bluuebunny/crossref_metadata_2025 huggingface dataset:
White matter lucencies on computed tomography, subacute arteriosclerotic encephalopathy (Binswanger's disease), and blood pressure.
Authors: McQuinn B A , O'Leary D H
Published: June 2011

Of 1,643 cranial computed tomography (CT) scans done in a primary-tertiary care private hospital over a 1-year period, 11 (0.67%) showed diffuse confluent white matter lucencies of less than 30 Hounsfield units. By retrospective analysis, at least 4 of the 11 were demented. Of these, 3 had clinical evidence of Binswanger's disease--characterized by progressive dementia, incontinence, variable pseudobulbar signs, and acute and subacute motor deficits. Two additional patients suffered only transient ischemic attacks or lacunar strokes; 2 had syncope; 1 had multiple sclerosis. The remaining patients were neurologically asymptomatic. In this small retrospective series, the severity of CT changes did not distinguish the patients with clinical Binswanger's syndrome from neurologically less symptomatic patients. Ten of the eleven patients had disordered blood pressure regulation--hypertension, labile systolic pressure, orthostatic hypotension, or a combination of these factors. The severity of CT changes correlated more clearly with blood pressure instability than with clinical encephalopathy. Asymptomatic adult patients with unexplained CT white matter hypodensity and blood pressure disorders may, however, be at risk for the development of subsequent subacute arteriosclerotic encephalopathy.
Regional cerebral blood flow, clinical manifestations, and age in children with moyamoya disease.
Authors: Tagawa T , Naritomi H , Mimaki T , Yabuuchi H , Sawada T
Published: June 2011

In children with Moyamoya disease, transient ischemic attacks often occur during hyperventilation, and the frequency of attacks usually decreases with advancing age. To elucidate the mechanism of the attacks, the regional cerebral blood flow was measured during rest and/or hyperventilation in children aged 3-16 with Moyamoya disease. Regional cerebral blood flow during rest was significantly higher in younger children with Moyamoya disease, and it progressively decreased with advancing age through childhood. During hyperventilation, regional cerebral blood flow decreased in all the children, although blood flow in younger children was still higher than that in the older children. Nevertheless, transient ischemic attacks were more readily precipitated by hyperventilation in the younger than in the older children. Cerebral metabolic demand is much higher in the first decade of life than in later decades. Therefore, it seems likely that even a moderate reduction in cerebral blood flow can cause metabolic impairment in young children. Such high cerebral metabolic demand may play an important role in the frequent occurrence of transient ischemic attacks in young children with Moyamoya disease.
Acute effect of angiographic contrast medium on cortical specific gravity after middle cerebral artery occlusion in rats.
Authors: Olson J J , Beck D W , Warner D S
Published: June 2011

Early angiography after cerebral arterial occlusion has been cited as potentially detrimental. This investigation evaluates the effect of acute angiographic contrast medium administration on the cortical edema induced by middle cerebral artery (MCA) occlusion. Sixteen rats underwent MCA occlusion, and after 1 hour half the rats underwent ipsilateral internal carotid injection of meglumine diatrizoate, whereas the remainder underwent cervical internal carotid exposure only. Six rats had only sham operations on the MCA and internal carotid, and 4 other rats served as normal controls. Cortical specific gravity was measured to reflect cerebral edema 4 hours after occlusion or sham operation. Specific gravity of the lateral frontal cortex in the hemisphere ipsilateral to occlusion was 1.0396 +/- 0.0011 (mean +/- SEM) when no angiographic contrast medium was administered, significantly less (p less than 0.01) than in rats exposed to contrast medium (specific gravity 1.0442 +/- 0.0005). The latter value was not significantly different from normal. Other cortical areas on the side of the contrast medium injection were also relatively dehydrated compared with normal controls. Early meglumine diatrizoate administration after MCA occlusion results in a decrease in cerebral cortical edema, possible by inducing an osmotic gradient that draws water from the extravascular space.
Endothelium-dependent relaxation of canine basilar arteries. Part 2: Inhibition by hemoglobin and cerebrospinal fluid from patients with aneurysmal subarachnoid hemorrhage.
Authors: Kanamaru K , Waga S , Kojima T , Fujimoto K , Niwa S
Published: June 2011

The effects of hemoglobin and cerebrospinal fluid from patients with subarachnoid hemorrhage (CSF-SAH) on endothelium-dependent relaxation were studied. At 10(-6) M, hemoglobin somewhat inhibited the endothelium-dependent relaxation induced by A23187 in rings of canine basilar artery. At 3 X 10(-6) M, it almost completely inhibited the same response. At 3 X 10(-6) M, hemoglobin did not significantly inhibit smooth muscle relaxation mechanisms as papaverine-induced relaxation was not inhibited by hemoglobin. It was also demonstrated that pretreatment of arterial rings with CSF-SAH resulted in a dose-dependent inhibition of relaxation induced by A23187. The inhibitory effect of CSF-SAH was prominent in the case in which a high oxyhemoglobin concentration was measured by spectrophotometry. Normal CSF from patients without SAH did not affect endothelium-dependent relaxation. These results suggest that hemoglobin released from lysed erythrocytes inhibits endothelium-dependent relaxation of canine basilar arteries and may also play an important role in the pathogenesis of cerebral vasospasm after aneurysmal subarachnoid hemorrhage.
Extracranial vertebral artery dissections: a review of 13 cases.
Authors: Mas J L , Bousser M G , Hasboun D , Laplane D
Published: June 2011

