bluuebunny/crossref_metadata_2025 huggingface dataset:
Cerebral vasospasm following aneurysmal subarachnoid hemorrhage.
Authors: Kassell N F , Sasaki T , Colohan A R , Nazar G
Published: June 2011

Cerebral vasospasm following aneurysmal subarachnoid hemorrhage is one of the most important causes of cerebral ischemia, and is the leading cause of death and disability after aneurysm rupture. There are two definitions of cerebral vasospasm: angiographic and clinical. Care must be exercised to be certain that it is clear which entity is being addressed. The diagnosis of the clinical syndrome is one of exclusion and can rarely be made with absolute certainty. The pathogenesis of cerebral vasospasm is poorly understood. Most current theories focus on the release of factors from the subarachnoid clot. More attention must be given to the role of endothelial damage and alterations in the blood-arterial wall barrier. The application of modern techniques for studying vascular smooth muscle which have been developed as a result of research in the areas of hypertension and atherosclerosis must be applied to the problem of cerebral vasospasm. A stress test to select patients with angiographic arterial narrowing who have adequate cerebral vascular reserve to undergo surgery should be developed. The optimal treatment of vasospasm awaits development of agents for blocking or inactivating spasmogenic substances or blocking arterial smooth muscle contraction. Rheological or hemodynamic manipulations to prevent or reverse ischemic consequences of vasospasm are relatively effective, but complicated and hazardous, and should be viewed principally as interim measures awaiting development of more specific therapies for the arterial narrowing.
Subarachnoid haemorrhage in the rat: angiography and fluorescence microscopy of the major cerebral arteries.
Authors: Delgado T J , Brismar J , Svendgaard N A
Published: June 2011

A subarachnoid haemorrhage (SAH) in the rat was produced by the injection of blood via a previously implanted catheter connected to the cisterna magna. Repeated angiographical examinations of the vertebro-basilar arteries revealed a biphasic vasospasm with a maximal acute spasm at ten minutes and a maximal late spasm at two days after cisternal blood injection. Fluorescence microscopical examination of the major cerebral arteries at day two after the SAH revealed a reduction in the fluorescence intensity and in the number of histochemically visible sympathetic nerve terminals.
CBF before and after extracranial-intracranial bypass surgery in patients with ischemic cerebrovascular disease studied with 133Xe-inhalation tomography.
Authors: Vorstrup S , Lassen N A , Henriksen L , Haase J , Lindewald H , Boysen G , Paulson O B
Published: June 2011

Cerebral blood flow (CBF) was studied by 133Xenon inhalation tomography in 22 patients with symptoms of ischemic cerebrovascular disease before and after establishment of an extracranial-intracranial bypass shunt. Selection of patients for shunting was based on angiographically demonstrated arterial occlusions and on the finding of focal low flow areas corresponding to the clinical symptoms, that consisted mainly of minor stroke with good remission and with or without subsequent TIAs. It was required that the area of low flow should clearly exceed the CT lesion present in practically all cases. Following surgery, the permanent neurologic deficits remained unchanged, while the TIAs stopped in all but one case. Two patients showed a definite increase of CBF in the low flow area while another two showed a questionable increase. All the other cases, 18 of the 22, showed an unchanged tomographic flow map with no trend towards diminution in extension or severity of the focal hypoperfused area. A persistent low flow in areas with no corresponding CT lesion following alleviation of a possible flow impediment is interpreted to represent an incomplete infarction or diaschisis.
5-hydroxytryptamine: source of activator calcium in human basilar arteries.
Authors: Rusch N J , Chyatte D , Sundt T M , Vanhoutte P M
Published: June 2011

We performed experiments in human cerebral arteries to determine the source of activator calcium during contractions induced by 5-hydroxytryptamine. Rings of human basilar artery obtained at autopsy were mounted for isometric tension recording in organ baths filled with a physiological salt solution. Contractile responses to 5-hydroxytryptamine were virtually abolished in Ca++-free solution, and inhibited significantly by nimodipine. In both cases, the depression of the response to 5-hydroxytryptamine was comparable to that seen when KCl was used to contract the vessels. These experiments demonstrate that 5-hydroxytryptamine mediates contraction of the smooth muscle in human basilar artery by increasing membrane permeability to extracellular calcium.
Baseline hemodynamic state and response to hemodilution in patients with acute cerebral ischemia.
Authors: Grotta J C , Pettigrew L C , Allen S , Tonnesen A , Yatsu F M , Gray J , Spydell J
Published: June 2011

Hemodynamic data were obtained in 9 patients (mean age 65 yrs) with carotid territory cerebral infarct within the preceding 24 hours (mean 14 +/- 8) as part of a pilot study testing the feasibility and safety of hypervolemic hemodilution. Pulmonary arterial catheters (PACs) were placed without complication in all patients, and after baseline measurements were obtained, up to 1500 cc of 6% hetastarch in 0.9% sodium chloride was administered the first day and up to 1000 cc per day the second and third days. Pulmonary wedge pressure (PWP) rose from 6.3 +/- 3.5 to 14.4 +/- 3.4 mm Hg (p less than 0.001) without development of congestive heart failure in any patient. This was accompanied by a drop in hematocrit (Hct) from 40.3 +/- 3.4 to 32.9 +/- 2.0 (p less than 0.001) and rise in cardiac output (CO) from 4.3 +/- 1.0 to 5.3 +/- 0.6 (p less than 0.05). Phlebotomy of 250 cc was performed in 2 patients and 500 cc in one in order to reduce Hct to desired levels. The volume of fluid needed to raise PWP to 15 was unpredictable (2361 +/- 1106 cc) and therefore PACs were necessary to monitor the rate and volume of fluid administration. The data show that PWP is sufficiently low and Hct sufficiently high following stroke in most patients that hemodilution by volume expansion with phlebotomy added if necessary can be undertaken safely with appropriate monitoring of hemodynamic function, and that this therapy results in optimal reduction of Hct and increased CO without risk of hypotension.
A new approach to antithrombotic therapy--evaluation of combined therapy of thromboxane synthetase inhibitor and very low dose of aspirin.
Authors: Nagatsuka K , Uyama O , Nakabayashi S , Yoneda S , Kimura K , Kamada T
Published: June 2011

