bluuebunny/crossref_metadata_2025 huggingface dataset:
Cerebral plasminogen activator activity in spontaneously hypertensive stroke-prone rats.
Authors: Matsuo O , Okada K , Fukao H , Suzuki A , Ueshima S
Published: June 2011

In the spontaneously hypertensive stroke-prone rat, it is unclear whether plasminogen activator plays a role in the development of stroke. The present study was undertaken to investigate brain levels of plasminogen activator activity in spontaneously hypertensive stroke-prone rats and Wistar-Kyoto rats.

Plasminogen activator was purified from the brains of rats of both strains. The purification involved used ammonium sulfate precipitation, gel filtration, a zinc chelate-Sepharose column, and a concanavalin A-Sepharose column. Fraction I (0.15 M KCl-soluble fraction) and fraction II (2 M KCl plus 6 M urea-soluble fraction) were purified from both strains.

Total plasminogen activator activity in the original homogenates for fractions I and II derived from spontaneously hypertensive stroke-prone rats was increased to twice the level found in Wistar-Kyoto rats. The final product purified from fractions I and II in both strains of rats revealed single bands of plasminogen activator activity on enzymatic analysis with a molecular weight of 72,000. The purified product had stronger S-2288 amidolytic activity than S-2444 amidolytic activity, and it also displayed fibrin-binding ability.

The study demonstrated that there is an increased content of plasminogen activator in the brains of spontaneously hypertensive stroke-prone rats that might be related to the development of stroke.
Serum autoantibodies in patients with Alzheimer's disease and vascular dementia and in nondemented control subjects.
Authors: Lopez O L , Rabin B S , Huff F J , Rezek D , Reinmuth O M
Published: June 2011

In this study we sought to evaluate the clinical significance of serum autoantibodies to dementing processes.

We assessed 40 age-matched subjects: 10 patients with probable Alzheimer's disease, 10 with possible Alzheimer's disease with cerebrovascular disease, 10 with vascular dementia, and 10 nondemented control subjects. Serum from each subject was tested for the presence of antithyroglobulin antibody, thyroid antimicrosomal antibody, gastric anti-parietal cell antibody, anti-smooth muscle antibody, antinuclear antibody, rheumatoid factor, antineuronal antibody, and anticardiolipin antibody. In addition, we investigated the sera of these patients for the presence of an antivascular antibody directed against the vascular basement membrane proteoglycan antigen and for circulating immune complexes.

Autoantibodies were present in 100% of the patients with possible Alzheimer's disease with cerebrovascular disease, 80% of those with vascular dementia, 40% of those with probable Alzheimer's disease, and 30% of the nondemented control subjects. The highest number of autoantibodies was observed in patients with vascular dementia and possible Alzheimer's disease with cerebrovascular disease. Antinuclear antibody was present in 60% of vascular dementia patients and antineuronal antibody in 50% of these patients. However, no individual autoantibody could differentiate Alzheimer's disease from cerebrovascular disorders. Immune complexes were detected in the serum of 20-30% of each patient group. Neither the patient nor the control sera was found to contain antiendothelial antibody.

Despite the relatively small number of individuals examined in each category, the elevated number of autoantibodies associated with possible Alzheimer's disease with cerebrovascular disease and vascular dementia indicates a possible link between the presence of autoantibodies and cerebrovascular disorders in dementia.
Facilitating postischemic reduction of cerebral lactate in rats.
Authors: Dimlich R V , Nielsen M M
Published: June 2011

Dichloroacetate facilitates a decrease in brain lactate during reperfusion after incomplete ischemia. This study examined the possible activation of pyruvate dehydrogenase enzyme by dichloroacetate to explain this effect. Because the duration of ischemia and hyperglycemia exacerbate ischemic brain damage, the effect of both of these factors on lactate reduction with and without dichloroacetate treatment after ischemia also was explored.

The two-vessel occlusion and controlled blood loss model of stroke was applied to anesthetized rats. Samples of cerebral cortex were analyzed for lactate by enzyme fluorometry and for pyruvate dehydrogenase activity by radioassay.

Treatment with dichloroacetate produced no significant stimulation of pyruvate dehydrogenase after ischemia. When the duration of ischemia was increased or 50% glucose was infused before ischemia, brain lactate was significantly higher (p less than 0.01, Duncan's test). After 30 minutes of ischemia, treatment with a low dose of dichloroacetate (25 mg/kg) improved the reduction in lactate (p less than 0.01, Duncan's test).

These results indicate that although dichloroacetate reduces brain lactate after cerebral ischemia, the mechanism of action does not involve dichloroacetate's known ability to stimulate pyruvate dehydrogenase. However, these data support the use of dichloroacetate to lower cerebral lactate, especially in cases where ischemia is greater than or equal to 30 minutes in duration. They also suggest that early restoration and maintenance of perfusion after ischemia and discontinuing the use of 50% glucose before impending ischemia likewise would facilitate reduction of postischemic brain lactate.
Incidence of stroke in Taiwan.
Authors: Hu H H , Sheng W Y , Chu F L , Lan C F , Chiang B N
Published: June 2011

Few epidemiological studies concerning the incidence of stroke have been conducted in Taiwan. In an attempt to investigate this common disease, we studied the incidence of stroke in Taiwan in a prospective incidence study.

