Abstracts of Literature
Endovascular Therapy of Idiopathic Cavernous Aneurysms Over 11 Years—Bavinzski G (Dept of Neurosurgery, Univ of Vienna, Waehringer Guertel 18–20, 1090 Vienna, Austria), Killer M, Ferraz-Leite H, Gruber A, Gross CE, Richling B—Am J Neuroradiol. 1998;19:559–565. ©American Society of Neuroradiology.
PURPOSE: We report our experience with 42 patients with 48 cavernous carotid aneurysms, of whom 32 were treated with endovascular techniques and 10 were managed conservatively.
METHODS: The 48 aneurysms were divided into two subgroups by location: 23 were at the C-3 portion of the carotid artery (small, saccular aneurysms with an epidural, partly intracavernous location) and 25 originated at the C4–5 segment (large or giant often fusiform aneurysms with a true intracavernous location). Morphologic features in both groups correlated well with differences in clinical presentation and also influenced therapy. Sixteen of the 25 C4–5 aneurysms (all large or giant) were treated by balloon occlusion of the parent artery, four (with narrow necks) were treated with Guglielmi detachable coils (GDCs), and five were not treated (asymptomatic or minimally symptomatic). Twelve of 13 C-3 aneurysms were treated with GDCs. Ten C-3 aneurysms were not treated.
RESULTS: Ophthalmoplegia resolved or improved in nine of 12 patients treated with parent artery occlusion. All aneurysms treated by carotid occlusion thrombosed. Twelve of the 17 aneurysms treated with GDCs were 100% filled by the coils, four were 80% to 95% filled, and one was only 40% filled. Seven of the 100% filled aneurysms remained completely occluded, two showed slight coil compaction, and in three, follow-up angiography was not available. Among the incompletely filled aneurysms, two remained unchanged, one showed progressive thrombosis, a fourth revealed coil compaction, and in one, follow-up angiography was not available. One thromboembolic stroke and three transient ischemic attacks occurred perioperatively, for a permanent morbidity of 3.5% and a transient morbidity of 9%. There was no mortality. Mean clinical follow-up was 33 months; mean angiographic follow-up of patients treated with GDCs was 11 months.
CONCLUSION: Surgically difficult cavernous aneurysms can be obliterated by embolization with excellent clinical results. Detachable coils have become an important endovascular tool, especially for narrow-necked cavernous aneurysms of the C-3 segment, which can be protected against rupture in the subarachnoid space in most cases.
Key Words: aneurysm, endovascular therapy
Autoregulatory Vasodilation of Parenchymal Vessels is Impaired During Cerebral Vasospasm—Yundt KD, Grubb RL Jr, Diringer MN, Powers WJ (East Building Imaging Center, 4525 Scott Ave, Box 8225, Washington Univ Medical Center, St Louis, MO 63110)—J Cereb Blood Flow Metab. 1998;18:419–424. ©1998 The International Society of Cerebral Blood Flow and Metabolism by Lippencott-Raven Publishers, Philadelphia.
Impaired CBF autoregulation during vasospasm after aneurysmal subarachnoid hemorrhage (SAH) could reflect impaired capacity of distal vessels to dilate in response to reduced local perfusion pressure or simply indicate that the perfusion pressure distal to large arteries in spasm is so low that vessels are already maximally dilated. Autoregulatory vasodilation can be detected in vivo as an increase in the parenchymal cerebral blood volume (CBV). Regional CBV, CBF, and oxygen extraction fraction in regions with and without angiographic vasospasm obtained from 29 positron emission tomography studies performed after intracranial aneurysm rupture were compared with data from 19 normal volunteers and five patients with carotid artery occlusion. Regional CBF was reduced compared to normal in regions from SAH patients with and without vasospasm as well as with ipsilateral carotid occlusion (P<.0001). Regional oxygen extraction fraction was higher during vasospasm and distal to carotid occlusion than both normal and SAH without vasospasm (P<.0001). Regional CBV was reduced compared to normal in regions with and without spasm, whereas it was increased ipsilateral to carotid occlusion (P<.0001). These findings of reduced parenchymal CBV during vasospasm under similar conditions of tissue hypoxia that produce increased CBV in patients with carotid occlusion provide evidence that parenchymal vessels distal to arteries with angiographic spasm after SAH do not show normal autoregulatory vasodilation.
Key Words: vasospasm, vasomotor reactivity
Computerized Tomography Angiography in Isolated Third Nerve Palsies—McFadzean RM (Dept of Neuro-ophthalmology, Institute of Neurological Sciences, Southern General Hospital, 1345 Govan Rd, G51 4TF Glasgow, Scotland), Teasdale EM—J Neurosurg. 1998;88:679–684.
Object: The goal of this study was to assess the value of computerized tomography (CT) angiography as a diagnostic tool in isolated oculomotor nerve palsies.
Methods: One hundred consecutive patients who presented with an isolated third nerve palsy were examined by CT angiography. This procedure was followed by conventional cerebral angiography in most patients in whom a vascular abnormality was noted on the CT angiography. Thus, all patients whose symptoms were caused by a compressive aneurysm were identified. The remaining patients were observed clinically to exclude the possibility that a missed cerebral aneurysm caused the isolated third nerve palsy.
Eighteen patients harbored a cerebral aneurysm responsible for causing the isolated third nerve palsy. Most of the remaining patients experienced some degree of spontaneous recovery. There was no clinical evidence to indicate that a case of compressive cerebral aneurysm causing the isolated third nerve palsy had been missed on CT angiography.
Conclusions: Computerized tomography angiography is a reliable diagnostic tool for use in the assessment of patients with an isolated third nerve palsy; it can identify the minority of patients in whom conventional cerebral angiography may be required.
Key Words: oculomotor nerve, angiography
Effect of 5% Albumin Solution on Sodium Balance and Blood Volume After Subarachnoid Hemorrhage—Mayer SA (Div of Critical Care Neurology, Neurological Institute, 710 W 168th St, Box 39, New York, NY 10032), Solomon RA, Fink ME, Lennihan L, Stern L, Beckford A, Thomas CE, Klebanoff LM—Neurosurgery. 1998;42:759–768.
OBJECTIVE: Subarachnoid hemorrhage (SAH) predisposes patients to excessive natriuresis and volume contraction. We studied the effects of postoperative administration of 5% albumin solution on sodium balance and blood volume after SAH. We also sought to identify physiological variables that influence renal sodium excretion after SAH.
METHODS: Forty-three patients with acute SAH were randomly assigned to receive hypervolemia or normovolemia treatment for a period of 7 days after aneurysm clipping. In addition to a base line infusion of normal saline solution (80 ml/hr), 250 ml of 5% albumin solution was administered every 2 hours for central venous pressure (CVP) values of ≤8 mm Hg (hypervolemia group, n=19) or ≤5 mm Hg (normovolemia group, n=24).
RESULTS:Both groups demonstrated relative volume expansion in base line measurements. The hypervolemia group received significantly more total fluid, sodium, and 5% albumin solution than did the normovolemia group and had higher CVP values and serum albumin levels (all P<0.02). Cumulative sodium balance was even in the hypervolemia group and persistently negative in the normovolemia group, because of sodium losses that occurred on Postoperative Days 2 and 3 (P=0.03). In a multiple-regression analysis of all patients, 24-hour sodium balance correlated negatively with glomerular filtration rate (GFR) and positively with serum albumin levels, after correction for sodium intake (P<0.0001). Hypervolemia therapy seemed to paradoxically lower GFR (P=0.10) and had no effect on blood volume, which declined by 10% in both groups. Pulmonary edema requiring diuresis occurred in only one patient in the hypervolemia group.
CONCLUSION: Supplemental 5% albumin solution given to maintain CVP values of >8 mm Hg prevented sodium and fluid losses but did not have an impact on blood volume in our patients, who were hypervolemic in base line measurements. The natriuresis that occurs after SAH may be mediated in part by elevations of GFR. In addition to acting as a colloid volume expander, 5% albumin solution lowers the GFR and promotes renal sodium retention after SAH. These properties may limit the amount of total fluid required to maintain a given CVP value and hence may minimize the frequency of pulmonary edema.
Key Words: subarachnoid hemorrhage, hyponatremia
Is the SF-36 Suitable for Assessing Health Status of Older Stroke Patients?—O’Mahony PG (Elderly Annexe, Newcastle General Hospital, Westgate Rd, Newcastle upon Tyne, NE4 6BE, UK), Rodgers H, Thomson RG, Dobson R, James OFW—Age Ageing. 1998;27:19–22.
Introduction: The Medical Outcomes Study short form 36 health survey (SF-36) is being increasingly used and recommended as a suitable measure of subjective health status. However, it is unlikely that any measure will be appropriate for all groups. We wished to determine the suitability of the SF-36 for assessing quality of life in older stroke patients.
Methods: A screening questionnaire was used to identify prevalent cases of stroke from a random sample of 2000 subjects aged 45 years and over. The SF-36 was included as part of a self-completion questionnaire posted to each stroke patient. Data quality indicators were analysed.
