bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transcranial Doppler detection of circulating cerebral emboli. A review.
Authors: Markus H 
Published: June 2011

The identification of gaseous emboli using Doppler ultrasound was described as early as the 1960s. Recently it has been demonstrated that this method can also detect solid emboli such as thrombi and platelet aggregates. This may make this technology useful in a large number of patients with, or at risk of, embolic stroke.
Emboli appear as short-duration, high-intensity signals in the Doppler spectrum. The intensity of the Doppler signal from an artery containing an embolus depends on the density difference between the embolic material and blood. This difference is greatest for gaseous emboli, which are therefore the most easy to detect. Gaseous emboli have been demonstrated during deep-sea diving, and their presence correlates with the occurrence of decompression sickness. Similar signals have been detected during cardiopulmonary bypass. A relation has been demonstrated between the number of emboli detected by transcranial Doppler and a decline in neuropsychological function after cardiopulmonary bypass. Solid emboli such as thrombi and platelet aggregates result in less intense signals than air emboli. Their detection, using Doppler ultrasound, has recently been described in patients with prosthetic heart valves, atrial fibrillation, and carotid artery disease. It may also help in the detection and localization of embolic sources in patients with stroke. Studies in in vitro and in vivo models demonstrate that this technique provides information on the size and type of emboli. Larger emboli produce signals of greater intensity and duration. Practical patient monitoring will require automatic emboli detectors incorporated into the Doppler machine; such programs are being developed.
Detection of solid emboli using Doppler techniques offers an exciting new diagnostic tool. It has been demonstrated that the technique can detect solid emboli. The prognostic significance of such emboli remains to be determined. It is hoped that the technique will allow detection of patients at high risk of embolic stroke in whom appropriate prophylactic treatment can then be instituted.
Predicting complications of carotid endarterectomy.
Authors: McCrory D C , Goldstein L B , Samsa G P , Oddone E Z , Landsman P B , Moore W S , Matchar D B 
Published: June 2011

Carotid endarterectomy has been shown to be beneficial in patients with high-grade carotid stenosis and ipsilateral transient ischemic attack or stroke. This benefit will be realized only if the operation is performed safely. We sought to determine the extent to which clinically significant adverse events occurring after carotid endarterectomy can be predicted from clinical data available before surgery.
Eleven hundred sixty patients were randomly selected from all patients who underwent carotid endarterectomy and were discharged during the calendar years 1988, 1989, and 1990 in 12 academic medical centers in 10 states. Clinical data abstracted from hospital charts were analyzed retrospectively. A model was developed and validated to predict the occurrence of stroke, myocardial infarction, or death during the postoperative period of hospitalization.
Eight patients (6.9%) suffered at least one adverse event. Rates for individual complications were as follows: death, 1.4%; nonfatal stroke, 3.4%; nonfatal myocardial infarction, 2.1%; and nonfatal stroke or death, 4.8%. Significant predictors of adverse events were age 75 years or older, symptom status (ipsilateral symptoms versus asymptomatic or nonipsilateral symptoms), severe hypertension (preoperative diastolic blood pressure of greater than 110 mm Hg), carotid endarterectomy performed in preparation for coronary artery bypass surgery, history of angina, evidence of internal carotid artery thrombus, and internal carotid artery stenosis near the carotid siphon. The presence of two or more of these risk factors was associated with a nearly twofold increase in risk of an adverse event (relative risk, 1.7; 95% confidence interval, 1.0 to 3.0).
Clinical data can be used to stratify patients undergoing carotid endarterectomy according to risk of postoperative in-hospital stroke, myocardial infarction, or death.
The relevance of detecting carotid artery calcification on plain radiograph.
Authors: Doris I , Dobranowski J , Franchetto A A , Jaeschke R 
Published: June 2011

The aim of this study was to determine the potential value of carotid artery calcification observed on plain radiographs in patients referred for carotid angiogram in the diagnosis of carotid artery stenosis.
One hundred sixty consecutive patients with suspected carotid artery stenosis underwent both plain radiographs of the carotid arteries and digital subtraction angiography of the same vessels. In addition, 108 of these patients also had duplex ultrasound of the same vascular area. The clinical usefulness of the carotid artery calcification was assessed by calculating the likelihood ratios for different test results against results of angiography and duplex ultrasound.
There is a statistically significant association between the degrees of calcification and carotid disease as demonstrated by angiography (P = .0001), although positive correlations of the degrees of stenosis and calcification was only fair (Spearman correlation coefficient r = .4). The sensitivity of carotid calcification in detecting clinically significant stenosis assuming any calcification is abnormal was 89% with a specificity of 46%. The likelihood ratios for 50% stenosis by angiography varied from 0.24 (no calcification) to 3.41 (level III) and for 50% stenosis by duplex ultrasound varied from 0.21 (no calcification) to more than 5.87 (level III). Assessments of the degree of calcification based on plain radiographs had excellent reproducibility (all intraclass correlation coefficients were greater than .9).
In this population with a high prevalence of carotid artery disease, there is an association between the presence of carotid calcification and atheromatous disease. If subsequent studies were to show this to apply in the general population, this could be of value in identifying asymptomatic patients at increased risk.
Lack of asymmetry of middle cerebral artery blood velocity in unilateral migraine.
Authors: Zwetsloot C P , Caekebeke J F , Ferrari M D 
Published: June 2011

