bluuebunny/crossref_metadata_2025 huggingface dataset:
Computer based classification of carotid arterial disease: a prospective assessment.
Authors: Knox R A , Greene F M , Beach K , Phillips D J , Chikos P M , Strandness D E
Published: June 2011

A minicomputer based pattern recognition method has been used to prospectively classify the category of disease involvement of 105 carotid arteries. The system utilized spectral patterns obtained from a combined B-mode/pulsed Doppler unit. All decisions are based upon comparison of an unknown, averaged waveform with a series of vessels with known severity of disease. The variability in the computer decision as compared to arteriography is discussed.
Experimental cerebral vasospasm arterial wall mechanics and connective tissue composition.
Authors: Nagasawa S , Handa H , Naruo Y , Moritake K , Hayashi K
Published: June 2011

The elastic properties of the basilar artery were studied in control and treated dogs in which 3 ml of blood was injected intracisternally. Vascular specimens were resected transclivally as cylindrical segments and their external diameters were measured in vitro in the pressure range from 0 mm Hg to 250 mm Hg in the active condition of smooth muscle in Krebs-Ringer solution and in the passive condition in saline solution. The development of cerebral vasospasm was confirmed comparing the diameter difference between these two conditions. The experimental data indicated that vasospasm was most prominent on the 7th day after the treatment of blood injection. In the passive condition no significant dimensional change (i.e. radius and wall thickness) was observed between the control and the treated arteries at various pressure levels. These results imply that the luminal narrowing under vasospasm is not attributable to an irreversible organic change in the wall but to the constriction of vascular smooth muscle. The treated arteries are more distensible and have lower elastic moduli than the control arteries, possibly due to a change in the content of their connective tissues. These changes of the passive elastic properties of arterial walls after blood injection might be one of the factors affecting the development of cerebral vasospasm.
Reperfusion of focal ischemia of varying duration: postischemic hyper- and hypo-perfusion.
Authors: Traupe H , Kruse E , Heiss W D
Published: June 2011

Reperfusion into focal ischemia was studied in 25 cats after middle cerebral artery (mca) occlusion of 15 min to 2 hours duration. Changes in cerebral blood flow (CBF) were followed with the hydrogen clearance method in the center and periphery of the ischemic lesion expected. Postischemic hyperperfusion was found often after 15 and 30 min ischemia and regularly after 60 min mca occlusion. It was followed by normal flow after 15 and 30 min occlusion and by postischemic hypoperfusion after 1 hour ischemia. After 2 hours occlusion hypoperfusion generally was not preceded by hyperperfusion. After 60 min ischemia hyperperfusion could not prevent the development of severe hypoperfusion, but often was accompanied by a marked flow reduction in the periphery of the mca territory. The data indicate that hyperperfusion after ischemic periods lasting 60 min and more induces hypoperfusion in the area itself and in neighbouring regions by affecting perfusion pressure and thereby may enlarge ischemic damage.
Epidemiology of stroke in Tilburg, the Netherlands. The population-based stroke incidence register: 2. Incidence, initial clinical picture and medical care, and three-week case fatality.
Authors: Herman B , Leyten A C , van Luijk J H , Frenken C W , Op de Coul A A , Schulte B P
Published: June 2011

The results of a prospective population study of stroke in Tilburg are reported. The average annual over-all incidence (per 100,000 population) for the period October 1, 1978-September 30, 1980 was 174 for total cases, 145 for first-ever cases. Males and older persons were at greater risk for a stroke. The vast majority of strokes were thrombo-embolic infarctions. Hemiplegia was the predominant neurological deficit resulting from an insult. Patients with speech problems, as opposed to those without, demonstrated more extreme motor deficit when such occurred. Seventy-four per cent of stroke cases had hypertensive blood pressure readings shortly after onset. Most patients were under hospital care during the initial phase of their attacks. The presence of such handling was related to specific patient characteristics. Three-week stroke case fatality was 30% for all patients registered, and varied significantly by age, sex and diagnostic type.
Predicting the stroke patient's ability to live independently.
Authors: DeJong G , Branch L G
Published: June 2011

The objective of this paper is to identify those variables that best predict a stroke patient's ability to live independently following his/her discharge from medical rehabilitation. The paper draws heavily on a formal research model grounded in independent living (IL) theory. Independent living is defined and operationalized as (1) the patient's ability to live in a nonrestrictive environment and (2) the patient's ability to live productively--not only in terms of gainful employment but also in terms of other contributions to community and family life. The main data source for the study is an extensive computer file of 84 stroke patients discharged from 8 medical rehabilitation centers. The multivariate statistical analysis indicates that 56 to 80 percent of the variance in a patient's ability to live independently can be explained or predicted mainly by the patient's marital status, age, Barthel score, communication impairments, and the ability to get into a motor vehicle. The paper concludes by discussing the implications of the findings for medical rehabilitation and public policy.
The amount of circumscribed brain edema and the degree of post-ischemic neuronal recovery do not correlate well.
Authors: Hallenbeck J M , Leitch D R , Dutka A J , Greenbaum L J
Published: June 2011