The effect of a selective thromboxane (TX) synthetase inhibitor (OKY-046), alone and in combination with a very low dose of aspirin, on the platelet function was studied in healthy and diseased subjects. A single dose of 100 mg OKY-046 was orally administered to patients with ischemic cerebrovascular disease (CVD) and healthy volunteers. TXB2 generation and platelet aggregation were measured before and at 1, 4, 6 and 8hr after dosing. In addition, after the administration of a very low dose of aspirin (0.1-0.25 mg/kg/day) for at least one month, a single dose of OKY-046 was given to CVD patients. TXB2 generation and platelet aggregation were measured in the same manner as OKY-046 alone. The effect of OKY-046 on platelet aggregation induced by arachidonic acid (AA) was different in each subject whereas platelet TXB2 generation was almost completely inhibited in all of the patients and healthy volunteers. OKY-046 had a slight inhibitory effect on collagen induced aggregation. A combination of OKY-046 with a very low dose of aspirin, on the other hand, produced additional inhibition of the platelet aggregation induced by both AA and collagen. The present results suggest that the accumulation and metabolism of cyclooxygenase products that accumulate when TX synthetase is blocked, differ in each subject, additional inhibition is caused by the combined use of TX synthetase inhibitor and a very low dose of aspirin because the very low dose of aspirin partially reduces the proaggregatory cyclooxygenase products that accumulate when TX synthetase is blocked.(ABSTRACT TRUNCATED AT 250 WORDS)
Double-blind controlled trial of the therapeutic effects of prostacyclin in patients with completed ischaemic stroke.
Authors: Huczynski J , Kostka-Trabka E , Sotowska W , Bieron K , Grodzinska L , Dembinska-Kiec A , Pykosz-Mazur E , Peczak E , Gryglewski R J
Published: June 2011

In a pilot study, 26 patients with acute completed strokes (48 hours to 5 days after cerebral infarction) were randomly assigned to the prostacyclin (PGI2) or placebo groups. PGI2 sodium salt (Epoprostenol, Wellcome Research Laboratories and Upjohn Company) or its solvent (glycine buffer) were infused into the subclavian vein for six-hour periods in five courses separated by six-hour intervals. Prostacyclin was administered at a rate of 2.5-5.0 ng/kg/min. A significant alleviation of neurological deficits occurred 6 and 54 hours after the treatment in patients receiving prostacyclin. This improvement lost its statistical significance at the end of a two-week observation period. It is concluded that further modified controlled studies are required to evaluate the therapeutic usefulness of PGI2 in the treatment of patients with cerebral ischaemia.
Non-invasive diagnosis of intracranial lesions in the vertebrobasilar system. A comparison of Doppler sonographic and angiographic findings.
Authors: Ringelstein E B , Zeumer H , Poeck K
Published: June 2011

The accuracy and the reliability of extracranial vertebral Doppler flow (continuous wave Doppler sonography) for the detection of intracranial vertebrobasilar lesions was studied prospectively in twenty-one patients with brainstem disturbances and/or coma. The Doppler findings were compared with cerebral angiography. Doppler sonography was highly reliable for both detection and exclusion of high grade intracranial vertebrobasilar lesions. The pathognomonic Doppler finding was an abrupt deceleration of the blood column during systole and stoppage or even reflux during diastole. The same blood flow alterations were found in two additional illustrative cases having therapeutically or brain-death induced blockages of the vertebral arteries. The pathophysiologic mechanisms of flow disturbances and the limitations of Doppler sonography in this area are discussed.
Brain metabolic changes in young vs aged rats during hypoxia.
Authors: Hoffman W E , Pelligrino D , Miletich D J , Albrecht R F
Published: June 2011

Brain energy state and glycolytic metabolites were measured in young (6 month) and aged (28 month) male rats under normoxic (70% nitrous oxide, 30% oxygen) or hypoxic (PaO2 = 25 mm Hg) test conditions. Hypoxic ischemia was induced in one cerebral hemisphere by ligation of one carotid artery. Under normoxic test conditions brain energy metabolite concentrations were similar between young and aged rats. Brain tissue glucose, glycogen, glucose-6-phosphate and critic acid cycle intermediate concentrations were decreased in aged rats during normoxia while fructose-6-phosphate and pyruvate were increased. Decreases in brain energy state and increases in lactate/pyruvate ratios were significant in both young and aged rats during hypoxia and were greater in aged animals in hypoxic-ischemic tissues. These results indicate that brain energy state is normal in aged rats under normoxic conditions but that hypoxic-ischemia produces a greater degree of brain energy failure compared to younger animals.
Topographical distribution of barrier function in cervico-cephalic arteries of dog. Major cerebral arteries possess definite barrier function?
Authors: Yamashita M , Kassell N F , Sasaki T , Fujiwara S , Zuccarello M , Spallone A
Published: June 2011

