Showing papers in "Stroke in 1984"

The natural history of carotid arterial disease in asymptomatic patients with cervical bruits.

Abstract: A prospective study was initiated in January 1980 to follow with Duplex scanning a consecutive series of 167 asymptomatic patients with cervical bruits. Patients were seen at six month intervals for the first year and yearly thereafter. Based on previously validated criteria, disease at the carotid bifurcation was classified into 6 categories: Normal, 1-15% diameter reduction, 16-49%, 50-79%, 80-99%, and occlusion. Patients were evaluated to assess: the occurrence of new neurological symptoms, the stability of the lesions at the carotid bifurcation, and the possible role of risk indicators on disease changes. During follow-up, ten patients became symptomatic (6 with TIA's and 4 with stroke). The development of symptoms was accompanied by disease progression in 8 patients. By life table analysis, the annual rate occurrence of symptoms was 4%. The mean annual rate of disease progression to a greater than 50% stenosis was 8%. When progression in all categories was considered, 60% of the sides showed some disease aggravation. The presence of or progression to a greater than 80% stenosis was highly correlated (p = 0.00001) with either the development of a total occlusion of the internal carotid artery or new symptoms. The major risk factors associated with disease progression were cigarette smoking, diabetes mellitus, and age. Those patients under 65 years of age were most likely to show progression. Despite high rates of disease progression, this study further supports the contention that it is prudent to follow a conservative course in the management of asymptomatic patients presenting with a cervical bruit.(ABSTRACT TRUNCATED AT 250 WORDS)

Early mortality following stroke: a prospective review.

Abstract: Analysis of early deaths after stroke is important, since some deaths may be preventable. Previous studies have relied on retrospective and often incomplete clinical data, for comparison with pathological findings. The present study is based on 1073 consecutive stroke patients admitted to an intensive care stroke unit from a well-defined population. There were 212 deaths within the first 30 days, yielding a mortality rate of 20%. Clinical, radiological, and laboratory data were collected prospectively according to a standardized protocol. Autopsies were performed on 90 of the 212 patients, and CT scanning on a further 27. Early mortality after stroke exhibits a bimodal distribution. One peak occurs during the first week, and a second during the second and third weeks. The majority of deaths in the first week are due to transtentorial herniation. Of these, deaths due to hemorrhage usually occur within the first three days, whilst deaths due to infarction peak between the third and sixth day post ictus. After the first week, deaths due to relative immobility (pneumonia, pulmonary embolism and sepsis) predominate, peaking towards the end of the second week. Cardiac deaths occur throughout the first month, and unfortunately account for many deaths in patients with small functional deficits.

Disablement and quality of life after stroke.

Abstract: This study concerns the quality of life of patients after stroke and how this is influenced by disablement and emotional factors. Ninety-six consecutive patients of mean age 71 years were followed for two years. At the end of that time 23% had experienced a recurrence of stroke and 27% were deceased. Of the survivors 76% were independent as regards activities of daily life (ADL) and lived in their own homes. Age as well as initial function were prognostically important factors. Patients who could participate in interviews marked on a visual analogue scale their evaluation of quality of life before and after stroke. Most of them had experienced a decrease and no improvement was observed during the two years. The deterioration was more pronounced in ADL dependent patients than among the independent. However, depression and anxiety were found to be of similar importance for quality of life as was physical disablement. These findings call for a greater emphasis on psychological support in the care of post stroke patients. The visual analogue scale can be a useful tool for detecting special needs.

The profile of recovery from stroke and factors influencing outcome.

Abstract: The recovery from stroke of 154 survivors out of 255 stroke patients was analyzed. The outcomes documented were: discharge from hospital, activities of daily living (ADL) and return to work. A clear improvement in neurological and neuropsychological deficits was seen from the acute stage to three months, and this continued to twelve months, but to a lesser degree. 69% and 78% respectively, of the patients were at home three and twelve months after stroke. Independence in ADL increased from 32% acutely to 62% and 68% by three and twelve months, respectively. Of those gainfully employed prior to stroke, 55% had returned to work after twelve months. As a group, SAH patients seemed to recover better, but, for those that could be age-matched with infarction patients, there was no difference in outcome. Old age, acute stage hemiparesis, impairment of intelligence and memory, visuoperceptual deficits, nonadequate emotional reactions, and living alone all had a major negative influence on outcome. This study suggests that neurological and neuropsychological deficits, as well as emotional reactions, influence the outcomes after stroke, and all should be taken into consideration in prognosis.

