bluuebunny/crossref_metadata_2025 huggingface dataset:
Intraluminal thrombus in the cerebral circulation. Implications for surgical management.
Authors: Buchan A , Gates P , Pelz D , Barnett H J
Published: June 2011

Thrombi defined as intraluminal filling defects detected by angiography were identified in 30 patients (29 in the carotid system, one in the vertebral artery). Stroke was the presentation ipsilateral to the thrombus in 22 patients (12 had previous transient ischemic attacks), transient ischemic attacks occurred alone in seven cases, and one patient was asymptomatic. Angiography revealed a severe stenosis in association with the thrombus in 23 patients, a moderate stenosis in four patients, and, in the three patients with only minimal stenosis presumably due to atherosclerosis, there was evidence for a coagulopathy. Sixteen of the 30 patients were operated on urgently, 10 within 24 hours of detection of the thrombus. Twelve of these 16 surgical patients were given anticoagulation before surgery. At endarterectomy, thrombus was identified in 11 of the 14 surgical patients in whom the thrombus was accessible; the other two surgical patients had intracranial thrombus only. In this group, four of 11 surgical patients with accessible thrombi suffered perioperative episodes of new or larger infarction. Fourteen of the 30 patients initially received medical management with no complication. Eight of these 14 medical patients had repeat angiography; seven exhibited complete resolution of thrombus, and six of these seven patients subsequently underwent delayed endarterectomy for the stenosis. No thrombus was identified at surgery in any of the six. One of the six delayed surgery patients suffered a perioperative stroke. Although these numbers are small, reflecting the rarity of thrombus demonstrated by angiography, undetected thrombus is often found at endarterectomy. Its presence may increase operative risk.(ABSTRACT TRUNCATED AT 250 WORDS)
Validation of the triple-tracer autoradiographic method in rats.
Authors: Nakai H , Diksic M , Yamamoto Y L
Published: June 2011

We have developed a quantitative autoradiographic technique to measure simultaneously local cerebral blood flow, tissue pH, and local cerebral glucose utilization using 4-[18F]fluoroantipyrine, [14C]dimethyloxazolidine-2,5-dione, and 2-[3H]deoxyglucose as radioactive tracers. Our technique was validated by measurements of local cerebral blood flow, tissue pH, and local cerebral glucose utilization in the brains of sham-operated rats. Sham-operated rats showed a 14% reduction in local cerebral blood flow and a 10% reduction in local cerebral glucose utilization in the most affected piriform and entorhinal cortical regions compared with the contralateral homologous regions. There was no difference in tissue pH measured in the sham-operated side compared with normal rats or with the contralateral region.
Two cases of occipital infarction following cardiac catheterization.
Authors: Oliva A , Scherokman B
Published: June 2011

Transient visual disturbance following cardiac catheterization has been regarded as a benign and transient complication. We describe two cases of computed-tomography-documented occipital infarction after cardiac catheterization that emphasize a complication more serious than previously thought.
Cerebral blood flow asymmetry in the detection of extracranial cerebrovascular disease.
Authors: Robertson W M , Welch K M , Tilley B C , Ewing J R
Published: June 2011

Regional cerebral blood flow was measured by the 133Xe inhalation technique in patients with unilateral carotid occlusion, unilateral carotid occlusion and contralateral carotid stenosis, bilateral carotid occlusion, or normal arteriograms. After adjusting for age, sex, and history of stroke, hemispheric blood flow asymmetry was shown to be a predictor of unilateral carotid occlusion with a sensitivity of 80.6% and a specificity of 80.5%. Asymmetry of regional cerebral blood flow is useful in the assessment of patients with extracranial cerebrovascular disease.
Spontaneous intracerebral hemorrhage and liver dysfunction.
Authors: Niizuma H , Suzuki J , Yonemitsu T , Otsuki T
Published: June 2011

We evaluated liver function and coagulation parameters in 117 patients with spontaneous intracerebral hemorrhage (68 men and 49 women) admitted to our clinic within 24 hours after onset. Liver dysfunction was more common among men than women due to differences in alcohol consumption. Number of thrombocytes and fibrinogen concentrations were lower, especially among men with elevated concentrations of glutamic oxaloacetic transaminase or glutamic pyruvic transaminase and/or elevated gamma-globulin fraction. Five of the 78 patients undergoing stereotactic hematoma aspiration and one of the 39 treated nonsurgically rebled. All six of the patients who rebled were men, heavy alcohol consumers with liver dysfunction. Fibrinogen concentration was abnormally low in four of the six and at the lower end of the normal range in one. Two showed thrombocytopenia and one case showed prolonged prothrombin time. These facts suggest that liver disorders produce a state in which hemorrhage occurs more readily and that this hemorrhagic tendency may be one of the causal factors of spontaneous intracerebral hemorrhage.
Photochemically stimulated blood-borne factors induce blood-brain barrier alterations in rats.
Authors: Dietrich W D , Prado R , Watson B D
Published: June 2011