Results: We identified 104 cases of stroke and the response rate for the SF-36 questionnaires sent was 83%. Completion rates for individual items ranged from 66 to 96%. All items in the role physical and role emotional scales had completion rates <75%. The percentage of subjects for whom an individual scale score could be computed ranged from 67 to 96%, being lowest for the role physical and role emotional scales. Floor effects were high (>15%) for these two scales and for the social functioning and physical functioning scales. Ceiling effects were substantial (>15%) for the two role effect scales and for social functioning and bodily pain.
Conclusions: This study has shown high response rates from older stroke patients to a postal questionnaire incorporating the SF-36. The poor completion rates and consequent inability to compute scores for a large proportion of responders in certain scales raises concerns about the perceived relevance of these sections. Results for the response effects suggest that, on its own, the instrument is not suitable for assessing outcome. When data quality indicators were examined, it appears that postal administration of the SF-36 is not appropriate for assessing quality of life of older stroke patients.
Key Words: stroke assessment, aged
Comparison of the Three Strategies of Verbal Scoring of the Glasgow Coma Scale in Patients With Stroke—Prasad K (Rm No. 704, CN Centre, All India Institute of Medical Sciences, New Delhi, 110029 India), Menon GR—Cerebrovasc Dis. 1998;8:79–85. ©1998 S. Karger AG, Basel.
Presence of aphasia in patients with stroke poses a problem in the use of the full form (eye-motor-verbal) Glasgow Coma Scale (GCS). Stroke investigators and clinicians have used three different strategies to deal with the untestable verbal subscale, ie, eliminating the verbal subscale; pseudoscoring with ‘one,’ and median value substitution; but the predictive accuracy of the strategies has not been compared. To compare the predictive accuracy of the three strategies for acute mortality in stroke, we prospectively applied the GCS to 275 consecutive patients with acute stroke and recorded their survival status before discharge from hospital. 95 (33.8%) patients died. 32 (12%) patients had untestable verbal score. Receiver-Operator-Characteristic curves for predicting mortality were constructed with the GCS sum score and with the multivariate logistic models, and areas under the curves were measured to compare the predictive accuracy. They were all found to be similar (0.87–0.88 sq unit). Specifically, the GCS with eye and motor subscale had 87% accuracy compared to 88% for the model with eye, motor and verbal scale. We conclude that the short-form (eye-motor) GCS is as good a predictor of early mortality (within 2 weeks) as the full form (eye-motor-verbal) GCS in patients with stroke.
Key Words: mortality, aphasia
Follow-up in Carriers of the “MELAS” Mutation Without Strokes—Damian MS (Neurologische Universitätsklinik, Fetscherstrasse 74, D-01307 Dresden, Germany), Hertel A, Seibel P, Reichmann H, Bachmann G, Schachenmayr W, Hoer G, Dorndorf W—Eur Neurol. 1998;39:9–15. ©1998 S. Karger AG, Basel.
Eight carriers of the A3243G mutation of mitochondrial DNA without stroke-like episodes were monitored for up to 7 years in clinical and metabolic studies, by magnetic resonance imaging (MRI) and positron emission tomography (PET). None developed mitochondrial encephalopathy (MELAS), but 2 developed diabetes mellitus, 1 terminal kidney failure and 2 cardiomyopathy. One patient improved markedly under ubiquinone. Electroencephalography showed progressive slowing in 2 cases; but electrophysiological tests and MRI were otherwise noncontributary. PET showed widespread cortical and basal ganglion metabolic deficits in 6 cases. We conclude that internal medical complications are more common than MELAS in adult carriers of the mutation. PET findings, firstly reported in such patients, suggest that chronic subclinical encephalopathy is very frequent, and PET may play a role in monitoring in the future.
Key Words: MELAS syndrome, outcome
Cost-effectiveness of Tissue Plasminogen Activator for Acute Ischemic Stroke—Fagan SC (Dept of Pharmacy Practice, Wayne State Univ, 1400 Chrysler, Detroit, MI 48202), Morgenstern LB, Petitta A, Ward RE, Tilley BC, Marler JR, Levine SR, Broderick JP, Kwiatkowski TG, Frankel M, Brott TG, Walker MD, NINDs rt-PA Stroke Study Group—Neurology. 1998;50:883–890. Copyright©1998 by the American Academy of Neurology.
Tissue plasminogen activator (tPA) has been shown to improve 3-month outcome in stroke patients treated within 3 hours of symptom onset. The costs associated with this new treatment will be a factor in determining the extent of its utilization. Data from the NINDS rt-PA Stroke Trial and the medical literature were used to estimate the health and economic outcomes associated with using tPA in acute stroke patients. A Markov model was developed to estimate the costs per 1,000 patients eligible for treatment with tPA compared with the costs per 1,000 untreated patients. One-way and multiway sensitivity analyses (using Monte Carlo simulation) were performed to estimate the overall uncertainty of the model results. In the NINDS rt-PA Stroke Trial, the average length of stay was significantly shorter in tPA-treated patients than in placebo-treated patients (10.9 versus 12.4 days; p=0.02) and more tPA patients were discharged to home than to inpatient rehabilitation or a nursing home (48% versus 36%; p=0.002). The Markov model estimated an increase in hospitalization costs of $1.7 million and a decrease in rehabilitation costs of $1.4 million and nursing home cost of $4.8 million per 1,000 eligible treated patients for a health care system that includes acute through long-term care facilities. Multiway sensitivity analysis revealed a greater than 90% probability of cost savings. The estimated impact on long-term health outcomes was 564 (3 to 850) quality-adjusted life-years saved over 30 years of the model per 1,000 patients. Treating acute ischemic stroke patients with tPA within 3 hours of symptom onset improves functional outcome at 3 months and is likely to result in a net cost savings to the health care system.
Key Words: plasminogen activator, tissue type, costs and cost analysis
Ischemic Stroke After Surgical Procedures: Clinical Features, Neuroimaging, and Risk Factors—Limburg M (Dept of Clinical Information Sciences, H2-214, Academic Medical Center, PO Box 22660, 1100 DD, Amsterdam, Netherlands), Wijdicks EFM, Li H—Neurology. 1998;50:895–901. Copyright©1998 by the American Academy of Neurology.
Objective: To describe risk factors and explore mechanisms of ischemic strokes after general surgery. Background:Strokes follow general surgery in about 0.08% to 2.9% of cases. Patients with previous cerebrovascular disease, atrial fibrillation, hypertension, advanced age, or atherosclerosis were found to have an increased risk. Knowledge of factors involved may guide physicians in determining the overall risk of surgery. Methods: This case-control study was performed in a referral center. A total of 61 patients identified through a computerized database with ischemic strokes after surgical procedures—excluding heart, brain, vessels, or neck—between July 1986 and July 1996 were studied. Procedures included 11 urogenital, 16 gastrointestinal, 17 orthopedic, 12 pulmonary, and 5 other. A total of 122 randomly selected controls were matched for age, sex, procedure, and year of procedure. Main outcome measures included arterial territory, timing, risk factors, and perioperative events. Differences were expressed as adjusted odds ratios (AOR) with 95% confidence limits (CL), using multivariate conditional logistic analyses for matched case-control design. Results: Arterial territory included 37 middle cerebral artery, 11 posterior circulation, 7 borderzone, and 6 multiple. Median procedure to stroke interval was 2 days (range, 0 to 16); 10 patients had intraoperative strokes. Three major risk factors emerged: previous cerebrovascular disease (AOR 12.57, 95% CL 2.14/73.70), chronic obstructive pulmonary disease (COPD) (7.51, 1.87/30.12), and peripheral vascular disease (PVD) (5.35, 1.25/22.94). After adding stroke-related factors, PVD (14.70, 2.01/107.71) and COPD (10.04, 1.90/53.14) remained the strongest variables; blood pressure (1.05, 1.01/1.10) and urea (1.04, 1.01/1.07) contributed slightly. Hypotension did not contribute. Four patients (6.6%) and no controls had diffuse intravascular coagulation (p=0.01). Four stroke patients had myocardial infarction (6.6% versus 0%; p=0.01). Conclusions:Ischemic strokes after general surgery most commonly occur after an asymptomatic interval. Previous cerebrovascular disease, COPD, and PVD greatly increase the risk. Hypotension rarely accounts for postoperative strokes. Major comorbidity of the patient at risk seems more important than complicating events during surgery.
Key Words: stroke, ischemic, surgery
Variation Between Studies in Reported Relative Risks Associated With Hypertension: Time Trends and Other Explanatory Variables—Marang-van de Mheen PJ (Institute of Social Medicine, Academic Medical Center, Meibergdreef 15, 1105 AZ Amsterdam, the Netherlands), Gunning-Schepers LJ— Am J Public Health. 1998;88: 618–622.