Regional cerebral blood flow and oxygen consumption in human aging.

Abstract: The oxygen-15 continuous inhalation technique and PET were used to study the age-related changes in regional CBF and CMRO2. Twenty-seven patients, aged 19 to 76 years, free of any history of cerebral disease and vascular risk factors were examined in "resting state." CBF, CMRO2 and oxygen extraction fraction (OEF) values were calculated in seven different brain structures as well as in mean gray matter. Left-right ratios were also computed for all symmetrical structures analyzed. Mean gray CBF, but not mean gray CMRO2, decreased linearly with age (p less than 0.02). However, when younger subjects (less than or equal to 50 yrs) were compared to older subjects (greater than 50 yrs), an age-related matched decrease in CBF and CMRO2 was observed in mean gray matter (18% and 17%, p less than 0.05) and in all gray matter regions analyzed, particularly in frontal, temporo-sylvian and parieto-occipital cortex. White matter CBF and CMRO2 remained remarkably stable with advancing age. Although the possibility of methodological artifacts was considered, we favor progressive loss of cortical neurones and/or diminished activity of those remaining to explain our findings. In addition, age-related changes in cognitive activities might also be involved.

The pilot Stroke Data Bank: definition, design, and data.

Abstract: Four university centers collaborated to contribute 1158 patients with acute episodes of cerebrovascular disease to the pilot Stroke Data Bank, initiated by NINCDS in 1978. During the pilot project a standard set of data collection forms were developed and used at each of the collaborating centers. Data on clinical course, laboratory findings, therapy and outcome were gathered prospectively throughout the patient's hospitalization and at specified follow-up intervals. Using operational definitions of stroke sub-types, consecutive cases were systematically allocated to specific categories of brain and vascular pathology. The definitions were based on clinical criteria as well as on laboratory data, including computerized tomography (CT), and angiography findings. This paper describes the pilot Stroke Data Bank and presents the distribution of cases by diagnostic and demographic categories. It represents one of the largest series of prospectively collected stroke cases studied by CT (90% of the cases) and angiography (42%). Based upon the methods and processes of this pilot study, a main phase of the Stroke Data Bank has been established to address a number of questions pertaining to stroke classification, evolution, diagnosis, and prognosis.

Moderate homocysteinemia--a possible risk factor for arteriosclerotic cerebrovascular disease.

Abstract: Highly elevated concentrations of homocysteine measured as homocysteine or cysteine-homocysteine mixed disulfide (MDS) are found in plasma and urine in subjects with inherited abnormalities of the methionine metabolism. These subjects have a high incidence of arteriosclerotic vascular complications during childhood. Homocysteine causes endothelial cell injury and cell detachment that initiates the development of arteriosclerosis. The present study demonstrates a significantly elevated mean plasma MDS concentration in 19 patients with arteriosclerotic cerebrovascular disease compared to 17 controls. Our findings suggest that moderate homocysteinemia might be a risk factor for arteriosclerotic cerebrovascular disease.

Cerebral aneurysms and variations in the circle of Willis.

Abstract: In order to obtain information about the relationship between variations in the circle of Willis and aneurysms, 44 complete circles of Willis with aneurysm were studied macroscopically. The incidence of variations was significantly higher in the aneurysm series than in the control circles without aneurysm. There was a definite correlation between asymmetric proximal segments of the anterior cerebral artery and aneurysms of the anterior communicating artery, and a tendency to correlation was found in the case of asymmetric posterior communicating arteries and aneurysms on the internal carotid artery-posterior communicating artery junction. In the light of these findings it seems likely that through hemodynamic changes variation in the circle of Willis plays some role in the development of cerebral aneurysms.

Flow patterns in the human carotid artery bifurcation.