We have tested the hypothesis that blood-borne substances released from a site of vascular thrombosis can lead to acute alterations in the blood-brain barrier. The right common carotid artery of rats was photothrombosed using a dye/light insult. Rats were given the photosensitizing dye rose bengal and irradiated for 4 minutes with an argon laser beam focused onto the exposed common carotid artery. During the irradiation, 3 ml of blood was taken from the right external carotid artery. After 10 minutes, the blood was infused into the external carotid artery of a recipient rat that had received horseradish peroxidase. Fifteen minutes after blood infusion, bilateral peroxidase extravasation was noted within cortical and subcortical areas of recipient rats, being most intense ipsilaterally. Ultrastructural studies demonstrated peroxidase reaction product within numerous endothelial vesicles of arteriolar segments. Infusion of blood from control rats did not produce similar changes. Thus, photoinduced vascular thrombosis of a large feeding artery leads to the formation of blood-borne factors that acutely alter cerebral vascular permeability.
Stroke risk factors prepare rat brainstem tissues for modified local Shwartzman reaction.
Authors: Hallenbeck J M , Dutka A J , Kochanek P M , Siren A , Pezeshkpour G H , Feuerstein G
Published: June 2011

Stroke risk factors such as hypertension, diabetes, advanced age, and genetic predisposition to stroke were demonstrated to prepare rat brainstem tissues for a modified local Shwartzman reaction. A single intracisternal injection of endotoxin provoked the reaction, and affected rats manifested neurologic deficits accompanied by pathologic lesions. Brainstem infarcts developed in only a small proportion of rats without recognized risk factors after intracisternal injection of endotoxin. Thus, stroke risk factors, which are ordinarily regarded as operating through acceleration of atherosclerosis, may predispose to brain ischemia by local effects on brain microcirculation such as those thought to underlie preparation of a tissue for the local Shwartzman reaction.
Asymptomatic cerebral infarction in patients with chronic atrial fibrillation.
Authors: Kempster P A , Gerraty R P , Gates P C
Published: June 2011

A retrospective analysis of 54 patients with atrial fibrillation presenting with symptoms of cerebral ischemia between 1980 and 1985 was performed. Seven patients (13%) had computed tomographic evidence of previous, clinically silent cerebral infarction. In a control group of 168 persons (studied prospectively) in sinus rhythm presenting with symptoms of cerebral ischemia, seven (4%) had computed tomographic evidence of previous, clinically silent cerebral infarction (p less than 0.05). In those patients with atrial fibrillation all infarcts were peripheral and consistent with embolism, while in three of the seven patients in sinus rhythm the asymptomatic infarcts were lacunes.
Clinical and hemodynamic significance of innominate artery lesions evaluated by ultrasonography and digital angiography.
Authors: Grosveld W J , Lawson J A , Eikelboom B C , vd Windt J M , Ackerstaff R G
Published: June 2011

To determine the hemodynamic and clinical consequences of an atherosclerotic obstructive lesion of the innominate artery on the cerebral circulation, 20 patients with an innominate artery lesion underwent neurologic examination and ultrasonic duplex scanning before and after right arm exercise. The patients were divided into two groups: Group 1, 12 patients with 40-80% stenosis and Group 2, eight patients with 80-100% stenosis. A significant difference between the groups was noted in both the hemodynamic and clinical manifestations. All 12 Group 1 patients compensated for the increased demand for blood of the right arm through the innominate artery itself, and only one showed symptoms of vertebrobasilar insufficiency associated with right arm exercise. In all eight Group 2 patients, compensation through the innominate artery failed; six (75%) showed symptoms of vertebrobasilar insufficiency after exercise. Dynamic duplex scanning is well suited to investigate stenotic lesions of the innominate artery, the effects of arm exercise on the development of cerebral symptoms, and the source of blood flow to the arm. Dynamic duplex scanning proved to be useful in selecting patients who may be candidates for direct arterial surgery.
Bilateral hemispheric reduction of cerebral blood volume and blood flow immediately after experimental cerebral hemorrhage in cats.
Authors: Kobari M , Gotoh F , Tomita M , Tanahashi N , Shinohara T , Terayama Y , Mihara B
Published: June 2011

Acute cerebral circulatory changes following experimental cerebral hemorrhage were investigated in eight cats. The cerebral hemorrhage was produced in the right basal ganglia by introducing arterial blood via a thin catheter, using the systemic arterial blood pressure of the cat as a driving force. Local cerebral blood volume was measured continuously in the bilateral parietotemporal cortexes employing photoelectric apparatuses. Carbon black dilution curves were recorded from the regions, and the mean transit time of blood was calculated. Local cerebral blood flow was estimated from mean transit time and cerebral blood volume. Intracranial pressure was monitored continuously in the right parietal epidural space. Five minutes after cerebral hemorrhage, intracranial pressure increased by 24.0 +/- 6.1 mm Hg, while mean arterial blood pressure increased by only 2.9 +/- 2.0 mm Hg. Cerebral blood volume decreased by 1.60 +/- 0.24 vol% in the hemorrhagic and 1.14 +/- 0.30 vol% in the nonhemorrhagic hemisphere. Cerebral blood flow decreased by 30.0 +/- 4.5 ml/100 g brain/min in the hemorrhagic (initially 64.5 +/- 13.6) and by 30.3 +/- 7.5 ml/100 g brain/min in the nonhemorrhagic (initially 60.9 +/- 6.9) hemisphere. Increased intracranial pressure appeared to be the main cause of the observed cerebral blood volume/flow reduction shortly after experimental hemorrhage in the basal ganglia. Several other factors and mechanisms involved are discussed.
The Lausanne Stroke Registry: analysis of 1,000 consecutive patients with first stroke.
Authors: Bogousslavsky J , Van Melle G , Regli F
Published: June 2011