Fifty-four dogs were exposed to multi-focal ischemia sufficient to maintain suppression of the P1--N1 amplitude of the cortical sensory-evoked response (CSER) for 60 minutes. Subsequently, the P1--N1 amplitude recovery of the CSER was followed for an additional 15, 60, or 120 min while the dogs were treated or left untreated. The combination of PGI2, indomethacin, and heparin promoted a statistically significant augmentation of CSER amplitude return relative to: 1) no treatment; 2) PGI2 alone; 3) indomethacin alone; 4) PGI2 and heparin; 5) indomethacin and heparin; 6) PGI2 and indomethacin. Percentage gray matter water by the wet weight/dry weight technique was significantly elevated in all embolized groups compared to ten non-embolized controls, but the percentage recovery of the CSER did not correlate with the presence or degree of gray matter edema among embolized animals followed for 1 hour. Separation of embolized animals by the presence or absence of "neuron-disabling" flows (defined as 0-15 ml/100 gm/min for gray matter and 0-6 ml/100 gm/min for white matter) did produce significantly different mean CSER percentage recoveries but percentage gray matter water in the two groups was comparable. A proposed explanation of the data is that brain ischemia engenders two parallel processes which may become uncoupled. Ischemia creates metabolic conditions that lead to increased cellular imbibition of water and produces increased vascular leakiness. These perturbations increase brain water content. Concomitantly, there is an occurrence of further metabolic derangements and multifactorial interaction at the blood-endothelial interface which have a direct influence on neuronal function and recovery.
A comparison of trends in mortality from stroke in the United States and Rochester, Minnesota.
Authors: Anderson G L , Whisnant J P
Published: June 2011

More uniform methods of diagnosis and determination of the cause of death result in greater reliability of trends in mortality from stroke. In all categories of stroke except subarachnoid hemorrhage, the mortality rates in Rochester, Minnesota, are lower and show a more rapid decline with time than in the United States as a whole. The differential between the rates for United States white population and the Rochester population is most evident in the older age groups. This difference may be due to the effects of revisions in the International Classification of Disease and/or to the assignment of nonstroke deaths to stroke causes in the United States as a whole to a greater extent than in Rochester. Whether different patterns of medical care affect the trends in stroke mortality has not been determined. The trends in mortality from various categories of stroke in Rochester are reliable because some of the inconsistencies of diagnosis, assignment of cause of death, and coding changes have been overcome. The decline in mortality rates for Rochester corresponds well with decreasing incidence rates and lack of change in case fatality rates previously reported.
Intracranial internal carotid artery stenosis: longterm prognosis.
Authors: Marzewski D J , Furlan A J , St Louis P , Little J R , Modic M T , Williams G
Published: June 2011

Sixty-six patients with greater than or equal to 50% stenosis of an intracranial internal carotid artery (IICA) were followed-up for an average of 3.9 years. Eighteen patients (27.3%) experienced ischemic events; 8 (12.1%) had isolated TIA and 10 (15.2%) a stroke. The observed stroke rate for patients 35 years and older are 13 times the expected infarction rate for a normal population. Patients with tandem extracranial stenosis had a greater risk of stroke than patients with isolated IICA stenosis. Thirty-three patients (50%) died during follow-up and 55% of all deaths were cardiac related. The observed 5 year survival rate was 60% compared to an expected rate of 87%. Patients with IICA stenosis had a higher risk of stroke and death compared to a previously reported referral population with ICA occlusion. IICA stenosis is a marker of extensive cerebrovascular and systemic atherosclerotic disease, especially coronary artery disease.
Is occult atrial disorder a frequent cause of non-hemorrhagic stroke? Long-term ECG in 86 patients.
Authors: Abdon N J , Zettervall O , Carlson J , Berglund S , Sterner G , Tejler L , Turesson I
Published: June 2011

To assess the importance of occult atrial disorder with possible embolization as a cause of non-hemorrhagic stroke, 68 patients with neurologic symptoms lasting 24 hours or more and 18 patients with transient ischemic attacks were examined by long-term electrocardiographic recording (LTER). Lacking matched controls we used a reference population of 103 elderly subjects selected at random from the general population for a previous LTER study. Permanent or episodic atrial arrhythmias of types known to cause cerebral embolization were detected by LTER in 32 (47%) of the 68 patients with a clinical diagnosis of cerebral embolization or thrombosis and in 6 (33%) of the 18 patients with transient ischemic attacks. Of the 38 patients with atrial arrhythmia during LTER 17 had such arrhythmias in their standard ECGs. This frequency of atrial arrhythmias during LTER differs from that of the reference population (p less than 0.025). Thirteen of 16 patients with multiple cerebral lesions had signs of atrial arrhythmia during LTER. Patients having occult atrial disorder with episodic atrial arrhythmia may be an important and common risk group for non-hemorrhagic stroke in addition to the previously recognized group of patients with atrial arrhythmia detectable in the standard ECG. LTER may be important in the evaluation of patients with unexplained stroke.
Cardiac sequelae of acute stroke.
Authors: Myers M G , Norris J W , Hachinski V C , Weingert M E , Sole M J
Published: June 2011