Abstract: To elucidate the connection between blood flow and the localized genesis and development of atherosclerosis and thrombosis at the human carotid artery bifurcation, detailed studies of the flow patterns and distributions of fluid velocity and wall shear rate in this region were carried out using a transparent segment of the carotid artery, prepared from a human subject postmortem, and cinemicrographic techniques. It was found that a recirculation zone which consisted of a pair of complex spiral secondary flows, symmetrical about the common median plane of the bifurcation, was formed in the carotid sinus over wide ranges of inflow Reynolds numbers, Re0, and flow rate ratios, Q1/Q0 (internal/common). The formation and the size of the recirculation zone were largely dependent on Q1/Q0, as well as on Re0. The size of the recirculation zone increased from approximately 4 mm at Re0 = 300 to a maximum of approximately 9 mm at Re0 greater than 800. The results suggest that, under physiological conditions (Re0 approximately 600, Q1/Q0 approximately 0.7), a standing recirculation zone exists in the carotid sinus, thereby affecting local mass transfer and interactions of blood cells with the vessel wall, which may lead to the incidence of atherosclerosis and thrombosis in this region.

Immediate anticoagulation of embolic stroke: brain hemorrhage and management options

Abstract: The clinical implications of hemorrhagic transformation of embolic brain infarction were explored by studying 30 patients with cardiogenic brain embolism and either hemorrhagic infarct (HI) or intracerebral hematoma (ICH) on CT. At the time of identification of hemorrhage, 19 patients were receiving anticoagulants and 11 were not. Eight anticoagulated patients and three nonanticoagulated patients developed late HI without attendant worsening after an initial CT was nonhemorrhagic. Hemorrhagic transformation without worsening most often occurred after 12 hours but before 48 hours following stroke onset and was associated with large infarcts (82%) but not with age, blood pressure or embolic source. Seven anticoagulated patients, six with large infarcts, and one nonanticoagulated patient with a small infarct abruptly worsened from eight hours to 11 days after stroke, with CT revealing ICH or severe HI. Excessive anticoagulation or acute hypertension potentially contributed to hemorrhagic transformation in four of five patients who were receiving heparin. Brain hemorrhage in embolic strokes most often occurs with large infarcts. Early CT may not allow the identification of large embolic infarcts that are destined to later undergo spontaneous hemorrhagic transformation. For large embolic infarcts, a delay of several days before anticoagulation and special efforts to avoid excessive anticoagulation and hypertension may be prudent. The initial administration of large, bolus doses of heparin should perhaps be avoided.

The pathogenesis of watershed infarcts in the brain.

Abstract: WATERSHED INFARCTS are ischemic lesions which are situated along the border zones between the territories of two major arteries, for example the anterior and middle or the middle and posterior cerebral arteries (fig. 1). They may also be located between the territories of the major cerebellar arteries and they have even been described between the territories of the small arteries in the basal ganglia. However, the exact nature of the latter lesions is more uncertain. The infarcts may be pale or hemorrhagic or mixed but generally the hemorrhagic component is not prominent. Altogether, approximately 10% of all brain infarcts are watershed lesions. Similar infarcts are also found in other organs, such as the heart and the kidneys, but they are more easily recognized in the brain because of the well defined course and extent of the cerebral arteries. The mechanisms whereby watershed infarcts develop have been debated for many years and they have been variously ascribed to cerebral thromboangiitis obliterans, 12 episodes of systemic hypotension, •'• \"• carotid occlusions\" and to microembolism.'It has now been convincingly shown that both hypotension and microembolism may cause such lesions. However, in some cases, particularly in those with a progressive or stepwise clinical course, the mechanism still remains uncertain.

Stroke in south Alabama: incidence and diagnostic features--a population based study.

Abstract: This study has attempted to identify all persons from an area of southern Alabama who had a stroke in 1980 and were hospitalized. Data were gathered on disease onset, clinical course, laboratory results, history of risk factors, and outcome. The age-adjusted incidence rates for initial stroke were 109 per 100,000 for whites and 208 per 100,000 for blacks. Age-specific rates were higher in blacks than whites, and highest for black females. The distribution of cases by type of stroke was: atherothrombotic (6%), embolic (26%), lacunar (13%), infarction of unspecified origin (40%), parenchymatous hemorrhage (8%), subarachnoid hemorrhage (6%), and unidentified type (1%). Blacks had higher incidence rates for hemorrhages, and black females had the highest incidence rate for lacunar stroke. The overall stroke incidence rates in this series were not significantly higher than those from prior population studies, suggesting that southern Alabama is not part of the so-called "Stroke Belt" area of the southeastern United States.