Clinical and radiologic findings in 13 patients (11 women, 2 men) with extracranial vertebral artery dissection are reported. Dissection was spontaneous in 8 patients, occurred after neck manipulation in 2 and after a potential minor injury to the neck in 3. Six had a history of common migraine, 4 were using oral contraceptives at the time of dissection, and 3 had fibromuscular dysplasia. Dissection was bilateral in 8 patients and associated with carotid dissection in 3. It usually presented with neck or occipital pain preceding basilar ischemic symptoms by a few minutes to 1 month. In 3 patients, transient ischemic attacks were the only manifestation of basilar ischemia, and in 1 patient there was no symptom of basilar ischemia despite bilateral vertebral dissection. In 19 of the 21 dissected vertebral arteries, the angiographic appearance was that of an irregular stenosis, which was associated in 6 arteries with pseudoaneurysmal formation. In 2 patients, 1 vertebral artery was occluded but the contralateral artery showed the typical irregular stenosis. The dissection involved only the third segment in 33%, only the second segment in 24%, and 2 or more segments in 38%. Eleven patients were treated with anticoagulants and 2 with aspirin; 11 recovered without sequelae and 2 had residual deficit. No recurrence was observed (mean follow-up 34 months). At control angiography (n = 12) or ultrasonic study (n = 1), 63% of dissected vertebral arteries had returned to normal, 26% showed marked improvement, and 11% were occluded. Our patient characteristics are compared with those of previously published cases. The validity of the distinction between spontaneous dissection and dissection associated with minor trauma is discussed.
Cerebral blood flow in normal pressure hydrocephalus.
Authors: Mamo H L , Meric P C , Ponsin J C , Rey A C , Luft A G , Seylaz J A
Published: June 2011

A xenon-133 method was used to measure cerebral blood flow (CBF) before and after cerebrospinal fluid (CSF) removal in patients with normal pressure hydrocephalus (NPH). Preliminary results suggested that shunting should be performed on patients whose CBF increased after CSF removal. There was a significant increase in CBF in patients with NPH, which was confirmed by the favorable outcome of 88% of patients shunted. The majority of patients with senile and presenile dementia showed a decrease or no change in CBF after CSF removal. It is suggested that although changes in CBF and clinical symptoms of NPH may have the same cause, i.e., changes in the cerebral intraparenchymal pressure, there is no simple direct relation between these two events. The mechanism underlying the loss of autoregulation observed in NPH is also discussed.
Ischemic stroke associated with anticardiolipin antibodies.
Authors: Levine S R , Kim S , Deegan M J , Welch K M
Published: June 2011

Anticardiolipin antibodies are a group of antiphospholipid autoantibodies seen primarily in patients with systemic lupus erythematosus and other autoimmune diseases. We report 3 patients, 2 without systemic lupus, who suffered ischemic brain infarction associated with these antibodies in the absence of detectable lupus anticoagulant activity. Anticardiolipin antibodies, possibly associated with a lupus anticoagulant-like thrombotic tendency, may be a newly recognized cause of ischemic stroke.
Multiple cerebral infarctions and dementia associated with anticardiolipin antibodies.
Authors: Coull B M , Bourdette D N , Goodnight S H , Briley D P , Hart R
Published: June 2011

Antibodies to negatively charged phospholipids including cardiolipin have been recognized in the sera of patients with systemic lupus erythematosus and other disorders. We report 4 patients who experienced cerebral infarctions and dementia in association with anticardiolipin antibodies. These patients did not have the characteristic lupus anticoagulant or systemic lupus erythematosus. The occurrence of anticardiolipin antibodies in patients with multiple cerebral infarctions who do not have evidence of a systemic vasculitis or inflammatory condition suggests that this association may be more common than previously recognized. It may be useful to test for the presence of anticardiolipin antibodies in patients who have unexplained cerebral infarctions.
Flunarizine reduces cerebral infarct size after photochemically induced thrombosis in spontaneously hypertensive rats.
Authors: Van Reempts J , Van Deuren B , Van de Ven M , Cornelissen F , Borgers M
Published: June 2011

The cerebroprotective effect of flunarizine was studied in a minimally invasive model of photochemically induced cerebral infarction in spontaneously hypertensive rats. Intravenous administration of the photosensitizing dye rose bengal and intense focal illumination of the brain produced a deep cortical infarction that resulted from singlet oxygen-induced peroxidative injury to the endothelial membrane, subsequent platelet adhesion, and eventual thrombus formation. The infarct size was calculated from area measurements on consecutive histologic sections prepared from the brain cortex 4 hours after the onset of the insult. Oral treatment with 40 mg/kg flunarizine 3 hours before photoexcitation resulted in a significant reduction of the median infarct size from 11.75 mm3 in the untreated group to 6.40 mm3 in the treated group (n = 13, p less than 0.001). At this dose, flunarizine had no effect on systemic blood pressure. In a separate experiment the area of thrombotic obstruction was quantified 30 minutes after the onset of light exposure. Flunarizine did not significantly reduce early thrombus formation (2.28 mm3 in the untreated and 1.78 mm3 in the treated group) (n = 12, p = 0.2). The infarcted area at 4 hours was considerably larger than the initial thrombotic area. Protection with flunarizine against development of cortical infarction has been unequivocally shown. Although some effect may already be present at the early stage of lesion formation, the major protective action admittedly occurred in the later postinsult period when the lesion was expanding.(ABSTRACT TRUNCATED AT 250 WORDS)
Spatial relations of dorsal anastomoses and lesion border after middle cerebral artery occlusion.
Authors: Coyle P
Published: June 2011

