bluuebunny/crossref_metadata_2025 huggingface dataset:
Endovascular Treatment of Intracranial Aneurysms With Guglielmi Detachable Coils
Authors: Ng P. , Khangure M.S. , Phatouros C.C. , Bynevelt M. , ApSimon H. , McAuliffe W.
Published: July 2002

Background and Purpose

—

The previous decade has witnessed increasing application of Guglielmi detachable coils (GDCs) for the treatment of intracranial aneurysms. However, the midterm angiographic and clinical outcomes are not well documented. We report here the angiographic and clinical outcomes of patients treated with GDCs over an 8-year period .

Methods

—

Between 1992 and 1998, 144 patients with 160 intracranial aneurysms were treated with GDCs. Clinical follow-up data were obtained from medical records, questionnaires, and telephone interviews. Angiographic studies were reviewed by 2 neuroradiologists to obtain consensus regarding the degree of aneurysm occlusion.

Results

—

Eighty-one patients had ruptured aneurysms; 63 had unruptured aneurysms. Technical success was achieved in 91% of patients, with complete aneurysm occlusion in 46%, neck remnants in 16%, and residual body filling in 38%. Angiographic follow-up revealed that residual body filling in some aneurysms was resolved, small neck remnants were stable, and the recanalization rate decreased with time. All 63 patients with unruptured aneurysms were discharged from hospital with independent clinical status (Glasgow Outcome Score, 1 or 2). For patients with ruptured aneurysms, discharge clinical status correlated with the Hunt & Hess clinical grade at the time of treatment. Clinical follow-up for a minimum of 2 years was available in 98.5% of patients. Ninety-four percent of patients treated for unruptured aneurysms were independent at 2 years, and 82% of Hunt & Hess grade I to II patients were independent.

Conclusions

—

Coil embolization is a safe and effective treatment for both ruptured and unruptured aneurysms. Increasing angiographic stability is demonstrated in treated aneurysms up to 3 years from coil embolization. Therefore, follow-up angiography until this time is advisable.
Does Psychological Distress Predict the Risk of Ischemic Stroke and Transient Ischemic Attack?
Authors: May Margaret , McCarron Peter , Stansfeld Stephen , Ben-Shlomo Yoav , Gallacher John , Yarnell John , Davey Smith George , Elwood Peter , Ebrahim Shah
Published: July 2002

Background and Purpose

—

Psychological distress is common after stroke, but little is known about its etiologic importance, although the general public often ascribes stroke to the experience of stress. Therefore, we examined whether psychological distress leads to an increased risk of ischemic stroke and transient ischemic attack (TIA).

Methods

—

The association between the 30-item General Health Questionnaire (GHQ), a measure of psychological distress, and the incidence of nonfatal and fatal ischemic stroke and TIA was measured by Cox regression modeling in a prospective observational study of 2201 men aged 45 to 59 years in phase II of the Caerphilly cohort. Hazard ratios comparing those with high (≥5) and normal GHQ scores were calculated with adjustment for age and other covariates.

Results

—

Twenty-two percent of men suffered from psychological distress, indicated by a score of ≥5 on the GHQ. There were 130 incident strokes recorded, of which 17 were fatal and 113 nonfatal. The relative risk of incident ischemic stroke was 1.45 (95% CI, 0.98 to 2.14) for those who showed symptoms of psychological distress compared with those who did not. For fatal stroke the relative risk was 3.36 (95% CI, 1.29 to 8.71) and for nonfatal stroke 1.25 (95% CI, 0.82 to 1.92). The relative risk of TIA for the distressed group was 0.63 (95% CI, 0.26 to 1.53). The results were unchanged after adjustment for body mass index, systolic blood pressure, smoking, heavy drinking, social class, and marital status. However, additionally controlling for previously diagnosed ischemic heart disease, diabetes, respiratory disease, and retirement due to ill health attenuated the relative risks, but not markedly. For fatal strokes the relative risk decreased to 2.56 (95% CI, 0.97 to 6.75) when all confounding variables were included in the model. There was a graded association between degree of psychological distress and risk of fatal ischemic stroke.

Conclusions

—

Psychological distress is a predictor of fatal ischemic stroke but not of nonfatal ischemic stroke or TIA. Further work examining the mechanisms of this association is required.
Cerebral Microbleeds in CADASIL
Authors: Dichgans Martin , Holtmannspötter Markus , Herzog Jürgen , Peters Nils , Bergmann Michael , Yousry Tarek A.
Published: July 2002

Background and Purpose

—

An increased frequency of clinically silent microbleeds (MB) has recently been observed in patients with sporadic small-vessel disease related to vascular amyloid deposition or hypertension. In this study, we searched for cerebral MBs in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), a unique type of small-vessel disease caused by mutations in the
Notch3
gene. Our purposes were (1) to determine the frequency, extent, and pattern of MBs in CADASIL; (2) to analyze the relationship between MBs and T2-hyperintense lesions; and (3) to evaluate the histopathology of brain tissue affected by MBs.

Methods

—

Gradient-echo, T2/PD-weighted dual-echo, and T1-weighted MRI scans of the brain were obtained from 16 consecutive CADASIL subjects and 16 age-matched control subjects. T2-lesion volume measurements were made with a semiautomated segmentation technique based on local thresholding. Postmortem examinations were performed on the brains of 7 additional CADASIL subjects.