Experimental ischemic stroke: a review.

Abstract: Pour ameliorer les connaissances de l'accident vasculaire cerebral ischemique on passe en revue la bibliographie sur ce type d'accident sous diverses sections: modele le plus approprie et reproductible, methodes experimentales de production, evolution, tentatives pour modifier l'evolution d'infarctus cerebral en cours de constitution

A two-year longitudinal study of post-stroke mood disorders: dynamic changes in associated variables over the first six months of follow-up.

Abstract: We are prospectively studying a group of 103 stroke patients over the first 2 years after infarction to determine the variables which are associated with the development of depression. At both 3 and 6 months post-stroke, patients with left hemisphere infarcts showed a strong relationship between severity of depression and distance of the lesion on CT scan from the frontal pole. The strength of this association was unchanged from the immediate post-infarction period. In contrast, the correlation between degree of functional physical impairment and severity of depression steadily increased over the 6 month follow-up. The correlation between severity of depression and Mini-Mental score or between depression and social functioning score dropped between in-hospital and 3 months but then increased significantly between 3 and 6 months post-stroke. Age did not correlate with depression beyond the acute post-stroke period. Whether the increasing strength of the relationships between impairment and depression over the first 6 months post-stroke indicates that continued depression led to delayed recovery or whether continued severe impairments led to depression is not known, however, this issue will be addressed in further data evaluation from this prospective study.

The practice of carotid endarterectomy in a large metropolitan area.

Abstract: All carotid endarterectomies performed in the greater Cincinnati metropolitan area during 1980 were reviewed. For the 431 procedures performed in 16 hospitals, the operative stroke rate was 8.6% (37 of 431), and the operative mortality rate was 2.8% (12 of 431). The combined morbidity and mortality was 9.5% (41 of 431). Fifty percent of the procedures were done for asymptomatic carotid disease (216 of 431) and 50% were done for symptomatic carotid disease (215 of 431). The stroke rate was 5.6% for the asymptomatic patients and 11.6% for the symptomatic patients (difference significant, p less than 0.05). Neurosurgeons and vascular surgeons had similar surgical morbidity. All of the operative strokes involved the hemisphere ipsilateral to the endarterectomy. Fifty-seven percent of the operative strokes (21 of 37) occurred after a neurologically intact interval lasting hours to days. Four occurred following combined endarterectomy-coronary bypass surgery, and one was an intracerebral hemorrhage. The other late strokes (17) occurred without evidence for cardiac embolus or hemorrhage, consistent with a thrombogenic-embologenic operative site, and raising the question of need for adjunctive perioperative medical therapy.

Myocardial damage from acute cerebral lesions.

Abstract: Autopsy findings in 58 patients with intracranial lesions were compared with those in 50 control patients for myocardial damage, characterised by a change from a myofibrillar to a granular staining pattern, using a histochemical method for succinic dehydrogenase. Transmurally scattered foci of damaged myocardial fibres were significantly more common (p less than 0.01) in patients with intracranial lesions (62%) compared to controls (26%). No victims of sudden violent deaths showed these cardiac lesions. Focal myocardial damage required at least six hours to develop after onset of the acute neurological event and was not observed after the second week. It was associated with lesions producing a rapid increase in intracranial pressure and was usually absent in patients with slowly enlarging or small cerebral lesions. Similar myocardial changes were seen in patients in the control group dying from prolonged shock or other forms of acute circulatory or metabolic failure. The postulated mechanism of cardiac damage in these patients is increased levels of plasma catecholamines secondary to rapidly increasing intracranial pressure, irrespective of the cerebral pathology.

The performance of endarterectomy for disease of the extracranial arteries of the head.

Abstract: Data from the National Hospital Discharge Survey, the Veterans Administration Hospitals and Armed Forces Hospitals were reviewed to estimate the number of endarterectomies of extracranial vessels of head and neck performed in the United States. The number increased from around 15,000 in 1971 to around 85,000 in 1982. An estimated 2.8% of those operated in non-federal hospitals were discharged dead.