Occlusion of the middle cerebral artery invariably results in infarction of tissue in stroke-prone spontaneously hypertensive rats (SHRSP). To determine if the lesion border extends beyond the territory of the occluded middle cerebral artery or if the lesion enlarges with time after the occlusion, spatial relations of the lesion and the primary anastomosing collateral branches were investigated. Measurements were made 1 day (n = 8) or 21 days (n = 8) after occlusion in 5-8-week-old SHRSP brains marked by triphenyltetrazolium chloride (TTC) or tissue atrophy. After 1 day of occlusion, the border between TTC-marked and -unmarked tissue was parallel to, and without spatial displacement from, the medial border of infarcted tissue measured 21 days after the occlusion. Thus, the TTC border accurately localizes the medial border of ischemic tissue that progresses to atrophy. The lesion border was 1.16 +/- 0.04 mm downstream from the anastomoses, and the mean distance was not significantly different in frontal, parietal, or rostral occipital regions or between the 2 groups of rats. Thus, a small but significant amount of tissue between the anastomoses and the lesion border was protected against infarction after middle cerebral artery occlusion in SHRSP. After 21 days of occlusion, the dorsal anastomoses were enlarged, bilaterally symmetric in position but not size, and without displacement from the anastomoses in 1-Day rats. Large-diameter anastomoses were further from the lesion than small-diameter anastomoses in both groups of rats, thus indicating that protection is greater near large anastomoses than near small ones.(ABSTRACT TRUNCATED AT 250 WORDS)
Hemorrhagic complications of thrombolytic therapy in experimental stroke.
Authors: Slivka A , Pulsinelli W
Published: June 2011

Recent success with thrombolytic therapy for acute myocardial infarction has stimulated interest in its use for stroke. To determine the hemorrhagic potential of thrombolytic therapy in experimental cerebral infarction, we compared a group of tissue plasminogen activator-treated rabbits (n = 4) with 2 groups of streptokinase-treated rabbits (n = 6 in each), as well as with 3 groups of heparin-treated rabbits (n = 5 in each) and untreated controls (n = 12). Focal cerebral infarction was produced in rabbits by occlusion of the right common carotid and middle cerebral arteries coupled with 2 hours of halothane-induced hypotension. Treatment with heparin or thrombolytic agents began 24 hours after occlusion. One additional group was treated with streptokinase 1 hour after occlusion (n = 6) to determine the hemorrhagic potential of thrombolytic agents in evolving infarction. Rabbits were killed 29-33 hours after occlusion, and brain sections were examined using light microscopy. The results demonstrate that microscopic hemorrhage is frequently present in infarcted tissue irrespective of treatment. Gross cerebral hemorrhage did not occur in untreated rabbits or in rabbits treated with streptokinase 1 hour after occlusion. Only rabbits treated with streptokinase, tissue plasminogen activator, or excessive doses of heparin 24 hours after occlusion, at a time when cerebral infarction was well established, exhibited gross hemorrhage in the area of infarction. These data suggest that treatment of ischemic stroke with thrombolytic agents carries an increased risk of cerebral hemorrhage unless the agents are given early after the onset of symptoms.
Is there a role for heparin in the management of complications of subarachnoid hemorrhage?
Authors: Chimowitz M I , Pessin M S
Published: June 2011

Proven effective therapy to prevent ischemic deficits and other complications after subarachnoid hemorrhage is lacking despite extensive research efforts. A literature review documented both clinical and experimental evidence suggesting that heparin may be effective in preventing ischemic deficits after subarachnoid hemorrhage by reversing vasospasm, improving blood flow through narrowed vessels, and preventing the development of a proliferative angiopathy. Additional evidence suggests that heparinization of the cerebrospinal fluid following subarachnoid hemorrhage may prevent the development of hydrocephalus. In the only clinical trial using heparin after subarachnoid hemorrhage, the incidence of rebleeding in the heparinized patients was no higher than in the control group. We conclude that the existing preliminary data concerning a role for heparin in the management of the complications of subarachnoid hemorrhage is promising, but further controlled studies are needed prior to clinical application.
The Canadian American Ticlopidine Study (CATS) in thromboembolic stroke. Design, organization, and baseline results.
Authors: Gent M , Blakely J A , Easton J D , Ellis D J , Hachinski V C , Harbison J W , Panak E , Roberts R S , Sicurella J , Turpie A G
Published: June 2011

The Canadian American Ticlopidine Study is a randomized, placebo-controlled, double-blind, multicenter study to assess the efficacy and safety of ticlopidine hydrochloride in patients who have suffered a thromboembolic stroke no less than 1 week and no more than 4 months before entry into the study. The primary assessment of efficacy will be based on the cluster of outcome events recurrent stroke, myocardial infarction, or vascular death. Twenty-five clinical centers, 12 in Canada and 13 in the United States, entered a total of 1,072 patients during a 3-year recruitment period; these patients were randomly allocated to receive either 250 mg ticlopidine or identical-appearing placebo tablets twice daily for up to 3 years. Patient recruitment was completed in December 1986. Patients were followed for a maximum of 3 years or until the close of the study in December 1987; at that time an average follow-up of 25 months had been achieved. We summarize the protocol and organization of the study and document the methods of execution and analysis, with corresponding criteria, before disclosure of the treatment code to any of the study investigators. We also provide a clinical description of the patients at entry into the study.
Family intervention after stroke: does counseling or education help?
Authors: Evans R L , Matlock A L , Bishop D S , Stranahan S , Pederson C
Published: June 2011