Results

—

Focal areas of signal loss on gradient-echo images suggesting past MBs were found in 11 CADASIL individuals (69%) and no control subjects (
P
<0.001). The average number of MBs was 5.9±7.3 (range, 0 to 22) in individual CADASIL patients. MBs were associated with age (
r
=0.71,
P
=0.002) and total lesion volume (
r
=0.75,
P
=0.001). However, after correction for age, the correlation with lesion volume was no longer significant. MBs were located simultaneously in various parts of the brain with a preference for cortical-subcortical regions (38%), white matter (20%), thalamus (13%), and brainstem (14%). Eighty-two percent of the MBs were located outside areas appearing hyperintense on T2-weighted images. Postmortem examination revealed focal accumulations of hemosiderin-containing macrophages in 6 of the 7 brains (86%). They were always found outside ischemic lesions.

Conclusions

—

This study shows a high frequency and multiplicity of MBs in individuals with CADASIL. Our results suggest that MBs and ischemic lesions are largely independent manifestations of the underlying angiopathy. The pattern of MBs shows a significant overlap with that reported in other types of small-vessel disease.
Mastoid Air Sinus Abnormalities Associated With Lateral Venous Sinus Thrombosis
Authors: Fink John N. , McAuley David L.
Published: July 2002

Background

—

Mastoiditis is a known cause of lateral venous sinus thrombosis (LST). We have encountered patients with LST associated with mastoid abnormality on MRI without any clinical signs of infection; the significance of these abnormalities is uncertain. This study examines the relationship of LST and mastoid air sinus abnormalities systematically.

Summary of Report

—

We performed a retrospective clinical and radiological review of a series of 26 patients with cerebral venous thrombosis. Mastoid abnormalities were detected ipsilateral to 9 of 23 thrombosed lateral sinuses (39%) and 0 of 29 unaffected lateral sinuses (
P
<0.001). No patient had clinical evidence of mastoiditis. Eight of 9 patients with mastoid abnormalities were treated without antibiotics; all made uneventful clinical recoveries. Repeated MRI in 1 patient revealed reversal of the mastoid changes.

Conclusions

—

The mastoid changes observed are likely to be due to venous congestion as a consequence of LST, not mastoiditis.
Effect of Socioeconomic Status on Treatment and Mortality After Stroke
Authors: Kapral Moira K. , Wang Hua , Mamdani Muhammad , Tu Jack V.
Published: July 2002

Background and Purpose

—

Socioeconomic status is associated with increased mortality from ischemic heart disease. We undertook a study to determine whether a similar association exists between socioeconomic status and stroke mortality.

Methods

—

We linked hospital discharge abstracts and vital-status data for all patients with acute stroke admitted to hospitals in Ontario between April 1994 and March 1997. Socioeconomic status for each patient was inferred on the basis of median neighborhood income. We determined the risk of death at 30 days and 1 year; secondary analyses compared the use of medications, inpatient rehabilitation services, and carotid endarterectomy by socioeconomic status. We used multivariate analyses to adjust for age, sex, stroke type, comorbid conditions, and hospital and physician characteristics.

Results

—

The study sample consisted of 38 945 patients. Each $10 000 increase in median neighborhood income was associated with a 9% reduction in the hazard of death at 30 days (adjusted hazard ratio 0.91, 95% CI 0.87 to 0.96) and a 5% reduction in the hazard of death at 1 year (adjusted hazard ratio 0.95, 95% CI 0.92 to 0.99). Patients in the lowest income quintile were less likely than those in the highest to receive in-hospital physiotherapy (58% versus 61%,
P
<0.001), occupational therapy (36% versus 47%,
P
<0.001), and speech pathology (21% versus 28%,
P
<0.001). There were no differences in the use of medications or carotid endarterectomy based on socioeconomic status. Waiting times for carotid surgery, however, were significantly longer in the lowest income quintile than the highest (90 days versus 60 days,
P
=0.002).

Conclusions

—

Socioeconomic status affects mortality and access to some health services after stroke, even in a country with a universal health insurance program. Understanding and reducing these socioeconomic disparities should be a priority for future research.
Reemergence of Stroke Deficits With Midazolam Challenge
Authors: Lazar Ronald M. , Fitzsimmons Brian-Fred , Marshall Randolph S. , Berman Mitchell F. , Bustillo Maria A. , Young William L. , Mohr J.P. , Shah Jinesh , Robinson Julie V.
Published: July 2002

Background and Purpose

—

Patients who have sustained a neurological injury and then improved may experience transient reemergence of their syndromes when given benzodiazepines. As a step toward assessing whether neurotransmitter systems underlie poststroke clinical improvement, we selected midazolam, a γ-aminobutyric acid
A
(GABA
A
) agonist, for systemic administration to measure general or stroke-specific effects in patients.

Methods

—

Eight patients with image-verified stroke (5 with left-sided and 3 with right-sided cerebral lesions) participated. The strokes had occurred from 7 days to 6 years earlier, with patients showing clinical improvement from their initial syndromes. Each patient underwent baseline testing for motor function, aphasia, and left hemispatial neglect, after which intravenous midazolam was delivered until mild drowsiness was detected. Patients were tested during this period and again after 2 hours when sedation had dissipated.

Results

—

After the administration of midazolam, the 5 patients with left hemisphere stroke demonstrated reemergence or worsening of their initial right hemiparesis and aphasia but showed no left neglect. The 3 patients with right cerebral stroke showed reemergence of left hemiparesis and left visual field neglect but no aphasia. All patients returned to baseline after 2 hours.