Behavioral performance of rats following transient forebrain ischemia.

Abstract: Rats subjected to transient forebrain ischemic injury by the method of four vessel occlusion (4-VO) develop irreversible injury to select populations of vulnerable neurons which include pyramidal cells in the CA-1 region of the hippocampus This brain area is thought to be crucial for learning and memory Rats subjected to 30 minutes of 4-VO, and then cerebral reperfusion were tested on a radial 8-arm maze task after they had recovered The data shows that both 4-VO and control animals improve their performance over trials, but that 4-VO rats are impaired on "working" and "reference" tasks The data suggest that 4-VO rats' impaired "working" performance is permanent, compared to their transient "reference" impairment Alterations in sensorimotor activity could not account for these performance deficits since control and 4-VO rats demonstrated equivalent choice time per maze arm Performance deficits in rats following forebrain ischemic injury may be similar to some of the cognitive deficits found in humans survivors of cerebral hypoxia-ischemia

Mild hypothermia and Mg++ protect against irreversible damage during CNS ischemia.

Abstract: Spinal cord ischemia was produced in rabbits by temporary occlusion of the abdominal aorta just distal to the renal arteries; and recovery, or failure to recover, was assessed by examining the rabbits for permanent loss of sensory and motor function in the hind limbs. A temperature reduction of 3 degrees C during the period of circulatory impairment caused a doubling of the duration of ischemia that could be reversibly sustained. Intravenous administration of 5 mmoles/kg of MgCl2 before the ischemia (a dose sufficient to produce neuromuscular blockade) caused a 50% increase in the tolerable duration. The combination of the 3 degrees C reduction in temperature and the elevated Mg++ increased by about 3 fold the duration of ischemia that could be sustained before irreversible damage occurred. These results may have implications for the care of patients subjected to marginal degrees of CNS ischemia.

Carotid endarterectomy--an expression of concern.

Abstract: THE READERS OF STROKE are offered in this issue the results of a series of studies and some critical observations relating to the performance of carotid endarter-ectomy on either asymptomatic or, more importantly, symptomatic patients. Some neurologists, neurosur-geons and vascular surgeons will undoubtedly disagree with the comments made or with the conclusions reached by several, or even by all, of the authors who have submitted these papers. Nevertheless, none can be lightly dismissed. During the professional lifetime of the present generation of neurologists, cerebral angiography has become widely accepted and practiced, the symptoms of impending ischemic stroke have been delineated, and putative prophylaxis either by anticoagulant therapy or by carotid endarterectomy have been widely utilized for the potential stroke victims identified because of these advances. Many practitioners have been unhappy with both anticoagulant therapy and carotid endarterectomy because the risk of producing stroke, including even fatal stroke, can be associated with either or both. Convincing studies clearly demonstrating reduced risk of stroke achieved with either treatment have not been forthcoming. Nevertheless, with varying degrees of enthusiasm, most practitioners concerned with stroke prevention have practiced or recommended either, or both, of these strategies. Recent developments provide a number of compelling reasons for reassessing efforts to prevent stroke by any established or innovative procedure which carries a high risk. The following comments could be applied equally to medical or surgical treatment but our observations below concentrate upon the results of endarterectomy: 1. The mortality and even the morbidity from stroke has been declining steadily for 25 years. Evidence is lacking that this decline relates to the practice of endarterectomy or any other form of secondary prevention. However, the numbers submitted to this surgical procedure may be too few to permit an accurate detection of its influence against the larger population of stroke victims. 2. The prognosis in individuals afflicted with transient ischemic attacks and/or minor strokes has been much better defined. The outlook in particular age groups, with precisely identified specific arterial le-sions and with a variety of associated risk factors has been reported. From these studies more credible prog-nostic data have emerged for selected populations but major differences between all such groups deny their utility as controls for any therapeutic trials. 3. Biostatistics and the methodology of clinical trials have matured, making the evaluation of new treatment strategies more credible. It has become imperative that healthy skepticism be directed towards older …

The decline of stroke.