Topographic distribution of barrier function in normal canine cervico-cephalic arteries was studied using horseradish peroxidase (HRP) and Evans blue as tracers. The carotid sinus of the internal carotid artery (ICA) was conspicuously permeable to HRP when compared to other areas of major cervical arteries. The cavernous portion of the ICA also showed prominent permeation of HRP, especially through the outer surface, which is covered with venous endothelial cells. On the luminal side of the cavernous portion of the ICA, barrier deficiency was noted at angulated segments such as the carotid siphon. Intracranial segments of both ICA and vertebral arteries demonstrated incomplete barrier function of the first 1 to 4 mm from the origin of the intradural segments. These areas were considered to be transitional sites in barrier function between extra- and intracranial arteries. Focal, but definite, barrier disruption was also noted at the distal ends of the ICA and other arterial branching sites of major intracranial arteries. While opening of the interendothelial junctions was considered to be one of the mechanisms causing increased permeability in the cavernous ICA, the mechanisms for the permeation of HRP into the major cerebral arteries could not be confirmed ultrastructurally.
Homovanillic acid and 5-hydroxyindoleacetic acid modifications in CSF of patients with stroke and multi-infarct dementia.
Authors: Smirne S , Franceschi M , Truci G , Camerlingo M , Pirola R , Ferini-Strambi L , Bareggi S R
Published: June 2011

Thirty four patients who had complete ischemic stroke confirmed by neurologic examination, were divided into three groups according to the time elapsed between the first signs of stroke and lumbar puncture: group A, 22-47 h; group B, 48-71 h; group C, 72-96 h. Nineteen patients with multi-infarct dementia (MID) assessed by neurologic and neurophysiologic examinations were also studied. The severity of the neurological deficit was assessed by the Norris rating scale. Nine age-matched subjects without neurologic disease served as controls. Levels of homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) were determined in lumbar CSF by a fluorimetric method after separation on Sephadex G-10 columns. HVA levels decreased as the length of time after stroke increased and were lower than controls in MID, while 5-HIAA levels were low in group B and MID. Our results in stroke can be interpreted as showing they are the consequence of dopamine and serotonin global depletion in the early phases of brain ischemia. In MID, the CSF changes might reflect not only tissue loss secondary to multiple infarcts but also the persistence of a state of diffuse ischemia.
Regional cerebral blood flow utilizing the gamma camera and xenon inhalation: reproducibility and clinical applications.
Authors: Fox R A , Knuckey N W , Fleay R F , Stokes B A , Van der Schaaf A , Surveyor I
Published: June 2011

A modified collimator and standard gamma camera have been used to measure regional cerebral blood flow following inhalation of radioactive xenon. The collimator and a simplified analysis technique enables excellent statistical accuracy to be achieved with acceptable precision in the measurement of grey matter blood flow. The validity of the analysis was supported by computer modelling and patient measurements. Sixty-one patients with subarachnoid haemorrhage, cerebrovascular disease or dementia were retested to determine the reproducibility of our method. The measured coefficient of variation was 6.5%. Of forty-six patients who had a proven subarachnoid haemorrhage, 15 subsequently developed cerebral ischaemia. These showed a CBF of 42 +/- 6 ml X minute-1 X 100 g brain-1 compared with 49 +/- 11 ml X minute-1 X 100 g brain-1 for the remainder. There is evidence that decreasing blood flow and low initial flow correlate with the subsequent onset of cerebral ischaemia.
Regional differences in stroke mortality and alcohol consumption in Japan.
Authors: Ueshima H , Ohsaka T , Asakura S
Published: June 2011

The relationship between alcohol consumption and stroke mortality in 1975 in 46 prefectures of Japan was investigated. This was done by adjusting salt intake and several socio-economic factors, i.e., the annual per capita income, the number of persons who received public aid, the number of tatamis (a Japanese traditional floor unit) per household, the unemployment rate, and the unmarried or divorce rate, using a stepwise multiple regression analysis. As dependent variables, the sex-specific and age-adjusted mortality for the middle-aged (35-59 years) and for all ages due to stroke were used. For men, alcohol consumption was significantly related to age-adjusted stroke mortalities for the middle-aged and for all ages independent of salt intake and several socio-economic factors. Alcohol consumption was more strongly related to age-adjusted stroke mortality for the middle-aged than for all ages. For women alcohol was weakly correlated with the stroke mortality of the middle-aged. Salt intake was significantly correlated with stroke mortality for women but not for men. Furthermore, the male: female ratios of the age-adjusted stroke mortality for the middle aged and for all ages were analyzed as well, because alcohol is mostly consumed by men in Japan, and it was expected that the sex ratios would be well correlated to alcohol consumption. The results were as expected. Therefore, it was suggested that the regional difference in stroke mortality in Japan may be explained in part by that of alcohol consumption.
Relationship of somatosensory evoked potentials and cerebral oxygen consumption during hypoxic hypoxia in dogs.
Authors: McPherson R W , Zeger S , Traystman R J
Published: June 2011