Two interventions for improving stroke caregiver knowledge, stabilizing family function, promoting patient adjustment, and enlisting the use of social resources after stroke were compared with routine medical and nursing care of stroke patients (n = 61) at a 440-bed Veterans Administration Medical Center. The education intervention (n = 64) consisted of classroom instruction for caregivers about basic stroke care principles. The counseling condition (n = 63) consisted of education plus seven follow-up problem-solving sessions with a social worker (for the caregiver). Six months and 1 year after the stroke, both interventions significantly improved caregiver knowledge and stabilized some aspects of family function better than routine care. Counseling was consistently more effective than education alone and resulted in better patient adjustment at 1 year. Neither intervention influenced the use of social resources.
Hyperglycemia is a stress response in acute stroke.
Authors: Woo E , Ma J T , Robinson J D , Yu Y L
Published: June 2011

To explore further the relation between admission glucose concentration and outcome in stroke, we measured glucose, fructosamine, and glycosylated hemoglobin concentrations on admission in 216 patients seen within 24 hours after the onset of their first stroke. Fructosamine concentration reflects the degree of glycemia in the preceding 4-6 weeks and glycosylated hemoglobin concentration reflects that in the preceding 3 months. Based on clinical, computed tomographic, and necropsy findings, strokes were classified as cortical infarction, lacunar infarction, or intracerebral hemorrhage. Analyses were done including and excluding 47 diabetic patients. No correlation between neurologic outcome as mortality and fructosamine or glycosylated hemoglobin concentration was found. Survival showed a significant correlation with admission glucose concentration only for patients with intracerebral hemorrhage. Our results suggest that hyperglycemia is unlikely to worsen the outcome of acute stroke and that hyperglycemia probably represents either a latent diabetic state or a stress response.
Superior cerebellar artery infarction and vertebral artery dissection.
Authors: Levine S R , Welch K M
Published: June 2011

Isolated superior cerebellar artery infarction is rare, and the mechanism is often not readily apparent. We describe a patient with an isolated superior cerebellar artery infarction resulting from an ipsilateral vertebral artery dissection. Angiography demonstrated intraluminal clot in the superior cerebellar artery, suggesting artery-to-artery embolus as a mechanism of this uncommon stroke syndrome.
Neurologic manifestations of atrial myxoma. A 12-year experience and review.
Authors: Knepper L E , Biller J , Adams H P , Bruno A
Published: June 2011

We present the results of a 12-year retrospective analysis of 11 patients, eight women and three men, aged 16-76 years, with pathologically documented atrial myxomas. Nine of the 11 patients were found to have a left atrial myxoma; right atrial myxomas were identified in two. Five of the 11 patients (45%) had abnormalities on neurologic examination, and five of five had computed tomographic evidence of nonhemorrhagic cerebral infarction. Neurologic symptoms were the initial presentation in four patients. Six patients reported a history of cardiac disease; eight of the 11 had abnormalities on cardiac auscultation. Echocardiography in 10 patients was diagnostic in all but one. Gated magnetic resonance imaging of the heart in two patients demonstrated myxoma position and movement. Follow-up examinations (varying from 1 month to 7 years after tumor resection) in nine of 11 patients demonstrated no recurrent neurologic symptoms. Cerebral infarction is a common complication of atrial myxomas and may be the presenting feature. Recurrent cerebral emboli before surgery is not uncommon. Cardiac auscultation may be normal, and electrocardiographic changes are often nonspecific. Delayed neurologic events following surgery are rare.
Striatal dopamine in acute cerebral ischemia of stroke-resistant rats.
Authors: Kawano T , Tsutsumi K , Miyake H , Mori K
Published: June 2011

We devised the present experiments to assess the effects of ischemia on the production of dopamine in the caudate nucleus of spontaneously hypertensive stroke-resistant rats. Ringer's solution was continuously perfused at a rate of 10 microliters/min through 0.2-mm-diameter dialysis tubing implanted in the rat's caudate nucleus. After bilateral occlusion of the common carotid artery, perfusate was collected at 20-minute intervals for 120 minutes and was analyzed for monoamines and their metabolites using high-performance liquid chromatography and an electrochemical detection system. The extracellular concentration of dopamine increased abruptly approximately 3 minutes after the ischemic insult, reached a maximum at between 20 and 40 minutes after the insult, and subsequently decreased. During the 120 minutes, 3,4-dihydroxyphenylacetic acid and 5-hydroxyindole-3-acetic acid concentrations decreased significantly, whereas 5-hydroxytryptamine was not detected. Our results indicate that during cerebral ischemia a large increase in extracellular dopamine concentration in the caudate nucleus occurs, probably as a result of energy failure of the cell membranes. This leakage of dopamine may be a causal factor in the neuronal damage associated with cerebral ischemia.
Aneurysmal subarachnoid hemorrhage in Izumo City and Shimane Prefecture of Japan. Outcome.
Authors: Inagawa T , Takahashi M , Aoki H , Ishikawa S , Yoshimoto H
Published: June 2011