Hypertension is an important risk factor for cardiovascular diseases, which are still the major killers in Western countries. Given the availability of effective blood pressure–lowering drugs, the rationale of (secondary) preventive programs can easily be understood. To estimate the potential health benefit of such programs in times of changing cardiovascular epidemiology, both with regard to risk factors and with regard to interventions, good estimates of the prevalence of hypertension and its associated relative risks are necessary. However, to obtain such estimates is difficult because of the large interstudy variation in both reported prevalences and reported relative risks. For studies in the Netherlands we recently showed that the variation in reported prevalences between studies was explained by differences in study populations and in study design, and by a period effect indicating a declining prevalence of hypertension over time, although we were not able to identify the underlying cause for this decline.
There are various sources for interstudy variation in relative risk estimates. One source is the definition of the exposure and outcome variables, e.g., the number of blood pressure measurements on which the definition of hypertension is based. A second source of variation is the difference in study design. Relative risks estimated in cohort studies may, for instance, differ from those estimated in case-control studies because of differential recall of exposure between case and control subjects. Furthermore, the average duration of follow-up may differ between studies, and the relative risks will be closer to 1 with longer duration of follow-up.
A third source of variation concerns true changes, for instance, changes with calendar time. In the case of increased accuracy of blood pressure measurements over time, the relative risk estimates would be expected to increase with calendar time. Alternatively, the relative risk estimates may decrease with calendar time owing to improved treatment over time. Previous studies have shown increasing proportions of the population treated for hypertension and increasing proportions in which hypertension is controlled over time. Finally, if the incidence of hypertension were to decrease over time, the relative risk estimates would be expected to remain the same with calendar time.
The purpose of this study was to examine the variation in reported relative risks of coronary heart disease (CHD) and stroke associated with hypertension, and to attribute the interstudy variation to differences in definitions and duration of follow-up and to time trends in diagnostic possibilities and treatment. The latter is not just an academic exercise, since decisions regarding future efforts to reduce hypertension are based on the part of the burden of disease attributable to hypertension, which is dependent upon the magnitude of the relative risk estimate.
Key Words: hypertension, risk factors
Stroke Register: Experience From the Eastern Province of Saudi Arabia—Al-Rajeh S (PO Box 85064 Riyadh 11691, Saudi Arabia), Larbi EB, Bademosi O, Awada A, Yousef A, Al-Freihi H, Miniawi H—Cerebrovasc Dis. 1998;8:86–89. ©1998 S. Karger AG, Basel.
A stroke registry was established in the Eastern Province of Saudi Arabia with an estimated population of 750,000 inhabitants of whom 545,000 are Saudi citizens. The register started in July 1989 and ended in July 1993. The Gulf war led to its interruption from August 1990 to August 1991. Four hundred eighty-eight cases (314 males, 174 females) of first-ever strokes affecting Saudi nationals were registered over the 3-year period. The crude incidence rate for first-ever strokes was 29.8/100,000/year (95% CI: 25.2–34.3/100,000 year). When standardized to the 1976 US population, it rose up to 125.8/100,000/year. Ischemic strokes (69%) predominated as in other studies but subarachnoid hemorrhage (SAH) was extremely rare (1.4%). The important risk factors were: systemic hypertension (38%), diabetes mellitus (37%), heart disease (27%), smoking (19%) and family history of stroke (14%). Previous transient ischemic attacks (3%) and carotid bruits (1%) were uncommon. The 30-day case fatality rate was 15%. The study showed that the age-adjusted stroke incidence rate for Saudis in this region is lower than the rates reported in developed countries but within the range reported worldwide. The pattern of stroke in Saudi Arabia is not different from that reported in other communities with the exception of the low incidence of SAH. The risk factors are similar to findings in other studies except for the high frequency of diabetes mellitus in our cases. The lower mortality rate was probably due to the younger age of the population and the availability of free medical services for management of cases.
Key Words: Saudi Arabia, epidemiology
Thromboembolic Stroke in Young Women: A European Case-Control Study on Oral Contraceptives—Heinemann LA (ZEG-Centre for Epidemiology and Health Research, Schoenerlinder Strasse 11-12, D-16341 Zepernick, Germany), Lewis MA, Spitzer WO, Thorogood M, Guggenmoos-Holzmann I, Bruppacher R, Transnational Research Group on Oral Contraceptives and the Health of Young Women—Contraception. 1998;57:29–37. 1998 Elsevier Science Inc.
A matched case-control study was performed between 1993 and 1996 in 16 centers in the United Kingdom, Germany, France, Switzerland, and Austria. The objective was to determine the influence of oral contraceptives (OC), particularly those containing modern progestins, on the risk for ischemic stroke in women aged 16–44 years.
A total of 220 women who had had an incident ischemic stroke and were compared with 775 control subjects who were unaffected by stroke. At least one hospital and one community control subject per patient was matched and interviewed with the corresponding patient for 5-year age band and for area of residence.
Crude odds ratios (95% confidence intervals [CI]) for ischemic stroke were as follows. For current use of any OC versus no use 2.3 (1.7–3.2), the adjusted odds ratio (OR) 3.6 (2.4–5.4). The OC associated risk was higher for first generation than for second or third generation OC. The risk estimates for patients versus community control subjects were always lower than for hospital control subjects. No major regional difference of the risk estimates was found. Compared with nonusers of OC without hypertension, women with hypertension who used OC had an almost 10-fold increased risk. However, OC users who had had a blood pressure check before OC prescription had a lower risk than did those without such a check. Smoking >10 cigarettes/day is associated with higher risk of stroke, particularly for OC users. No significant effect was found for duration of OC use.
We conclude that although there is a small relative risk of occlusive stroke for healthy women currently using OC, the attributable risk is very small because the incidence in this age group is very low. The small increase in risk of OC use may be further reduced by preventive efforts for cardiovascular risk factors, particularly hypertension and smoking.
Key Words: contraceptives, oral, stroke, ischemic
Trends in Cerebrovascular Disease Mortality in Singapore: 1970–1994—Venketasubramanian N (Dept of Neurology, Tan Tock Seng Hospital, Moulmein Rd, Singapore 1130)—Int J Epidemiol. 1998;27:15–19. ©International Epidemiological Association 1998.
Background Cerebrovascular disease has been the third leading cause of death in Singapore for the last 25 years. This study was carried out to examine recent trends in cerebrovascular disease mortality in Singapore, and to study corresponding changes in stroke risk factors in our population.
Methods The Registry of Births and Deaths, Singapore, publishes annual reports on births and deaths. The cause of death is coded using the International Classification of Diseases Revisions 8 (1969–1978) and 9 (1979 onwards). Data for this study were obtained using rubrics 430–438. Death rates were age- and sex-standardized to the World Standard Population, and separately for males and females. Cerebrovascular disease risk factor patterns were derived from national epidemiological health surveys conducted from 1970 and 1994.
Results The absolute number of deaths annually from cerebrovascular disease rose from 1041 in 1970 to 1692 in 1994. Crude death rates remained stable at 50–60 per 100 000, accounting for 10–12% of all deaths. Standardized death rates showed a distinct fall from 99 per 100 000 in 1976 to 59 per 100 000 in 1994, 101 to 60 per 100 000 in males and 95 to 57 per 100 000 in females. National health surveys have shown a fall in the prevalence of undetected hypertension, smoking and hyperlipidaemia; the prevalence of obesity was unchanged, while that of diabetes mellitus rose over the same period. The mortality trends found in this study are unlikely to be due to changing fashions in coding or inadequate data collection.
Conclusion As in many countries in the world, cerebrovascular disease mortality in Singapore has fallen over the last 25 years; this may in part be related to the decline in stroke risk factors in our population.
Key Words: cerebrovascular disorders, mortality
Public Perception of Stroke Warning Signs and Knowledge of Potential Risk Factors—Pancioli AM (Dept of Emergency Medicine, Univ of Cincinnati College of Medicine, 231 Bethesda Ave, PO Box 670769, Cincinnati, OH 45267-0769), Broderick J, Kothari R, Brott T, Tuchfarber A, Miller R, Khoury J, Jauch E—JAMA. 1998;279: 1288–1292.
Context—Decreasing the time from stroke onset to hospital arrival and improving control of stroke risk factors depend on public knowledge of stroke warning signs and risk factors.
Objective—To assess current public knowledge of stroke warning signs and risk factors.
Design—A population-based telephone interview survey using random digit dialing conducted in 1995.
Setting—The Greater Cincinnati, Ohio, metropolitan area, the population of which is similar to that of the United States overall in age, sex, percentage of blacks, and economic status.
Participants—Respondents with age, race, and sex that matched the population of patients with acute stroke.
Main Outcome Measures—Knowledge of risk factors for stroke and warning signs of stroke as defined by the National Institute of Neurological Disorders and Stroke.
Results—Telephone calls were made to 17 634 households, which yielded 2642 demographically eligible individuals. Interviews were completed by 1880 respondents (response rate, 71.2%). A total of 1066 respondents (57%) correctly listed at least 1 of the 5 established stroke warning signs, and of all respondents, 1274 (68%) correctly listed at least 1 of the established stroke risk factors. Of the respondents, 469 (57%) of 818 respondents with a history of hypertension listed hypertension, 142 (35%) of 402 respondents who were current smokers listed smoking, and 32 (13%) of 255 respondents with diabetes listed diabetes as a risk factor for stroke. Compared with those younger than 75 years, respondents 75 years or older were less likely to correctly list at least 1 stroke warning sign (60% vs 47%, respectively; P<.001) and were less likely to list at least 1 stroke risk factor (72% vs 56%, respectively; P<.001).