Conclusions

—

Under conditions of light sedation, patients whose initial stroke syndrome had substantially improved clinically showed transient reemergence of their initial focal syndrome. These data suggest a possible role for GABA
A
-mediated neurochemical mechanisms in poststroke improvement and sensitivity to medication effects.
Apolipoprotein A-I and B and Stroke Events in a Community-Based Cohort in Taiwan
Authors: Chien Kuo-Liong , Sung Fung-Chang , Hsu Hsiu-Ching , Su Ta-Chen , Lin Ruey-S. , Lee Yuan-Teh
Published: July 2002

Background and Purpose

—

There are limited prospective cohort studies of the well-known association between stroke events and serum lipids for the Taiwanese population, in whom stroke is the second most common cause of death.

Methods

—

This report describes the effect of dyslipidemia on the risk of stroke in a community-based cohort consisting of 3602 adults aged ≥35 years, established in 1990 in the Chin-Shan community in Taipei County, Taiwan.

Results

—

As of the end of 1998, 97 stroke incidence cases were identified from medical records and death certificates (53 in men and 44 in women). The female-to-male stroke event rates increased from 0.42 in the youngest group (aged 35 to 44 years) to 1.38 in the oldest (aged ≥75 years). Multiple Cox proportional hazard regression models controlling for age and sex revealed that individuals with serum apolipoprotein A-I (apoA-I) at the highest quartile were more likely to have a stroke event than those at the lowest quartile level (relative risk [RR]=2.02,
P
for trend=0.010). The corresponding risk of stroke predicted by apolipoprotein B (apoB) was also significant (RR=1.88,
P
for trend=0.020). After adjustment for age, sex, hypertension, and diabetes status, the interaction between hypertension and apoA-I level remained significant in predicting stroke events in men but not in women (RR=1.71,
P
=0.033 in men; RR=2.29,
P
=0.071 in women).

Conclusions

—

We conclude that apoA-I but not apoB levels may serve as an effect modifier of hypertension for the risk of stroke events.
Does Acupuncture Have Additional Value to Standard Poststroke Motor Rehabilitation?
Authors: Sze Frank Kai-Hoi , Wong Eric , Yi Xiang , Woo Jean
Published: July 2002

Background and Purpose

—

A significant number of patients remain severely disabled after stroke despite rehabilitation with standard treatment modalities. Acupuncture has been reported as an alternative modality. This study aims to examine whether acupuncture has additional value to standard poststroke motor rehabilitation.

Methods

—

A prospective randomized controlled trial (RCT) was carried out in a stroke rehabilitation unit in Hong Kong. One hundred six Chinese patients with moderate or severe functional impairment were included at days 3 to 15 after acute stroke. They were stratified into the moderate and the severe groups before randomization into the control arm receiving standard modalities of treatment, which included physiotherapy, occupational and speech therapy, and skilled medical and nursing care, and the intervention arm receiving in addition traditional Chinese manual acupuncture. A mean of 35 acupuncture sessions on 10 main acupoints were performed over a 10-week period. Outcome measures included Fugl-Meyer assessment, Barthel Index, and Functional Independence Measure, respectively, at weeks 0, 5, and 10, performed by blinded assessors.

Results

—

At baseline, patients in each arm were comparable in all important prognostic characteristics. No statistically significant differences were observed between the 2 arms for any of the outcome measures at week 10 or outcome changes over time.

Conclusions

—

Traditional Chinese manual acupuncture on the body has no additional value to standard poststroke motor rehabilitation.
Cerebral Atherosclerosis as Predictor of Stroke and Mortality in Representative Elderly Population
Authors: Lernfelt B. , Forsberg M. , Blomstrand C. , Mellström D. , Volkmann R.
Published: July 2002

Background and Purpose

—

The aim of this study was to assess the relationship between cardiovascular risk factors, atherosclerotic disease in the carotid bifurcation, and the risk of stroke and mortality in a representative population sample.

Methods

—

One hundred forty-two men and women participated in a population study at ages 70 and 76 years. At age 78, extracranial and intracranial circulation was examined by means of duplex sonography and transcranial Doppler techniques. Mortality and hospitalization for stroke were analyzed over a 5-year follow-up period up to age 83 years.

Results

—

Carotid plaques were identified in 82% of the men and 79% of the women. Bilateral plaques were found in 57% of the men and 46% of the women, and stenosis resulting in >50% diameter reduction occurred in 28% of the men and 17% of the women. Carotid stenosis >75% was observed in 7 subjects (0.5%). Bilateral plaques at age 78 were correlated with systolic blood pressure and ischemic heart disease at age 70 years. The pulsatility index was 1.0 to 1.4 in 63% and ≥1.5 in 13% of the study population. The pulsatility index was correlated with systolic and diastolic blood pressure, serum cholesterol, and triglycerides. Men with bilateral carotid plaques at age 78 years had an increased risk of stroke or mortality during the 5-year follow-up period (74% bilateral plaques versus 21% unilateral or no plaques). This was not found in the women (33% versus 26%).

Conclusions

—

Carotid atherosclerosis was prevalent in a majority of elderly subjects. Bilateral plaques were correlated with systolic blood pressure and ischemic heart disease at age 70 years and predicted the risk of stroke and mortality in men but not in women.
Association Between Influenza Vaccination and Reduced Risk of Brain Infarction
Authors: Lavallée Philippa , Perchaud Véronique , Gautier-Bertrand Marion , Grabli David , Amarenco Pierre
Published: July 2002

Background and Purpose

—

Because infections subsequent to influenza may play a role in promoting the complications of atherosclerotic disease and may also induce hypercoagulation, we hypothesized that influenza vaccination may protect against brain infarction.