A cohort of 8,562 stroke-free people were followed up for 4 years to observe new stroke occurrence. The methods of sampling the study population have been reported elsewhere. In addition to the help of local doctors, who reported the new stroke cases, we also sent public nurses to visit the study population annually to screen the new cases of stroke.

There were 104 (61 men and 43 women) first-ever stroke cases identified by a neurologist in a period between October 1, 1986 and December 31, 1990. The average annual incidence rate of first-ever stroke for people aged 36 years or older in this study was 330 per 100,000. Incidence rate was higher in eastern Taiwan and in rural communities. Percentages of the major types of stroke were as follows: cerebral infarction, 71%; cerebral hemorrhage, 22%; subarachnoid hemorrhage, 1%; and unclassified, 6%. The significant risk factors for stroke were hypertension and intake of food with a high sodium content.

The age-specific incidence rates in this study are higher than those reported from the United Kingdom and the United States. The rates are close to those in a report from Japan and a report from a city in mainland China at the same latitude. Cerebral hemorrhages are more common among people in Taiwan than among Occidental people.
Hyperhidrosis as a reflection of autonomic failure in patients with acute hemispheral brain infarction. An evaporimetric study.
Authors: Korpelainen J T , Sotaniemi K A , Myllylä V V
Published: June 2011

Sweating dysfunction is one of the most frequently encountered symptoms of autonomic failure but has received scant attention in patients with cerebrovascular diseases. Our purpose was to evaluate the prevalence, pathogenesis, and clinical correlates of sweating dysfunction in stroke.

We studied sweating at baseline and after a heating stimulus in 53 patients with acute hemispheral brain infarction and in 40 healthy control subjects by using a quantitative evaporimetric method.

Significant hyperhidrosis on the paretic side of the body was verified in 55% of the patients at baseline, in 74% after 5 minutes of heating, and in 77% after 10 minutes of heating. Hyperhidrosis was established throughout the body and correlated with the severity of paresis, the presence of reduced muscle tone, and the extensor plantar response.

The phenomenon of hyperhidrosis in hemiparetic patients reflecting autonomic dysfunction seems to be a common manifestation that should be listed among the expected consequences of brain infarction. This sweating disturbance might be attributed to a lesion of a putative sympathoinhibitory pathway controlling sweating. The failure of this pathway could also be related to other manifestations of sympathetic hyperfunction, e.g., cardiac complications. Therefore, assessment of sweating may provide a new, important aspect in the evaluation of stroke patients.
Evaluation of the vertebrobasilar-posterior system by transcranial color duplex sonography in adults.
Authors: Schöning M , Walter J
Published: June 2011

The transcranial color duplex sonography technique was applied to the vertebrobasilar-posterior system to provide normal data for clinical application.

The intracranial posterior circulation was studied in 49 healthy volunteers (mean +/- SD age, 35 +/- 12 years) by a transcranial and suboccipital approach with a 2.0-MHz sector transducer of a computed sonography system.

The posterior cerebral artery and the vertebrobasilar system were depicted clearly in the color Doppler mode. Pulsed Doppler signals could be recorded in the posterior cerebral (100%), basilar (92%), and vertebral arteries (89%). The following normal values were provided for all vessels: systolic peak, end-diastolic maximum, time-averaged, and time-averaged maximum velocities; resistance and pulsatility indexes; and a spectral broadening index. Mean +/- SD values were 45.9 +/- 9.6, 45.5 +/- 10.8, and 39.2 +/- 10.6 cm/sec for time-averaged maximum velocity, and 28.3 +/- 6.5, 30.6 +/- 7.2, and 24.7 +/- 8.4 cm/sec for time-averaged velocity in the posterior cerebral, basilar, and vertebral arteries, respectively. In a reproducibility study, duplex measurements of the posterior cerebral arteries were repeated in 27 subjects. The correlation between the two examiners was high (r = 0.56, p less than or equal to 0.0001 for time-averaged maximum velocity).

Color duplex sonography of the vertebrobasilar-posterior system is a new, noninvasive, bedside investigative technique. It permits visualization of artery flow in real time, relating these to adjacent brain and cranial structures, as well as angle-corrected duplex measurement of "true" flow velocities at defined sites of the vessels. Thus, it will open new diagnostic possibilities in disorders of the posterior circulation.
Reperfusion increases neutrophils and leukotriene B4 receptor binding in rat focal ischemia.
Authors: Barone F C , Schmidt D B , Hillegass L M , Price W J , White R F , Feuerstein G Z , Clark R K , Lee E V , Griswold D E , Sarau H M
Published: June 2011

Neutrophils are critically involved with ischemia and reperfusion injury in many tissues but have not been studied under conditions of reperfusion after focal cerebral ischemia. The present studies were conducted to confirm our previous observations quantifying neutrophils in rat permanent focal stroke using a myeloperoxidase activity assay and to extend them to transient ischemia with reperfusion. In addition, leukotriene B4 receptor binding in ischemic tissue was evaluated as a potential marker for inflammatory cell infiltration.

Histological, enzymatic, and receptor binding techniques were used to evaluate neutrophil infiltration and receptor binding in infarcted cortical tissue 24 hours after permanent middle cerebral artery occlusion (n = 25) or temporary occlusion for 80 (n = 12) or 160 (n = 22) minutes followed by reperfusion for 24 hours in spontaneously hypertensive rats.