Abstract: Stroke mortality in the United States has declined since 1900. The mortality rates from stroke in Rochester, Minnesota, have declined 76% since 1950, and the primary cause for the declines is a decrease in the incidence of new cases of cerebral infarction and cerebral hemorrhage. There are no data on the incidence of stroke prior to 1945 to confirm the US mortality trend. The decline in incidence was noted in women 10-15 years before it was seen in men. Hypertension is the most important risk factor for stroke. Hypertension surveys have shown an increasing effectiveness of antihypertensive medication in lowering blood pressure, and the effect was noted earlier in women. Available evidence is consistent with the idea that treatment of hypertension is the only significant contributor to the decline of stroke.

Carotid endarterectomy: does it work?

Abstract: IF CAROTID ENDARTERECTOMY WAS A DRUG its efficacy would require scrutiny and licensure by the Committee on Safety of Medicines in the United Kingdom and by the Food and Drug Administration in the United States. Surgical procedures, unlike drugs, are exempt from the requirement that the risks of treatment be shown to be unequivocally less than the risks of notreatment. That carotid endarterectomy can and does cause stroke and death is not in doubt and the main issue is whether this risk is greater or less than that of restricting therapy to medical treatment. While thousands of patients having the operation have been reported in the literature, and it is said to be \"the most commonly performed vascular operation, and \"one of the most commonly performed operations\" in the United States, ony one inconclusive randomised trial has been published.*

Interobserver agreement for the diagnosis of transient ischemic attacks.

Abstract: The interobserver agreement for the diagnosis of a cerebral transient ischemic attack (TIA) was investigated in a pool of eight senior and interested neurologists from the same department. They interviewed 56 patients in alternating pairs. The diagnosis was based on internationally accepted criteria. The agreement rates were corrected for chance (kappa statistics). Both neurologists agreed that 36 patients had a TIA and 12 had not, but they disagreed about 8 patients (kappa = 0.65; for perfect agreement kappa would be 1.0). The vascular territory (carotid or vertebrobasilar) was agreed upon in only 24 of the 36 patients in whom both diagnosed TIA's (kappa = 0.31). We concluded that currently the diagnosis of a TIA, made by a single neurologist, is a poorly defined entity.

The International Cooperative Study on Timing of Aneurysm Surgery--an update.

Abstract: The timing of aneurysm surgery is one of the major controversies in the management of subarachnoid hemorrhage. The Cooperative Aneurysm Study is conducting an international epidemiological study to determine mortality and morbidity related to timing of surgery. From January, 1981 to July, 1983 over 3,500 patients have been registered from 68 centers. This preliminary report updates the progress of the study, describes the patient population, and presents overall outcome results.

Prognosis for patients treated conservatively for spontaneous intracerebral hematomas.

Abstract: The long-term clinical and CT-outcome of 53 conservatively treated patients with spontaneous intracerebral hematomas (ICH) was studied in relation to the acute findings. The acute mortality of ICH was 27%. Determinant for the immediate prognosis was the level of consciousness and the volume of the hematoma. The crucial size was 50 ml with a mortality of 90% for hematomas larger and 10% for hematomas smaller than that. Intraventricular hemorrhage was a bad prognostic sign only in the ganglionic-thalamic hematomas. At follow-up at a median of 4 1/2 years after ICH, 30% of the total series had a completely normal neurological examination and 28% had resumed work. Thirteen per cent had minor neurological deficits and 17% had debilitating sequelae. During the follow-up period 7 patients had died, which indicates an excess mortality for ICH survivors. The CT findings at follow-up consisted of low density areas smaller than the original hematomas, focal atrophy, calcifications and porencephalic cysts. In 10% the CT scan revealed no trace of the previous hematoma.

Headache in cerebrovascular disease.

Abstract: Two hundred fifteen consecutive patients with cerebrovascular events were evaluated prospectively for the incidence and characteristics of headache. Of 163 patients able to communicate, headache occurred in 29% with bland infarcts, 57% with parenchymal hemorrhage, 36% with transient ischemic attacks and 17% with lacunar infarcts. Patients with a history of recurrent throbbing headache were significantly more likely to have headache, usually throbbing in quality, during the present illness. Women developed headache significantly more often than men. Headache began prior to the vascular event in 60% of patients and at its onset in 25%. The quality, onset and duration of the headache varied widely among patients. Headache in cerebrovascular disease is common, though neither its occurrence nor characteristics predict lesion type or location. Though the pathogenesis of the headache is unknown, its association with prior throbbing headache suggests that similar factors may operate in both.