The possibility that acute stroke produces an increase in sympathetic tone with resultant cardiac abnormalities was examined in 100 stroke patients admitted to a stroke ICU and in 50 controls found to have diagnoses other than stroke or TIA after admission to the Unit. Continuous 24 hour Holter ECG tapings were performed and serum cardiac enzymes and plasma norepinephrine concentrations were measured within 48 hours after admission. Significantly, (p less than .001) more serious arrhythmias were observed during 24 hour Holter ECG monitoring in stroke patients compared with controls and the difference remained (p less than .01) after matching for age and co-existing heart disease. Arrhythmias were more common in older stroke (p less than .001) and older control (p = .05) patients and with infarction of the cerebral hemispheres (p less than .05) as compared to brainstem lesions. Arrhythmia occurrence was independent of the presence of co-existing heart disease and the level of sympathetic activity. However, the 15 stroke patients with abnormally high CK values (mean 34.3 units) had a higher (p less than .02) mean plasma norepinephrine concentration (650.4 pg/ml) than stroke patients with normal CK (427.7 pg/ml). Acute stroke may cause cardiac arrhythmias and myocardial cell damage, the latter through stroke induced increases in sympathetic tone.
Moyamoya disease--a review.
Authors: Suzuki J , Kodama N
Published: June 2011

One hundred cases of Moyamoya disease were encountered between 1961 and 1980. This report describes the clinical characteristics and emphasizes the angiographic findings and clinical correlation in this disease. Reasons for the differences in clinical and radiological presentation in children versus adults are proposed and a possible pathophysiological mechanism is outlined. Treatment with perivascular sympathectomy and superior cervical ganglionectomy may be useful but more investigation needs to be carried out into the pathogenesis of the disease before more definitive therapy is realized.
Effect of mannitol on rCBF in canine thalamic ischemia--an experimental study.
Authors: Seki H , Yoshimoto T , Ogawa A , Suzuki J
Published: June 2011

Using the canine thalamic infarction model, we have investigated the effects of 10 ml/kg of 20% mannitol on the hemodynamics of the ischemic brain. Mannitol was found to cause an increase in rCBF, but it is not marked in animals with severe ischemic foci. Increases were statistically significant in the animals with moderate ischemia. Increases in rCBF due to mannitol administration lasted for about 1 hour, as did the rise in serum osmolarity. The actual relationship between these two parameters, remains unclear.
Histopathology of the brain vascular network in moyamoya disease.
Authors: Yamashita M , Oka K , Tanaka K
Published: June 2011

There is an unusual vascular network at the base of the brain in patients with moyamoya disease. We detected various histologic lesions in the perforating arteries of 22 patients. Vessels showing rupture ranged from 50 to 530 microns in diameter; they were dilated, some had fibrin deposits in the wall, fragmented elastic laminae and attenuated media. Non-ruptured perforating arteries (diameter 200 to 550 microns) revealed microaneurysm formation, focal fibrin deposits and marked attenuation of the wall thickness with diminution of the elastic lamina. These changes seem to predispose to rupture of perforating arteries. Stenotic changes such as fibrous intimal thickening, collapse of the lumen and thrombosis were detected in 14 out of 22 cases. Morphometric analysis of perforating arteries indicated that arteries showing extreme degrees of stenosis or dilatation were more frequent in the patients with moyamoya disease than in the control cases. Dilative arteries were more frequent in the young patients and stenotic vessels were, in contrast, less frequent in the young patients.
Shape changes at the apex of isolated human cerebral bifurcations with changes in transmural pressure.
Authors: Macfarlane T W , Canham P B , Roach M R
Published: June 2011

The geometry of arterial bifurcations appears to play a significant role in the development of vascular disease. We have investigated the changes in bifurcation geometry with changes in distending pressure over the range 0.0 to 190.0 mm Hg. Five cerebral arterial bifurcations from human subjects were studied. The investigation focussed on the shape and on changes in the shape of the leading edge of the flow divider (internal apical curve). The curve outline at each transmural pressure increment (each 10.0 mm Hg) was photographed and digitized. The curves were plotted serially on an expanded scale. Visual comparison of the curves indicated flattening in the central region and broadening of the shoulders of the curves with increasing transmural pressure. Regression analysis using second order polynomials was used to obtain coefficients for equations defining short, overlapping segments of each curve. Twenty-four coordinates were used for each successive regression. Each curve was characterized by 85 to 100 digitized coordinates. The regression equations for each curve were used to calculate the curvature parameter, K, and the radius of curvature, R. Three of the five bifurcations demonstrated a negative correlation of K with increasing transmural pressure (p less than .001). This result supports the visual observation that the internal apical curve flattens with increasing transmural pressure. Flattening of the internal apical curve together with thinning of the arterial wall with increasing transmural pressure would contribute to a stress concentration at the apex of a cerebral bifurcation. This stress concentration would be more pronounced in the presence of a medial gap at the apex of the bifurcation. It is on or near this region of stress concentration that aneurysms develop.
Lack of evolution of the cerebral blood flow during clinical recovery of a stroke.
Authors: Demeurisse G , Verhas M , Capon A , Paternot J
Published: June 2011

Cerebral blood flow and clinical parameters were studied in 30 stroke patients at 15th, 30th, 60th, 90th days after the cerebral insult (Xenon 133 inhalation method). The clinical improvement was not accompanied by a progressive normalization of the CBF at rest. No relationship was found between the clinical data and the CBF values; either on the affected hemisphere or on the contralateral one. It is concluded that measurement of the CBF at rest has no predictive value as regards further clinical evolution.
Transtentorial diaschisis: reduction of cerebellar blood flow caused by supratentorial local cerebral ischemia in the gerbil.
Authors: Naritomi H
Published: June 2011