Sham surgery (n = 26) produced no changes in any parameter measured. After permanent middle cerebral artery occlusion, neutrophil accumulation was observed histologically, but the infiltration was moderate and typically within and adjacent to blood vessels bordering the infarcted cortex. After temporary middle cerebral artery occlusion with reperfusion, marked neutrophil infiltration was observed throughout the infarcted cortex. Myeloperoxidase activity was increased (p less than 0.05) after permanent occlusion and to a greater extent after temporary occlusion with reperfusion. Myeloperoxidase activity (units per gram wet weight) in ischemic cortex was increased over that in nonischemic (control) cortex 32.2-fold, 54.6-fold, and 92.1-fold for permanent occlusion and 80 and 160 minutes of temporary occlusion with reperfusion, respectively (p less than 0.05). Sham surgery produced no changes in myeloperoxidase activity. Leukotriene B4 receptor binding also was increased (p less than 0.05) after focal ischemia and paralleled the increases in myeloperoxidase activity. Ischemic cortex-specific receptor binding (femtomoles per milligram protein) was 3.87 +/- 0.63 in sham-operated rats and 4.57 +/- 0.98, 8.98 +/- 1.11, and 11.12 +/- 1.63 for rats subjected to permanent occlusion and 80 and 160 minutes of temporary occlusion with reperfusion, respectively (all p less than 0.05 different from sham-operated). Cortical myeloperoxidase activity was significantly correlated with the degree of cortical leukotriene B4 receptor binding (r = 0.66 and r = 0.79 in two different studies, p less than 0.01).

These data indicate that neutrophils are involved in focal ischemia and that there is a dramatic accumulation of neutrophils in infarcted tissue during reperfusion that can be quantified using the myeloperoxidase activity assay. Leukotriene B4 receptor binding increases in infarcted tissue in a parallel manner, which suggests that the increased leukotriene B4 binding is to receptors located on the accumulating neutrophils.
Caudate hemorrhage with moyamoya-like vasculopathy from atherosclerotic disease.
Authors: Steinke W , Tatemichi T K , Mohr J P , Massaro A , Prohovnik I , Solomon R A
Published: June 2011

Caudate hemorrhage usually results from hypertension, rupture of arteriovenous malformation or aneurysm, or rarely, moyamoya disease. Moyamoya-like changes related to severe atherosclerotic occlusive disease, usually causing ischemic stroke, have been reported.

A 51-year-old normotensive patient was admitted with headache due to a left caudate hematoma with ventricular extension. There was a history of smoking, leg claudication, elevated cholesterol, and coronary artery disease. Angiography demonstrated complete extracranial carotid occlusion on the left and atherosclerotic stenosis at the bifurcation on the right, with supraophthalmic occlusion distally. At the base of the brain, bilateral moyamoya-like vessels, presumed to be secondary to atherosclerotic occlusion, were evident, but neither aneurysm nor arteriovenous malformation was present. Cerebral blood flow and transcranial Doppler studies indicated severely impaired cerebral perfusion that improved after bilateral extracranial-to-intracranial bypass surgery.

Atherosclerotic occlusive carotid disease with moyamoya-like changes may be a rare cause of caudate hemorrhage. A decrease in moyamoya vessels with bypass surgery may reduce the risk of recurrent hemorrhage.
Postpartum cerebral angiopathy with cerebral infarction due to ergonovine use.
Authors: Barinagarrementeria F , Cantú C , Balderrama J
Published: June 2011

Earlier cases of stroke due to postpartum cerebral angiopathy have been reported. The mechanism of this angiopathy has not been explained.

We present a case of cerebral infarction with evidence of occlusive change in the vertebrobasilar system as a complication of intravenous ergonovine use after cesarean section delivery.

Ergonovine therapy is a likely cause of so-called postpartum cerebral angiopathy and stroke.
Autosomal dominant leukoencephalopathy and subcortical ischemic stroke. A clinicopathological study.
Authors: Baudrimont M , Dubas F , Joutel A , Tournier-Lasserve E , Bousser M G
Published: June 2011

We recently described an autosomal dominant syndrome characterized mainly by recurrent strokes and neuroimaging evidence of leukoencephalopathy. We now report the pathological findings in one of the affected subjects.

A 40-year-old woman experienced her first grand mal seizure in 1971. From 1983 on she suffered recurrent strokes, seizures, and psychiatric disturbances with depressions, manic episodes, and dementia. In 1988, after her fourth stroke, she became tetraplegic with a severe pseudobulbar palsy, and she died in 1990. Pathological examination disclosed a recent capsulolenticular hematoma, multiple small deep infarcts, a diffuse myelin loss and pallor of the hemispheric white matter, and a widespread vasculopathy of the small arteries penetrating the white matter. The arterial wall was markedly thickened with an extensive nonamyloid eosinophilic deposit in the media and reduplication of the internal elastic lamella.