Methods

—

During the influenza epidemic period we studied 270 subjects, including 90 consecutive patients older than 60 years admitted to the hospital for brain infarction and 180 population-based controls, matched for age, sex, and district of residency in Paris. We conducted a structured interview on whether they had been vaccinated during the last influenza vaccination campaign or every year during the 5 last years.

Results

—

We found significantly fewer vaccinated subjects during the last vaccination campaign among patients with brain infarction than among controls (46.7% versus 59.4%;
P
=0.036) and fewer patients vaccinated every year during the last 5 years (41.1% versus 56.1%;
P
=0.017). After adjustment for age, traditional risk factors, and recent use of antibiotics, the risk of stroke was reduced in the subjects vaccinated during the year of the study and in those vaccinated during the last 5 years, with an odds ratio of 0.50 (95% CI, 0.26 to 0.94;
P
=0.033) and 0.42 (95% CI, 0.21 to 0.81;
P
=0.009), respectively. Similar associations were observed in cases and controls free of previous cardiovascular history. Subjects younger than 75 years and subjects free of risk factors or in high social class were significantly less often vaccinated than controls.

Conclusions

—

Influenza vaccination may protect against brain infarction by reducing infections or may identify a subgroup of patients at low risk for stroke because of a better lifestyle. These results give rise to a new hypothesis for research into stroke prevention.
What Is Effective in Malignant Middle Cerebral Artery Infarction: Reperfusion, Craniectomy, or Both?
Authors: Engelhorn T. , von Kummer R. , Reith W. , Forsting M. , Doerfler A.
Published: July 2002

Background and Purpose—

We sought to evaluate the effects of reperfusion and craniectomy treatment at different time points after middle cerebral artery (MCA) occlusion on infarct volume and neurological outcome in MCA infarction in rats.

Methods—

We used an endovascular technique to obtain MCA occlusion in 182 rats. Thirteen groups with 14 animals each were investigated: control group 1 with no treatment; groups 2 to 7 with only reperfusion or craniectomy at 1, 4, or 12 hours, respectively; and groups 8 to 13 with reperfusion at 1 or 4 hours combined with craniectomy at 1, 4, or 12 hours, respectively. We used infarct volume and neurological performance as study end points in all animals at day 7.

Results—

Neurological score and infarct volume in animals undergoing early reperfusion at 1 hour were significantly smaller (1.8/79±59 mm
3
) than those in control animals (3.8/225±26 mm
3
) (
P
<0.01). Reperfusion at 4 hours (2.8/182±62 mm
3
) and 12 hours (3.7/231±69 mm
3
) did not result in significant improvement. Animals undergoing craniectomy at 1, 4, and 12 hours demonstrated significantly better outcome and significantly reduced infarct volume (1.6/96±30 mm
3
, 1.9/109±39 mm
3
, and 2.6/150±34 mm
3
, respectively) (
P
<0.05). Compared with 1 treatment at a time, combined reperfusion and craniectomy did not result in a significant additional benefit.

Conclusions—

Early reperfusion and craniectomy at 1 hour are both effective in large MCA infarction. While reperfusion later than 1 hour was not beneficial, late craniectomy at 4 and 12 hours still resulted in significant improvement of neurological score and reduction of infarction size. Combined treatment at different time points yields no significant additional benefit compared with 1 treatment at a time.
Elevated Cerebral Blood Flow Velocities in Fabry Disease With Reversal After Enzyme Replacement
Authors: Moore David F. , Altarescu Gheona , Ling Geoffrey S.F. , Jeffries Neal , Frei Karen P. , Weibel Thais , Charria-Ortiz Gustavo , Ferri Raymond , Arai Andrew E. , Brady Roscoe O. , Schiffmann Raphael
Published: July 2002

Background and Purpose

—

Fabry disease is an X-linked inherited disorder resulting from a deficiency of α-galactosidase A. Cerebrovascular disease in Fabry disease includes small-vessel disease and larger-vessel ectasia in a predominantly posterior distribution. We assessed transcranial Doppler (TCD) blood flow velocities in naive and enzyme-treated Fabry patients.

Methods

—

TCD was used to noninvasively examine patients with Fabry disease for abnormal cerebral blood flow velocities. TCD measurements were also made during CO
2
retention by breathholding to examine cerebrovascular vessel reactivity. Twenty-six patients were enrolled in a 6-month, double-blind, placebo-controlled trial of enzyme replacement therapy consisting of biweekly intravenous α-galactosidase A infusions, with a subsequent 18-month follow-up in an open-label trial. Statistical analysis consisted of applying a mixed-effects ANOVA model for correlated outcomes.

Results

—

Peak velocity, mean velocity, pulsatility index, and resistance index were found to be significantly higher in patients compared with control subjects. When the individual vessels were considered, elevated flow velocities were found in the middle cerebral M1 branch and the posterior cerebral artery. Enzyme replacement therapy significantly decreased peak, mean, and end-diastolic velocities and flow acceleration at the 18-month follow-up time point.

Conclusions

—

Patients with Fabry disease have elevated cerebral blood flow velocities. These velocities significantly improved with enzyme replacement therapy.
Progression of Middle Cerebral Artery Occlusive Disease and Its Relationship With Further Vascular Events After Stroke
Authors: Wong Ka Sing , Li Huan , Lam Wynnie W.M. , Chan Yu Leung , Kay Richard
Published: July 2002

Background

—

Serial changes of flow velocities of transcranial Doppler ultrasound (TCD) in symptomatic middle cerebral artery (MCA) occlusive disease may be related to the occurrence of further vascular events, but prospective data are lacking.