Conclusion—Considerable education is needed to increase the public’s awareness of the warning signs and risk factors for stroke. Respondents with self-reported risk factors for stroke are largely unaware of their increased risk. The population at greatest risk for stroke, the very elderly, are the least knowledgeable about stroke warning signs and risk factors.
Key Words: risk factors, stroke, ischemic
The Risk of Hospitalization for Ischemic Stroke Among Older Adults—Wolinsky FD (Saint Louis Univ School of Public Health, 3663 Lindell Blvd, St Louis, MO 63108-3342), Wan GJ, Gurney JG, Bentley DW—Med Care. 1998;36:449–461. ©1998 Lippincott-Raven Publishers
Objectives. The purpose of this study was to identify risk factors for stroke and to estimate their relative importance in a large, nationally representative sample of very old men and women.
Methods. The study was designed as a secondary analysis of the Longitudinal Study on Aging. Baseline (1984) in-person interview data were linked to Medicare hospitalization records for 1984 to 1991. Participants were 6,071 noninstitutionalized adults 70 years old or older at baseline. Hospitalization for ischemic stroke was defined as having one or more episodes with a primary discharge diagnosis containing ICD-9-CM codes of 433.0–434.9, 436, and 437.0–437.1. Multivariable proportional hazards regression was used to estimate the risks associated with previously identified epidemiologic factors.
Results. Five hundred and three persons (8.3%) had at least one primary discharge diagnosis of ischemic stroke. In descending order of importance based on the partial r statistics associated with their adjusted hazards ratios (AHRs), the salient risk factors were having a previous history of stroke (AHR=2.86), age (AHR=1.04 per year), diabetes (AHR=1.78), male gender (AHR=1.42), lower body limitations (AHR=1.09 per limitation), arthritis (AHR=0.74), hypertension (AHR=1.29), and poverty (AHR=1.33).
Conclusion. Patients presenting with the high risk factors identified in this study should be considered for further evaluation and monitoring. Current protocols for the therapeutic management of these higher risk patients should be considered, and compliance should be encouraged.
Key Words: hospitalization, stroke, ischemic
Platelet-Derived Growth Factor, Intimal Hyperplasia, and Ischemic Complications in Giant Cell Arteritis—Kaiser M, Weyand CM, Bjornsson J, Goronzy JJ (Mayo Clinic, 200 First St SW, Rochester, MN 55905)—Arthritis Rheum. 1998;41:623–633. ©1998. American College of Rheumatology.
Objective. To explore whether vasoocclusion in giant cell (temporal) arteritis (GCA) is related to intimal hyperplasia and in situ production of platelet-derived growth factor (PDGF).
Methods. Temporal artery biopsy specimens from patients with GCA were analyzed for the presence of intimal hyperplasia. Expression of PDGF-A and PDGF-B was assessed by immunohistochemistry and digitized image analysis.
Results. PDGF-A and PDGF-B were widely expressed in inflamed arteries. CD68+ macrophages, smooth muscle cells, and multinucleated giant cells produced PDGF, whereas hyperplastic intimal tissue did not. Arteries with marked luminal narrowing and those with no or minimal luminal narrowing differed in the extent and distribution of PDGF expression. Concentric intimal hyperplasia was associated with the accumulation of PDGF-A– and PDGF-B–producing CD68+ macrophages at the media–intima junction. PDGF+, CD68+ macrophages in close proximity to the internal elastic lamina frequently coproduced matrix metalloproteinase 2. Intimal hyperplasia of the temporal artery correlated with ischemic complications of GCA, such as ocular involvement, jaw claudication, and aortic arch syndrome.
Conclusion. Production of PDGF has a role in arterial occlusion in GCA. The excessive fibroproliferative response leading to luminal narrowing can be distinguished from the stenosing process in atherosclerosis and postangioplasty restenosis, suggesting that there are different response patterns to arterial injury. In GCA, macrophages at the media–intima border are the dominant source of PDGF. Since vasoocclusion is associated with a number of serious complications in GCA, inhibition of intimal proliferation should be a major goal of treatment.
Key Words: giant cell arteritis, ischemia
Topographic Pattern of Advanced Atherosclerotic Lesions in Carotid Arteries—Khatibzadeh M, Sheikhzadeh A (Dept of Cardiology, Medical Univ of Lübeck, Ratzeburger Allee 160, D-23538 Lübeck Germany), Gromoll B, Stierle U—Cardiology. 1998;89:235–240. ©1998 S. Karger AG, Basel.
Ulcers in extracranial carotid arteries are a known source of cerebral embolism. However, there are no data available on the prevalence of ulcerations located at the origin of these vessels in the aortic arch. Therefore, in this pathological study the topographic distribution of ulcerated lesions were determined in these arteries. One hundred and one consecutively autopsied patients composed the study group. Ulcerated plaques were sought for in both carotid arteries, from their origin in the arch up to the carotid canal, and also in the aortic arch and ascending aorta. The two anatomical sites mostly affected by atherosclerosis were the region of the carotid sinus and the orifices of cervical arteries in the aortic arch. More than one third of all ulcers were at the orifices of cervical arteries in the arch. Interestingly, ulcers at the orifice of the left common carotid artery in the arch were accompanied with other ulcers located elsewhere in the remaining segments of the left carotid system, whereas ulcerations at the orifice of brachiocephalic trunk were not accompanied with other concomitant lesions in the right carotid system. Furthermore, there was no symmetric distribution of ulcerated plaques in both carotid systems.
Key Words: carotid arteries, atherosclerosis
Reperfusion After Thrombolytic Therapy of Embolic Stroke in the Rat: Magnetic Resonance and Biochemical Imaging—Busch E, Krüger K, Allegrini PR, Kerskens CM, Gyngell ML, Hoehn-Berlage M, Hossmann K-A (Max-Planck-Institut für neurologische Forschung, Gleuelerstrasse 50, D-50931 Köln Germany)—J Cereb Blood Flow Metab. 1998;18:407–408. ©1998 The International Society of Cerebral Blood Flow and Metabolism by Lippincott-Raven Publishers, Philadelphia.
The effect of thrombolytic therapy was studied in rats submitted to thromboembolic stroke by intracarotid injection of autologous blood clots. Thrombolysis was initiated after 15 minutes with an intracarotid infusion of recombinant tissue-type activator (10 mg/kg body weight). Reperfusion was monitored for 3 hours using serial perfusion- and diffusion magnetic resonance imaging, and the outcome of treatment was quantified by pictorial measurements of ATP, tissue pH, and blood flow. In untreated animals, clot embolism resulted in an immediate decrease in blood flow and a sharp decrease in the apparent diffusion coefficient (ADC) that persisted throughout the observation period. Thrombolysis successfully recanalized the embolized middle cerebral artery origin and led to gradual improvement of blood flow and a slowly progressing reversal of ADC changes in the periphery of the ischemic territory, but only to transient and partial improvement in the center. Three hours after initiation of thrombolysis, the tissue volume with ADC values less than 80% of control was 39±22% as compared to 61±20% of ipsilateral hemisphere in untreated animals (means±SD, P=.03) and the volume of ATP-depleted brain tissue was 25±31% as compared to 46±29% in untreated animals. Recovery of ischemic brain injury after thromboembolism is incomplete even when therapy is started as early as 15 minutes after clot embolism. Possible explanations for our findings include downstream displacement of clot material, microembolism of the vascular periphery, and events associated with reperfusion injury.
Key Words: reperfusion, magnetic resonance imaging
677C to T Mutation in the 5,10-Methylenetetrahydrofolate Reductase (MTHFR) Gene and Plasma Homocyst(e)ine Levels in Patients With TIA or Minor Stroke—Lalouschek W (Univ Clinic for Neurology, Univ Vienna Medical School, Währinger Gürtel 18–20, Vienna, Austria), Aull S, Korninger L, Mannhalter C, Pabinger-Fasching I, Schmid RW, Schnider P, Zeiler K—J Neurol Sci. 1998;155:156–162. ©1998 Elsevier Science B.V.