The underlying lesion of this hereditary disorder is located in the small arteries and is of unknown etiology. It differs from arteriosclerotic and amyloid angiopathies but is similar to that described in some cases of hereditary multi-infarct dementia.
Lobar hemorrhage in the elderly. The undiminishing importance of hypertension.
Authors: Broderick J , Brott T , Tomsick T , Leach A
Published: June 2011

We sought to determine whether hypertension is less common in primary lobar hemorrhage than intracerebral hemorrhage in other locations and whether the frequency of hypertension in lobar hemorrhage diminishes with advancing age.

We identified all cases of intracerebral hemorrhage in Greater Cincinnati during 1988 by review of hospital and autopsy records as well as computed tomographic and magnetic resonance scans.

During 1988, 66 primary lobar hemorrhages occurred, constituting 46% of all intracerebral hemorrhages in those under 75 years of age and 34% in those age 75 and older. A history of hypertension was present in 67% of patients with lobar, 73% of those with deep, 73% of those with cerebellar, and 78% of those with pontine hemorrhages. Left ventricular hypertrophy was present in 21% of patients with lobar, 27% of those with deep, and 47% of those with pontine/cerebellar hemorrhages. The frequency of hypertension in patients with lobar hemorrhage did not decrease with advancing age.

The proportion of all intracerebral hemorrhages that are lobar does not increase with advancing age. Hypertension is nearly as common in primary lobar hemorrhage as in deep, cerebellar, and pontine hemorrhages, and its importance as an associated condition for lobar hemorrhage does not diminish with advancing age.
Measuring physical impairment and disability with the Chedoke-McMaster Stroke Assessment.
Authors: Gowland C , Stratford P , Ward M , Moreland J , Torresin W , Van Hullenaar S , Sanford J , Barreca S , Vanspall B , Plews N
Published: June 2011

The Chedoke-McMaster Stroke Assessment measures the physical impairments and disabilities that impact on the lives of individuals with stroke. This measure has three overall purposes: 1) to stage motor recovery to classify individuals in terms of clinical characteristics, 2) to predict rehabilitation outcomes, and 3) to measure clinically important change in physical function. This study was carried out to evaluate the ability of this measure to yield reliable and valid results.

Thirty-two subjects from a stroke rehabilitation treatment unit were assessed by research and treating physical therapists using multiple measures on multiple occasions. The measure's three purposes dictated the study objectives and design.

Intrarater, interrater, and test-retest reliabilities of the impairment and disability inventories were estimated. Reliability coefficients for the total scores ranged from 0.97 to 0.99. Construct and concurrent validities were studied by examining the correlations between this and other measures. A priori hypothetical constructs stated that these correlations should exceed 0.60. These constructs were confirmed; the impairment inventory total score was found to correlate with the Fugl-Meyer Test (r = 0.95, p < 0.001) and the disability inventory with the Functional Independence Measure (r = 0.79, p < 0.05). Additional study hypotheses were also substantiated.

This study confirms that the Chedoke-McMaster Stroke Assessment yields both reliable and valid results. With the evaluation study now completed, the Chedoke-McMaster Stroke Assessment can be used with confidence as both a clinical and a research tool that can discriminate among subjects and evaluate patient outcomes.
Efficacy of ticlopidine and aspirin for prevention of reversible cerebrovascular ischemic events. The Ticlopidine Aspirin Stroke Study.
Authors: Bellavance A
Published: June 2011

This subgroup analysis from the Ticlopidine Aspirin Stroke Study (TASS) compared ticlopidine, a new antiplatelet agent, with aspirin for the prevention of recurrent transient ischemic attacks in patients who had a recent reversible cerebrovascular event.

This was a multicenter, double-blind, randomized trial in patients with a recent cerebral ischemic history. Patients with a reversible cerebral ischemic event within 3 months of enrollment were eligible for the study. All patients received either aspirin 650 mg twice daily or ticlopidine 250 mg twice daily for up to 5.8 years. The primary end point in this analysis was the first occurrence of a reversible ischemic event either alone or combined with nonfatal stroke or death and fatal or nonfatal stroke.

Overall, ticlopidine was better than aspirin for reducing the risk of reversible ischemic events either alone or as a composite with death and/or stroke or with fetal and/or nonfatal stroke (P = .007 to P < .001). The risk reductions with ticlopidine were maintained for the duration of the 5-year follow-up. The most frequent or clinically important adverse effects associated with ticlopidine were diarrhea, rash, and neutropenia. Neutropenia was severe in 13 patients but resolved promptly with discontinuation of therapy.

The results in this subgroup of patients with reversible ischemic disease, as well as the overall analysis of TASS, suggest that ticlopidine is a more effective agent than aspirin for the prevention of recurrent transient ischemic attacks.
Alcohol and stroke. A case-control study of drinking habits past and present.
Authors: Rodgers H , Aitken P D , French J M , Curless R H , Bates D , James O F
Published: June 2011

Previous studies have reported a U-shaped relation between alcohol consumption and stroke. Those studies have been criticized for failing to distinguish between lifelong abstainers from alcohol and those who have given up drinking.

We examined current and previous drinking habits of 364 cases of acute stroke and 364 community-based control subjects matched for age, sex, and family practitioner.

Stroke patients were more likely to have been lifelong abstainers from alcohol than were the control subjects. The odds ratio (OR) or lifelong abstainers versus those who had ever drunk regularly was 2.36 (95% confidence interval [CI], 1.67 to 3.37). No relation was found between stroke and current nondrinkers. Current male heavy drinkers also had an increased risk of stroke (OR, 2.88; 95% CI, 1.08 to 2.31).