Methods

—

We conducted a prospective study on patients with cerebral ischemia who were hospitalized with symptomatic MCA stenosis or occlusion. We repeated TCD examinations 6 months after the initial examinations and recorded any stroke or coronary events during this period. The changes of MCA flow velocities were categorized as normalized artery, stable artery, and progressed artery, which were determined according to the changes of MCA velocities at 6 months.

Results

—

We studied 143 consecutive patients who had relevant MCA occlusive diseases (107 with stenosis and 36 with occlusion). At 6 months, the velocities in the MCA returned to normal in 42 patients (29%), they were stable in 80 patients (62%), and they progressed in 13 patients (9%). The number of clinical events varied significantly among the 3 groups: there were 2 patients (4.8%) with clinical events in the normal group, 11 patients (12.5%) with clinical events in the stable group, and 5 patients (38.5%) with clinical events in the progressed group (
P
=0.004). The 18 recurrent events included 10 recurrent strokes, 5 transient ischemic attacks, and 3 acute coronary syndromes.

Conclusions

—

Progression of MCA occlusive diseases is associated with an increased risk of vascular events. Further studies are required to establish the value of serial TCD examinations in predicting future clinical events.
17β-Estradiol Increases Rat Cerebrovascular Prostacyclin Synthesis by Elevating Cyclooxygenase-1 and Prostacyclin Synthase
Authors: Ospina Jose A. , Krause Diana N. , Duckles Sue P.
Published: July 2002

Background and Purpose

—

It has been reported that estrogens modulate peripheral vascular synthesis of vasodilatory hormones, including prostacyclin. If this occurs in the cerebral circulation, it could have important consequences in the modulation of cerebral hemodynamic function and improvement of stroke outcome. We investigated the hypothesis that in vivo 17β-estradiol treatment of ovariectomized rats increases cerebrovascular prostacyclin production via elevation of the enzymes responsible for prostacyclin synthesis.

Methods

—

Cerebral blood vessels from 17β-estradiol–treated and nontreated ovariectomized rats were isolated and examined for prostacyclin synthesis by enzyme-linked immunosorbent assay or for protein levels of cyclooxygenase-1, prostacyclin-synthase, and cytosolic phospholipase A
2
by immunoblot analysis.

Results

—

We report that chronic in vivo 17β-estradiol treatment significantly enhanced basal prostacyclin synthesis in rat cerebral blood vessels by 2.6-fold over control. 17β-Estradiol treatment also resulted in a 5.1-fold increase of cyclooxygenase-1 protein and a 6.7-fold increase of prostacyclin-synthase protein in the cerebral vasculature. There was no effect of estrogen on levels of cytosolic phospholipase A
2
.

Conclusions

—

Our findings suggest that estrogen influences the biosynthesis of prostacyclin, which may be important in the regulation of cerebral blood flow and thrombosis. This finding may shed light on the mechanisms that govern sex-based differences in cerebrovascular disease.
Penumbral Microcirculatory Changes Associated With Peri-infarct Depolarizations in the Rat
Authors: Pinard Elisabeth , Nallet Hélène , MacKenzie Eric T. , Seylaz Jacques , Roussel Simon
Published: July 2002

Background and Purpose

—

This study was designed to investigate the influence of peri-infarct depolarization elicited by occlusion of the middle cerebral artery on the dynamics of the microcirculation.

Methods

—

The microcirculation in the frontoparietal cortex of 9 rats was visualized in real time through a closed cranial window with the use of laser-scanning confocal fluorescence microscopy combined with intravenous fluorescein isothiocyanate (FITC)–dextran and FITC-labeled erythrocytes. The direct current potential/electrocorticogram was continuously monitored. Intraluminal focal ischemia was induced for 2 hours in 6 rats anesthetized with halothane and mechanically ventilated. Reperfusion was monitored for 1 hour. Three rats underwent sham operation. Brains were removed 24 hours after occlusion and processed for histology.

Results

—

In control conditions, the velocity of fluorescent erythrocytes through capillaries was 0.51±0.19 mm/s (mean±SD), and the diameter of the arterioles studied was 33±12 μm. Under ischemia, erythrocyte velocity through capillaries was significantly decreased to 0.33±0.14 mm/s, while arteriole diameter did not change significantly. During spontaneous peri-infarct depolarizations, arteriole diameter was significantly increased (119±23% of baseline), while capillary erythrocyte velocity was further decreased by 14±34%. The direction of arteriolar blood flow episodically and transiently reversed during approximately half of the peri-infarct depolarizations. The decrease in capillary erythrocyte velocity was more pronounced (23±37%) in these cases. After reperfusion, the microcirculatory variables rapidly returned to baseline. All rats in the ischemic group had infarcts 24 hours after occlusion.

Conclusions

—

Peri-infarct depolarization has an adverse influence on penumbral microcirculation, reducing capillary perfusion by erythrocytes, despite dilatation of arterioles. These findings suggest that a steal phenomenon contributes to the deleterious effect of these depolarizations.
Costs and Benefits of Carotid Endarterectomy and Associated Preoperative Arterial Imaging
Authors: Benade Marikie M. , Warlow Charles P.
Published: July 2002

Background and Purpose—

Carotid endarterectomy (CEA) reduces the risk of stroke in patients with severe stenosis of the internal carotid artery. However, the cost implications of this procedure have not yet been satisfactorily addressed. The objective of this systematic review was to critically appraise the studies addressing the economic implications of CEA and the associated preoperative arterial imaging.