A recent transcranial Doppler study found reduced blood velocity in seven patients during migraine attacks in the middle cerebral artery at the headache side. This would implicate vasodilation of the middle cerebral artery in the pathogenesis of headache in migraine. We attempted to confirm this finding.
We determined blood velocity with transcranial Doppler ultrasonography in the middle cerebral arteries of 51 migraine patients with unilateral headache (5 with aura, 46 without aura) and of 14 patients with bilateral headache, during and outside attacks. During attacks, median time from onset of attack to transcranial Doppler examination was 6 hours (range, 1 to 35 hours).
We found no difference between blood velocity at the headache and nonheadache sides nor between blood velocity during and outside attacks. Similar results were obtained in a subgroup of 11 patients who were investigated in the first 4 hours of an attack. There were also no differences between attacks with unilateral or bilateral headache.
We cannot support the hypothesis that migraine is associated with vasodilation of the middle cerebral artery ipsilateral to the headache.
Familial aggregation of stroke. The Framingham Study.
Authors: Kiely D K , Wolf P A , Cupples L A , Beiser A S , Myers R H 
Published: June 2011

Family history is perceived to be an important risk factor for stroke despite conflicting published data. We examined patterns of familial aggregation of stroke among three generations using data from the Framingham Study.
Cox proportional hazards analyses, adjusting for known stroke risk factors, were used to examine familial concordance in three groups: (1) members of the original Framingham cohort using reported parental stroke death; (2) members of the Framingham Offspring Study and their parents (members of the original Framingham Study); and (3) sibships within the original Framingham cohort.
We found no association between stroke or transient ischemic attack among original cohort members and their reported parental stroke death (n = 4933; relative risk [RR] = 1.07). Using verified cases of parental stroke or transient ischemic attack, the Offspring analyses revealed that both paternal (n = 1762; RR = 2.4; 95% confidence interval [CI], 0.96 to 6.03) and maternal (n = 2074; RR = 1.4; 95% CI, 0.60 to 3.25) histories were associated with an increased risk. Parental history of coronary heart disease was strongly associated with stroke or transient ischemic attack among Offspring Study members (RR = 3.33; 95% CI, 1.27 to 8.72). Sibling history of stroke or transient ischemic attack was not associated with stroke or transient ischemic attack among original cohort members, although a non-statistically significant increased risk associated with sibling history of atherothrombotic brain infarction was observed (RR = 1.8; 95% CI, 0.68 to 4.94).
These analyses suggest that parental history of stroke may be a risk factor for stroke. As more stroke or transient ischemic attack events develop among the Offspring Study members, it will be valuable to reexamine these associations.
Suppressed sympathetic skin response in brain infarction.
Authors: Korpelainen J T , Tolonen U , Sotaniemi K A , Myllylä V V 
Published: June 2011

Autonomic failure is known to manifest commonly in stroke, but very little attention has been given to various features of sympathetic dysfunction such as sudomotor dysregulation in cerebrovascular diseases. In the present study, our purpose was to assess quantitatively sympathetic reflex activity in brain infarction by measuring the sympathetic skin response.
We recorded the sympathetic skin response to electric and auditory stimulations simultaneously on both hands in 58 patients with brain infarction and in 36 healthy control subjects.
The response amplitudes were significantly decreased and the latencies prolonged in both hemispheral (n = 49) and brain stem (n = 9) infarctions compared with the control subjects. The amplitudes were diminished in both the acute and late phases of infarction, but the latencies were prolonged only in the acute phase.
Sympathetic dysfunction in brain infarction seems to be much more extensive than has previously been thought. In the present study, we have demonstrated impaired sympathetic skin responses, reflecting definite suppression of the reflex activity of the sympathetic nervous system.
Intracerebral hemorrhage caused by transmural dissection of the anterior cerebral artery.
Authors: Guridi J , Gállego J , Monzón F , Aguilera F 
Published: June 2011