Lifelong abstention from alcohol is associated with an increased risk of stroke. Moderate alcohol consumption may protect against cerebrovascular disease.
The influence of depression, social activity, and family stress on functional outcome after stroke.
Authors: Angeleri F , Angeleri V A , Foschi N , Giaquinto S , Nolfe G
Published: June 2011

This study was designed to assess the quality of life after an active poststroke period of rehabilitation and to investigate the possibility of a return to a working environment for those still of working age.

The study was conducted on 180 consecutive patients affected by stroke who were hospitalized for the first time and discharged at least 1 year before the study. The group consisted of 65% men and 35% women with a mean age 65.29 years (SD, 11.22). The period between the stroke and the interview ranged from 12 to 196 months, with a mean of 37.5 months. The average Rankin score on discharge from the rehabilitation center was 2.718 (moderate handicap). The interview took place at home after consent obtained by telephone. The questionnaire included general and personal information regarding the individuals, their socioeconomic position, and scales for daily activity, depression, social activity, and stress produced in the family. The control group consisted of 167 age-matched subjects.

A close correlation was observed in all patients between depression, social activity, and stress caused to relatives. The scores on the individual scales were clearly worse than those for control subjects. The patients received approximately 5 months of rehabilitation after the stroke. Differences emerged between men and women for depression and social activities, with the women scoring worse. In reference to daily life, 70% of prestroke ability was required on average after rehabilitation. The daily activity score at the time of the interview was also strongly influenced by the discharge score. The majority of patients were retired. Of the total, 20.64% returned to work, but not always to the same job and often after readapting to new conditions. Of this population, only 31.5% were women. With regard to the population aged younger than 65 years, 21.42% returned to work. Lesions in the dominant hemisphere do not necessarily seem to rule out return to work, even if associated with aphasia. The main discriminating element was the ability to understand language. The patients were often criticized by their cohabitants; the criticisms most often raised concerned apathy, irritability, and self-centeredness. Sexual activity was depressed in almost all cases.

Despite the progress made in studying cerebral vasculopathies, patients in the aftermath of a stroke still seem to live unsatisfactorily, as they did many years ago. Useful measures include valid treatment against spasticity, psychological assistance, and greater social support.
Early prognostic factors in ischemic stroke. The role of protein C and protein S.
Authors: Anzola G P , Magoni M , Ascari E , Maffi V
Published: June 2011

Protein C and protein S have been found reduced in some patients with ischemic cerebrovascular diseases, but the relevance of this finding for prognosis is unsettled.

In 43 consecutive patients admitted over 6 months for acute ischemic stroke, protein C and free protein S were evaluated on admission, and at 2 and 6 months after stroke. Excluded were all patients with known causes liable to reduce the levels of protein C, free protein S, or both.

In 14% of patients, abnormally low levels of protein C were found at entry. In comparison to the remaining sample, this group had a significantly lower initial score on the Barthel and Canadian neurological scales, a higher prevalence of emboligenic cardiac diseases, and had a higher mortality at 6 months. No statistical difference was found for the other vascular risk factors. Eight patients (18.4%) had abnormally low levels of free protein S at entry. In comparison to the remaining sample, there was no statistical difference in the severity scores, prevalence of emboligenic cardiac diseases, mortality, or vascular risk factors.

These findings suggest that low levels of protein C in the acute stroke reflect the massive activation of coagulation factors and are predictive of adverse outcome, whereas the significance of low levels of free protein S remains to be clarified.
In vivo radiofrequency-based ultrasonic tissue characterization of the atherosclerotic plaque.
Authors: Urbani M P , Picano E , Parenti G , Mazzarisi A , Fiori L , Paterni M , Pelosi G , Landini L
Published: June 2011

The ultrasonic image can offer unique information on the composition of atherosclerotic plaque, ie, the relative content of lipids, fibrous tissue, and calcific deposits. To date, however, the echographic assessment of plaque structure is based on a subjective, qualitative evaluation of the bidimensional images. We evaluated the feasibility and accuracy of assessing, in vivo, the acoustic properties of arterial carotid plaques by means of a suitably modified echographic apparatus allowing direct access to the radiofrequency signal.

In 15 patients undergoing carotid thromboendarterectomy, the ultrasonic findings in 70 discrete sites (within the plaque, n = 54; normal sites, n = 11; or intraluminal thrombi, n = 5) were correlated with the histological analysis (hematoxylin-eosin and Mallory trichrome stains) independently performed on the arterial samples. The pathological examination was carried out at a similar level of the insonation; the sites analyzed within the plaque were chosen because of their uniform echoic characteristics. In each ultrasonic region of interest selected from the echographic image, the integrated amplitude of the rectified radiofrequency signal was measured as the integrated backscatter index.

The intimal-medial layer of normal carotid wall (n = 11) exhibited values of -32.5 +/- 9.4 dB. The integrated backscatter index in fatty sites (n = 11, -40.3 +/- 5.4 dB) differed from that of fibrous (n = 12, -23.8 +/- 5.0 dB) and calcified (n = 26, -11.5 +/- 5.2 dB, P < .01 for all intergroup differences) sites. Intraluminal thrombotic sites (n = 5, -42 +/- 5.1 dB, P < .01) differed from fibrous and calcified subsets (P < .01) but overlapped (P = NS) with fatty sites. Histological sampling also showed two sites of intraplaque hemorrhage that exhibited very low backscatter values (-53 and -58 dB) and three fibrofatty sites showing backscatter values (-28, -28, and -32 dB) intermediate between the fibrous and the fatty subsets.