We present epidemiologic, etiologic, and clinical data for 1,000 consecutive patients with a first stroke (cerebral infarction or hemorrhage) admitted to the Centre Hospitalier Universitaire Vaudois since 1982. The patients were evaluated using a standard protocol of tests (computed tomography, Doppler ultrasonography, and electrocardiography in all patients, as well as angiography and specific cardiac investigations in selected patients). Each case was coded prospectively into a computerized registry. We believe that the Lausanne Stroke Registry is the first registry with complete computed tomography and Doppler ultrasonography data on all patients, which allows correlation between clinical findings, presumed etiology, and stroke location. Although the Lausanne Stroke Registry is not population-based, it gives a good estimate of the stroke-related problems in patients admitted to a primary-care center since our hospital is the sole acute-care facility for stroke in the Lausanne area.
Carotid angiography in patients with lacunar infarction. A prospective study.
Authors: Kappelle L J , Koudstaal P J , van Gijn J , Ramos L M , Keunen J E
Published: June 2011

We prospectively studied the results of carotid angiography in 45 patients with transient or nondisabling neurologic deficits caused by lacunar infarction in the internal capsule or corona radiata and demonstrated by computed tomography. An ipsilateral stenosis at the bifurcation of the internal carotid artery was found in 14 patients (31%, 95% confidence limits 18-47%), seven of whom also had stenosis of the contralateral internal carotid artery. In previous studies an average of 65% of patients with transient hemispheric deficit had internal carotid artery stenosis or occlusion. Hypertension and hypertensive retinal vasculopathy assessed by fundus photographs were found in most patients, but not significantly more often in the patients without internal carotid artery stenosis. Our findings support the notion that small vessel disease rather than emboli from the carotid bifurcation is the most common cause of lacunar infarction.
Quality of life 4 years after stroke.
Authors: Niemi M L , Laaksonen R , Kotila M , Waltimo O
Published: June 2011

The quality of life for 46 stroke survivors under the age of 65 years in a stroke register was studied 4 years after their first stroke. A questionnaire covering four domains of life (working conditions, activities at home, family relationships, and leisure time activities) was used for investigation of the quality of life. The results showed that in spite of a good recovery in terms of discharge from the hospital, activities of daily living, and return to work, the quality of life of most patients (83%) had not been restored to the prestroke level. Deterioration among the several domains of life ranged from 39% to 80%, the lowest being in the domain of activities at home and the highest in the domain of leisure time activities. Hemispheral localization of the lesion, paresis, coordination disturbances, and especially subjective tendency to depression were highly correlated with a deterioration in the quality of life. Dependence in activities of daily living and an inability to return to work were also associated with the lack of restoration. Our results suggest that much more attention should be paid to the quality of life of stroke patients.
Plasma atrial natriuretic factor and subarachnoid hemorrhage.
Authors: Diringer M , Ladenson P W , Stern B J , Schleimer J , Hanley D F
Published: June 2011

Hyponatremia is common following aneurysmal subarachnoid hemorrhage and has been linked to the syndrome of inappropriate secretion of antidiuretic hormone. However, the demonstration of volume depletion and natriuresis in some patients has suggested that salt wasting is a more likely etiology. Atrial natriuretic factor appears to play a role in both central and peripheral regulation of sodium homeostasis. To investigate the behavior of circulating atrial natriuretic factor following subarachnoid hemorrhage, we studied 25 patients with intracranial aneurysms: 21 after acute subarachnoid hemorrhage and four without evidence of recent rupture. Atrial natriuretic factor was measured by radioimmunoassay of extracted plasma (normal value, 20.8 +/- 24.6, mean +/- 3 SD). Mean +/- SEM plasma atrial natriuretic factor concentration was elevated to 84 +/- 25 pg/ml on Day 1, rose to 134 +/- 29 pg/ml on Day 3, and fell to 86 +/- 17 pg/ml by Day 7 after subarachnoid hemorrhage (p less than 0.01). In two patients (9.5%) who developed hyponatremia after aneurysm rupture, plasma concentrations were no different from that in the group as a whole; concentrations in patients with no evidence of recent subarachnoid hemorrhage were not elevated. Neither fluid administration nor timing of surgery could account for the elevated concentrations. We conclude that concentrations of circulating atrial natriuretic factor are elevated after subarachnoid hemorrhage but do not solely account for the accompanying hyponatremia.
Thromboxane A2 in severe hypertension and stroke in stroke-prone spontaneously hypertensive rats.
Authors: Stier C T , Benter I F , Levine S
Published: June 2011