It was the aim of this study to determine the associations of clinical and laboratory data with plasma homocyst(e)ine levels in patients with transient ischemic attack (TIA) or minor stroke (MS), with special reference to their 677C to T mutation status in the 5,10-methylenetetrahydrofolate reductase (5,10-MTHFR) gene. Seventy-six patients with TIA or MS were investigated at least 3 months after their (last) clinical event. By means of univariate analysis, significant correlations of homocyst(e)ine levels with male gender (P<0.02), age (P<0.0005), creatinine levels (P<0.0002), folate levels (inversely, P<0.05), and alcohol use (P<0.02) were found, but not with vitamin B12 levels. Multivariate regression analysis, including age, creatinine levels, and folate levels as independent variables, revealed age (P<0.01) and creatinine levels (P<0.02) to be significantly correlated with homocyst(e)ine levels. After adjustment for age, creatinine levels and homocyst(e)ine levels remained significantly correlated to each other (P<0.005), whereas the relation between folate levels and homocyst(e)ine levels was no longer significant (P=0.10). Mutation-positive patients exhibited moderately and statistically non-significantly higher homocyst(e)ine levels than mutation-negative patients, particularly those who were homozygous positive. Homocyst(e)ine levels were closely correlated with creatinine levels (P<0.0002) and with folate levels (inversely, P<0.05), but only in mutation-positive and not in mutation-negative patients. Homozygous positive, heterozygous positive, and mutation-negative patients did not differ with respect to clinical and laboratory data concerning ‘risk factors for stroke’ or co-existing vascular disease. In conclusion, the associations of creatinine levels and, inversely, of folate levels with plasma homocyst(e)ine levels in patients with TIA or MS are dependent on the 5,10-MTHFR mutation status. Significant correlations between these variables were found only in mutation-positive but not in mutation-negative patients.
Key Words: homocyst(e)ine, cerebral ischemia, transient
Progression of Cerebral Amyloid Angiopathy: Accumulation of Amyloid-β 40 in Affected Vessels—Alonzo NC, Hyman BT, Rebeck GW, Greenberg SM (Massachusetts General Hospital, Wang ACC 836, Boston, MA 02114)—J Neuropath Exp Neurology. 1998;57:4. ©1998 by the American Association of Neuropathologists.
Cerebrovascular deposits of amyloid (cerebral amyloid angiopathy, or CAA) are generally asymptomatic, but in advanced cases, they can lead to vessel rupture and hemorrhage. The process of progression in CAA was studied by comparison of postmortem brains with asymptomatic (“mild”) CAA to brains with the form of the disease associated with hemorrhage (“severe CAA”). Cortical and meningeal vessels were immunostained for β-amyloid and examined by confocal microscopy and by systematic quantitative sampling. We focused on 2 quantitative parameters: the proportion of vessels affected by amyloid (a measure of amyloid seeding of vessels) and the amount of amyloid per affected vessel (a measure of growth of existing lesions). Surprisingly, there was no difference between the proportion of affected cortical vessels in mild and severe CAA (0.29 vs 0.32, p=0.65), but rather an increase in the area of the 40 amino acid form of β-amyloid per affected cortical vessel (198.5±38.7 vs 455.8±100.9 μm2/vessel, p<0.007). Increasing doses (from 0 to 1 to 2 copies) of the apolipoprotein E ε4 allele were also associated with greater amyloid per vessel without change in the proportion of affected vessels within each class of CAA severity. These findings suggest that progression from asymptomatic to advanced CAA reflects progressive accumulation of amyloid in vessels previously seeded with amyloid, and that this process is selectively enhanced by apolipoprotein E ε4.
Key Words: amyloid, hemorrhagic stroke
Subclinical Cerebral Lesion Accumulation on Serial Magnetic Resonance Imaging (MRI) in Patients With Hypertension: Risk Factors—Shintani S (Dept of Neurology, Toride Kyodo General Hospital, 2-1-1 Hongoh, Toride City, 302 Ibaraki, Japan), Shiigai T, Arinami T—Acta Neurol Scand. 1998;97:251–256. ©Munksgaard 1998.
Objectives—We investigated the occurrence in hypertensive patients of new subclinical changes in the brain by serial magnetic resonance imaging (MRI). Methods—MRI was performed serially in 98 hypertensive subjects without neurologic deficits at least once a year for 3 years. All received antihypertensive medicines. Blood pressure, serum lipids, diabetes mellitus, body mass index (BMI), and other clinical factors were correlated with results. Results—Seventy-nine patients had unchanged MRI findings, while 19 developed new lesions (silent lacunar infarct and état criblé in 3, silent lacunar infarct in 9, and état criblé in 7). Follow-up systolic blood pressures were significantly higher than individual baselines in the unchanged group, while the follow-up diastolic blood pressures in the new lesion group were significantly lower than in the unchanged group. BMI was significantly lower in the new lesion group. Follow-up HbA1c levels in both groups were significantly higher than at baseline. Diabetes mellitus was significantly more frequent in the new lesion group than in the unchanged group. No significant differences were apparent in serum lipids level, prescribed antihypertensive medications, and other potential risk factors. Conclusions—New subclinical MRI changes in hypertensive subjects occurred relatively frequently (19 of 98 subjects, or 19.4%). An excessive fall in diastolic blood pressure, diabetes mellitus, and low BMI emerged as candidate risk factors for these changes.
Key Words: hypertension, magnetic resonance imaging
Cranial Computed Tomography Interpretation in Acute Stroke: Physician Accuracy in Determining Eligibility for Thrombolytic Therapy—Schriger DL (924 Westwood Blvd, Suite 300, Los Angeles, CA 90024), Kalafut M, Starkman S, Krueger M, Saver JL—JAMA. 1998;279:1293–1297.
Context—Intracranial hemorrhage must be excluded prior to administration of thrombolytic agents in acute stroke.
Objective—To evaluate physician accuracy in cranial computed tomography scan interpretation for determining eligibility for thrombolytic therapy in acute stroke.
Design—Administration of randomly selected, randomly ordered series of 15 computed tomography scans from a pool of 54 scans that demonstrated intracerebral hemorrhage, acute infarction, intracerebral calcifications (impostor for hemorrhage), old cerebral infarction (impostor for acute infarction), and normal findings.
Participants—A convenience sample of 38 emergency physicians, 29 neurologists, and 36 general radiologists.
Main Outcome Measures—Physician determination of eligibility for thrombolytic therapy based on computed tomography scan interpretation.
Results—Average correct score by all physicians on all computed tomography scans was 77% (95% confidence interval, 74%–80%). Of 569 computed tomography readings by emergency physicians, 67% were correct; of 435 readings by neurologists, 83% were correct; and of 540 readings by radiologists, 83% were correct. Overall sensitivity for detecting hemorrhage was 82% (95% confidence interval, 78%–85%); 17% of emergency physicians, 40% of neurologists, and 52% of radiologists achieved 100% sensitivity for identification of hemorrhage.
Conclusion—Physicians in this study did not uniformly achieve a level of sensitivity for identification of intracerebral hemorrhage sufficient to permit safe selection of candidates for thrombolytic therapy.
Key Words: thrombolytic therapy, tomography, x-ray computed
Cerebral Blood Flow and Oxygen Metabolism in Senile Dementia of Alzheimer’s Type and Vascular Dementia With Deep White Matter Changes—Tohgi H (Dept of Neurology, Iwate Medical Univ, 19-1 Uchimaru, Morioka 020, Japan), Yonezawa H, Takahashi S, Sato N, Kato E, Kudo M, Hatano K, Sasaki T—Neuroradiology. 1998;40:131–137. ©Springer-Verlag 1998.
Regional cerebral blood flow (rCBF), cerebral metabolic rate of oxygen (rCMRO2), oxygen extraction fraction (rOEF), and cerebral blood volume (rCBV) were investigated using positron emission tomography (PET) in 16 patients with senile dementia of Alzheimer’s type (SDAT), and compared with those of 6 nondemented and 3 demented patients with deep white matter high signal (DWMH) on T2-weighted MRI and 6 controls. rCBF, rCMRO2 and rCBV were determined using C15O2, 15O2 and C15O, respectively. rCBF and CMRO2 were significantly decreased in the frontal, parietal and temporal cortex (P<0.05) in patients with SDAT, and showed a significant correlation with the severity of dementia (P<0.05). In patients with DWMH rCBF was significantly decreased in the parietal cortex and in the frontal white matter in nondemented patients, and in the cerebral cortex and white matter of most regions studied in demented patients (P<0.05), whereas rCMRO2 was significantly reduced in only the frontal and temporal cortex of demented patients (P<0.05). rOEF was significantly increased in the parietal cortex of patients with SDAT and in the white matter of patients with SDAT or DWMH (P<0.05), and the increase in the frontal white matter significantly paralleled the progression of dementia in patients with SDAT (P<0.05). rCBV was significantly decreased in the parietal and temporal cortex of patients with SDAT (P<0.05), but not in any areas of those with DWMH. These results suggest that rOEF is increased in both SDAT and patients with DWMH. The increase in rOEF in patients with SDAT may be accounted for by reduction in rCBV resulting from decreased activity in the vasodilatory cholinergic system, impairment of glucose metabolism and white matter changes; the rOEF increase in patients with DWMH suggests relative preservation of oxidative metabolism compared to disturbed perfusion.
Key Words: cerebral blood flow, dementia
Acute Occlusion of the Middle Cerebral Artery: Early Evaluation with Triphasic Helical CT: Preliminary Results—Na DG (Dept of Radiology, College of Medicine, Sung Kyun Kwan Univ, Samsung Medical Center, 50 Irwon-Dong, Kangnam-Ku, Seoul 135-710, South Korea), Byun HS, Lee KH, Chung CS, Kim EY, Ro DW, Jeong YK, Kim HD, Kim SH—Radiology. 1998;207:113–122. ©RSNA, 1998.