Quantitative analysis of integrated backscatter of the arterial wall is feasible in humans and provides an operator-independent assessment of plaque echoic structure. In particular, integrated backscatter is effective in distinguishing lipidic, fibrotic, and calcific components in human atherosclerotic plaques.
Transcranial color-coded duplex sonography of intracerebral hematomas in adults.
Authors: Seidel G , Kaps M , Dorndorf W
Published: June 2011

It is well established from pediatric experience and animal experiments that intracerebral blood can be demonstrated by B-mode real-time duplex scanning. This has recently become feasible in adults as well. The present study investigated the changes in the sonographic appearance of intracerebral hematomas over the course of time.

Starting in May 1991, 23 consecutive patients with intracerebral hematoma confirmed by computed tomography (21 spontaneous and 2 traumatic hematomas) were investigated within 1 year. They were monitored by repeated ultrasound scanning via the transtemporal approach. The sonographic appearance of the hematomas on B-mode scans and the angle-corrected blood flow velocity in the basal cerebral arteries were assessed.

There was unequivocal localization of the hematoma in 18 patients (78%). In 3 cases (13%), an adequate acoustic window could not be found. One small intracerebral hemorrhage was overlooked, and one extensive hemorrhage in the basal ganglia was misdiagnosed as a lobar hematoma. There was an alteration of the appearance of the hematoma with time. This was divided into three sonographic stages (initial stage, days 1 to 5; intermediate stage, days 6 to 10; and capsular stage, from day 10). In 14 of the 20 patients with an appropriate acoustic bony echo window, the blood flow velocity in the middle cerebral artery could be measured; in 1 of these patients, the signs of increasing intracranial pressure were apparent from Doppler frequency spectrum. In 5 patients, the intracerebral hematoma could be imaged but not the ipsilateral middle cerebral artery. One female patient showed cerebral circulatory arrest at the time of examination, which took place within 24 hours after the onset of clinical symptoms.

Most intracerebral hematomas in adults can be imaged in B-mode. Their sonographic appearance changes over the course of the disease. The advantages of this noninvasive method are its easy bedside operation and its suitability for follow-up; it is also less stressful than other imaging procedures. It yields a combination of structural and functional diagnostic information. In approximately 13% of the cases, the investigation was not feasible because of inadequate ultrasonic penetration of the intact skull.
Transient platelet accumulation in the rat brain after common carotid artery thrombosis. An 111In-labeled platelet study.
Authors: Dietrich W D , Dewanjee S , Prado R , Watson B D , Dewanjee M K
Published: June 2011

Thromboembolic events are a major cause of ischemic stroke. To obtain evidence for platelet embolization after cerebrovascular injury, the accumulation of indium-labeled platelets was documented after photothrombosis of the rat common carotid artery.

Heterologous blood was collected from donor rats, and the isolated platelets were labeled with 111In-tropolone. Labeled platelets were then infused into Wistar rats 30 minutes before right carotid artery thrombosis. Nonocclusive common carotid artery thrombosis was induced by a laser-driven rose bengal-mediated photochemical insult to the vascular endothelium, and the rats were killed 15 minutes or 3 hours later. Carotid arteries and brains were immediately removed and dissected for regional radioactivity assessment or sectioned for the autoradiographic visualization of platelet emboli.

At 15 minutes after thrombosis, the ratio of right-to-left common carotid artery radioactivity was significantly elevated compared with control (33 +/- 12 [mean +/- SEM] versus 0.97 +/- 0.2). Within individual brain regions, including the frontal and frontoparietal cortices and hippocampus, significant elevations in right-to-left radioactivity ratios were also documented. Autoradiographic images revealed multiple foci of 111In-labeled platelets throughout the thrombosed hemisphere. At the level of the frontal cortex, bilateral platelet accumulation was seen. Regional counts demonstrated significantly increased platelet density within selective cortical and subcortical regions. In contrast to the 15-minute findings, right-to-left ratios of carotid arteries or brain regional radioactivities were not significantly elevated at 3 hours after injury. In addition, the areal densities of autoradiographically visualized platelets in the 3-hour group were not different from control except in the right frontal cortex.

These data demonstrate (1) the acute accumulation of labeled platelets in downstream vessels after nonocclusive common carotid artery thrombosis, (2) that platelet accumulation is widespread and also involves contralateral areas, and (3) that platelet accumulation within the thrombosed carotid artery and brain is largely transient.
Trends in survival of hospitalized stroke patients between 1970 and 1985. The Minnesota Heart Survey.
Authors: McGovern P G , Pankow J S , Burke G L , Shahar E , Sprafka J M , Folsom A R , Blackburn H
Published: June 2011

Age-adjusted stroke mortality rates declined approximately 50% between 1970 and 1990 in both the United States and Minnesota, but the reasons for this decline are not clear. This report examines possible improvements in short- and long-term survival of hospitalized definite stroke patients in the Minneapolis-St Paul (the Twin Cities) metropolitan area during this period.