The effects of hypoxic hypoxia on cerebral hemodynamics and somatosensory evoked potential (SEP) were studied in 10 pentobarbital anestheteized dogs. Cerebral blood flow (CBF) was measured using the venous outflow technique and cerebral oxygen consumption (CMRO2) was calculated from the arterio-cerebro-venous oxygen difference times CBF. SEP was evaluated by percutaneous stimulation of an upper extremity nerve and was recorded over the contralateral somatosensory cortex. The latencies of the initial negative wave (N1), second positive wave (P2) and the amplitude of the primary complex (P1N1) were measured. Animals were breathed sequentially with oxygen concentrations of 21, 10, 6, 5, and 4.5% for five minutes each. Animals were returned to room air breathing when the amplitude of the SEP decreased to less than 20% of control and were observed for 30 minutes following reoxygenation. Severe hypoxia (4.5% O2) increased CBF to 200% of control, decreased CMRO2 to 45% of control, decreased amplitude and increased latency of SEP. Following reoxygenation, as CMRO2 increased toward control, latency of SEP decreased and amplitude increased and CBF returned to baseline within 30 min. During hypoxia and reoxygenation, the latencies of N1 and P2 and the amplitude of P1N1 were correlated with CMRO2 in individual animals. We conclude that changes in SEP amplitude and latency reflect changes in CMRO2 despite high CBF during rapidly progressive hypoxic hypoxia and following reoxygenation.
Hypesthetic-ataxic-hemiparesis in thalamic hemorrhage.
Authors: Verma A K , Maheshwari M C
Published: June 2011

Acute onset hypesthetic-ataxic-hemiparesis is described in two hypertensive patients. Computed tomography (CT) showed an area of increased attenuation consistent with blood in contralateral thalamus. The pathophysiologic implications of the cerebellar and pyramidal system in thalamic hemorrhage is discussed.
Influence of serotinin and norepinephrine on flow capacity/pressure characteristics of feline isolated cerebral arteries.
Authors: Lou H C , Edvinsson L
Published: June 2011

Isolated feline pial vessel segments (250-400 microns in diameter, 4 mm long) were mounted in Krebs solution in organ baths on L-shaped metal holders connected to pressure transducers. From the distance between the outer limits of the wires (f) and the force recorded by the transducers (F), the transmural pressure and the flow capacity were calculated. Changes in these parameters were produced by increasing the distance between the holders. Norepinephrine (10(-5) M) and serotonin (10(-6) M) were added to the tissue bath at different resting wall tensions. Both norepinephrine and serotonin resulted in contractile responses that were maximal at a resting wall tension of 2 nM/mm. Norepinephrine and serotonin displaced the flow capacity/pressure curve to the right up till at least 112 mm Hg, indicating a displacement of the autoregulatory range to the right.
Hemorrhagic cerebral infarction--a prospective study.
Authors: Hornig C R , Dorndorf W , Agnoli A L
Published: June 2011

In 65 cases of ischemic cerebral infarction, CT scans and quantitative assessments of the neurological disturbances were undertaken at specific intervals during the 4 week period after stroke. Forty-three patients underwent lumbar puncture to determine the serum/CSF albumin ratio. The etiology of the infarction was evaluated on the basis of angiographic, ultrasonic and cardiologic findings. A hemorrhagic transformation of the infarction occurred in 28 patients, eleven within the first week, and 15 within the second. Risks of hemorrhage were correlated with a severe neurological deficit, disturbance of consciousness, large infarction with a mass effect, enhancement of contrast medium in CT (especially if occurring early), involvement of the cortex, and distinct blood/CSF barrier disturbances. Cardiac embolism was a frequent etiology in patients with secondary hemorrhagic infarction, especially when transformation occurred within the first week after stroke. In addition to a heterogeneous pattern of hemorrhage, frank hematoma predominated in those infarcts which underwent early transformation, while those transforming late often showed less hyperdense cortical hemorrhagic changes. Deterioration evident on clinical evaluation was caused by the hemorrhagic transformation in three cases, in each instance within the first week after stroke.
Holter monitoring in patients with transient and focal ischemic attacks of the brain.
Authors: Koudstaal P J , van Gijn J , Klootwijk A P , van der Meche F G , Kappelle L J
Published: June 2011

The results of Holter monitoring in 100 patients with transient and focal cerebral ischemia were studied retrospectively. Atrial fibrillation (AF) was found in five patients compared with two from a group of 100 age and sex-matched control patients. Four of these had a previous history of AF or showed AF on the standard electrocardiogram. Episodic forms of sick sinus syndrome, which have also been related to cerebral embolism, were found in 32 of the TIA patients against 13 of the controls (p less than 0.0025). Sick sinus syndrome was of the bradyarrhythmia-tachyarrhythmia type in 14 of the TIA patients and in three of the controls (p less than 0.01). The relationship between TIAs and transient sinus node dysfunction could not be explained by concomitant heart disease. It is not yet clear whether the relationship is causal or indirect.
Cerebral blood flow and tissue metabolism in experimental cerebral ischemia of spontaneously hypertensive rats with hyper-, normo-, and hypoglycemia.
Authors: Ibayashi S , Fujishima M , Sadoshima S , Yoshida F , Shiokawa O , Ogata J , Omae T
Published: June 2011

