, corresponding to the severity of histological injury later detected in infarct core and border-zone regions. There were only minor differences between the three durations of ischemia in the degree of enzyme depression noted in the more peripheral regions, indicating that the initial decrease in calcium/calmodulin-dependent protein kinase II activity is an early, sensitive marker for an ischemic insult. After reperfusion, the differences between the 5-minute group and longer periods of ischemia widened because of an increase toward baseline in the 5-minute group and a trend toward further decrease in the 30- and 60-minute groups.
The extreme sensitivity of calcium/calmodulin-dependent protein kinase II to focal ischemia and the parallel temporal and regional changes in its activity to those of more delayed cell injury point to a potential role for this enzyme in the process of excitotoxic injury.
Diffusion nuclear magnetic resonance imaging in experimental stroke. Correlation with cerebral metabolites.
Authors: Back T , Hoehn-Berlage M , Kohno K , Hossmann K A 
Published: June 2011

Diffusion-weighted nuclear magnetic resonance imaging has been shown to detect early ischemia-related alterations in experimental stroke. This raises the question of whether the observed increase in signal intensity is correlated with changes in cerebral metabolism. After middle cerebral artery occlusion, nuclear magnetic resonance diffusion images were recorded and compared with the regional concentration of cerebral metabolites and with histology of identical planes.
Seven anesthetized Fischer rats were subjected to permanent occlusion of the middle cerebral artery. T1, T2, and diffusion images (b factors ranging from 0 to 1500 s/mm2) were measured in three to five planes after 7 hours. Thereafter, brains were frozen in situ for histology and quantitative bioluminescence imaging of ATP, glucose, lactate, and for fluorescence imaging of tissue pH.
Seven hours after middle cerebral artery occlusion, the apparent diffusion coefficient was reduced from 615 +/- 97 x 10(-6).mm2.s-1 (contralateral brain) to 359 +/- 42 x 10(-6).mm2.s-1 (ischemic brain; mean +/- SD, P < .01). A precise topical coincidence was demonstrated between changes in nuclear magnetic resonance diffusion images, pattern of histological damage, ATP-depleted areas, and local tissue acidosis, the lesion area amounting to between 24.1% and 27.6% of the hemisphere at the level of the caudate-putamen. The area of elevated brain lactate clearly exceeded the acidic core of the infarct and included the slightly alkaline border zone.
The data demonstrate that after 7-hour middle cerebral artery occlusion, the reduction of the apparent diffusion coefficient in nuclear magnetic resonance diffusion images reflects precisely the region of histological injury, breakdown of energy metabolism, and tissue acidosis.
Motor recovery after early brain damage. A case of brain plasticity.
Authors: Sabatini U , Toni D , Pantano P , Brughitta G , Padovani A , Bozzao L , Lenzi G L 
Published: June 2011

Motor recovery is remarkable when the brain is damaged early in life. We describe a case of early damage to the right hemisphere with remarkable reorganization and plastic functional changes, studied by computed neuroimaging.
A 31-year-old man had a left-sided hemiplegia at the age of 12, followed by good motor recovery despite a large right cortical-subcortical lesion. Single-photon emission computed tomography with motor activation study showed cerebral blood flow increase in the left premotor and sensorimotor cortices irrespective of the hand he was moving, without flow changes in the right hemisphere.
A remarkable reorganization and plastic brain functional changes occurred in a patient after early diffuse damage of the right hemisphere. The study points to a potential role of ipsilateral cortical efferent pathways in subserving hand movements after early cerebral damage.
Malignant brain stem hyperthermia caused by brain stem hemorrhage.
Authors: Kitanaka C , Inoh Y , Toyoda T , Sasaki T , Eguchi T 
Published: June 2011

We report two cases of brain stem hemorrhage characterized by severe hyperthermia, rhabdomyolysis, acute renal failure, and a rapidly fatal course.
A 55-year-old man and a 65-year-old man were admitted with coma-producing brain stem hemorrhage accompanied by hyperthermia. Both underwent ventricular drainage.
Within 1 day of onset, both patients developed hyperthermia of over 41 degrees C, increased serum creatine phosphokinase (CPK) level indicating rhabdomyolysis, and acute renal failure. One patient died on the second day and the other on the third day after onset despite supportive treatment.
These cases of brain stem hemorrhage with fulminant hyperthermia should be distinguished from those with simple hyperthermia. They may represent a kind of malignant hyperthermia, in which case dantrolene sodium might be beneficial. Monitoring serum CPK levels would be of help in making the diagnosis early in the course.
Asymptomatic carotid lesions and silent cerebral infarction.
Authors: Hougaku H , Matsumoto M , Handa N , Maeda H , Itoh T , Tsukamoto Y , Kamada T 
Published: June 2011

Few studies have investigated the relationships between asymptomatic carotid lesions and silent infarcts confirmed on magnetic resonance imaging.
A consecutive series of 117 subjects (average age, 62 +/- 9.4 years) who were free from neurological deficit but had at least one established risk factor for stroke were investigated by B-mode carotid ultrasonography and magnetic resonance imaging of the brain. Carotid lesions were evaluated by plaque score, maximum percent stenosis, and the existence of ulcerated lesions. The relations between the carotid lesions and the incidence, size, or localization of the brain lesions were investigated.
The incidence of silent infarcts was 42% in all subjects and significantly increased with advancing age (P < .05). Most lesions were smaller than 1 cm in diameter and were usually localized in the subcortical white matter or the basal ganglia. The percentage of subjects with infarcts increased significantly as the plaque score increased (P < .05) or when subjects had high-grade stenosis (P < .05) or ulcerated lesions (P < .01). These relationships were also noted in each decade of age. A higher incidence of larger lesions (> 1 cm) was found in the brain hemisphere ipsilateral to the carotid lesion, particularly in subjects with high-grade stenosis or ulcerated lesions (P < .01). Multivariate analysis indicated significant correlations with silent infarcts for age, hypertension, and plaque score.
Both the severity and characteristics of asymptomatic carotid lesions estimated by B-mode ultrasonography were closely related to the appearance of silent infarcts. These results demonstrate that noninvasive assessment of carotid lesions can be useful in predicting the existence of silent cerebral infarction even in patients free from neurological deficits.
Cerebral blood flow and effects of cerebrospinal fluid on calcium transport in patients with cerebral infarction.
Authors: Akopov S E , Grigorian G S , Gabrielian E S 
Published: June 2011

In this study we investigated whether cerebrospinal fluid in patients with brain infarction possesses an activity that contributes to the evolution of brain ischemia. As a test, the effect of cerebrospinal fluid on Ca2+ influx into the intracellular space was chosen because this process is a mechanism for vasospasm, platelet aggregation as thrombi, and neuron damage.
Effects of cerebrospinal fluid taken from 48 patients with cerebral hemispheric infarction on the concentration of cytosolic free Ca2+ in platelets were studied using the fluorescent probe quin-2. Hemispheric cerebral blood flow was measured using 133Xe intravenous injection.
Cerebrospinal fluid in 19 of 48 patients with cerebral hemispheric infarction increased the level of cytosolic free Ca2+ in platelets. The course of the disease in the patients who showed a positive effect of cerebrospinal fluid on Ca2+, when compared with that of patients who showed a negative effect, was characterized by a more severe clinical manifestation and mortality. The decrease in hemispheric cerebral blood flow was more marked in both ischemic and contralateral hemispheres in patients with positive effects of cerebrospinal fluid on the level of Ca2+.
These data suggest that the ability of cerebrospinal fluid to evoke Ca2+ influx into the intracellular space in patients with brain infarction is a factor that aggravates ischemic brain damage.