Purpose: To evaluate use of triphasic helical computed tomography (CT) for early diagnosis of occlusion and assessment of ischemia in cases of acute middle cerebral arterocclusion.
Materials and Methods: Thirty-five patients with acute ischemia underwent triphasic helical CT within 6 hours after symptom onset. Early arterial, perfusion, and delayed phase CT scans were obtained 18, 30, and 80 seconds, respectively, after contrast material administration. Eighteen patients had proximal middle cerebral arterial occlusion diagnosed at magnetic resonance (MR) or digital subtraction angiography. Follow-up CT or MR imaging was performed in all patients. Two independent observers interpreted images for signs of arterial occlusion, collateral vessels, and the ischemic zone.
Results: One observer found at least one of three signs in 17 of the 18 patients with occlusion, and the other found at least one sign in all 18: Early decreased arterial contrast enhancement was seen by both observers in 11 patients (κ=0.77), a nonenhancing arterial segment was seen by the two observers in 12 and 14 (κ=0.73), and delayed asymmetric arterial enhancement was seen in 13 and 16 (κ=0.49). Triphasic CT findings of the ischemic zone were consistent with follow-up CT or MR imaging findings in seven of 12 patients.
Conclusion: Triphasic helical CT is useful for early diagnosis of acute proximal middle cerebral arterial occlusion and assessment of the ischemic zone.
Key Words: middle cerebral artery occlusion, tomography, x-ray computed
Predicting Hemodynamic Ischemia by Transcranial Doppler Monitoring During Therapeutic Balloon Occlusion of the Internal Carotid Artery—Eckert B (Universitätskrankenhaus Hamburg-Eppendorf, Abteilung für Neuroradiologie, Martinistr 52, D-20246 Hamburg, Germany), Thie A, Carvajal M, Groden C, Zeumer H—Am J Neuroradiol. 1998;19:577–582. ©American Society of Neuroradiology.
PURPOSE: Our objective was to evaluate the sensitivity of transcranial Doppler (TCD) sonographic monitoring during permanent balloon occlusion of the internal carotid artery (ICA) in predicting hemodynamic ischemia.
METHODS: Thirty-two consecutive patients underwent controlled therapeutic balloon occlusion of the ICA. Selection criteria included assessment of the circle of Willis by compression angiography, clinical tolerance during a 20-minute test occlusion, and TCD monitoring of the ipsilateral middle cerebral artery. The mean blood flow velocity (MBFV) (n=32) and pulsatility index (PI) (n=28) were recorded. In 25 patients, MBFV changes upon motor stimulation were recorded before and after ICA occlusion.
RESULTS: Twenty-eight (88%) of the patients had no complications. Three patients suffered delayed symptoms 30 minutes to 20 hours after balloon detachment. Two of these patients recovered spontaneously within 1 day, the other improved after extracranial/intracranial (EC/IC) bypass surgery. One patient, who did not tolerate the test occlusion, suffered a hemodynamic stroke despite EC/IC bypass before permanent balloon occlusion. No embolic complications occurred. The mean MBFV reduction was 20% (range, 0% to 55%); the mean PI reduction was 20% (range, 0% to 56%). No complications occurred in patients who had mild MBFV and PI reduction (30% or less, n=21). All three patients with severe MBFV or PI reduction (>50%) had neurologic symptoms. Among those with moderate MBFV or PI reduction (30% to 50%, n=8), symptoms developed in only one patient who had moderate reduction of both MBFV (33%) and PI (38%). Motor vasoreactivity showed wide variation and was markedly reduced in two symptomatic patients.
CONCLUSION: TCD monitoring reflects changes in cerebral hemodynamics after therapeutic balloon occlusion of the ICA. MBFV and PI reductions under 30% are highly predictive of clinical tolerance. A reduction of more than 50% may be a critical threshold for the occurrence of symptoms; in such cases, EC/IC bypass should be considered before proceeding with permanent balloon occlusion.
Key Words: carotid artery occlusion, hemodynamics
Preserved Endothelial Function in IDDM Patients, but Not in NIDDM Patients, Compared With Healthy Subjects—Enderle MD (Eberhard-Karls-Universität Tübingen, Medizinische Klinik und Poliklinik, Abt Innere Medizin IV, Otfried-Müller-Str, 10 D-72076, Tübingen, Germany), Benda N, Schmuelling R-M, Haering HU, Pfohl M—Diabetes Care. 1998;21:271–277.
Objective—To examine endothelial function (EF) noninvasively in IDDM and NIDDM patients with long diabetes duration.
Research Design and Methods—We studied EF in 17 IDDM patients without diabetic complications and in 25 NIDDM patients with comparable glycemic control and with diabetic complications and compared both with nondiabetic control subjects matched for age, sex, and lumen diameter. Using high-resolution ultrasound, we measured the endothelial-dependent (FAD%) and independent vasodilation (GTN%); the blood flow at rest, postocclusive, and after application of 400 μg glyceroltrinitrate of the brachial artery; and the intima media thickness (IMT) of the common carotid artery.
Results—In the IDDM patients, neither FAD% (8.2±4.6 vs. 7.6±4.2%), GTN% (16.3±4.9 vs. 18.4±6.4%), nor postocclusive blood flow (40.6±19.1 vs. 39.3±23.6 cm/s) differed from the control subjects. IMT (0.59±0.10 vs. 0.55±0.14 mm) was slightly, but not significantly, elevated. In contrast, the NIDDM patients showed an impaired FAD% (3.8±3.3 vs. 6.9±4.4%, P<0.01), no difference in GTN%, and a decreased postocclusive blood flow (18.5±13.8 vs. 32.7±20.0 cm/s, P<0.01). IMT was significantly increased in NIDDM patients (0.77±0.14 vs. 0.62±0.10 mm, P<0.001).
Conclusions—In contrast to NIDDM patients with cardiovascular complications, IDDM patients with long diabetes duration and good long-term metabolic control do not have impaired EF compared with control subjects.
Key Words: endothelium, vascular, diabetes mellitus
Transcranial Dopper, MRA, and MRI as a Screening Examination for Cerebrovascular Disease in Patients With Sickle Cell Anemia: An 8-Year Study—Seibert JJ (Dept of Radiology/Slot 105 Arkansas Children’s Hospital, 800 Marshall St., Little Rock, AR 72202-3591), Glasier CM, Kirby RS, Allison JW, James CA, Becton DL, Kinder DL, Cox KS, Flick EL, Lairry F, Jackson JF, Graves RA—Pediatr Radiol. 1998;28:138–142. ©Springer-Verlag 1998.
Objective. The authors previously reported five transcranial Doppler ultrasonography (TCD) findings as significant in detecting clinical cerebrovascular disease in a 4-year study in patients with sickle cell disease. This is a follow-up to evaluate the validity of the original findings over another 4-year period during which the study population doubled. A clinical follow-up of the original asymptomatic sickle cell patients with positive TCD, MRA, and MRI was also made.
Materials and methods. Over an 8-year period TCD, MRI, and MRA were prospectively performed in 90 sickle cell patients who were clinically asymptomatic for stroke and in 27 sickle cell patients with clinical stroke.
Results. Of the 4 out of original 46 control patients in 1992 who had positive MRA and TCD, 3 have subsequently had clinical stroke. None of the 9 original patients with positive TCD and positive MRI but negative MRA have developed stroke. All five original TCD indicators of disease were still significant (P<0.05) for detecting clinical disease: maximum velocity in ophthalmic artery (OA) >35 cm/s, mean velocity in middle cerebral artery (MCA) >170 cm/s, resistive index (RI) in OA <50, velocity in OA greater than in MCA, and velocity in posterior cerebral (PCA), vertebral, or basilar arteries greater than in MCA. Four additional factors were also significant: turbulence, PCA or ACA without MCA, RI <30, and maximum velocity in MCA >200 cm/s.
Conclusion. Positive MRA with a positive TCD in an asymptomatic patient in long-term follow-up suggests a trend for developing clinical stroke. A 4- to 8-year follow-up of nine patients with positive TCD, positive MRI, but not positive MRA did not show development of clinical stroke. Nine Doppler findings are significant in screening for clinically symptomatic vascular disease in sickle cell patients. It is recommended that children with sickle cell disease be screened for cerebrovascular disease with TCD. If one or two indicators of abnormality are present, MRA is recommended. If the MRA is positive, the patient may be considered for transfusion therapy or other treatment for prevention of stroke.
Key Words: anemia, sickle cell, ultrasonography
Predictors of Stroke Complicating Carotid Artery Stenting—Mathur A, Roubin GS (Lenox Hill Hospital, Black Hall, 130 E 77th St, New York, NY 10021-1803), Iyer SS, Piamsonboon C, Liu MW, Gomez CR, Yadav JS, Chastain HD, Fox LM, Dean LS, Vitek JJ—Circulation. 1998;97:1239–1245. ©American Heart Association, Inc.