To assess the effect of supratentorial cerebral ischemia on infratentorial brain function, changes in regional cerebellar blood flow (rCeBF), after right carotid occlusion for 4 hours, were studied in 30 mongolian gerbils. The regional cerebral blood flow (rCBF) in the occluded cerebral hemisphere and rCeBF in both cerebellar hemispheres were measured simultaneously by hydrogen clearance methods. Before carotid occlusion, rCBF was 0.44 +/- 0.07 ml/g brain/min, and rCeBF in the left and right cerebellar hemispheres was 0.37 +/- 0.09 and 0.40 +/- 0.09 ml/g brain/min, respectively. After carotid occlusion, rCBF decreased in all animals showing levels of above 0.20 ml/g brain/min in 14 (group A), between 0.10 and 0.19 ml/g brain/min in 7 (group B) and below 0.10 ml/g brain/min in 9 (group C). rCeBF exhibited no changes in group A and a mild reduction in group B after carotid occlusion. In group C, rCeBF was significantly reduced 30 min after carotid occlusion in the left cerebellar hemisphere followed subsequently by bilateral reduction. In groups B and C, supratentorial brain edema was observed 4 hours after occlusion, but the degree of edema was moderate. The results of the present study suggest that depression of infratentorial brain function may occur after supratentorial local cerebral ischemia, presumably due to diaschisis.
Pathophysiology of ischemic cell death: II. Changes in plasma membrane permeability and cell volume.
Authors: Ames A , Nesbett F B
Published: June 2011

Isolated rabbit retinas were subjected for various durations to several types of ischemic insult, and then returned to control medium for periods of up to 4 3/4 h before measurements were made of total water, inulin-free water, and plasma membrane permeability as assessed by mannitol penetration into the inulin-free water. Neither anoxia nor substrate deprivation alone, for as long as 50 min, caused significant irreversible swelling, but they were synergistic in combination. Restricting the volume of extracellular fluid during the combined deprivation caused the changes responsible for swelling to occur much sooner. There was a progressive increase in membrane permeability, with a delayed increase in intracellular water beginning about 2 h after the ischemic insult. Cell swelling correlated closely with loss of viability as evidenced by failure to reinstitute protein synthesis, but the swelling appeared to be the consequence rather than the cause of the initial irreversible damage.
Auscultation of cervical and ocular bruits in extracranial carotid occlusive disease: a clinical and angiographic study.
Authors: Pessin M S , Panis W , Prager R J , Millan V G , Scott R M
Published: June 2011

The clinical and angiographic features of cervical and ocular bruits were correlated in 50 consecutive patients with severe extracranial internal carotid artery occlusive disease. Cervical bruits, generally localized to the carotid bifurcation, were highly associated (P = 0.004) with "tight" (residual lumen less than or equal to 2 mm) internal carotid artery stenosis, but significantly less often with a widely patent or occluded internal carotid artery. Angiographic features of a "slow-flow" state through a patent, but "tight" stenosis were identified as the apparent explanation for the absence of bruit in some patients. A unilateral ocular bruit contralateral to the side of internal carotid artery occlusion occurred in 9 of 10 patients, more often than an associated cervical bruit, and was interpreted as a sign of augmentation flow.
CT and arteriographic comparison of patients with transient ischemic attacks--correlation with small infarction of basal ganglia.
Authors: Araki G , Mihara H , Shizuka M , Yunoki K , Nagata K , Yamaguchi K , Mizukami M , Kawase T , Tazawa T
Published: June 2011

Fifty patients presenting clinically with TIAs were examined angiographically. Twenty one patients (42%) had no abnormality. Twenty patients (40%) had stenosis or occlusion in the MCA, ACA or intracranial carotid, whereas 11 (22%) had involvement of their extracranial internal carotid artery. Seven of the 28 CTs performed showed basal ganglia infarcts. This suggests that the cause for the TIA was an infarct in the vascular territory of a lenticulostriate artery.
Platelet aggregability in cerebral thrombosis--analyzed for vessel stenosis.
Authors: Otsuki Y , Kondo T , Shio H , Kameyama M , Koyama T
Published: June 2011

Platelet aggregation in the post-acute phase of 48 patients with cerebral thrombosis was measured to see if any specific type of cerebral infarction is associated with enhanced platelet aggregation. All patients were examined with cerebral angiography and computed tomography (CT). Stenotic lesions in major cranial arteries were analyzed by measuring the apparent diameter. Severe stenosis was defined as 75 per cent constriction or more. Enhanced aggregation of platelets (secondary aggregation at 1 microM ADP or less) was present in 5 of 25 patients (20%) who had severe vessel stenosis or occlusion. CT examination frequently revealed both cortical and deep involvement. On the other hand, 13 of 23 patients (57%) with less stenotic lesions showed enhanced aggregation and that was statistically significant (p less than 0.05). Many patients of this group had persistent hypertension and small deep infarctions. Platelet aggregation was also measured in 20 hypertensive control subjects without stroke. Four of them (20%) showed enhanced aggregation. These findings suggest that a combination of enhanced platelet aggregation and hypertension increases the risk of small deep infarctions accompanied by mild stenotic changes of the major cranial arteries.
Recurrent ischemic attacks in two young adults with lupus anticoagulant.
Authors: Landi G , Calloni M V , Grazia Sabbadini M , Mannuccio Mannucci P , Candelise L
Published: June 2011