A randomized controlled trial of hemodilution therapy in acute ischemic stroke.

Abstract: Rapid hemodilution in the early phase of ischemic stroke by the combination of venesection (250-650 ml during the first 2 days) and administration of low-molecular weight dextran was evaluated in a prospective controlled trial. Fifty-two patients were randomized to hemodilution therapy and 50 to a control group; the two groups were comparable in important prognostic variables. Mean hemoglobin was reduced from 147 to 127 g/l, hematocrit from 43 to 37% and, in a subsample of patients, whole-blood viscosity at a shear rate of 23 sec-1 from 7.0 to 4.3 cps over the first 2 days. Hemodilution was then maintained by repeated dextran infusions. Of the hemodiluted patients, 85% improved in neurological scoring over the first 10 days as compared to 64% of the control patients (p less than 0.025). The case fatality rate during the first 3 months was little affected by hemodilution. Among the survivors, 8% of the hemodiluted and 31% of the non-hemodiluted patients were unable to walk at 3 months. The proportion of surviving patients still hospitalized at the 3-month follow-up was 13% in the hemodilution group and 39% in the control group (p less than 0.01). The combination of venesection and dextran 40 administration is thus an unsophisticated but effective way to achieve rapid hemodilution in patients with acute cerebral infarction, and it improves the overall clinical outcome over the first 3 months.

The case against surgery for asymptomatic carotid stenosis.

Abstract: Asymptomatic cervical bruits with their implication of underlying carotid artery disease, carry an established but low risk of stroke. In spite of the rising numbers of patients subjected to carotid endarterectomy for this condition, there is little evidence that the benefits outweight the risks. Outcome data from community studies and the current prospective Toronto study of patients with asymptomatic neck bruits indicate that the annual stroke rate is 1-2%, and the annual cardiac death rate is 2-4%. Published data of the results of carotid surgery suggest that surgical risks outweigh any possible benefits, unless a subgroup with spontaneous stroke risk of at least 5% can be identified.

Cerebral infarction associated with lupus anticoagulants--preliminary report.

Abstract: Hypercoagulability may contribute to stroke in young adults. Lupus anticoagulants (LA) were identified in six patients (4%) of 145 young adults with cerebral infarction. The clinical features of the 6 patients in this survey plus an additional patient from another institution with LA-associated stroke are presented. Four had systemic lupus erythematosus and 3 had idiopathic LA; all had mild thrombocytopenia. In 2 patients, no other conditions associated with stroke were discovered after thorough evaluation. Recurrent arterial thrombosis occurred in 4 of 7 patients during an average of two years of follow-up. Evidence suggests that inhibition of prostacyclin formation may occur with LA, promoting a prothrombotic state.

Epidemiologic studies of coronary heart disease and stroke in Japanese men living in Japan, Hawaii and California: incidence of stroke in Japan and Hawaii.

Abstract: As part of the Ni-Hon-San Study, stroke incidence was compared in the Japan and Hawaii cohorts. Stroke cases were classified in two types, intracranial hemorrhage (ICH) and thrombo-embolic stroke (T-E). For each type the incidence in Japan was about three times as great as in Hawaii. The ratio ICH/T-E was 1/2.2 and 1/1.6 in Japan and Hawaii, respectively. Blood pressure was the most important risk factor, followed by age for total stroke in both Japan and Hawaii. Proteinuria was also a risk factor in Hawaii. Conversely, an index of animal food intake was inversely related to total stroke, significantly in Hawaii, and at a suggestive level for total and hemorrhagic stroke in Japan. Since the levels of blood pressure do not differ between Japan and Hawaii, one possible explanation for the large difference in stroke incidence between the two cohorts may be the fact that animal protein and saturated fat intake, which is inversely associated with stroke incidence, is much greater in Hawaii than in Japan. This explanation would support epidemiologic and experimental studies in Japan which suggest that dietary animal protein and fat exert an inhibitory effect on the incidence of stroke.