Methods—

A systematic search strategy was developed to identify research articles related to the economic evaluation of CEA and the associated preoperative imaging. MEDLINE, EMBASE, and BIOSIS were electronically searched, and reference lists from identified studies were searched manually. Methods used to critically appraise these studies followed proposed guidelines for an economic evaluation that addresses 10 distinct aspects under 3 separate headings.

Results—

Studies identified were either partial economic or full economic evaluations, with the majority coming from the United States. The methodological quality seems to have improved over time. The studies that assessed cost-effectiveness of CEA were all modeling studies; although the same baseline parameters were used, divergent conclusions were reached. Variation in the cost estimates of CEA ($9500 to $11 500) in the same health care system was also observed in the studies reporting only on the cost of carotid surgery. For a symptomatic patient, the benefit of CEA ranged from 0.35 quality adjusted life years (QALYs) (4.2 months) at a cost of $4100 per QALY to 0.93 QALYs (11.2 months) at a cost of $434 per QALY. For an asymptomatic patient, the cost-effectiveness of CEA varied from 0.15 QALYs (1.8 months) at a cost of $52 700 per QALY to 0.25 QALYs (3 months) at a cost of $8004 per QALY.

Conclusions—

Divergent conclusions of the cost-effectiveness of CEA were reported from studies that addressed the same questions and using similar parameters in their models. The cost estimates of the procedure and the different time periods used in the studies might explain these inconsistencies. Modeling studies in hypothetical cohorts might also be to blame. The cost-effectiveness of CEA will only definitively be assessed when real patient data are used.
High Rate of Recanalization of Middle Cerebral Artery Occlusion During 2-MHz Transcranial Color-Coded Doppler Continuous Monitoring Without Thrombolytic Drug
Authors: Cintas Pascal , Le Traon Anne Pavy , Larrue Vincent
Published: July 2002

Background and Purpose—

Experimental evidence indicates that ultrasound can accelerate thrombolysis. We report our findings on early recanalization during transcranial color-coded Doppler (TCCD) continuous monitoring in acute stroke patients with middle cerebral artery (MCA) main stem occlusion.

Methods—

We performed continuous TCCD monitorings in 6 consecutive patients with acute MCA main stem occlusion using a 2-MHz transducer. Patients were not treated with recombinant tissue plasminogen activator.

Results—

Partial recanalization, defined as blunted waveforms, occurred during monitoring in 5 patients (83%). The mean time to beginning of recanalization was 17.2±9.6 minutes. Complete recanalization at 24 hours occurred in only 1 patient. The mean National Institutes of Health Stroke Scale score in the patients who recanalized during monitoring was 21.2±4.1 at baseline, 19.2±5 at 2 hours, and 15.6±3.4 at 24 hours (
P
=0.1).

Conclusions—

In this short series of patients with acute MCA main stem occlusion, not treated with recombinant tissue plasminogen activator, we found a high rate of early partial recanalization during continuous exposure to 2-MHz ultrasound.
Functional Reorganization of Motor Cortex Increases With Greater Axonal Injury From CADASIL
Authors: Reddy H. , De Stefano N. , Mortilla M. , Federico A. , Matthews P. M.
Published: July 2002

Background and Purpose

—

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited small-artery disease that clinically involves only the brain. Particularly early in the disease, patients can show substantial or complete recovery after individual strokes. Cortical functional reorganization may contribute to limiting disability with such ischemic injury. We sought to test whether the extent of any functional changes in the motor cortex increases with greater brain axonal injury from CADASIL.

Methods

—

Functional MRI (fMRI) was used to characterize cortical activation during a simple hand-tapping task. Disease-associated pathology in subcortical white matter was assessed with the use of conventional fluid-attenuated inversion recovery (FLAIR) MRI and MR spectroscopic imaging for measurement of
N
-acetyl aspartate decreases, a relatively specific measure of axonal injury.

Results

—

There was evidence for variable but substantial hyperintense white matter signal in all of the patients with FLAIR imaging. With the use of fMRI, the brain regions activated during motor tasks were similar for the 9 CADASIL patients and 7 controls, except that most (6 of 9) patients showed primary motor cortex activation both ipsilateral and contralateral to the hand moved, a finding in only 1 of 7 healthy controls. Ipsilateral motor cortex activation increased (
r
=−0.77,
P
<0.05) and motor cortex activation lateralization index decreased (
r
=0.68,
P
<0.02) with greater white matter injury (as assessed from decreases in the relative
N
-acetyl aspartate concentration) in a region of interest including descending motor fibers of the corticospinal pathway.

Conclusions

—

The extent of functional reorganization of motor cortex increases with increasing axonal injury, consistent with an adaptive role for these changes. Increased functional recruitment of cortex ipsilateral to the limb moved therefore may contribute to limiting motor impairment from the subcortical injury of CADASIL.
Fractures After Stroke
Authors: Dennis M. S. , Lo K. M. , McDowall M. , West T.
Published: July 2002

Background and Purpose
—

Stroke patients may have an increased risk of fractures because of weak bones or an increased risk of falling. Our goal was to estimate the frequency of fracture after stroke and to identify those at greatest risk.

Methods
—

This study incorporated 2 complementary strategies: a prospective, single-center, cohort study and an analysis of Scottish routine hospital discharge data.