Two young adults with lupus anticoagulant had multiple attacks of cerebrovascular ischemia in different arterial territories. Cerebral angiography was normal. One patient had a new episode during anticoagulant therapy, but has remained asymptomatic on antiplatelet treatment. In the other, further events occurred during treatment with platelet-inhibiting drugs, but there have been no recurrences with adequate anticoagulant therapy. Lupus anticoagulants are possible causes of otherwise unexplained thromboembolic events. Due to the variable mode of action of these immunoglobulins, platelet-inhibiting drugs may in some cases be considered as a prophylactic alternative to anticoagulant treatment.
Medial medullary infarction from fibrocartilaginous embolism to the anterior spinal artery.
Authors: Kase C S , Varakis J N , Stafford J R , Mohr J P
Published: June 2011

A previously healthy young woman presented with sudden onset of quadriplegia, anesthesia below the C3 dermatome, respiratory paralysis, vertical nystagmus, ocular bobbing and cortical blindness. After partial resolution of the latter deficits, she remained quadriplegic, with a C3 level of anesthesia, and in respiratory paralysis until death from complications of a fulminant pulmonary infection. Autopsy disclosed bilateral infarctions of the medial aspect of the medulla and the upper cervical cord, in the distribution of the anterior spinal artery. Multiple sites of arterial occlusion by fibrocartilaginous material were found in branches of the anterior spinal artery, in correspondence with the sites of infarction. A review of the literature disclosed only 2 examples of medial medullary syndrome from embolism to the anterior spinal artery.
Focal cerebral ischemia distal to a cerebral aneurysm in hereditary hemorrhagic telangiectasia.
Authors: Fisher M , Zito J L
Published: June 2011

Neurologic complications in patients with Hereditary Hemorrhagic Telangiectasia (HHT) occur as a consequence of a variety of vascular malformations. One type of intracranial malformation, saccular aneurysm, has recently been appreciated as a potential source of ischemic cerebrovascular disease on the basis of aneurysm to artery emboli. We report a patient with HHT and an unruptured saccular intracranial aneurysm presenting with ischemic vascular events.
Hypertensive putaminal hemorrhage: treatment and results. Is surgical treatment superior to conservative one?
Authors: Waga S , Yamamoto Y
Published: June 2011

Seventy-four patients with hypertensive putaminal hemorrhage (HPH) were followed at least 6 months after treatment and estimated by ADL. They were graded according to the state of consciousness on admission. The grading consists of 6 grades: Grade 1, fully conscious; Grade 2, somnolent; Grade 3, stuporous; Grade 4, semi-comatose; and Grade 5, deeply comatose. Removal of HPH was performed in 18 patients and conservative treatment was done in 56 patients. The mortality in surgically treated group was 28% while that in conservatively treated group was 14%. The patients who returned to full work or independent life without disability and with minimal disability after surgical treatment were, 50% in Grade 1, 33% in Grade 2, and 50% in Grade 3. The patients without disability and with minimal disability after conservative treatment were; 87% in Grade 1, 80% in Grade 2, and 22% in Grade 3. None below Grade 4 returned to full work or independent life in both groups. There was good correlation between the state of consciousness and CT findings on admission. There was no correlation between good recovery and the side of HPH. Our results do not support the view that the surgical treatment is superior to the conservative one in the management of HPH.
Secondary brain stem hemorrhage in stroke.
Authors: Nedergaard M , Klinken L , Paulson O B
Published: June 2011

The occurrence of secondary brain stem hemorrhage was studied in 435 autopsies from patients with recent cerebral hemorrhage, infarction or ruptured cerebral aneurysms. The frequency of secondary brain stem hemorrhage was found to be 45% in cerebral hemorrhage, 15% in cerebral infarction, and 36% in ruptured aneurysms. In the majority of cases the secondary brain stem hemorrhage occurred a few days after the onset of cerebral hemorrhage or infarction. Ruptured aneurysms showed a more widespread temporal distribution of secondary brain stem hemorrhage. The median survival time was 2 days in cases of cerebral hemorrhage, 4 days in ruptured aneurysm and 4 days in cerebral infarction. The frequency of secondary brain stem hemorrhage was significantly lower in patients younger than 20 years. No significant difference was found in its distribution between the sexes. Secondary occipital lobe infarction was present in 3.5% of the patients. It is concluded that secondary brain stem hemorrhage is a common major contribution to the cause of death in stroke.
Platelet function tests in thrombotic cerebrovascular disorders.
Authors: Uchiyama S , Takeuchi M , Osawa M , Kobayashi I , Maruyama S , Aosaki M , Hirosawa K
Published: June 2011

A variety of platelet function tests were performed in patients with four forms of obstructive cerebrovascular disease (CVD); transient ischemic attacks (TIA), reversible ischemic neurological deficit (RIND), cerebral infarct, and cerebral embolism of cardiac source in rheumatic valvular heart disease (RVHD). Platelet studies included platelet aggregation induced by ADP and ristocetin, spontaneous platelet aggregation, von Willebrand factor (VIII:vWF), platelet aggregation enhancing factor (PAEF), and percentage of large platelets (megathrombocytes). Serial testing was carried out in acute stroke patients. The effect of aspirin therapy was also evaluated. A clear difference in results was observed between patients with cardiogenic embolism and those with other forms of CVD. In patients with TIA, RIND, and cerebral infarct, platelet aggregation, both induced and spontaneous, was enhanced along with elevation of plasma VIII:vWF and PAEF, and increased percentage of megathrombocytes. In patients with cardiogenic embolism, however, these studies were negative except for percent megathrombocytes. This value was increased in the embolic patients with RVHD in comparison with non-embolic patients with RVHD. Increase in platelet aggregation to ADP and percent megathrombocytes developed slowly over a week following stroke. Induced and spontaneous platelet aggregation, and percent megathrombocytes could be normalized with 600 mg aspirin p.o. These studies suggest that a systemic increase of hyperaggregable platelets and of plasma activators of platelet function exists in thrombotic CVD and may be related to its pathogenesis, while local hemodynamic factors may be more important in the thrombogenesis of cardiogenic embolism.
Central nervous system complications of coronary artery bypass graft surgery: prospective analysis of 421 patients.
Authors: Breuer A C , Furlan A J , Hanson M R , Lederman R J , Loop F D , Cosgrove D M , Greenstreet R L , Estafanous F G
Published: June 2011