Spontaneous dissection of the intracranial carotid artery or its main branches is an unusual condition.
A 72-year-old hypertensive woman after an intense nuchal rigidity showed a subarachnoid hemorrhage and an interhemispheric hematoma by computed tomography. The neuropathological study revealed a transmural dissection of the pericallosal artery.
The authors suggest that the dissection origin is an atheromatous plaque that bleeds, producing a dissection plane from the lumen to the adventitial artery.
Autonomic consequences of cerebral hemisphere infarction.
Authors: Barron S A , Rogovski Z , Hemli J 
Published: June 2011

Recently, supraventricular tachycardia has been reported following right hemisphere stroke, suggesting a reduction in parasympathetic cardiac innervation after stroke of the right hemisphere. We performed power spectrum analysis of fluctuations in RR interval duration in the electrocardiogram in an attempt to determine how ischemic stroke influences autonomic cardiac innervation.
Power spectrum analysis of the variation in 256 consecutive electrocardiographic RR intervals was performed using the fast-Fourier transformation. The area under the spectral curve from 0 to 0.5 Hz and the area under the portion of the curve produced by parasympathetically mediated respiratory variations were determined in 20 patients with right-hemisphere and 20 patients with left-hemisphere ischemic stroke confirmed by computerized tomography. Data were compared with 40 age- and sex-matched healthy controls.
Total cardiac autonomic innervation was reduced after a stroke of either hemisphere without regard to laterality. Cardiac parasympathetic innervation was reduced after stroke of either hemisphere with a significantly greater reduction after stroke on the right (P = 2.9 x 10(-5).
Power spectral analysis of heart rate variability can detect autonomic consequences of stroke. The spectral data predict that, to the degree that cardiac arrhythmia is produced by unbalanced cardiac autonomic activity favoring the sympathetic system, such arrhythmias could be seen after stroke of either hemisphere and would be more common after cerebral infarction on the right. This is consistent with evidence from the recent literature.
Recovery of sensorimotor function after distal middle cerebral artery photothrombotic occlusion in rats.
Authors: Markgraf C G , Green E J , Watson B , McCabe P M , Schneiderman N , Dietrich W D , Ginsberg M D 
Published: June 2011

The purpose of the present study was to delineate the behavioral correlates of focal thrombotic occlusion of the distal middle cerebral artery in rats and to compare the pattern of deficits and subsequent recovery to that following proximal middle cerebral artery occlusion.
Ten Sprague-Dawley rats underwent photothrombotic occlusion of the distal middle cerebral artery with tandem occlusion of the common carotid arteries (dMCAO group); 10 animals served as operated controls. Beginning on postischemia day 2, animals were given a battery of five tests that assessed sensorimotor integration, attentional mechanisms, and muscle strength; testing continued twice weekly until day 30. Nine days of cognitive testing on the learning set of the water maze task were then given. Infarct volume and hemispheric atrophy were determined for each dMCAO animal.
After ischemia, the dMCAO group exhibited significant behavioral deficits in posture reflex, ability to place a forelimb to various stimuli, limb adduction during rearing, and neglect of contralateral space. These deficits showed variable recovery rates. No deficits were observed in muscle strength or cognitive performance. The deficits and patterns of recovery were related to infarct location and to degree of hemisphere atrophy.
The present study suggests that a battery of tests is necessary to fully characterize the pattern of behavioral deficits after focal cerebral ischemia. Location of infarct damage and associated degree of hemispheric atrophy were important variables in determining behavioral outcome. The present results are compared with those of the more traditional model of electrocoagulation of the proximal middle cerebral artery.
P-selectin and intercellular adhesion molecule-1 expression after focal brain ischemia and reperfusion.
Authors: Okada Y , Copeland B R , Mori E , Tung M M , Thomas W S , del Zoppo G J 
Published: June 2011

Polymorphonuclear leukocytes have been implicated in the development of the "no-reflow" phenomenon after focal cerebral ischemia and reperfusion. To further understand the role of granulocytes in microvascular occlusions, the responses of the granulocyte-endothelial cell adhesion molecules P-selectin and intercellular adhesion molecule-1 during middle cerebral artery ischemia and reperfusion were examined in a primate model.
Twelve adolescent male baboons were used for 2-hour middle cerebral artery occlusion (n = 3) or for 3-hour occlusion with 1-hour (n = 3), 4-hour (n = 3), and 24-hour (n = 3) reperfusion, and three separate unoperated primates served as controls. A quantitative immunohistochemical study of the microvascular distribution of P-selectin and intercellular adhesion molecule-1 was performed using 10-microns frozen sections from basal ganglia analyzed with computerized light microscopy video imaging.
Significant (P < .05) persistent upregulation of P-selectin (beginning during ischemia) and transient upregulation of intercellular adhesion molecule-1 (at 1 and 4 hours of reperfusion) were observed on endothelium of selected post-capillary microvessels of the ischemic lenticulostriate artery territory. Platelet accumulation also occurred in this territory and was responsible for a significant proportion of the nonendothelial P-selectin signal at 24 hours after reperfusion.
Focal cerebral ischemia/reperfusion stimulates endothelial P-selectin and intercellular adhesion molecule-1 expression in brain microvessels in the ischemic zone, which may contribute to enhanced leukocyte adherence and persistent activation.
Venous sinus thrombosis associated with androgens in a healthy young man.
Authors: Jaillard A S , Hommel M , Mallaret M 
Published: June 2011