Results
—

Eighty-eight fractures (30% hip) occurred in 2696 hospital-referred stroke patients. The proportions sustaining any fracture or hip fracture within 2 years were 4% and 1.1%, respectively, 1.4 (95% CI, 0.92 to 2.07) times the rate of hip fracture in the general population (ie, observed number divided by expected number or standardized morbidity ratio). Female sex, older age, low abbreviated mental test score, and prestroke dependence were associated with an increased hip fracture rate. Routine data identified 129 935 acute stroke patients admitted to Scottish hospitals. During 363 447 patient-years, 4528 patients had hip fractures, 2.0% had fractures by 1 year, and 10.6% had fractures by 10 years. This is 1.7 times the rate of hip fracture in the general population and 2.3 times that in patients with myocardial infarction. Older patients predictably had the highest rate of poststroke hip fractures but a lower standardized morbidity ratio than younger patients.

Conclusions
—

Fractures after stroke are probably frequent and serious enough to justify the development of preventive strategies, but the modest event rate would mean that randomized, controlled trials to test these strategies specifically in stroke patients would need to enroll thousands of patients.
Handicap After Stroke: How Does It Relate to Disability, Perception of Recovery, and Stroke Subtype?
Authors: Sturm Jonathan W. , Dewey Helen M. , Donnan Geoffrey A. , Macdonell Richard A.L. , McNeil John J. , Thrift Amanda G.
Published: July 2002

Background and Purpose
—

Knowledge of patterns of handicap after stroke and of the relationship among handicap, disability, perception of recovery, and stroke subtype is limited. The aim of this study was to assess handicap 3 and 12 months after first-ever stroke in a community-based study.

Methods
—

All strokes occurring in a population of 133 816 people were found and assessed. Patients were classified as having cerebral infarction (CI) or intracerebral hemorrhage (ICH) according to imaging or autopsy findings. Cases of CI were categorized using the Oxfordshire stroke classification. Handicap, disability, and perception of recovery were assessed 3 and 12 months after stroke using the London Handicap Scale, Barthel Index, and the question “Have you made a complete recovery from your stroke?” The association between disability and handicap was examined using Pearson’s correlation. Differences in handicap among subtypes of CI were evaluated using one-way ANOVA.

Results
—

There were 264 cases of CI or ICH. Of surviving patients, 113 (59%) were assessed at 3 months and 107 (64%) at 12 months. The domains of handicap most affected were physical independence and occupation. Only half the variance in handicap was due to disability. Of patients without disability, those who claimed complete recovery were less handicapped than those who claimed incomplete recovery. Patients with total anterior circulation infarction were more handicapped at 3 and 12 months than those with other subtypes of CI.

Conclusions
—

Stroke patients were handicapped across many domains. Handicap is only partly explained by disability. Stroke subtype should be considered in the interpretation of outcome data.
Neurovascular Complications of Marfan Syndrome
Authors: Wityk Robert J. , Zanferrari Carla , Oppenheimer Stephen
Published: July 2002

Background and Purpose

—

Small case series have associated Marfan syndrome with cerebral and spinal ischemia or hemorrhage. However, there has been no investigation of the frequency and etiology of neurovascular disorders in a large series of Marfan patients.

Methods

—

We conducted a retrospective, hospital-based study of all Marfan syndrome patients seen in an 8-year period. Records were reviewed in detail, and clinical characteristics of those with and without a neurovascular diagnosis compared.

Results

—

Of 513 patients, 18 (3.5%) had a neurovascular diagnosis, as follows: transient ischemic attack (11), cerebral infarction (2), spinal cord infarction (2), subdural hematoma (2), and spinal subarachnoid hemorrhage (1). A cardioembolic source was identified in 12 of 13 patients with cerebral ischemia, as follows: prosthetic heart valves (9), mitral valve prolapse (2), and atrial fibrillation (1). Chronic anticoagulant therapy was a likely cause in 2 of 3 patients with hemorrhagic events. Compared with other Marfan syndrome patients, those with neurovascular events were older (39.6 versus 31.7 years,
P
=0.04) and more likely to be in atrial fibrillation (22.2% versus 3.2%,
P
=<0.01), to have prosthetic heart valves (61.1% versus 7.7%,
P
=0.001), and to be taking anticoagulant therapy (72.2% versus 16.1%,
P
<0.001). Aortic disease, a putative factor in the etiology of neurovascular complications, was present in equal measure in Marfan patients with and without neurovascular complications (78% versus 65%,
P
=NS).

Conclusions

—

Neurovascular complications of Marfan syndrome are rare during 8 years of follow-up, and generally are ischemic in nature. A high-risk cardiac source was identified in the majority. A significant association with vascular dissection was not established.
Role of Endothelial Nitric Oxide and Smooth Muscle Potassium Channels in Cerebral Arteriolar Dilation in Response to Acidosis
Authors: Horiuchi Tetsuyoshi , Dietrich Hans H. , Hongo Kazuhiro , Goto Tetsuya , Dacey Ralph G.
Published: July 2002

Background and Purpose

—

Potassium channels or nitric oxide or both are major mediators of acidosis-induced dilation in the cerebral circulation. However, these contributions depend on a variety of factors such as species and vessel location. The present study was designed to clarify whether potassium channels and endothelial nitric oxide are involved in acidosis-induced dilation of isolated rat cerebral arterioles.

Methods

—

Cerebral arterioles were cannulated and monitored with an inverted microscope. Acidosis (pH 6.8 to 7.4) produced by adding hydrogen ions mediated dilation of the cerebral arterioles in a concentration-dependent manner. The role of nitric oxide and potassium channels in response to acidosis was examined with several specific inhibitors and endothelial damage.