A prospective analysis of 421 patients undergoing coronary artery bypass graft (CABG) surgery as the sole cardiac procedure was carried out to assess the frequency of central nervous system (CNS) complications. In all, 451 variables were assessed in each patient. Stroke occurred in 5.2% but was severe in only 2%. Prolonged encephalopathy occurred in 11.6% but usually resolved before discharge. No statistically significant pre- or intraoperative risk variables for CNS complications were found; specifically, age or pump times in excess of two hours were not significant factors. Postoperative use of an intraaortic balloon pump and pressor agents were significantly correlated with prolonged encephalopathy. The frequency of CNS injury in CABG surgery is similar to that in other forms of open heart surgery, and there has been little change in the frequency of CNS complications over the past seven years. Possible mechanisms of CNS damage during CABG surgery are discussed.
Early recurrent embolism associated with nonvalvular atrial fibrillation: a retrospective study.
Authors: Hart R G , Coull B M , Hart D
Published: June 2011

Nonvalvular atrial fibrillation (NVAF) can be a source of cardiogenic brain embolism. We retrospectively reviewed the clinical features of 56 patients with acute brain infarction and NVAF. Based on clinical criteria, 35 infarcts (63%) were classified as probably embolic, 13 infarcts (23%) as probably nonembolic and 8 infarcts (14%) as of indeterminate pathogenesis. Among the 35 patients with presumed embolic infarcts, 12 patients were immediately anticoagulated without hemorrhagic complications. Of 23 patients who did not receive immediate anticoagulation, three (13%) experienced recurrent embolism (one each to brain, kidney and leg) within 10 days of initial embolism. There were no early recurrent emboli in patients receiving immediate anticoagulation or patients in the nonembolic or indeterminate category. Five additional patients experienced probable brain or systemic emboli within the 11 days prior to the marker stroke event. Including these patients, 20% (8 of 40) of all NVAF patients who were not immediately anticoagulated experienced recurrent embolism within 11 days of the initial embolus. Early recurrent emboli are common in NVAF patients who experience embolic stroke.
Ethanol intoxication: a risk factor for ischemic brain infarction.
Authors: Hillbom M , Kaste M
Published: June 2011

One hundred consecutive patients (67 men, 33 women) aged from 15-55 with acute ischemic brain infarction verified by computed tomography and/or angiography and/or brain scanning were studied. In 40 cases the onset of symptoms was preceded within 24 hours by ethanol intoxication. Ethanol intoxication preceding brain infarction was 4-7 times as common in men and 6-15 times as common in women as ethanol intoxication in the general Finnish population of the same age and sex. Nineteen of the patients were heavy drinkers. Heavy drinking was twice as common in men and 5 times as common in women as heavy drinking in the general Finnish population of the same age and sex. Both occasional ethanol intoxication and regular heavy drinking seem to carry an increased risk of ischemic brain infarction. The ethanol-induced risk was highest in middle-aged women and young men.
Effects of smoking on regional cerebral blood flow in neurologically normal subjects.
Authors: Kubota K , Yamaguchi T , Abe Y , Fujiwara T , Hatazawa J , Matsuzawa T
Published: June 2011

The chronic effects of smoking on regional cerebral blood flow (CBF), and on serum lipids and lipoprotein levels in neurologically normal subjects, were studied. CBF was studied by the 133-Xenon inhalation method and gray matter flow was calculated following the method of Obrist et al. One hundred and eleven subjects, who had no abnormalities in neurological examinations nor in CT scans, were divided into two groups: smokers (37) and non-smokers (74). Those who had a smoking index (Number of cigarettes/day) X (years of smoking history) greater than 200 were designated as smokers. The mean smoking index of smokers was 760. Sixty-two of the 74 subjects in the non-smoking group had never smoked, and the mean smoking index of non-smokers was 17. In the male, CBF was significantly lower in smokers than in non-smokers (mean CBF, 12.5% lower in smokers, p less than 0.001). Increased reduction of CBF with advancing age was also observed. Compared to non-smokers, CBF in smokers was found to be significantly lower than the expected age matched value. Serum high density lipoprotein cholesterol values in smokers were significantly lower, and total cholesterol levels significantly higher than in non-smokers. We concluded that smoking chronically reduces CBF. Decrease of CBF in smokers was probably due to advanced atherosclerosis which produces vascular narrowing and raised resistance in cerebral blood vessels.
Massive cerebellar infarction: "conservative" management.
Authors: Khan M , Polyzoidis K S , Adegbite A B , McQueen J D
Published: June 2011