The present study was designed to clarify the effect of blood glucose level on cerebral blood flow and metabolism during and after acute cerebral ischemia induced by bilateral carotid ligation (BCL) in spontaneously hypertensive rats (SHR). Blood glucose levels were varied by intraperitoneal infusion of 50% of glucose (hyperglycemia), insulin with hypertonic saline (hypoglycemia) or hypertonic saline (normoglycemia). Cerebral blood flow (CBF) in the parietal cortex and thalamus was measured by hydrogen clearance technique, and the supratentorial metabolites of the brain frozen in situ were determined by the enzymatic method. In non-ischemic animals, blood glucose levels had no influence on the supratentorial lactate, pyruvate or adenosine triphosphate (ATP) concentrations. In ischemic animals, however, cortical CBF was reduced to less than 1% of the resting value at 3 hours after BCL. However, there were no substantial differences of CBF during and after ischemia among 3 glycemic groups. Cerebral lactate in the ischemic brain greatly increased in hyperglycemia (34.97 +/- 1.29 mmol/kg), moderately in normoglycemia (23.43 +/- 3.13 mmol/kg) and less in hypoglycemia (7.20 +/- 1.54 mmol/kg). In contrast, cerebral ATP decreased in hyperglycemia (0.93 +/- 0.19 mmol/kg) as much as it did in normoglycemia (1.04 +/- 0.25 mmol/kg), while ATP reduction was much greater in hypoglycemia (0.45 +/- 0.05 mmol/kg). At 1-hour recirculation after 3-hour ischemia, ATP tended to increase in all groups of animals, indicating the recovery of energy metabolism. Such metabolic recovery after recirculation was good in hypo- and normoglycemia, and was also evident in hyperglycemia. Our results suggest that hyperglycemia is not necessarily an unfavorable condition in acute incomplete cerebral ischemia.
Evaluation of a scoring system for extracranial carotid atherosclerosis extent with B-mode ultrasound.
Authors: Crouse J R , Harpold G H , Kahl F R , Toole J F , McKinney W M
Published: June 2011

We have developed a scoring system to quantify extent of extracranial carotid artery atherosclerosis using real-time ultrasound (B-mode). To evaluate repeatability of this scoring system we correlated repeat scores obtained within a short interval of one another (6 months) in 52 individuals. We compared repeatability of extent measurements with repeatability of a measure of severity (single most severe lesion). Correlations between first and second studies for severity were weak (r2 = 0.20) but significant (p less than 0.001). Extent scores correlated much better (r2 = 0.77, p less than 0.001). In another group of 22 patients we found that the extent of atherosclerosis decreased following endarterectomy. We used this method to determine changes in extent of carotid atherosclerosis with age in two sets of individuals. One consisted of a cohort of 22 patients who underwent repeat B-mode studies separated by 1 1/2-3 years. This cohort demonstrated an increase in carotid score with age (p less than 0.05). In a second group of volunteers undergoing cardiac catheterization and B-mode evaluation of the carotid system, carotid scores could be compared in individuals with age differences that averaged 15 years. Extent of carotid atherosclerosis was significantly greater in older individuals (p less than 0.01) and differences in extent with age were exaggerated in patients with coronary disease compared to coronary disease free controls.
Community Hospital-based Stroke Programs: North Carolina, Oregon, and New York. II: Description of study population.
Authors: Becker C , Howard G , McLeroy K R , Yatsu F M , Toole J F , Coull B , Feibel J , Walker M D
Published: June 2011

The three Community Hospital-based Stroke Programs collected data on 4132 stroke patients admitted to acute care hospitals during 1979 and 1980. White female stroke patients were older than the white male, nonwhite female and nonwhite male stroke patients. Nearly one-fourth (23%) of stroke patients were employed at the time of the event. Most (77%) of the patients were hospitalized for first stroke episodes. Eighty-three percent of the patients had at least one of the four major risk factors for stroke, namely, hypertension, diabetes, transient ischemic attacks and cardiac disease. Half (49%) of the patients were alert at the time of admission. The three diagnostic categories included infarction (60%), stroke not otherwise specified (30%) and hemorrhage (10%). Fourteen days was the median length of hospitalization; 50% of the stroke patients were discharged to a home setting, 31% were institutionalized and 19% died while in the hospital. The mean Barthel Index score for 2400 patients at the time of discharge was 61.8 (normal is 100). Of those patients who were working at the time of the stroke, 22% returned to work. In comparison to the patients in the National Survey of Stroke, patients in this Study were less severe at the time of admission (49% of patients in the National Survey of Stroke were stuporous or comatose compared to 21% of the patients in the current Study). The inhospital fatality was 30.7% in the National Survey of Stroke, and 19.7% in the current Study.
Clinical use of nuclear magnetic resonance imaging in stroke.
Authors: DeWitt L D
Published: June 2011

There are many positive aspects to the use of MRI in the evaluation of cerebrovascular disease. First, the MR imaging technique appears to be essentially without hazard. It does not rely on ionizing radiation, and no intravenous injections of contrast agent are necessary. MRI exploits the tissue's inherent biophysical characteristics to provide superior contrast. Infarctions are well delineated by MRI, often better and earlier than CT. Because of the lack of MRI signal from bone and thus the lack of transverse artifact from bone often seen with CT, lesions in the posterior fossa are very well visualized. With MRI it is possible to obtain images in the transverse, coronal, and sagittal planes, which provides for good evaluation of lesion size and extent. Arteriovenous malformations have been visualized by MRI, but it is still too early to know whether MRI has any detection capability over CT in this disorder. Subdural hematomas have been well visualized by MRI, including cases of isodense subdurals not visualized by CT. On the other hand, MRI has not proven to have any advantage over CT in the evaluation of intracerebral hemorrhage, hemorrhagic infarction, and subarachnoid hemorrhage. In fact, for detection of intracerebral hemorrhage and subarachnoid hemorrhage, CT may be better at the present time. In chronic infarction the surrounding area of Wallerian degeneration may cause the area of infarction to appear larger than it actually is. Hopefully, with further research into the use of different pulse sequence techniques and with good neuropathological correlation, the present limitations of MRI can be eliminated.(ABSTRACT TRUNCATED AT 250 WORDS)
Stroke unit care--who benefits? Comparisons with general medical care in relation to prognostic indicators on admission.
Authors: Strand T , Asplund K , Eriksson S , Hägg E , Lithner F , Wester P O
Published: June 2011