Thromboxane A2 is a prostanoid having potent platelet aggregatory and vasoconstrictor properties. To determine a possible role for thromboxane A2 in the development of severe hypertension and stroke, we chronically administered the selective thromboxane A2 synthase inhibitor UK-38,485 (Dazmegrel) to stroke-prone spontaneously hypertensive rats (SHRSP). Serum thromboxane B2 (the stable hydrolysis product of thromboxane A2) generation was significantly greater in incubates of whole blood from SHRSP than in those from normotensive control Wistar-Kyoto rats and was inhibited greater than 89% by UK-38,485 administered in vivo. In 10 male SHRSP fed a Japanese-style rat chow and given 1% NaCl in drinking water to accelerate the occurrence of stroke, treatment with 100 mg/kg/day UK-38,485 by gavage starting at 8.6 weeks of age diminished systolic blood pressure elevation at 10 (205 +/- 2 vs. 220 +/- 4 mm Hg, p less than 0.01) and 11 weeks of age (210 +/- 4 vs. 239 +/- 7 mm Hg, p less than 0.01) compared with 10 untreated SHRSP. The ultimate establishment of severe hypertension was not prevented by UK-38,485. Stroke-related mortality was 70% in both UK-38,485-treated and control SHRSP at 14 weeks of age. Histologic examination revealed cerebrovascular lesions consistent with the occurrence of stroke in both control and UK-38,485-treated SHRSP. Our results support a possible role for thromboxane A2 in the elevation of blood pressure in SHRSP but do not support a possible role for the prevention of stroke by thromboxane A2 synthase inhibition in these rats.
Reversible cerebral segmental vasoconstriction.
Authors: Call G K , Fleming M C , Sealfon S , Levine H , Kistler J P , Fisher C M
Published: June 2011

Vasoconstriction is not recognized as a cause of cerebrovascular disease except in the vasospasm seen following subarachnoid hemorrhage and possibly in migraine. However, we found four patients to have transient, fully reversible vasoconstriction and dilatation prominently involving arteries around the circle of Willis. All four patients were evaluated for severe headaches and fluctuating or recurring motor or sensory deficits. No cause for the clinical syndromes and angiographic abnormalities was found. Similar patients are reported in the literature under various nosologies. This newly recognized clinical-angiographic syndrome should be differentiated from other known causes of vessel constriction and dilatation; the precipitants of reversible vasoconstriction may then be better defined.
Record Linkage in Studies of Cerebrovascular Disease in Oxford, England
Authors: ACHESON ROY M. , FAIRBAIRN ANTHONY S.
Published: June 2011

Data collected by record linkage are used as a basis for an analysis of the burden of cerebrovascular diseases in a population of 340,000 in central England. Comparison with studies which use other methods in the United States and England indicate that for all Cerebrovascular diseases together, and for subarachnoid hemorrhage, the assumptions underlying the analysis may have reflected the overall incidence of and survival from serious disease in Oxford reasonably accurately, but this may not be true for two individual rubrics, cerebral hemorrhage and infarction. Criticisms made of this conclusion in the recent literature are discussed. The system in its present state does not permit the study of transient ischemic attacks. Data shown here and elsewhere indicate that subarachnoid hemorrhage is the most reliable of the stroke diagnoses, and the Oxford data show reasonable consistency with others gathered elsewhere using other methods. It would appear that there are considerable age-specific and sex-specific differences for subarachnoid hemorrhage in terms of incidence and survival. Attention is drawn to the extent to which cerebrovascular disease occurs in people under age 65 years.
Quantitative Comparison of Passive Motion and Tendon Reflex Responses in Biceps and Triceps Brachii Muscles in Hemiplegic or Hemiparetic Man
Authors: SIMONS DAVID G. , BINGEL A.G. A.
Published: June 2011

The clinical impression that severe hyperreflexia is not consistently associated with severe spasticity in hemiplegia or hemiparesis due to vascular pathology was tested by objective measurement in 11 patients. The intensity of tendon reflex responses of the triceps and biceps brachii muscles was measured as the reflex sensitivity ratio (evoked twitch tension/stimulating hammer force). The degree of spasticity was measured as the threshold rate of elbow flexion or extension above which a myotatic response was elicited, determined by both a sudden increase in passive resistance and a burst of antagonist electromyographical activity.

Rate thresholds were rank ordered for flexion data and for extension data with their corresponding reflex sensitivity ratios. Numerous individual discrepancies stood out. Correlation coefficients between rate thresholds and reflex sensitivities determined at two elbow angles were -0.52 and -0.35 during extension, and -0.47 and 0.03 during flexion.

Differences in rate of stretch, differences in the sensory structures stimulated, and differences in the distortion of the organization of motor control may account for the difference in responses to the two tests.
An Improved Thermal Dilution Method for Measuring Jugular Venous Flow
Authors: WILSON EDWIN M. , HALSEY JAMES H.
Published: June 2011

The local thermal dilution method of performing serial bilateral measurements of internal jugular venous flow is significantly improved by injecting a bolus of saline rather than by using a continuous injection of saline. New thermistor catheter designs maintain the proper separation between the sites of injection and of sampling and require only a single insertion per side. The method measures mean flow rates over a two-second to three-second interval. Measurements were made in 14 patients with cerebrovascular disease. Studies of five patients are presented to illustrate the value of the method for assessing internal jugular venous hemodynamics. Positive response to injection of acetazolamide was noted in four of these five patients. Cyclic variations in jugular flow were observed in one patient with Cheyne-Stokes respiration. Occasional retrograde flow in one jugular vein was recorded in another patient.
Fatal Foam Cell Arteritis of the Brain After Irradiation for Hodgkin's Disease: Angiography and Pathology
Authors: KAGAN A. ROBERT , BRUCE DANIEL W. , DI CHIRO GIOVANNI
Published: June 2011

A case of foam cell arteritis of the brain following irradiation of the neighboring structures for Hodgkin's disease is described. A differential diagnosis of the unique angiographical findings is presented.