Eleven patients with large cerebellar infarctions were admitted recently to our service. Eight of them showed evidence of hydrocephalus on the CT scan examination. Five were treated with controlled external ventricular drainage and six were managed conservatively. One death, most likely due to progressive brainstem infarction, occurred. The outcome was favorable in the other patients. It is suggested that prompt treatment of the acute obstructive hydrocephalus may obviate the need for posterior fossa decompression in patients with massive cerebellar infarction.
CT visualization of intracranial arterial thromboembolism.
Authors: Gács G , Fox A J , Barnett H J , Vinuela F
Published: June 2011

Eight cases of presumed acute occlusion of intracranial arteries, 7 middle cerebral and 1 posterior cerebral, demonstrated the occluded artery as an abnormal high density structure on non-enhanced computed tomography. Three cases underwent subsequent angiography which confirmed the diagnosis. CT scanning is therefore able to visualize acute thromboembolism in the intracranial arteries. In the appropriate clinical setting of acute stroke, an artery visualized on non-contrast CT scan as diffuse high density and higher in density than other visualized vessels should be suspected as acutely occluded by clot.
The pathogenesis of strokes from internal carotid artery occlusion. Diagnostic and therapeutical implications.
Authors: Ringelstein E B , Zeumer H , Angelou D
Published: June 2011

In order to relate clinical, angiologic and brain-morphological findings, 107 patients with internal carotid artery occlusion were examined clinically and by Doppler sonography, computerized tomography and cerebral angiography. During computerized tomography, haemodynamically induced infarctions could be differentiated from those, caused by periocclusive embolism towards the major brain arteries. This differentiation was based on an integration of angiological as well as brain-morphological data and implicates some important diagnostic, therapeutic and prognostic consequences. The first group may benefit from immediate surgical restoration of carotid blood flow and have a relatively good prognosis. By contrast, subjects presenting territorial infarctions mostly experience severe and permanent neurological deficits. They should not undergo revascularization since endarterectomy increases the risk of cerebral hemorrhage but cannot cause clinical improvement. In five patients, following special angiographic techniques, the lesions of the internal carotid artery turned out to be pseudoocclusions. This condition threatens the patient considerably but is well accessible to surgical reconstruction. Thus, pseudooclusion seems to be one of the most convincing indication for emergency endarterectomy of the internal carotid artery.
Inaccuracy of angiography in the diagnosis of carotid ulceration.
Authors: Eikelboom B C , Riles T R , Mintzer R , Baumann F G , DeFillip G , Lin J , Imparato A M
Published: June 2011

It is generally stated that ulceration of the carotid bifurcation plaque may give rise to embolization and symptoms of cerebral ischemia. It has been suggested that prophylactic carotid endarterectomy is indicated in asymptomatic patients if the angiogram is interpreted as showing ulceration. We therefore determined the accuracy of the radiologic diagnosis of ulceration by comparing the radiologic and morphologic findings in 155 carotid endarterectomies. Ulceration was diagnosed in 54% of the angiograms and 47% of the surgical specimens and was not related to the degree of stenosis. Angiography had a sensitivity of 73%, a specificity of 62% and an overall accuracy of 67%. For the non-flow-restrictive lesions these figures were 65%, 66%, and 66%. If surgery were based on the angiographic diagnosis of ulceration in plaques with less than 50% stenosis, 16 out of 42 operations (38%) would have been done unnecessarily. Variability of the angiographic diagnosis of ulceration is also shown by a high interobserver variability; two sets of two authors read the angiograms independently and disagreed in 24% of the cases. The decision to operate should not depend entirely upon the angiographic diagnosis of ulceration.
Observer variability in evaluating extracranial carotid artery stenosis.
Authors: Chikos P M , Fisher L D , Hirsch J H , Harley J D , Thiele B L , Strandness D E
Published: June 2011

One hundred twenty eight cervical carotid arteriograms were twice viewed by three readers for the evaluation of atherosclerotic disease at the carotid bifurcation. Stenoses were estimated using calipers to the nearest 5% and lesions were qualitatively characterized as smooth, irregular, or ulcerated. The intraobserver correlation coefficient between estimates of percent stenosis was .94 overall and .98 for the internal carotid artery. The average intraobserver variability in estimating percent stenosis was 5.23% for all vessels and 6.04% with a standard deviation of 8.09% for the internal carotid artery. The intraobserver percent agreement at a fixed stenosis is defined as the percent of the time one reader on two readings would read at least the fixed percent stenosis among cases that might be read as having the fixed percent stenosis. The intraobserver percent agreement rate for the internal carotid artery was 95.9% at greater than 0% stenosis, 90.4% for 50% or greater stenosis, and 96.8% for 100% stenosis (total occlusion). The interobserver correlation coefficient between readers was .92 overall and .97 for the internal carotid artery. The absolute difference in percent stenosis between readers was 7.21% for all vessels and 8.64% for the internal carotid artery with a standard deviation of 9.5%. The interobserver agreement rate for the internal carotid artery at greater than 0% stenosis was 93.0%, 85.4% for 50% or greater stenosis and 96.8% at 100% stenosis. The addition of oblique views had no statistical effect on estimates of percent stenosis but increased the frequency with which irregularity and ulceration were diagnosed in the internal carotid artery.
Regional cerebral blood flow in patients with transient ischemic attacks studied by Xenon-133 inhalation and emission tomography.
Authors: Vorstrup S , Hemmingsen R , Henriksen L , Lindewald H , Engell H C , Lassen N A
Published: June 2011