Background—The evolving technique of carotid stenting is being evaluated as an alternative to endarterectomy. Identification of the factors that predispose a patient to neurological complications would facilitate further refinement of the technique and optimize patient selection.
Methods and Results—We analyzed the impact of various clinical, morphological, and procedural determinants on the development of procedural strokes in 231 patients who underwent elective (primary) stenting of 271 extracranial carotid arteries. The mean age of the patients was 68.7±10 years, 165 (71%) were males, and 139 (60%) had symptoms attributed to the lesion treated. This series represented a high-risk subset with 164 patients (71%) having significant coronary artery disease, 91 (39%) having bilateral disease, and 28 (12%) having contralateral carotid occlusion. Of the treated vessels, 59 (22%) had prior carotid endarterectomy, 66 (24%) had ulcerated plaques, and 87 (32%) had calcified lesions. Only 37 treated vessels (14%) would have been eligible for inclusion in the North American Symptomatic Carotid Endarterectomy Trial (NASCET). There were 17 (6.2%) minor and 2 (0.7%) major strokes during and within 30 days of the procedure. NASCET-eligible patients had a low (2.7%) risk of procedural strokes after carotid stenting. The results of multivariate analysis revealed advanced age (P=.006) and presence of long or multiple stenoses (P=.006) as independent predictors of procedural strokes.
Conclusions—During this procedural developmental phase of carotid stenting, neurological complications were highly dependent on patient selection. Advanced age and long or multiple stenoses were independent predictors of procedural stroke.
Key Words: stents, complications
Low Molecular Weight Heparinoid ORG 10172 (Danaparoid) and Outcome After Acute Ischemic Stroke: A Randomized Controlled Trial—Adams HP (Div of Cerebrovascular Diseases, Dept of Neurology, University of Iowa College of Medicine, 200 Hawkins Dr, Iowa City, IA 52252), The Publications Committee for the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) Investigators—JAMA. 1998;279:1265–1272.
Context—Anticoagulation with unfractionated heparin is used commonly for treatment of acute ischemic stroke, but its use remains controversial because it has not been shown to be effective or safe. Low molecular weight heparins and heparinoids have been shown to be effective in preventing deep vein thrombosis in persons with stroke, and they might be effective in reducing unfavorable outcomes following ischemic stroke.
Objective—To test whether an intravenously administered low molecular weight heparinoid, ORG 10172 (danaparoid sodium), increases the likelihood of a favorable outcome at 3 months after acute ischemic stroke.
Design—Randomized, double-blind, placebo-controlled, multicenter trial.
Setting and Participants—Between December 22, 1990, and December 6, 1997, 1281 persons with acute stroke were enrolled at 36 centers across the United States.
Intervention—A 7-day course of ORG 10172 or placebo was given initially as a bolus within 24 hours of stroke, followed by continuous infusion in addition to the best medical care. Doses were adjusted in response to anti-factor Xa activity.
Main Outcome Measures—Favorable outcome rated as the combination of a Glasgow Outcome Scale score of I or II and a modified Barthel Index of 12 or greater on a scale of 0 to 20 at 3 months or 7 days; very favorable outcome was recorded for the combination of a Glasgow Outcome Scale of I and a Barthel Index of 19 or 20 at 3 months or 7 days.
Results—At 3 months, 482 (75.2%) of 641 persons assigned to treatment with ORG 10172 and 467 (73.7%) of 634 patients treated with placebo had favorable outcomes (P=.49); 49.5% and 47%, respectively, of patients in each group had very favorable outcomes at 3 months. At 7 days, 376 (59.2%) of 635 persons given ORG 10172 and 344 (54.3%) of 633 receiving placebo had favorable outcomes (P=.07). For the same interval, 215 (33.9%) of 635 persons given ORG 10172 and 176 (27.8%) of 633 persons administered placebo had very favorable outcomes (P=.01; odds ratio, 1.36; 95% confidence interval, 1.06–1.73). Within 10 days of onset of treatment, serious intracranial bleeding events occurred in 14 patients given ORG 10172 (15 events) and in 4 placebo-treated patients (5 events) (P=.05).
Conclusion—Despite an apparent positive response to treatment at 7 days, emergent administration of the antithrombotic agent, ORG 10172, is not associated with an improvement in favorable outcome at 3 months.
Key Words: anticoagulants, stroke outcome
Patients With Nonvalvular Atrial Fibrillation at Low Risk of Stroke During Treatment With Aspirin: Stroke Prevention in Atrial Fibrillation III Study—McBride R (SPAF Statistical Coordinating Center, 1107 NE 45th St, Suite 520, Seattle, WA 98105), The SPAF III Writing Committee for the Stroke Prevention in Atrial Fibrillation Investigators—JAMA. 1998;279:1273–1277.
Context—Nonvalvular atrial fibrillation (AF) carries an increased risk for stroke, but absolute rates of stroke vary widely within the broad spectrum of AF patients.
Objective—To prospectively validate a risk stratification scheme identifying patients with AF with low rates of stroke when given aspirin.
Design—Prospective cohort study with mean duration of follow-up of 2.0 years, conducted between 1993 and 1997.
Setting—Outpatient clinics affiliated with academic medical centers.
Patients—Patients with AF categorized as “low risk” based on the absence of 4 prespecified thromboembolic risk factors: recent congestive heart failure or left ventricular fractional shortening of 25% or less, previous thromboembolism, systolic blood pressure greater than 160 mm Hg, or female sex at age older than 75 years.
Intervention—All participants given aspirin, 325 mg/d.
Main Outcome Measures—Ischemic stroke (considered disabling when Rankin score was II or worse 1–3 months later) and systemic embolism (primary events).
Results—Among 892 participants, the mean (SD) age was 67 (10) years, 78% were men, and histories of hypertension, diabetes, and ischemic heart disease were present in 46%, 13%, and 16%, respectively. The rate of primary events was 2.2% per year (95% confidence interval [CI], 1.6%–3.0%), of ischemic stroke was 2.0% per year (95% CI, 1.5%–2.8%), and of disabling ischemic strokes was 0.8% per year (95% CI, 0.5%–1.3%). Those with a history of hypertension had a higher rate of primary events (3.6% per year) than those with no history of hypertension (1.1% per year) (P<.001). The rate of disabling ischemic stroke was low in those with and without a history of hypertension (1.4% per year and 0.5% per year, respectively). The rate of major bleeding during aspirin therapy was 0.5% per year.
Conclusion—Patients with AF who have relatively low rates of ischemic stroke, particularly disabling stroke, during treatment with aspirin can be reliably identified.
Key Words: atrial fibrillation, aspirin
Entering the Ninth Decade Is Not a Contraindication for Carotid Endarterectomy—Hoballah JJ (Dept of Surgery, The University of Iowa Hospitals and Clinics, 200 Hawkins Dr, Iowa City, Iowa), Nazzal MM, Jacobovicz C, Sharp WJ, Kresowik TF, Corson JD—Angiology. 1998;49:275–278. ©Westminister Publications, Inc.
The role of carotid endarterectomy (CEA) in stroke prevention is now better defined. However, its role in patients older than 79 years of age is controversial. This group of patients has been excluded in most clinical trials. In this study the authors reviewed their experience with CEA patients >79 years old. The records of all patients older than 79 years of age who underwent a CEA in a recent time period from January 1988 to December 1996 were retrospectively reviewed. Forty-one patients (31 men, 10 women) were identified by computer search. The indication for operation included transient ischemic attack in 12 (29.3%), amaurosis fugax in nine (22%), stroke in two (4.9%), and nonhemispheric symptoms in three (7.3%). Fifteen patients (36.6%) were asymptomatic. Medical risk factors included coronary artery disease in 26 (63.4%), hypertension in 22 (53.7%), and smoking in 12 (29.3%). The procedure was performed under EEG monitoring in all patients. General anesthesia was administered in 37 (90%) and regional anesthesia in four (10%). Shunts were used in four (10%) patients. The internal carotid artery was patched in 16 patients (39%). One patient (2.4%) developed a perioperative stroke and only one patient developed perioperative myocardial infarction (MI). None of the patients died within 30 days of surgery. In addition to the one MI case, five patients developed minor complications. The average length of time for stay after CEA was 3.4 days. Patients were followed up for an average of 20.7 months. Six patients died during follow-up. Four of those died from an MI and two from a stroke. The authors conclude that with proper selection of patients, CEA is safe in the octogenarian. Age alone should not be a contraindication for CEA.
Key Words: carotid endarterectomy, aging
Influence of Surgical Experience on the Results of Carotid Surgery—Kantonen I (Div of Vascular Surgery, Dept of Surgery, Helsinki Univ Central Hospital, Kasarmikatu 11-13, SF-00130 Helsinki, Finland), Lepäntalo M, Salenius J-P, Mätzke S, Luther M, Ylönen, Finnvasc Study Group—Eur J Vasc Endovasc Surg. 1998;15:155–160. ©1998 W.B. Saunders Company Ltd.
Objective: To assess the 30-day mortality and morbidity rates related to carotid endarterectomy on a nation-wide basis.