The overall outcome of patients with aneurysmal subarachnoid hemorrhage was investigated in Izumo City and Shimane Prefecture. Of the patients from Izumo City, the clinical grade on admission was Grade I or II in 41% and Grade IV or V in 31%. Of those from Shimane Prefecture, 49% were graded as Grade I or II and 24% as Grade IV or V. The overall mortality rates 1 year after subarachnoid hemorrhage were 46% for Izumo City and 35% for Shimane Prefecture, while the surgical mortality rates were 18 and 15%, respectively. The mortality rates were particularly high among the elderly over the age of 70 years and among unoperated cases. The leading cause of death in these cases was the effect of aneurysm rupture itself, followed by rebleeding and vasospasm. The 5-year survival probabilities according to life table analysis were 50% for Izumo City and 59% for Shimane Prefecture, and a significant difference was observed in survival curves between Izumo City and Shimane Prefecture. It is concluded that the smaller the community studied, the less favorable the overall outcome, mainly because of poorer clinical conditions on admission.
Treatment of acute cerebral infarction with a choline precursor in a multicenter double-blind placebo-controlled study.
Authors: Tazaki Y , Sakai F , Otomo E , Kutsuzawa T , Kameyama M , Omae T , Fujishima M , Sakuma A
Published: June 2011

A multicenter double-blind placebo-controlled study of cytidine 5'-diphosphocholine (CDP-choline) was conducted to evaluate possible clinical benefits of the drug in patients with acute, moderate to severe cerebral infarction. The patients included also suffered from moderate to mild disturbances of consciousness, and all were admitted within 14 days of the ictus. Patients were allocated randomly to treatment with either CDP-choline (1,000 mg/day i.v. once daily for 14 days) or with placebo (physiological saline). One hundred thirty-three patients received CDP-choline treatment, and 139 received placebo. The group treated with CDP-choline showed significant improvements in level of consciousness compared with the placebo-treated group, and CDP-choline was an entirely safe treatment.
Regional cerebral blood flow during hypoxia-ischemia in immature rats.
Authors: Vannucci R C , Lyons D T , Vasta F
Published: June 2011

Immature rats subjected to a combination of unilateral common carotid artery ligation and hypoxia sustain brain damage confined largely to the ipsilateral cerebral hemisphere. To ascertain the extent and distribution of ischemic alterations in the brains of these small animals, we modified the Sakurada technique to measure regional cerebral blood flow using carbon-14 autoradiography. Seven-day-old rats underwent right common carotid artery ligation following which they were rendered hypoxic with 8% O2 at 37 degrees C. Before and during hypoxia, the rat pups received an injection of iodo[14C]antipyrine for determination of regional cerebral blood flow. Blood flows to individual structures of the ipsilateral cerebral hemisphere were not influenced by arterial occlusion alone; flows to the contralateral hemisphere and to the brainstem and cerebellum actually increased by 25-50%. Hypoxia-ischemia was associated with decreases in regional cerebral blood flow of the ipsilateral hemisphere such that by 2 hours, flows to subcortical white matter, neocortex, striatum, and thalamus were 15, 17, 34, and 41% of control, respectively. The hierarchy of the blood flow reductions correlated closely with the distribution and extent of ischemic neuronal necrosis. However, unlike the pathologic pattern of this model, the degree of ischemia appeared homogeneous within each brain region. Blood flows to contralateral cerebral hemispheric structures were relatively unchanged from prehypoxic values, whereas flows to the brainstem and cerebellum nearly doubled and tripled, respectively. Thus, ischemia is the predominant factor that determines the topography of tissue injury to major regions of immature rat brain, whereas metabolic factors (intrinsic vulnerability) may influence the heterogeneous pattern of damage seen within individual structures.
Nuclear magnetic resonance image white matter lesions and risk factors for stroke in normal individuals.
Authors: Lechner H , Schmidt R , Bertha G , Justich E , Offenbacher H , Schneider G
Published: June 2011

The incidence, average number, and localization of lesions of the white matter detected by the T2-weighted nuclear magnetic resonance images among volunteers without cerebrovascular symptoms have been correlated with the number of risk factors for stroke. Accepted risk factors were arterial hypertension, diabetes mellitus, smoking, hypercholesterolemia, and cardiac disease. The 42 subjects examined were divided into Group A (0-1 risk factor, mean age 59.36 +/- 5.73 years), Group B (2 risk factors, mean age 61.54 +/- 8.33 years), and Group C (greater than or equal to 3 risk factors, mean age 62.57 +/- 9.83 years). Multiple risk factors among the age-matched groups was accompanied by a highly significant increase (p less than 0.001, Group A versus Group B; p less than 0.01, Group A versus Group C) of the incidence of white matter lesions. The average number of white matter lesions was increased (p less than 0.001) when Group A was compared with Groups B and C. Ninety-two percent of the white matter lesions were localized in watershed zones. Only 11 of the 155 abnormalities of the white matter detected by nuclear magnetic resonance imaging could be detected by computed tomography. White matter lesions in T2-weighted images appear to be an early stage of cerebrovascular disease.
Early diagnosis of basilar artery occlusion using magnetic resonance imaging.
Authors: Biller J , Yuh W T , Mitchell G W , Bruno A , Adams H P
Published: June 2011