Fifty percent random samples of patients discharged with an acute stroke diagnosis from area hospitals were selected in 1970 (n = 1200), 1980 (n = 1040), and 1985 (n = 896). Trained nurses abstracted pertinent clinical data from the hospital charts. By standardized clinical criteria similar to World Health Organization criteria (without computed tomography data), 376, 442, and 453 definite strokes were established for 1970, 1980, and 1985, respectively.

Age- and sex-adjusted 28-day case fatality of definite stroke improved significantly from 1970 to 1985; the odds ratio (OR) of death within 28 days in 1985 (versus 1970) patients was 0.55 (95% confidence interval [CI], [0.39, 0.77]). Substantial improvements in 28-day mortality were observed both from 1970 to 1980 and from 1980 to 1985, although the latter change was not statistically significant. Further adjustment for predictors of early stroke mortality (such as level of consciousness) somewhat attenuated these results. Age- and sex-adjusted 5-year survival of definite stroke also improved significantly from 1970 to 1985 (OR, 0.72; 95% CI, [0.54, 0.96]), although the improvement was restricted to the 1970 to 1980 time period (OR, 0.76; 95% CI, [0.57, 1.01]). None of the survival trends differed significantly between men and women.

There were marked improvements in survival from 1970 to 1985 among hospitalized stroke patients in the Twin Cities. These improvements occurred almost exclusively in the acute hospitalization phase. Although the advent of computed tomography and improvements in hospital record-keeping during this period prevent an unequivocal conclusion, improved medical care and decreased severity of stroke probably contributed to gains in survival.
Transhemispheric passage of microemboli in patients with unilateral internal carotid artery occlusion.
Authors: Georgiadis D , Grosset D G , Lees K R
Published: June 2011

Ischemic episodes distal to an internal carotid artery occlusion are common. We undertook this study to look for evidence of transhemispheric passage of embolic material in this patient category as a mechanism for embolic events.

Seven symptomatic patients with unilateral internal carotid artery occlusion and contralateral stenosis were examined by transcranial Doppler ultrasonography with 2-MHz probe (average monitoring time, 2.5 hours per patient). Both middle cerebral arteries and (if present) the reverse-flow anterior cerebral artery ipsilateral to the occluded internal carotid were monitored. Three patients were reexamined 1 month after carotid endarterectomy.

Embolic signals were detected in the middle cerebral artery ipsilateral to the stenosed internal carotid artery in all seven patients and in the opposite middle cerebral artery in four patients. In these four patients, a reverse-flow anterior cerebral artery was observed in which embolic signals were detected. No embolic signals were detected after surgery in any of the three patients who underwent carotid endarterectomy.

Transhemispheric passage of embolic material occurs in patients with unilateral internal carotid artery occlusion and contralateral stenosis. Endarterectomy of the stenosed internal carotid artery may eliminate the detected embolic signals in both hemispheres. Transcranial Doppler ultrasonography could be used as a diagnostic tool to identify the embolic source in patients with unilateral carotid occlusion.
Computerized detection of cerebral emboli and discrimination from artifact using Doppler ultrasound.
Authors: Markus H , Loh A , Brown M M
Published: June 2011

Transcranial Doppler ultrasound can detect circulating cerebral emboli. Monitoring of patients with potential embolic sources may allow identification of high-risk patients who can then be selected for prophylactic treatment. However, practical patient monitoring will require automated programs that can detect emboli and differentiate them from artifact.

A new off-line algorithm for the detection of emboli, which detects the characteristic relative power increase occurring with an embolus, was evaluated in both an animal model and in patients. (1) In a sheep model, solid embolic materials (thrombus, platelet aggregates, and atheroma) were introduced into the proximal carotid artery while the distal carotid artery or a major branch was insonated. The signals resulting from 77 emboli (mean size, 1.77 mm) were studied and compared with the Doppler signals resulting from artifact. (2) In patients, 100 embolic signals occurring in three patients were analyzed and compared with signals associated with artifact in the same patients.

(1) In the sheep model, emboli resulted in a short-duration, high-intensity signal, but intensity increase alone did not distinguish between emboli and artifact. In contrast, the algorithm discriminated embolus from artifact with a sensitivity of 98.7% and a specificity of 98.0%. (2) In patient studies, embolic signals were differentiated from artifact with a sensitivity of 97.2% and a specificity of 97.0% by the algorithm.

Using such an algorithm, detection of cerebral emboli and discrimination from artifact are possible with a high sensitivity and specificity. Incorporation of such an algorithm into an on-line system should make prolonged patient monitoring practical.
Internal carotid artery dissection in a community. Rochester, Minnesota, 1987-1992.
Authors: Schievink W I , Mokri B , Whisnant J P
Published: June 2011

Cervical internal carotid artery dissections are diagnosed with an increasing frequency, but reliable epidemiologic data are not available. The aim of this study was to determine the incidence rate of spontaneous cervical internal carotid artery dissection in a defined population.

Using the medical record linkage system used for epidemiologic studies in Rochester, Minn, all patients diagnosed with spontaneous cervical ICA dissection for 1987 through 1992 were identified.