Cerebral blood flow CBF was studied in 14 patients with transient ischemic attacks TIA and arteriosclerotic neck vessel disease. CBF was measured by a rapidly rotating single photon emission computerized tomograph using Xenon-133 inhalation. This method yields images of 3 brain slices depicting CBF with a spatial resolution of 1.7 cm. Based primarily on the clinical evidence and on the angiographical findings embolism was considered the pathogenetic factor in 10 cases, whereas chronic hemodynamic insufficiency rendered symptomatic by postural factors probably accounted for the symptoms in 4 patients. Of the 14 patients, all studied days to weeks after the most recent TIA, four showed hypoperfused areas on the CBF-tomograms and with roughly the same location hypodense areas on CT-scanning, i.e. areas of complete infarction. However, an additional five patients showed reduction of CBF in areas with no abnormality on the CT-scan. The abnormal blood flow pattern was found to be unchanged after clinically successful reconstructive vascular surgery. This suggests the presence of irreversible ischemic tissue damage without gross emollition (incomplete infarction). It is concluded, that TIAs are often harmful events, as no less than 9 of the 14 patients studied had evidence of complete and/or incomplete infarction. Thorough examination and rational therapy should be instituted as soon as possible to prevent further ischemic lesions.
Cerebral infarction of the basal ganglia due to embolism from the heart.
Authors: Santamaria J , Graus F , Rubio F , Arbizu T , Peres J
Published: June 2011

We studied 8 patients with cerebral infarction in the deep territory of the middle cerebral artery (MCA). All patients had a definite cardiac source of emboli and no known factors for thrombosis. Mixed sensory and motor deficit was found in all but one patient and CT scan showed larger lesions than usually reported in lacunar infarcts. Contrast enhancement was seen in all cases in which CT scan was performed in the second or third week. It is concluded that embolic infarcts in deep cerebral territory of MCA from a cardiac source are more frequent than previously reported. This diagnosis has to be considered when CT scan demonstrates a deep cerebral infarct.
Middle cerebral artery occlusion as a cause of isolated subcortical infarction.
Authors: Adams H P , Damasio H C , Putman S F , Damasio A R
Published: June 2011

We report two patients with large subcortical hemispheric infarctions, located in areas prone to the development of lacunes, who had occlusion of the middle cerebral artery demonstrated by arteriography. The cortical vessels were perfused by leptomeningeal collaterals. We suggest that large vessel arterial disease should be considered as a possible etiology of large subcortical infarctions and propose that the term lacune should not be used in cases in which neither the size nor the pathophysiologic mechanism of the lesion conform to C.M. Fisher's description.
Occurrence and mechanisms of occlusion of the anterior cerebral artery.
Authors: Gacs G , Fox A J , Barnett H J , Vinuela F
Published: June 2011

Occlusion of the anterior cerebral artery is a rare condition. A review of CT scans from 413 patients with ischemic infarction confirmed this low relative incidence: only 3% of CT scans evidencing infarction involved the territory of the anterior cerebral artery. Four major mechanisms of anterior cerebral artery occlusion have been identified in this series: Emboli in unusual hemodynamic circumstances such as patients presumed to have increased flow through the anterior communicating artery because of unilateral internal carotid artery occlusion. Propagation of thrombotic material from an occluded internal artery into the intracranial branches. Spasm, emboli or propagating thrombosis associated with anterior communicating aneurysm.
Paraplegia associated with intraaortic balloon pump counterpulsation.
Authors: Singh B M , Fass A E , Pooley R W , Wallach R
Published: June 2011

Two patients developed paraplegia associated with the use of the intraaortic balloon pump. In one patient, transient spinal ischemic episodes ceased after removal of the intraaortic balloon and the second patient apparently sustained spinal cord infarction. Possible etiologic mechanisms include vascular occlusion due to balloon position, arterial spasm, thromboembolic phenomena, hypotension, hypoxia and arterial dissection.
Nerve terminal damage in cerebral ischemia: greater susceptibility of catecholamine nerve terminals relative to serotonin nerve terminals.
Authors: Weinberger J , Cohen G , Nieves-Rosa J
Published: June 2011

The energy-dependent uptake of (3H)-dopamine (DA), (3H)-norepinephrine (NE) and (3H)-serotonin (5-HT) was measured in synaptosomes isolated from either the whole cerebral hemispheres or the striata of gerbils after cerebral ischemia. Ischemic stroke was induced in the Mongolian gerbil by left common carotid ligation. Uptake values in the affected hemisphere (expressed as a percent of the corresponding control hemisphere) were 32.6% for DA, 35.1% for NE, and 52.0% for 5-HT, 16 hours after stroke. The differential reduction in uptake of the catecholamines relative to 5-HT was significant (p less than 0.005). This differential persisted when measures were made on isolated striata from the ischemic and control hemispheres. In the latter measurements, uptake of DA was 20.7% of control and uptake of 5-HT was 44.7% of control. Uptake of both DA and NE were significantly reduced in animals exhibiting milder circling behavior, while uptake of 5-HT was not. There was no significant reduction of uptake in animals subjected to left common carotid ligation not exhibiting signs of stroke. These studies indicate a selective sensitivity of catecholamine nerve terminals to damage in ischemic stroke.