Design: Retrospective cross-sectional study based on vascular registry Finnvasc.
Materials and methods: A total of 17 465 recorded vascular and endovascular procedures included exactly 1600 carotid endarterectomies performed by 104 surgeons in 23 hospitals. Fourteen per cent of the patients were operated on for asymptomatic carotid stenosis.
Results: The combined mortality and permanent stroke rate was 3.3%, without any difference between operations done on symptomatic or asymptomatic patients. There was a clear inverse association between surgeon’s carotid case load and poor outcomes in carotid surgery (p<0.005), the critical patient mass per surgeon and year being 10 operations. There was no association between outcome after carotid surgery and hospital volume of carotid operations.
Conclusions: Surgeon’s experience in carotid surgery clearly improves the results of carotid surgery.
Key Words: carotid endarterectomy, outcome
Indications, Outcomes, and Provider Volumes for Carotid Endarterectomy—Cebul RD (MetroHealth Medical Center, 2500 MetroHealth Dr, Rm 220A, Cleveland, OH 44109-1998), Snow RJ, Pine R, Hertzer NR, Norris DG—JAMA. 1998;279:1282–1287.
Context—While trials have demonstrated that carotid endarterectomy is superior to best medical therapy, most recently among asymptomatic patients, uses and outcomes of the procedure in more representative settings have not been established.
Objectives—To profile the use and outcomes of carotid endarterectomy in a representative sample of Ohio’s Medicare beneficiaries and to examine the relationships between provider-specific procedural volumes and patient outcomes.
Design—Retrospective cohort using Medicare Provider Analysis and Review files supplemented by detailed reviews of medical records on a random sample of patients.
Setting—Ohio hospitals performing carotid endarterectomy.
Patients—A random sample of 678 charts of the 4120 non–health maintenance organization Medicare beneficiaries who underwent carotid endarterectomy between July 1, 1993, and June 30, 1994.
Main Outcome Measures—Nonfatal stroke or death within 30 days of surgery.
Results—The reviewed patients were similar to all eligible patients in sociodemographic characteristics and 30-day mortality rates. Among the 678 patients, indications for surgery were asymptomatic carotid stenosis in 167 (24.6%), transient ischemic attack in 294 (43.4%), completed stroke, in 62 (9.1%), and nonspecific symptoms in 155 (22.9%). Thirty-two patients (4.7%) died or suffered nonfatal strokes by 30 days postoperatively. In univariate analyses, rates varied by hospital volume (P=.004) but not surgeons’ volume (P=.47), although power to detect this difference was limited. Patients at higher- and lower-volume hospitals had similar indications and distributions of comorbidities. In analyses controlling for indications, comorbid conditions, and surgeon’s volume, being operated on in a higher-volume hospital conferred a 71% reduction in risk for 30-day stroke or death (odds ratio, 0.29; 95% confidence interval, 0.12–0.69; P=.006).
Conclusions—Almost half (47.5%) of the carotid endarterectomies among Ohio’s Medicare population are performed on persons who are asymptomatic or who have nonspecific symptoms. These results highlight the importance of identifying patients and providers having the most favorable outcome profiles. The higher rate of adverse outcomes observed in lower-volume hospitals deserves further investigation, as it does not appear to be due to differences in patient selection.
Key Words: carotid endarterectomy, outcome
Variation in Carotid Endarterectomy Mortality in the Medicare Population—Wennberg DE (Div of Health Services Research, Maine Medical Center, Portland, ME 04102), Lucas FL, Birkmeyer JD, Bredenberg CE, Fisher ES—JAMA. 1998;279:1278–1281.
Context—The North American Symptomatic Carotid Endarterectomy Trial (NASCET) and the Asymptomatic Carotid Atherosclerosis Study (ACAS) demonstrated the efficacy of carotid endarterectomy (CEA) in reducing the risk of stroke and death in selected patients when surgery was performed in institutions whose participation depended on demonstrated excellence. Thirty-day mortality rates in the trials were very low: 0.6% in NASCET and 0.1% in ACAS.
Objective—To assess perioperative mortality among Medicare patients undergoing CEA in all nonfederal institutional settings.
Design—Retrospective national cohort study.
Setting and Patients—All 113 300 Medicare patients undergoing CEA during 1992 and 1993 in “trial hospitals” (those participating in NASCET and ACAS, n=86) and “nontrial hospitals” (all other nonfederal institutions performing CEAs, n=2613). Nontrial hospitals were stratified into terciles based on volume of CEAs performed.
Main Outcome Measures—Crude and adjusted perioperative (30 day) mortality rates.
Results—The perioperative mortality rate was 1.4% (95% confidence interval [CI], 1.2%–1.7%) at trial hospitals; mortality in nontrial hospitals was higher: 1.7% (95% CI, 1.6%–1.8%) (high volume); 1.9% (95% CI, 1.7%–2.1%) (average volume); 2.5% (95% CI, 2.0%–2.9%) (low volume); (P for trend, <.001). In multivariate modeling, patients undergoing their procedures at trial hospitals had a mortality risk reduction of 15% (95% CI, 0%–31%) compared with high-volume nontrial hospitals, 25% (95% CI, 7%–40%) compared with average-volume hospitals, and 43% (95% CI, 25%–56%) compared with low-volume hospitals (P for trend, <.001).
Conclusion—Medicare patients’ perioperative mortality following CEA is substantially higher than that reported in the trials, even in those institutions that participated in the randomized studies. Caution is advised in translating the efficacy of carefully controlled studies of CEA to effectiveness in everyday practice.
Key Words: carotid endarterectomy, mortality
Items of Interest
Anticoagulation to Prevent Stroke in Atrial Fibrillation and Its Implications for Managed Care
—Singer DE (Clinical Epidemiology Unit, S50-9, Massachusetts General Hospital, Boston MA)—
Am J Cardiol. 1998;81:35C–40C. ©1998 by Excerpta Medica Inc.
Brain Damage During Cardiopulmonary Bypass—Taylor KM (NHLI, Imperial College School of Medicine at Hammersmith Hospital, DuCane Rd, London, England W12)—Ann Thorac Surg. 1998;65:S20–S26. ©1998 by The Society of Thoracic Surgeons.
Quantitative Neuroimaging for the Evaluation of the Effect of Stroke Treatment—Heiss W-D (Dept of General Neurology, Max-Planck-Institute for Neurological Research, Gleuelerstrasse 50, D 50931 Köln, Germany), Graf R, Grond M, Rudolf J—Cerebrovasc Dis. 1998;8:23–29. ©1998 S. Karger AG, Basel.
Mitochondrial DNA in Stroke and Migraine With Aura—Ojaimi J, Katsabanis S, Bower S, Quigley A, Byrne E (Dept of Clinical Neurosciences, St Vincent’s Hospital, 41 Victoria Parade, Fitzroy, Victoria 3065, Australia)—Cerebrovasc Dis. 1998;8:102–106. ©1998 S. Karger AG, Basel.
Complications of Acute Ischaemic Stroke—van der Worp HB (Dept of Neurology, University Hospital Utrecht, Heidelberglaan 100, PO Box 85500, NL-3508 GA Utrecht The Netherlands), Kappelle LJ—Cerebrovasc Dis. 1998;8:124–132. ©1998 S. Karger AG, Basel.
The Recruitment Triangle: Reasons Why African Americans Enroll, Refuse to Enroll, or Voluntarily Withdraw From a Clinical Trial—Gorelick PB (Center for Stroke Research, 1645 W Jackson, Ste 400, Chicago, IL 60612), Harris Y, Burnett B, Bonecutter FJ—J Natl Med Assoc. 1998;90:141–151.
Pulsatile Tinnitus: A Review of 84 Patients—Waldvogel D, Mattle HP, Sturzenegger M, Schroth G (Dept of Neuroradiology, Univ of Bern, Inselspital, Bern, Switzerland)—J Neurol. 1998;245:137–142. ©Springer-Verlag 1998.
Plasticity of Primary Somatosensory Cortex Paralleling Sensorimotor Skill Recovery From Stroke in Adult Monkeys—Xerri C, Merzenich MM (Keck Center, 828-HSE, USCF, San Francisco, CA 94143-0732) Peterson BE, Jenkins W—J Neurophys. 1998;79:2119–2148. ©1998 The American Physiological Society.
Calcium Antagonists in Patients With Aneurysmal Subarachnoid Hemorrhage: A Systematic Review—Feigin VL, Rinkel GJE, (Dept of Neurology, Univ Hospital of Utrecht, PO Box 85500, 3500 GA Utrecht, Netherlands), Algra A, Vermeulen M, van Gijn J—Neurology. 1998;50:876–883. ©1998 by the American Academy of Neurology.
Homocysteine and Atherothrombosis—Welch GN, Loscalzo J (Boston Univ School of Medicine, 715 Albany St, W-507, Boston, MA 02118)—N Engl J Med. 1998:1042–1050. ©1998, Massachusetts Medical Society.
The abstracts in this section have been typeset for consistency with journal format but otherwise appear as in the original articles.
- Copyright © 1998 by American Heart Association