A total of 10 patients with spontaneous cervical internal carotid artery dissection (6 women and 4 men; mean age, 44 years) were identified. For the period 1987 through 1992, the average annual incidence rate for all ages was 2.6 per 100,000 (95% confidence intervals, 0.9 to 4.2).

This study, for the first time, provides incidence rates for spontaneous cervical internal carotid artery dissections. No diagnoses were made before 1987, probably reflecting an increased awareness of the disorder among physicians.
Cerebellar infarction. Clinical and neuroimaging analysis in 293 patients. The Tohoku Cerebellar Infarction Study Group.
Authors: Tohgi H , Takahashi S , Chiba K , Hirata Y
Published: June 2011

We performed this multicenter study to explore the full spectrum of the clinical characteristics and neuroimaging findings of cerebellar infarction, including patients with mild to severe illnesses.

We studied 293 consecutive patients with cerebellar infarction diagnosed by computed tomography and/or magnetic resonance imaging who were admitted to 36 hospitals during 5 years.

Cerebellar infarcts constituted 2.3% of the total patients with acute brain infarction. The backgrounds and risk factors were similar to those in patients with infarctions of the cerebral hemispheres. At least 24% were embolic, and the diagnosis of embolism could not be ruled out in 27%. Infarcts involving the superior cerebellar artery (SCA) region (52%) and the posterior inferior cerebellar artery (PICA) region (49%) were far more frequent than those involving the anterior inferior cerebellar artery (AICA) region (20%). Patients with SCA infarcts exhibited obtunded consciousness and ataxia more frequently than those with PICA infarcts (P < .05). Infarcts in the PICA regions were associated with abnormalities of the PICA (64%) or the vertebral arteries (57%), whereas infarcts in the SCA and AICA regions were associated with abnormalities in the SCA or AICA, respectively, in approximately 30% of patients, in the basilar artery in approximately 16%, and in the vertebral artery in more than 60% of patients. Outcomes were poorer with SCA infarcts than with AICA and PICA infarcts.

These data indicate similar frequencies of SCA and PICA infarcts and illustrate the difference in clinical presentation and outcomes between SCA and PICA infarcts. They also indicate that not only in situ thrombosis but also cardiogenic or artery-to-artery embolism and the insufficiency of collateral circulation play important roles in the pathogenesis of cerebellar infarction.
Retention of cerebrovascular dilation after cortical spreading depression in anesthetized rabbits.
Authors: Busija D W , Meng W
Published: June 2011

We examined responses of rabbit pial arterioles to three different stimuli before and after induction of cortical spreading depression.

In urethane-anesthetized rabbits equipped with a closed cranial window, we measured pial arteriolar diameter during baseline conditions, topical application of calcitonin gene-related peptide (CGRP), topical application of acetylcholine, and inhalation of 10% CO2 in air (arterial hypercapnia) before cortical spreading depression and 30, 60, and 120 minutes after cortical spreading depression. Cortical spreading depression was induced by localized application of a 5% KCl solution anterior to the arteriole being measured.

Average baseline diameter was approximately 90 microns. During cortical spreading depression, arteriolar diameter increased to a peak value that was 50 +/- 4% above baseline (n = 32). Before cortical spreading depression, arteriolar diameter changed 47 +/- 7% (n = 9) during hypercapnia, 17 +/- 3% (n = 4) during 10(-9) mol/L CGRP, 42 +/- 10% (n = 7) during 10(-7) mol/L CGRP, 29 +/- 6% (n = 4) during 10(-6) mol/L acetylcholine, and 61 +/- 13% (n = 6) during 10(-4) mol/L acetylcholine. Arteriolar responsiveness to any of these stimuli was not changed significantly by prior cortical spreading depression.

Dilator capacity of pial arterioles is still intact in urethane-anesthetized rabbits after cortical spreading depression.
Stroke subtypes among Hispanics living in Guayaquil, Ecuador. Results from the Luis Vernaza Hospital Stroke Registry.
Authors: Del Brutto O H , Mosquera A , Sánchez X , Santos J , Noboa C A
Published: June 2011

Racial differences in stroke subtypes have been documented. Asians have a higher rate of cerebral hemorrhage than whites; however, there is little information about stroke subtypes among Hispanics. The purpose of this study was to determine the patterns of stroke subtypes in a population of Hispanics.

Five hundred consecutive patients with a first stroke were included. Patients were collected from hospital wards, the emergency department, and the outpatient clinic to ensure inclusion of patients with a wide range of stroke severity. Computed tomography was available in all cases. Patients with pure subarachnoid hemorrhage were excluded.

There were 313 (62.6%) patients with an infarct and 187 (37.4%) with a hemorrhage. Hypertensive arteriolopathy was the most common cause of both infarcts and hemorrhages. The carotid territory was involved in 70.6% of the 313 patients with infarcts, the vertebrobasilar territory in 17.9%, multiple territories in 6.7%, and a watershed area in 4.8%. Hemorrhages were most often lobar (36.4%), followed by putaminal (30.5%), brain stem (9.1%), cerebellar (8%), thalamic (8%), ventricular (5.3%), and caudate (2.7%).

This hospital-based stroke registry suggests that stroke in Hispanics has a pattern different from that in whites but similar to that in Asians. Cerebral hemorrhages occur three times more frequently in Hispanics than in whites.