Results

—

The dilation was significantly inhibited by potassium chloride (30 mmol/L) and glibenclamide (3 μmol/L; ATP-sensitive potassium channel inhibitor). We found that 30 μmol/L BaCl
2
(concentration-dependent potassium channel inhibitor) also affected the dilation; however, an additional treatment of 3 μmol/L glibenclamide did not produce further inhibition. Tetraethylammonium ion (1 mmol/L; calcium-activated potassium channel inhibitor) and 4-aminopyridine (100 μmol/L; voltage-dependent potassium channel inhibitor) as well as ouabain (10 μmol/L; Na-K ATPase inhibitor) and
N
-methylsulphonyl-6-(2-proparglyloxyphenyl) hexanamide (1 μmol/L; cytochrome P450 epoxygenase inhibitor) did not alter acidotic dilation.
N
ω
-Monomethyl-
l
-arginine (10 μmol/L) and
N
ω
-nitro-
l
-arginine (10 μmol/L) as nitric oxide synthase inhibitor blunted the dilation. Furthermore, the dilation was significantly attenuated after the endothelial impairment. Additional treatment with glibenclamide (3 μmol/L) further reduced the dilation in response to acidosis.

Conclusions

—

Endothelial nitric oxide and smooth muscle ATP-sensitive potassium channels contribute to acidosis-induced dilation of rat cerebral arterioles. Endothelial damage caused by pathological conditions such as subarachnoid hemorrhage or traumatic brain injury may contribute to reduced blood flow despite injury-induced cerebral acidosis.
Involvement of Matrix Metalloproteinase in Thrombolysis-Associated Hemorrhagic Transformation After Embolic Focal Ischemia in Rats
Authors: Sumii Toshihisa , Lo Eng H.
Published: July 2002

Background and Purpose

—

Thrombolytic therapy with tissue plasminogen activator (tPA) for acute ischemic stroke remains complicated by risks of hemorrhagic transformation. In this study we used a previously established quantitative rat model of tPA-associated hemorrhage to test the hypothesis that matrix metalloproteinases (MMPs) are involved.

Methods

—

Spontaneously hypertensive rats were subjected to embolic focal ischemia by placing homologous blood clots into the middle cerebral artery. Three groups of rats were studied: (1) untreated controls that received saline at 6 hours after ischemia; (2) rats that received tPA alone (10 mg/kg at 6 hours after ischemia); and (3) rats that received tPA plus the broad-spectrum MMP inhibitor BB-94 (50 mg/kg of BB-94 before ischemia and at 3 and 6 hours after ischemia plus tPA at 6 hours). Gelatin zymography was used to quantify MMP levels. A hemoglobin spectrophotometry method was used to quantify cerebral hemorrhage. Ischemic lesions were measured at 24 hours with tetrazolium staining.

Results

—

At 6, 12, and 24 hours, pro-MMP-9 and cleaved MMP-9 were upregulated in ischemic brain. At 12 hours, tPA-treated rats showed significantly higher levels of pro-MMP-9 and cleaved MMP-9 than untreated controls. By 24 hours, all rats showed evidence of hemorrhagic transformation in the ischemic territory. Rats treated with BB-94 and tPA showed significantly reduced hemorrhage volumes compared with those that received tPA alone. There was no effect on infarct size.

Conclusions

—

These results indicate that (1) tPA treatment increases levels of MMP-9 after embolic focal cerebral ischemia, (2) MMPs are involved in the mechanism of tPA-associated hemorrhage, and (3) combination therapies with MMP inhibitors may be useful for decreasing the risk and severity of this dreaded complication of thrombolytic therapy.
Clinical and Imaging Findings in Cryptogenic Stroke Patients With and Without Patent Foramen Ovale
Authors: Lamy C. , Giannesini C. , Zuber M. , Arquizan C. , Meder J.F. , Trystram D. , Coste J. , Mas J.L.
Published: July 2002

Background and Purpose
—

Patent foramen ovale (PFO) has been identified as a potential risk factor for stroke, but the mechanisms of PFO-associated stroke remain unsettled. The aim of our study was to evaluate possible differences in stroke risk factors and stroke patterns between patients with and without PFO that may give clues to the mechanism of PFO-associated stroke.

Methods
—

This prospective, multicentric study involved 581 young cryptogenic stroke patients. The presence of PFO and atrial septal aneurysm was assessed by transesophageal echocardiography and reviewed independently by 2 experienced sonographers. Clinical, brain, and vascular imaging findings were reviewed by 2 neurologists and 2 neuroradiologists.

Results
—

Of the 581 stroke patients, 267 (45.9%) had PFO. Patients with PFO were younger (OR, 0.95; 95% CI, 0.93 to 0.97) and less likely to have traditional risk factors such as hypertension (OR, 0.49; 95% CI, 0.28 to 0.85), hypercholesterolemia (OR, 0.56; 95% CI, 0.34 to 0.93), or current smoking (OR, 0.67; 95% CI, 0.47 to 0.97). Features suggestive of paradoxical embolism, such as Valsalva-provoking activities or deep vein thrombosis, were not more frequent in patients with PFO. Migraine was more common in patients with PFO (27.3%) than in those without PFO (14.0%). PFO (OR, 1.75; 95% CI, 1.08 to 2.82), particularly when associated with atrial septal aneurysm (OR, 2.71; 95% CI, 1.36 to 5.41), was significantly associated with migraine after adjustment for age and sex.

Conclusions
—

Differences in stroke risk factors and stroke patterns suggest that different stroke mechanisms occur in patients with and without PFO. PFO is significantly and independently associated with migraine, and this association is even stronger in patients with PFO and atrial septal aneurysm.