The clinical outcome in 110 patients admitted to a non-intensive stroke unit was compared to that in 183 patients treated for acute stroke in general medical wards. At entry, the two groups of patients were closely similar in all prognostic indicators. Subsets of patients were analyzed in an attempt to identify groups that benefit more than others from stroke unit care. The stroke unit regime had little effect on short-term and long-term mortality rates in the entire stroke population as well as in subgroups. But after the care in the stroke unit, the need for long-term hospitalization in survivors was reduced (p = 0.0001). This difference in favour of the stroke unit was independent of the patients' age, the extent of neurological deficit on admission and previous history. In subgroups where the general prognosis is fair or good (minor neurological deficits and less than 75 yrs), SU care accelerated the process of rehabilitation, but the need for institutional care very late after the stroke was influenced only little. In groups with a poor general prognosis (major deficits and greater than or equal to 75 yrs), the ultimate proportion of patients able to return home was enhanced by SU care. It is concluded that care in a stroke unit benefits the great majority of stroke patients and that such a unit should be designed to admit all acute stroke patients without selection.
Evaluation of the North Carolina Stroke Care Program.
Authors: Dignan M B , Howard G , Toole J F , Becker C , McLeroy K R
Published: June 2011

A study of 774 patients in eastern North Carolina was undertaken to determine the effects of a coordinated program of care and follow-up on recovery from stroke. The program was designed to coordinate and improve in-hospital stroke care and rehabilitation, to provide for education and training of the family for post-hospital care, and to coordinate and facilitate continued access to services after discharge. As measured by the Barthel Index at discharge, three, six and 12 months, the impact of the program was found to be minimal. Patients' scores throughout follow-up were influenced by age, whether the stroke event was new or recurrent, and the state of consciousness at admission. Follow-up Barthel scores were also related to scores obtained at discharge.
Vasomotor effects of dimethyl sulfoxide on cat cerebral arteries in vitro and in vivo.
Authors: Pitts L H , Young A R , McCulloch J , MacKenzie E
Published: June 2011

We studied the direct vascular effects of dimethyl sulfoxide (DMSO) in isolated middle cerebral arteries and on pial arteriolar caliber after subarachnoid perivascular microinjection in chloralose-anesthetized cats, and on brain retraction in cats given DMSO intravenously. DMSO did not constrict isolated cerebral arteries at any of the concentrations studied (10(-10) to 4 X 10(-1) M). In middle cerebral arteries precontracted with potassium, 5-hydroxytryptamine, prostaglandin F2 alpha, or with mechanically raised tone, DMSO at concentrations of 10(-10) to 10(-2) M had no significant effects; at concentrations greater than 10(-2) M, DMSO consistently relaxed the arteries, probably because of the hyperosmolarity of the bathing solution. Microapplication of DMSO (10(-6) to 10(-2) M) around pial arterioles on the cortical surface did not change arteriolar caliber significantly. Higher concentrations of DMSO (1%) increased arteriolar caliber by 56 +/- 4% (p less than 0.001), probably as a consequence of solution hypertonicity. DMSO did not modify in vivo cerebrovascular responses to alterations in perivascular potassium ion concentrations. Intravenous administration of DMSO did cause obvious brain shrinkage. These data provide no support for the view that direct cerebral vascular effects play a major role in the clinical efficacy of DMSO, but are consistent with the hypothesis that DMSO's ability to lower intracranial pressure derives from its osmotic effect on cerebral issue.
Painless dissections of the aorta presenting as acute neurologic syndromes.
Authors: Gerber O , Heyer E J , Vieux U
Published: June 2011

We describe three patients who had painless dissections of the aorta which resulted in neurologic syndromes at the time of presentation. Two patients had acute hemimotor and sensory findings. In one of these cases progression to paraplegia occurred. In a third patient, acute weakness and ischemia of a leg occurred at presentation. We review previously described painless aortic dissections. Such aortic dissections may be suspected in the setting of an acute neurologic event by abnormalities in the examination of the peripheral pulses and the heart and by attention to characteristic chest x-ray changes.
The epidemiology of stroke in an urban black population.
Authors: Rosman K D
Published: June 2011

Hospital admissions for acute stroke were monitored over a twelve month period. Only patients age 20 and over were studied. Out of a population at risk of 114931 there were 116 cases, giving an overall incidence of 1.01 admissions per 1000 population per year over age 20. Cerebral hemorrhages were present in 32.8%, large artery thromboses in 31.9%, cerebral embolism in 13.8% and lacunar infarctions in 20.7% of cases. Atrial fibrillation was the presumed cause of cerebral embolism in 6.9% of patients. Hypertension was present in 69.8% of patients. Further studies are needed to establish the characteristics of stroke in the Third World.
Cerebral thromboembolism among young women and men in Denmark 1977-1982.
Authors: Lidegaard O , Soe M , Andersen M V
Published: June 2011