The etiology of foam cell arteritis restricted to the brain is considered. It is hoped that the experience of this case encourages a careful neuroradiological and neuropathological examination of the brain in all patients with Hodgkin's disease who present with the stroke syndrome.
An Assessment of Early Platelet Activity in Experimental Subarachnoid Hemorrhage and Middle Cerebral Artery Thrombosis in the Cat
Authors: DENTON IRA C. , ROBERTSON JAMES T. , DUGDALE MARION
Published: June 2011

There is increasing evidence that platelets play a key role in the development of arterial occlusive lesions and in the tissue response to them. Direct evidence for a platelet contribution in experimental vascular occlusive stroke and subarachnoid hemorrhage was sought. Platelet counts were done on jugular blood before and after production of the vascular lesion. Craniectomy had little or no effect but occlusion or puncture of the middle cerebral artery invariably produced a prompt and striking fall in the platelet count of venous blood draining the affected side. Some implications of this observation are discussed.
Cerebral Atherosclerosis in Japanese. I. Age Related to Atherosclerosis
Authors: NAKAMURA M. , YAMAMOTO H. , KIKUCHI Y. , ISHIHARA Y. , SATA T. , YOSHIMURA S.
Published: June 2011

During a period of approximately two years (1965 through 1966), 717 intracranial cerebral arteries (males and females) were obtained from the medicolegal autopsy cases. Systematic grading of the macroscopic severity of cerebral atherosclerosis was performed and the results were reported. In general, cerebral atherosclerosis appeared as early as the second decade and increased in severity with age, particularly at the fifth decade in males and the sixth decade in females. The prevalence of localization of early and/or severe cerebral atherosclerosis was studied. The results in the present study were not the same as in the previous investigations on Caucasians. The common sites of the severe cerebral atherosclerosis causing marked lumen narrowing were the proximal portion of posterior cerebral arteries, peripheral portion of the middle cerebral arteries, and the vertebral arteries and their fusing site at the basilar artery; the internal carotid artery was the least commonly involved.

In the present study, the influence of sex in the production of cerebral atherosclerosis was suggested, and the simple senescence theory of cerebral atherosclerosis was not supported. The macroscopic severity of cerebral atherosclerosis of Japanese in the present study appeared to be equal to or slightly greater than that in Americans and Norwegians reported by Baker et al.
Intimal Fibroplasia of the Internal Carotid Arteries
Authors: SUKOFF M. H. , DORSEY T. J. , JOHNSON D. A. , HEPPS S. A. , BERGGREN R. L.
Published: June 2011

Intimal fibroplasia of the extracranial internal carotid arteries can cause symptoms of transient neurological deficit in young patients which are similar to the transient ischemic attacks of arteriosclerotic origin.

The clinical, angiographical and histological features of such a case are presented and discussed.
Occlusio Supra Occlusionem: Intracranial Occlusions Following Carotid Thrombosis as Diagnosed by Cerebral Angiography
Authors: RING B. ALBERT
Published: June 2011

Collateral circulation between internal and external carotid arteries was sufficient to thoroughly opacify the middle cerebral artery on cerebral angiography in 11 of 100 patients with internal carotid occlusion. In four of the 11, the branches of the middle cerebral were intact. In two of the four, the carotid occlusion was an incidental finding; one patient presented with transient ischemic attacks and one had a stroke of the border zone variety. The remaining seven patients all had clinical strokes and showed occlusion of one or more branches of the middle cerebral artery. The stroke appeared to be the result of the intracranial occlusion rather than that of the internal carotid.
Cerebral Embolization: Prospective Clinical Analysis of 42 Cases
Authors: MEYER JOHN STIRLING , CHARNEY JONATHAN Z. , RIVERA VICTOR M. , MATHEW NINAN T.
Published: June 2011

The sites, sources, and incidence of cerebral embolization were established in an unselected series of hospitalized patients using recommended epidemiological criteria. Criteria for diagnosis of cerebral embolization as a cause of stroke are defined.

Forty-two (15%) from a total of 280 patients with various forms of cerebrovascular disease were diagnosed as having cerebral embolization. The epidemiology has been altered by antibiotics and cardiac surgery, particularly the use of prosthetic heart valves. In this series, the mortality rate was 9.5%, which is lower than in previously reported series probably due to emergency medical treatment. The heart was the most common source. Prosthetic heart valves emerged as the most common source of emboli in this series. Ulcerated plaques of the carotid arteries in the neck ranked second. Seizures occurred in 42.8% of cases. The left cerebral hemisphere was involved approximately twice as frequently as the right one.