Three patients with a clinical diagnosis of pontine infarction probably due to basilar artery occlusion were studied with magnetic resonance imaging within 24 hours after onset or latest progression of symptoms. The earliest changes on magnetic resonance images were an absence of signal void in the basilar artery suggestive of severe reduction of blood flow or occlusion (flow-void phenomena). The presumed basilar artery thrombosis was best demonstrated as a linear structure isointense or hyperintense with the brainstem in the pontine cistern on T1-weighted parasagittal images and as either absence of flow-void phenomena or higher signal intensity at various levels corresponding to the course of the basilar artery on the axial T2-weighted images. Brainstem parenchymal changes characteristic of infarction were not obvious for at least 12 hours after onset or 90 minutes after latest progression of symptoms and were best shown by both axial and coronal T2-weighted images. Recognition of these magnetic resonance imaging findings may allow earlier diagnosis and treatment of acute ischemia in the vertebrobasilar system.
Local intra-arterial fibrinolytic therapy in acute carotid territory stroke. A pilot study.
Authors: del Zoppo G J , Ferbert A , Otis S , Brückmann H , Hacke W , Zyroff J , Harker L A , Zeumer H
Published: June 2011

The possibility that intra-arterial local infusion of fibrinolytic agents may achieve recanalization of previously occluded carotid territory arteries in acute stroke was tested in a prospective angiography-based open pilot study at two centers. Fifteen of 20 patients with acute symptoms (mean treatment-onset interval 7.6 hours) demonstrated complete recanalization; 10 of the 15 patients exhibited clinical improvement of varying degree by the time of hospital discharge. Four of the 20 patients suffered hemorrhagic transformation of the infarcted territory without clinical deterioration or demise. Because of the study format and the limited number of patients, dose responses for recanalization and risk relations were not established. We conclude that local intra-arterial fibrinolytic therapy may lead to cerebral arterial recanalization in acute carotid territory thrombotic stroke. The particular implications and limitations of this approach are discussed.
Treatment of systemic hypertension and intracranial hypertension in cases of brain hemorrhage.
Authors: Hayashi M , Kobayashi H , Kawano H , Handa Y , Hirose S
Published: June 2011

We studied the effects of nifedipine, chlorpromazine, reserpine, furosemide, and thiopental on the mean arterial blood pressure, mean intracranial pressure, and cerebral perfusion pressure in 38 patients with increased intracranial pressure resulting from either hemorrhagic cerebrovascular disease or systemic hypertension. These agents are widely used in neurosurgical practice for the treatment of systemic hypertension. Patients were assigned to two groups on the basis of their mean intracranial pressure. Group I comprised 20 patients with a mean intracranial pressure of 20-40 mm Hg (moderately increased ICP group), and Group II consisted of 18 patients with a mean intracranial pressure of greater than 40 mm Hg (severely increased ICP group). Nifedipine, chlorpromazine, and reserpine reduced mean arterial blood pressure by 18-20% in both groups (p less than 0.05 in each). In Group I these agents raised mean intracranial pressure by 10-35% and decreased cerebral perfusion pressure by 20-32% (p less than 0.05 for both), but in Group II these changes were more marked: mean intracranial pressure increased 38-64% and cerebral perfusion pressure decreased 40-54% (p less than 0.01 for both). Furosemide did not significantly reduce mean arterial blood pressure but slightly reduced mean intracranial pressure in each group. Thiopental reduced both mean arterial blood pressure and intracranial pressure in both groups. The effect on intracranial pressure was pronounced in Group II, in which mean arterial blood pressure fell by 18% (p less than 0.05) and mean intracranial pressure decreased 50% (p less than 0.01), whereas in Group I mean arterial blood pressure was reduced by 16% and mean intracranial pressure dropped 23% (p less than 0.05 in each).(ABSTRACT TRUNCATED AT 250 WORDS)
Trends in mortality from cerebrovascular disease in France from 1968 to 1978. With reference to cardiovascular and all causes of death.
Authors: Doyon B , Serrano G , Marc-Vergnes J P
Published: June 2011

Cerebrovascular disease mortality in France during the period 1968-1978 was compared with cardiovascular and all other causes of death. Our study demonstrated a 25% decline in the age-adjusted cerebrovascular disease mortality rates in both sexes and particularly in the middle-aged groups. This decline is greater than that of the general causes of mortality, which was on the order of 20%. It parallels the decline in congestive heart failure mortality but differs from that of ischemic heart disease. Nevertheless, despite the increase in the proportion of elderly people in the population, the total number of deaths from cerebrovascular diseases has remained almost unchanged, although the deaths occur at a higher age than previously. If this trend is confirmed, cerebrovascular diseases will remain one of the more frequent causes of death in the elderly and thus a social problem of crucial importance.
Prostaglandin concentrations in cerebrospinal fluid of rabbits under normal and ischemic conditions.
Authors: Katz B , Sofonio M , Lyden P D , Mitchell M D
Published: June 2011

Clinical studies have demonstrated elevated levels of both arachidonic acid and prostaglandins in the cerebrospinal fluid of humans after ischemic stroke and subarachnoid hemorrhage. Such increases in free fatty acid, arachidonic acid, and prostaglandin concentrations suggest excessive production and accumulation of these substances in the ischemic brain. We used a rabbit model of ischemic infarction to examine the relation between controlled central nervous system ischemia and cerebrospinal fluid prostaglandin levels. We found that following stroke PGF2 alpha and not PGD2 was the predominant prostaglandin present in the cerebrospinal fluid. PGF2 alpha also underwent the largest percent increase over control prostaglandin concentrations. This is similar to human and dog cerebrospinal fluid studies, which demonstrate PGF2 alpha as the predominant prostaglandin following ischemic injury. The lack of PGD2 elevation under ischemic conditions may suggest that the rabbit model is more like stroke in humans than the rat or gerbil models. Our preliminary work demonstrates that it is practical to study postischemic prostaglandin changes in cerebrospinal fluid rather than in brain tissue in a rabbit model of central nervous system ischemia.
A new model of brainstem ischemia in dogs.
Authors: Kuwabara S , Uno J , Ishikawa S
Published: June 2011