In the period 1977-1982, the Danish National Patient Register recorded 1000 cases of cerebral thromboembolic attacks among women 15-44 years of age, and 971 cases among men of the same age. Cerebral infarction accounted for 70% of cases and transient ischemic attacks (TIA) for the remaining 30%. By analysing this material we found an average age-adjusted incidence rate of cerebral thromboembolism of 14.4/100.000 among men and 15.5/100.000 among women. The incidence rates rose rapidly with increasing age. Women aged 15-34 had significantly higher incidence rates of brain infarction and TIA compared to those of men of the same age. This was reversed in the age group 35-44. The magnitude of the ratio between the female and the male mean incidence rates by increasing age corresponded exactly to the age distribution of the use of oral contraceptives in Denmark. The relative risk for developing cerebral thromboembolism among users of oral contraceptives was estimated to be 3.2-6.5. The mortality in male patients with brain infarction was 3.3% and in females 1.7%. The mean duration of stay in hospital was 8.8 days for TIA and about 26 days for cerebral infarction. Sixteen percent of men and 13.6% of women had hypertension during their stay.
Incidence of stroke in a Finnish prospective population study.
Authors: Reunanen A , Aho K , Aromaa A , Knekt P
Published: June 2011

The incidence of stroke was investigated in a large Finnish prospective population study. The study population consisted of 11,984 men and 11,682 women aged 15 years and over drawn from four geographical regions of the country. In a mean follow-up time of six years, 174 men and 169 women suffered a fatal or non-fatal stroke. The age-adjusted mean annual incidence of stroke in men, 4.0/1000, was statistically significantly higher than the annual incidence in women, 3.3/1000. In twelve percent of the cases stroke was caused by subarachnoid hemorrhage and in ten percent by cerebral hemorrhage. In 30 percent of the cases, cerebral infarction was ascertained as the cause of the stroke; while in 49 percent of the cases, the type of stroke could not be specified with certainty. The incidence of stroke was significantly higher in non-attendants than in attendants at the initial survey. The incidence of cerebral infarction appeared to be higher in men from eastern Finland than in men from southwestern Finland.
Prevalence of stroke in Finland.
Authors: Aho K , Reunanen A , Aromaa A , Knekt P , Maatela J
Published: June 2011

The prevalence of stroke was investigated in a Finnish population study. The results were based on cross-sectional data from a follow-up examination of a prospective study conducted in 1973-1976. The study population drawn from four regions of the country comprised 11,103 men and 11,096 women aged 20 years and over. The age-adjusted prevalence of stroke was 10.3/1000 in men and 5.8/1000 in women. The prevalence was significantly higher in non-attendants at the examination than in attendants. In 15 per cent of the prevalence cases the stroke was caused by subarachnoid hemorrhage, in six per cent by cerebral hemorrhage and in the remainder by cerebral infarction or the type could not be specified. Over half (57 per cent) of the survivors of stroke had no or only slight disability; eight per cent were totally disabled. Some form of organic heart disease and hypertension was significantly more common in the prevalence cases than in the others.
Hematocrit as a risk factor of cerebral infarction: long-term prospective population survey in a Japanese rural community.
Authors: Kiyohara Y , Ueda K , Hasuo Y , Fujii I , Yanai T , Wada J , Kawano H , Shikata T , Omae T , Fujishima M
Published: June 2011

To elucidate the relation of hematocrit (Hct) to the incidence of cerebral infarction, a prospective follow-up study of 16 years (1965-81) was performed in a general population sample of 1220 Hisayama residents aged 44 and over, of both sexes. Most of the subjects who died during the follow-up period were autopsied, the rate being 89.0%. Hct decreased with advancing age in men, but not in women. The average value for Hct was significantly lower in women than in men. According to the mean value +/- 1 SD of Hct, the subjects were grouped into 3, in each sex as follows: low (less than 35%), normal (35-45%) and high (greater than or equal to 45%) for men, and, low (less than 30%), normal (30-40%) and high (greater than or equal to 40%) for women. During the follow-up period, cerebral infarction occurred in 117 patients. The cumulative incidence of cerebral infarction in the low Hct group for men was the lowest, even after adjustments for age and blood pressure. Conversely, the incidence in the low Hct group of women was significantly higher than that in the normal Hct group and was consistently increased with time during 2-5 years of the follow-up. After the 6th year or later, however, the incidence was gradually but significantly increased in the high Hct group, compared with the normal Hct group. Since Hct levels were related with other variables such as serum total cholesterol, serum total protein, Quetelet index and prevalence of hypertension in both sexes, heavy alcohol consumption in men, and glucose intolerance in women, such variables were taken into account using Cox's proportional hazards regression model.(ABSTRACT TRUNCATED AT 250 WORDS)
Measurement of regional cerebral blood flow, blood volume and oxygen metabolism in patients with sickle cell disease using positron emission tomography.
Authors: Herold S , Brozovic M , Gibbs J , Lammertsma A A , Leenders K L , Carr D , Fleming J S , Jones T
Published: June 2011