Possible explanations based on the anatomy of the great vessels are described which predispose to embolization of the left carotid artery. Recommendations are suggested for preventing further embolization and for treatment of acute embolic cerebral infarction by the use of anticonvulsant drugs and hyperosmolar agents designed to reduce cerebral edema.
Brain Lipid Changes Following Hypoxia
Authors: YATSU F. M. , MOSS S. A.
Published: June 2011

Biochemical changes signaling irreversible damage in brain cells following hypoxia are incompletely understood. Disruption of membrane structure may play a role in this process. Lipids and long-chain fatty acids are important constituents of neural membranes and could serve as markers of membrane breakdown. The present study was undertaken to assess the brain lipid profile and the process of fatty acid elongation in adult rats subjected to hypoxia and unilateral carotid ligation. Following functional recovery from hypoxia, the brain lipids were analyzed in both hemispheres and disclosed a significant reduction of inositide glycerophosphatide (PI) and serine glycerophosphatide (PS). Mitochondrial fatty acid elongation was increased by more than 100% and the pattern of elongation more closely resembled that seen during myelination rather than maturity. Although the degree of brain hypoxia is not predictable in the rat model, the lipid alterations indicate a reparative process following a suppression of lipid metabolism during hypoxia. Delineation of biochemical processes signaling irreversible brain damage will await further studies on regional and subcellular changes.
Effect of lidocaine on forebrain ischemia in rats.
Authors: Sutherland G , Ong B Y , Louw D , Sima A A
Published: June 2011

We examined the effect of lidocaine on ischemic neuronal injury in the rat forebrain ischemia model. Cerebral ischemia was achieved with bilateral carotid artery occlusion and controlled hypotension to a mean of 50 torr for 10 minutes. Perfusion-fixation was performed 7 days after ischemia, subsequent to which the brains were sectioned coronally and stained with hematoxylin and eosin. Ischemic neuronal injury was quantitatively expressed (after direct counting) as a percentage of total neurons, that is, ischemic neurons divided by (ischemic neurons + normal neurons). Predictably, the selectively vulnerable hippocampal areas exhibited the most marked neuronal injury. In the CA1/CA2 sectors, lidocaine-treated rats demonstrated less injury (34 +/- 14%) than untreated (64 +/- 9%) or saline-treated (70 +/- 10%) rats. However, these superficially pronounced numerical differences were not of statistical significance (p greater than 0.05). In the CA3 sector, neuronal injury in lidocaine-treated rats (31 +/- 14%) was significantly different at p less than 0.05 from the untreated (80 +/- 5%) but not the saline-treated (59 +/- 13%) group. We conclude that lidocaine may have an only marginal beneficial effect on forebrain ischemia in rats.
Infrequency of blacks among patients having carotid endarterectomy.
Authors: Maxwell J G , Rutherford E J , Covington D , Clancy T V , Tackett A D , Robinson N , Johnson G
Published: June 2011

We reviewed demographic data on patients having 2,256 carotid endarterectomies in eight large hospitals in North Carolina to determine the frequency of blacks among these patients. Blacks comprised only 4.6% of the patients having carotid endarterectomy even though they comprised 26% of all patients discharged and 22% of the general population of the state. Data from the National Inpatient Profile of the Commission on Professional and Hospital Activities, which represents patients discharged from short-term, nonfederal hospitals throughout the United States, show that nationwide, blacks comprise only 2.7% of the patients having carotid endarterectomy, whereas they comprise 12.0% of all patients discharged, 12.1% of the general population, and 10.7% of patients discharged following Class I surgical procedures. Blacks have only 67 carotid endarterectomies per 100,000 patients discharged; this rate is five or more times higher in whites. Among black patients having carotid endarterectomy, women predominate, whereas men predominate among white patients having carotid endarterectomy (p = 0.006). The underrepresentation of blacks among patients having carotid endarterectomy lends support to the concept that carotid vascular disease in blacks is distributed intracranially rather than extracranially as opposed to the extracranial rather than intracranial distribution in whites.
Whole blood platelet function in acute ischemic stroke. Importance of dense body secretion and effects of antithrombotic agents.
Authors: Joseph R , D'Andrea G , Oster S B , Welch K M
Published: June 2011

We studied platelet function in whole blood, a situation that better reflects the in vivo state, from 85 patients with acute ischemic stroke and from 19 healthy controls. Patients receiving no antithrombotic drugs demonstrated increased platelet dense body secretion without an associated increase in platelet aggregation, thus raising the possibility that dense body secretion may be of separate importance in cerebral infarction. Our results also suggest that dense body secretion may occur independently of aggregation. Heparin and heparin plus warfarin were ineffective in reducing the high level of dense body secretion seen in acute cerebral infarction, whereas treatment with aspirin plus dipyridamole inhibited both dense body secretion and platelet aggregation. It seems worthwhile to investigate the usefulness of antiplatelet drugs in the treatment of acute ischemic stroke wherein clinical outcome is correlated with the extent of suppression of platelet dense body secretion.
Clinical and radiologic features of lacunar versus nonlacunar minor stroke.
Authors: Norrving B , Cronqvist S
Published: June 2011

We determined the angiographic presence of extracerebral and intracerebral arterial disease in 122 patients with minor stroke within the carotid territory; we excluded patients with a recognized cardiac source of emboli. Based on clinical features and computed tomographic findings, patients were classified as having lacunar infarcts (n = 61), nonlacunar infarcts (n = 53), and infarcts of indeterminate type (n = 8). Severe carotid bifurcation disease (greater than or equal to 50% stenosis or occlusion) was significantly more common in nonlacunar than in lacunar infarcts, on both the ipsilateral (p less than 0.001) and the contralateral (p less than 0.01) sides; 79% of the patients with nonlacunar infarcts had severe carotid bifurcation and/or middle cerebral artery disease on the ipsilateral side compared with 3.3% of the patients with lacunar infarcts. Our data underscore the need for classification of patients by the underlying mechanisms in future studies of treatment of ischemic stroke.
Clustering of strokes in association with meteorologic factors in the Negev Desert of Israel: 1981-1983.
Authors: Berginer V M , Goldsmith J , Batz U , Vardi H , Shapiro Y
Published: June 2011