A new model of brainstem ischemia in dogs is described. The perforating arteries arising from the posterior cerebral arteries as far as the bilateral junctions with the posterior communicating arteries were occluded using a subtemporal approach to the region of the interpeduncular cistern. Infarction of the posterior thalamus, subthalamus, midbrain, and upper pons was consistently produced. The dogs survived for greater than 1 week while exhibiting such clinical symptoms as disturbance of consciousness, tetraparesis, oculomotor paralysis, respiratory abnormalities, bradycardia, and arrhythmia. The clinical features and extent of infarction observed in this model closely resemble those of rostral brainstem infarction in human stroke. The model may be useful in studying the pathophysiology of brainstem ischemia.
Lateralized effect of cerebral infarction on spinal fluid monoamine metabolite concentrations in rats.
Authors: Parikh R M , Justice A , Moran T H , Robinson R G
Published: June 2011

Using a rat model of stroke, we studied the effect of unilateral middle cerebral artery ligation on cerebrospinal fluid monoamine metabolites at different intervals over a 40-day postoperative period. Male Sprague-Dawley rats were divided into four groups: an unoperated control group (n = 9), a sham-operated group (n = 9), a right middle cerebral artery ligation group (n = 10), and a left middle cerebral artery ligation group (n = 10). One hundred microliters of cerebrospinal fluid were collected percutaneously from the cerebellomedullary cistern just before and 5, 20, and 40 days after the surgical procedure. Monoamine metabolites--3-methoxy-4-hydroxyphenylglycol (MHPG), 5-hydroxy-indoleacetic acid (5-HIAA), and homovanillic acid (HVA)--were measured using high-performance liquid chromatography. MHPG concentration in the right lesion group was significantly depleted from control levels 5, 20, and 40 days after surgery. No such depletion was observed in the left lesion rats. Concentration of 5-HIAA was relatively lower at Days 5 and 20 in the right lesion group than in the left lesion group. HVA concentration did not differ among the groups at any time. Our study has demonstrated a differential effect of unilateral ischemia on cerebrospinal fluid neurochemistry in rats dependent on the cerebral hemisphere involved.
Are blood platelets involved in the pathogenesis of ischemic brain edema in gerbils?
Authors: Turcáni P , Gotoh F , Ishihara N , Tanaka K , Gomi S , Takashima S , Mihara B
Published: June 2011

Edema formation following severe permanent or temporary cerebral ischemia in gerbils with an artificially reduced platelet count was investigated. Acute focal cerebral ischemia was produced by extracranial carotid ligation, and the local cerebral blood flow was estimated using the hydrogen clearance method. Brain tissue water and sodium and potassium contents were taken as indexes of brain edema. The platelet count was reduced in some gerbils by intravenous injection of neuraminidase. After 60 minutes of ischemia, a marked increase in tissue water and sodium contents accompanied by a decrease in potassium content was observed in untreated gerbils. However, gerbils with a reduced platelet count revealed similar but significantly smaller changes in all the measured parameters. Restoration of blood flow after 60 minutes of ischemia resulted in further accumulation of water and sodium and in depletion of potassium in both groups. These changes were significantly smaller in the gerbils with a reduced platelet count. It is concluded that platelets, activated by cerebral ischemia, may be involved in the development of ischemic brain edema in gerbils.
Predictive value of resting electrocardiograms for 12-year incidence of stroke in the Honolulu Heart Program.
Authors: Knutsen R , Knutsen S F , Curb J D , Reed D M , Kautz J A , Yano K
Published: June 2011

The importance of electrocardiographic (ECG) abnormalities at baseline examination for subsequent risk of stroke was analyzed in a 12-year follow-up of 7,560 men in the Honolulu Heart Program, aged 45-68 years, who were free of coronary heart disease and stroke at baseline. Age-adjusted univariate analysis showed that men with major ST depression, left ventricular strain, left ventricular hypertrophy, major T wave inversion, and overall major ECG abnormalities had considerably higher (2.5-5.4 times) incidence rates of both thromboembolic and hemorrhagic stroke than those with normal baseline ECG. When blood pressure, age, cigarette smoking, alcohol consumption, fat intake, serum glucose concentration, serum uric acid concentration, years of education, and years lived in Japan were taken into consideration through multivariate analysis, the ECG abnormalities retained a significant relation with stroke. Our study demonstrates that resting ECG abnormalities are independent predictors of both thromboembolic and hemorrhagic stroke.
Effect of mannitol, nimodipine, and indomethacin singly or in combination on cerebral ischemia in rats.
Authors: Sutherland G , Lesiuk H , Bose R , Sima A A
Published: June 2011