Cerebral venous sinus thrombosis is rare and can be promoted by various conditions. We report the case of cerebral venous thrombosis in a patient using androgens.
A 31-year-old man using androgens for bodybuilding was admitted for headache and vomiting. He had cerebral venous sinus thrombosis, but extensive examinations did not reveal any known cause.
We suggest that androgens may promote cerebral venous thrombosis. The mechanisms of venous thrombosis related to androgens may be platelet activation or an increase in coagulation factors. Because androgen use may be frequent and hidden in athletes, it may be an underestimated cause of cerebral venous sinus thrombosis in the young.
Involuntary tonic spasms of a limb due to a brain stem lacunar infarction.
Authors: Kaufman D K , Brown R D , Karnes W E 
Published: June 2011

Although repetitive involuntary movements are a well-recognized manifestation of carotid occlusive disease, similar movements have not been reported with a lacunar infarction outside of the basal ganglia or subthalamic nucleus. We describe a man with tonic spasms associated with a lacunar infarction in the right ventral pons.
Involuntary tonic spasms of a paretic limb developed acutely in a 69-year-old hypertensive man with a clinical presentation of pure motor hemiparesis. Magnetic resonance imaging demonstrated a lacunar infarction of the ventral pons. There was no evidence for carotid occlusive disease. An electroencephalogram recorded during the movements showed no abnormality. The abnormal movements responded well to treatment with oral diazepam.
A brain stem lacunar infarction may be associated with involuntary tonic limb spasms clinically similar to those reported as paroxysmal symptoms of multiple sclerosis.
Transesophageal echocardiographic findings in stroke subtypes.
Authors: Albers G W , Comess K A , DeRook F A , Bracci P , Atwood J E , Bolger A , Hotson J 
Published: June 2011

Transesophageal echocardiography has a high yield for detecting potential cardiac sources of embolism in patients with clinical risk factors for cardioembolism or unexplained stroke. The yield in other stroke subtypes is unknown.
We classified 145 consecutively admitted patients into stroke subtypes based on clinical findings, brain imaging, and carotid ultrasound. Both transesophageal and transthoracic echocardiography were performed to detect left atrial thrombi, spontaneous echo contrast, atrial septal aneurysm, interatrial shunts, ventricular thrombus or aneurysm, and myxomatous mitral valve.
Transesophageal echocardiography documented at least one of these findings in 46% of the patients compared with an 8% yield on the transthoracic study (P = .002). The yield of transesophageal echocardiography was substantial in all stroke subgroups. Patients with clinical risk factors for cardiac embolism had the highest frequency of spontaneous echo contrast (P = .001). Atrial septal aneurysms were most frequent in patients with lacunar syndromes (P = .012), and interatrial shunts were common in all stroke subtypes.
Transesophageal echocardiographic findings vary considerably between stroke subgroups.
The role of lifestyle factors in the etiology of stroke. A population-based case-control study in Perth, Western Australia.
Authors: Jamrozik K , Broadhurst R J , Anderson C S , Stewart-Wynne E G 
Published: June 2011

We sought to examine risk factors for all strokes and for ischemic stroke and primary intracerebral hemorrhage separately.
This was a population-based case-control study. Each case subject meeting World Health Organization criteria for stroke (n = 536) from a population-based register of acute cerebrovascular events compiled in Perth, Western Australia, in 1989 to 1990 was matched for age and sex with up to five control subjects drawn from the same geographical area. Objective confirmation of the type of stroke was available from computed tomography, magnetic resonance imaging, or necropsy for 86% of the case subjects. Data on medical history and lifestyle factors were collected from case and control subjects by interview of the subject or a proxy informant.
Current smoking, consumption of meat more than four times weekly, and a history of hypertension or intermittent claudication were each associated with increased risk in multivariate models for all strokes and for all first-ever strokes. Consumption of 1 to 20 g/d alcohol in the preceding week was associated with a significant reduction in the risk of all strokes, all ischemic strokes, and of primary intracerebral hemorrhage, while eating fish more than two times per month appeared to protect against first-ever stroke and against primary intracerebral hemorrhage. Diabetes mellitus was associated with a significantly increased risk of ischemic stroke but a decreased risk of hemorrhagic stroke.
Risk factors for ischemic and hemorrhagic stroke are not exactly the same. Changes in lifestyle relating to tobacco and diet might make important contributions to further reductions in the incidence of stroke.