Clinical observations of the apparent clustering of daily stroke admissions to a regional hospital in an arid climate prompted our investigation of possible meteorologic factors associated with stroke admissions. Daily hospitalization and meteorologic data were studied for 895 patients with stroke admitted to Soroka Medical Center, Beer-Sheva, Israel, during 1981, 1982, and 1983. The average daily incidence of stroke was about twice as great on relatively warm days as on relatively cold ones. This increase may be explained by increases in thromboembolic mechanisms secondary to physiologic changes in response to heat. When heat waves are predicted, information on the added risk for stroke needs to be disseminated to both the population and to health care providers so preventive measures can be instituted. Special attention should be devoted to air conditioning and adequate consumption of liquids, and antiplatelet aggregation medication such as aspirin should be considered.
Beneficial effect of nimodipine on metabolic and functional disturbances in rabbit hippocampus following complete cerebral ischemia.
Authors: Lazarewicz J W , Pluta R , Salinska E , Puka M
Published: June 2011

We investigated the effects of intravenous application of nimodipine on the neurophysiologic, biochemical, and morphologic consequences of 15 minutes of global cerebral ischemia in seven rabbits. In vivo dialysis of the hippocampus was used to determine changes in extracellular concentrations of extracellular calcium and amino acids and blood-brain barrier permeability. Ischemia without treatment produced a rapid disappearance of electroencephalographic activity, a decrease in the concentration of extracellular calcium, the release of neuroactive amino acids, and leakage of methionine to the tissue fluid, plus a significant increase of the blood-brain barrier permeability to fluorescein. Except for permeability and electroencephalographic activity, these parameters normalized during 45 minutes of recirculation; permeability and activity failed to normalize completely during 3 hours of recirculation. After 3 hours of recirculation, morphologic changes in the CA1 hippocampal area were observed. Treatment with nimodipine significantly enhanced electroencephalographic activity recovery and normalization during recirculation, reduced the decrease in extracellular calcium concentration, and prevented the increased permeability of the blood-brain barrier. Nimodipine protected the CA1 area from early morphologic changes and reduced leakage of methionine from brain cells. The beneficial cytoprotective effect of nimodipine, probably related to normalization of calcium homeostasis and blood-brain barrier permeability after ischemia, may reflect both vascular and cellular sites of action.
Brain damage after open heart surgery in patients with acute cardioembolic stroke.
Authors: Maruyama M , Kuriyama Y , Sawada T , Yamaguchi T , Fujita T , Omae T
Published: June 2011

We evaluated 14 patients with acute cardiogenic embolism who underwent open heart surgery soon after the onset to determine the cerebral and cardiac factors that influence neurologic outcome. The mean interval from onset of cerebral embolism to surgery was 5.3 (range 1-16) days. Five of the 14 patients had vegetations from infective endocarditis (including prosthetic valve endocarditis) as embolic sources, eight had intracardiac thrombi, and one had atrial myxoma. The diagnosed site of infarction before surgery was based on computed tomographic and/or angiographic findings. Of the 14 patients, four had infarcts due to major artery occlusion, seven due to cortical branch occlusion, and two due to perforating artery occlusion; one patient presented with a transient ischemic attack without computed tomographic abnormalities. Ten patients (71%) showed no clinical aggravation after open heart surgery; however, two patients died of massive cerebral hemorrhage, one died of deterioration of brain edema, and another became comatose from midbrain hemorrhage immediately after surgery. The four patients with clinical aggravation comprised three with septic embolism and one with aseptic occlusion of a major artery. From these results, infective endocarditis and a large infarct appear to be possible aggravating factors when patients with recent cerebral embolism undergo open heart surgery.
Platelet ultrastructure and secretion in acute ischemic stroke.
Authors: Joseph R , Riddle J M , Welch K M , D'Andrea G
Published: June 2011

We used transmission electron microscopy to count the organelles (dense bodies, alpha granules, and mitochondria) contained within platelets from 11 acute ischemic stroke patients and 12 healthy controls. We randomly selected for evaluation 25 platelet profiles in ultrathin sections cut from three separate blocks. Compared with those from controls, platelets from stroke patients contained significantly fewer alpha granules (p less than 0.001) and mitochondria (p less than 0.02) and showed a trend toward fewer dense bodies. Supportive of our previous studies, the amount of adenosine triphosphate secreted following stimulation by collagen also tended to be greater in platelets from stroke patients. These observations support the presence of increased platelet secretion associated with acute cerebral infarction and raise the possibility that platelet secretion may be of separate importance to the mechanical occlusion of blood vessels by platelet aggregates in the pathogenesis of cerebral infarction.
Correlation of carotid bruits and carotid atherosclerosis detected by B-mode real-time ultrasonography.
Authors: Howard V J , Howard G , Harpold G J , Nunn C L , Myers L G , McKinney W M , Murros K E , Toole J F
Published: June 2011