Regional cerebral blood flow, blood volume, fractional oxygen extraction and oxygen consumption were measured by positron emission tomography in six patients with sickle cell disease to see how oxygen delivery to the brain is maintained in the presence of both anemia and a low oxygen affinity hemoglobin. Both regional cerebral blood flow and blood volume were found to be markedly increased compared to values obtained from 14 normal subjects in the same age range. The mean fractional oxygen extraction was not significantly different in the two groups. Mean oxygen consumption in the two groups was also not significantly different but low values in individual patients with sickle cell disease and the presence of atrophy on the CT-scans of three of them were suggestive of some neuronal loss in patients without any history of nervous system involvement. In view of the known high values of cerebral blood flow and metabolism in childhood, it is suggested that when compounded by anemia and abnormal red cells, a hypercirculatory state may make patients in this age-group particularly prone to ischemic infarction.
Progress review: hypoglycemic brain damage.
Authors: Auer R N
Published: June 2011

The central question to be addressed in this review can be stated as "How does hypoglycemia kill neurons?" Initial research on hypoglycemic brain damage in the 1930s was aimed at demonstrating the existence of any brain damage whatsoever due to insulin. Recent results indicate that uncomplicated hypoglycemia is capable of killing neurons in the brain. However, the mechanism does not appear to be simply glucose starvation of the neuron resulting in neuronal breakdown. Rather than such an "internal catabolic death" current evidence suggests that in hypoglycemia, neurons are killed from without, i.e. from the extracellular space. Around the time the EEG becomes isoelectric, an endogenous neurotoxin is produced, and is released by the brain into tissue and cerebrospinal fluid. The distribution of necrotic neurons is unlike that in ischemia, being related to white matter and cerebrospinal fluid pathways. The toxin acts by first disrupting dendritic trees, sparing intermediate axons, indicating it to be an excitotoxin. Exact mechanisms of excitotoxic neuronal necrosis are not yet clear, but neuronal death involves hyperexcitation, and culminates in cell membrane rupture. Endogenous excitotoxins produced during hypoglycemia may explain the tendency toward seizure activity often seen clinically. The recent research results on which these findings are based are reviewed, and clinical implications are discussed.
Basilar artery narrowing and hyperparathyroidism: illustrative case.
Authors: Yarnell P R , Caplan L R
Published: June 2011

A patient presenting with a pontine infarction caused by mid-basilar artery narrowing associated with hyperparathyroidism is described. The narrowing reversed with surgical removal of his parathyroid adenoma and normalization of his serum calcium. This patient's illness lends evidence to the role of calcium in cerebral vasoconstriction.
Horizontal gaze paresis in hemispheric stroke.
Authors: Kelley R E , Kovacs A G
Published: June 2011

Of 156 stroke patients prospectively and consecutively evaluated, one-third had a homonymous hemianopia. Of those 52 patients, 46% had a horizontal conjugate gaze paresis at the time of presentation. This gaze paresis was most commonly seen with large hemispheric stroke. The overall prognosis in patients with a gaze paresis was poor. The 30-day case fatality rate was 49% which was significantly higher than for stroke patients presenting with homonymous hemianopia without a gaze paresis.
Late-life migraine accompaniments--further experience.
Authors: Fisher C M
Published: June 2011

In 1980, 120 cases with late-life migrainous accompaniments resembling transient ischemic attacks were presented. In the present paper, 85 further cases examined in the past five years are analyzed. The findings support the concept advanced previously. In general, the cases are divided into the same categories: visual--21 cases, visual and paresthesias--6, visual and speech disturbance--2, visual, paresthesias and speech disturbance--3, visual, paresthesias, speech disturbance, and weakness--20, visual and brainstem symptoms--3, and cases without visual symptoms--32. The ages ranged from 40 to 73 years. Headache occurred in association with the episodes in only 40% of cases. There was a history of recurrent headache in 65%. The condition can justifiably be regarded as benign. Migrainous accompaniments account for some of the cases of transient ischemia with normal angiograms. Knowledge of the condition helps in the planning of rational management.
Contrast enhancement CT scan and post-endarterectomy hemorrhage.
Authors: Ropper A H , Kehne S M
Published: June 2011

Cerebral hemorrhage, an unusual complication of endarterectomy, is often attributed to postoperative hypertension. A patient with a middle cerebral artery stroke had a hemorrhage without hypertension, 2 days postoperatively. Pronounced contrast enhancement of the infarction during the 7 weeks prior to surgery reflected severe disruption of the blood-brain barrier. Contrast CT scans may detect patients at risk for post-endarterectomy hemorrhage even 2 months after a stroke or TIA.
Transorbital Doppler diagnosis of intracranial arterial stenosis.
Authors: Spencer M P , Whisler D
Published: June 2011

Forty-two intracranial internal carotid arteries were visualized by both arteriography and 2 MHz pulse ultrasonic Doppler examinations. The intracranial internal carotid artery Doppler signals were studied at 5-7 cm depth behind the eyelid using frequency spectral analysis. Stenosis criteria were developed and methods of avoiding confusion with collateral effects devised. Among 33 intracranial ICAs visualized on the arteriograms, 22 were normal without stenosis and 11 displayed some degree of stenosis ranging from 20 to 75 percent. An additional 7 were totally occluded. Doppler criteria of stenosis representing elevated frequencies and symmetrical prominent low frequencies (SPLF) were utilized and separated from collateral effects to provide an overall accuracy of the technique of 88 percent with a 95 percent specificity and a 73 percent sensitivity. The technique appears sufficiently promising to justify further development and utilization.