The effects of mannitol, nimodipine, and indomethacin on ischemic neuronal injury were examined in 45 rats divided equally into nine groups subjected to 10 minutes of forebrain ischemia. Of two control groups, one received maintenance fluids while the other received a normal saline bolus. In the remaining seven groups, mannitol, nimodipine, and indomethacin were administered singly or in combination 5 minutes before forebrain ischemia. Seven days after ischemia, the brains were perfusion-fixed, sectioned coronally into 2.8-mm slices, and stained with hematoxylin and eosin. Ischemic neurons were directly counted on predetermined regions of standardized serial sections. Considerable amelioration of ischemic injury (ischemic neurons/total neurons) was observed with mannitol (ischemic injury, 7 +/- 5% in the hippocampal CA1/CA2 sectors and 28 +/- 17% in the CA3 sector). This is in contrast to control values of 64 +/- 11% and 80 +/- 6%, respectively, and those obtained in the normal saline group of 70 +/- 10% and 59 +/- 13%, respectively. The beneficial effect with nimodipine reached significance in only the hippocampal CA3 sector (ischemic injury, 35 +/- 21%). Indomethacin showed no significant benefit. Combining the agents resulted in significantly reduced neuronal injury compared with control groups, although the effect was not greater than that achieved with mannitol alone. The degree of ischemic injury was least when all three agents were used in combination (ischemic injury, 12 +/- 12% in the hippocampal CA1/CA2 sectors and 4 +/- 4% in the CA3 sector). Our data support the concept that successfully blocking the ischemic cascade with a single, diversely acting agent or multiple agents will evoke the best beneficial response.
Correlation of continuous-wave Doppler spectral flow analysis with gross pathology in carotid stenosis.
Authors: Call G K , Abbott W M , Macdonald N R , Megerman J , Davis K R , Heros R C , Kistler J P
Published: June 2011

Preoperative continuous-wave Doppler spectral analysis was used to generate two parameters, peak frequency in the internal carotid artery (fmax) and the ratio of peak frequencies in the internal and common carotid arteries (carotid index). These were compared with direct measurement of residual lumen diameter in pathologic specimens obtained from carotid endarterectomy in 37 patients. Doppler shift frequency parameters were well correlated with residual lumen diameter when the latter was at least 1 mm. Residual lumens of less than or equal to 2 mm were found to have an fmax of greater than 7.5 kHz and a carotid index of greater than 3.8. If fmax was greater than 14 kHz or the carotid index was greater than 7, the residual lumen diameter was nearly always less than or equal to 1 mm. Thus, the severity of the stenosis correlated directly with Doppler shift frequencies. The length of stenoses did not affect the correlations.
Increasing incidence of stroke among Swedish women.
Authors: Terént A
Published: June 2011

The incidence of stroke and transient ischemic attack was studied prospectively in the municipality of Söderhamn, Sweden, during the periods 1975-1978 and 1983-1986. A total of 723 cases of stroke and 111 cases of transient ischemic attack were registered during the two periods. The number of first-ever strokes increased by 28% between the 1970s and the 1980s, while the annual incidence of first-ever stroke rose from 2.90 to 3.53/1,000 (p less than 0.02). Female incidence increased by 38%, from 2.62 to 3.62/1,000 (p less than 0.05) between the study periods. Male incidence, however, changed nonsignificantly from 3.19 in the first period to 3.43 in the second. In 1975-1978, male incidence was four times greater than that of females up to 65 years of age, but the distribution became balanced in 1983-1986, when the increment of female incidence was 47% in the group 25-44 years old and 232% (p less than 0.05) in the group 45-64 years old. The annual incidence of first-ever transient ischemic attack was 0.43/1,000 in men and 0.48/1,000 in women in 1975-1978. The corresponding rates for 1983-1986 were 0.56 and 0.45/1,000, respectively. These changes were not significant. The cause of the increase in the incidence of stroke among women has not been established.
Impairment of cerebellar blood flow autoregulation during cerebral ischemia in spontaneously hypertensive rats.
Authors: Shiokawa O , Sadoshima S , Fujii K , Yao H , Fujishima M
Published: June 2011

Participation of the autonomic nervous system in cerebellar autoregulation during supratentorial cerebral ischemia induced by bilateral carotid ligation was studied using 23 spontaneously hypertensive rats. Cerebral and cerebellar blood flows measured by a hydrogen clearance method were evaluated under stepwise hemorrhagic hypotension before and 30 minutes after ligation and after a 30-minute recirculation period following 1 hour of ligation. alpha-Adrenergic blockade with phenoxybenzamine, beta-adrenergic blockade with propranolol, and muscarinic cholinergic blockade with atropine were selectively administered before ligation for inhibition of sympathetic and parasympathetic tone. Cerebral blood flow autoregulation was severely impaired during and after cerebral ischemia in each treatment group. During cerebral ischemia, cerebellar blood flow autoregulation was also significantly impaired in both the propranolol and atropine groups although it was better preserved in the phenoxybenzamine group. After recirculation, cerebellar blood flow autoregulation recovered almost to the normal range in the phenoxybenzamine and atropine groups but remained impaired in the propranolol group. Our results suggest that impaired cerebellar blood flow autoregulation in supratentorial cerebral ischemia is partly modulated by the alpha-adrenoceptor system, which is activated by hypertensive stimuli and cerebral ischemia, leading to vasoconstriction in the cerebellum.
Prognosis of acute hemiplegia estimated by transcranial Doppler ultrasonography.
Authors: Halsey J H
Published: June 2011

Blood velocity in the middle cerebral artery was measured by transcranial Doppler ultrasonography in 15 patients suffering complete hemiplegia of less than 12 hours' duration, presumed due to cerebral ischemia. Among seven patients in whom blood velocity was greater than 30 cm/sec, five made complete or partial useful recovery of the involved hand and arm. Among eight patients in whom blood velocity was less than 30 cm/sec, one recovered completely while the other seven retained permanent total paralysis of the hand and arm.