The extent of carotid atherosclerosis evaluated by B-mode real-time ultrasound and the presence of bruits established by carotid phonoangiography were determined in 1,107 patients. Unilateral bruit was associated with increased atherosclerosis compared with no bruit (p less than or equal to 0.0001). However, there was no association between laterality of the bruit and the degree of atherosclerosis (p = 0.66). There was marginal evidence that patients with bilateral bruits had more severe atherosclerosis than patients with unilateral bruit (p = 0.046). The relation between bruit and atherosclerosis categorized by B-mode ultrasound was not sufficient to reliably predict the presence or absence of disease in an individual patient, though the presence of a bruit should be viewed as a risk factor for, or an indicator of, increased risk of systemic atherosclerosis.
Accurate noninvasive method to diagnose minor atherosclerotic lesions in carotid artery bulb.
Authors: van Merode T , Lodder J , Smeets F A , Hoeks A P , Reneman R S
Published: June 2011

In a prospective study using a multigate pulsed Doppler system, minor (less than 30% diameter reduction) carotid artery lesions were diagnosed by detecting not only abnormalities in the blood flow pattern, but also local changes in artery wall distensibility. For the diagnosis of more severe lesions, additional information was obtained from disturbances in the Doppler audio spectrum. Biplane arteriography was used as a reference. The observed agreement, sensitivity, and specificity were 86.6%, 90.3%, and 88.6%, respectively, for all lesions and 85.7%, 82.1%, and 88.6%, respectively, when only minor lesions were considered. kappa (a chance-corrected measure of agreement) was 81.7%. If only blood flow abnormalities were used to detect minor lesions, 43.5% would be missed. Our results indicate that minor carotid artery lesions can be diagnosed noninvasively more accurately when both local blood flow irregularities and local changes in vessel wall distensibility are taken into account.
Microanatomy and possible clinical significance of anastomoses among hypothalamic arteries.
Authors: Marinković S V , Milisavljević M M , Marinković Z D
Published: June 2011

We examined anastomoses among the hypothalamic arteries in 14 human brains using an injection technique, microdissection, and a stereoscopic microscope. Five to 22 anastomoses (mean 10.1) were found in all 14 brains on each side, varying from 20 to 280 (mean 71) microns in diameter and from 0.1 to 5.3 (mean 1.52) mm long. A single hypothalamic artery may be connected to other vessels by one to 10 anastomoses. The anastomoses were channel-like or plexiform; both types may be ipsilateral or right-left. They connected the hypothalamic arteries "end-to-end," "end-to-side," and "side-to-side." The interconnected arteries ranged from 30 to 1,900 (mean 148) microns in diameter. Anastomoses were most frequent among the commissural arteries and in the distribution of the superior hypophyseal arteries and the tuberoinfundibular branches of the posterior communicating artery. The largest anastomoses were found among the tuberoinfundibular branches of the posterior communicating and internal carotid arteries, as well as among the premamillary arteries and the mamillary branches. We discuss the neurologic, neuroendocrinologic, and neurosurgical significance of the described anastomoses.
Pathogenesis of carotid thrombosis.
Authors: Torvik A , Svindland A , Lindboe C F
Published: June 2011

We histologically examined specimens from 11 patients with recent occluding thrombi at the carotid bifurcation to study local factors in the vessel wall that precipitated the thrombi. The area of stenosis of the vessel lumen was determined morphometrically. Severe atherosclerotic stenosis was frequent but was not a prerequisite for thrombus formation since specimens from almost one half of the patients had only moderate narrowing of the lumen (less than 60% stenosis). Specimens from three patients showed ulcerations, those from one showed intraplaque hemorrhage, and those from one massive plaque rupture, all of which were thought to be important in thrombogenesis. All such types of plaque complications may thus precipitate thrombi but no single complication was particularly predominant, and specimens from one half of the patients showed no complications at all. Screening of the carotid arteries for stenosis can therefore detect only one half of the individuals who ultimately will develop thrombosis, and the risk caused by plaque complications seems to be moderate in unselected materials.
Postoperative hemodynamic and metabolic changes in patients with subarachnoid hemorrhage.
Authors: Hino A , Mizukawa N , Tenjin H , Imahori Y , Taketomo S , Yano I , Nakahashi H , Hirakawa K
Published: June 2011

Positron emission tomography was performed using an oxygen-15 gas inhalation technique to measure regional cerebral blood flow, metabolic rate for oxygen, oxygen extraction fraction, and cerebral blood volume in 13 patients with subarachnoid hemorrhage during the period of delayed vasospasm after surgery as well as in 10 volunteers as controls. Compared with the controls, the patients showed decreased hemoglobin concentration and decreased total arterial oxygen content due to postoperative hemodilution. Global reductions in the metabolic rate for oxygen and in the tissue oxygen supply were noted even in the apparently normal cortex of the patients in spite of adequate blood flow and adequate oxygen extraction fraction. In addition, regional reductions in blood flow and in perfusion reserve were seen in the cortical territory corresponding to cerebral vasospasm. Our results indicate that two processes are involved in the pathophysiology of cerebral vasospasm: 1) generalized impairment of oxygen metabolism with a reduced tissue oxygen supply, even in the apparently normal cortex, and 2) additional impairment of regional perfusion in the territory of vasospasm.