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Biomedical subjects

B Norrving

Publications and source records attributed to B Norrving.

At least 19 recordsLinked to original sources
PubMed1999

[Stroke unit care saves lives. The Swedish national quality assessment registry of stroke care is the first of its kind in the world].

Meta-analyses of randomised trials of acute stroke treated in specialised stroke units have yielded convincing evidence of benefits in terms of reduced mortality rates, as compared with treatment in a general ward. However, no studies had been performed to ascertain whether the promising results could be reproduced in routine clinical practice. Accordingly, a comparison of routine care of acute stroke patients in stroke units (SUs) with that in general wards (GWs) was made on the basis of data for the 14,300 cases of acute stroke from 87 units in 80 Swedish hospitals registered in 1996 at the Swedish national stroke registry, the first of its kind in the world. Among patients capable of independent daily life and fully conscious at admission, the mortality rate was lower in the SU than in the GW subgroup, both at discharge from hospital and three months after the stroke event; and three months after stroke, a greater proportion of SU patients had been discharged to their homes, and a smaller proportion were in long-term care. However, no such subgroup differences were found among patients with impaired consciousness at admission. Thus, the promising results of the randomised trials of SU treatment would appear to be reproducible in routine clinical practice, though the beneficial effect is smaller in magnitude.

Aged↗
PubMed1999

Complications after carotid endarterectomy are related to surgical errors in less than one-fifth of cases. Swedvasc--The Swedish Vascular Registry and The Quality Committee for Carotid Artery Surgery.

OBJECTIVES: to study possible relations between indications, contraindications and surgical technique and stroke and/or death within 30 days of carotid endarterectomy (CEA). DESIGN: analysis of hospital records for patients identified in a national vascular registry. METHOD: during 1995-1996, 1518 patients were reported to the Swedish Vascular Registry - Swedvasc. Among these the sixty-five with a stroke and/or death within 30 days were selected for study. Complete surgical records were reviewed by three approved reviewers using predetermined criteria for indications and possible errors. RESULTS: an error of surgical technique or postoperative management was found in eleven patients (17%). In six cases (9%) the indication was inappropriate or there was an obvious contraindication. The indication was questionable in fourteen (21.5%). Half of the patients (52.5%) had surgery for an appropriate indication, and no contraindication or error in surgical technique or management was identified. CONCLUSION: more than half the complications of CEA represent the "method cost", i.e. the indication, risk and surgical technique were correct. However, the stroke and/or death rate might be reduced if all operations conformed to agreed criteria.

Aged↗
PubMed1999

Stroke units in their natural habitat: can results of randomized trials be reproduced in routine clinical practice? Riks-Stroke Collaboration.

BACKGROUND AND PURPOSE: Meta-analyses of randomized controlled trials of acute stroke care have shown care in stroke units (SUs) to be superior to that in conventional general medical, neurological, or geriatric wards, with reductions in early case fatality, functional outcome, and the need for long-term institutionalization. This study examined whether these results can be reproduced in clinical practice. METHODS: A multicenter observational study of procedures and outcomes in acute stroke patients admitted to designated SUs or general medical or neurological wards (GWs), the study included patients of all ages with acute stroke excluding those with subarachnoid hemorrhage, who were entered into the Riks-Stroke (Swedish national quality assessment) database during 1996 (14 308 patients in 80 hospitals). RESULTS: Patients admitted to SUs who had lived independently and who were fully conscious on admission to the hospital had a lower case fatality than those cared for in GWs (relative risk [RR] for death, 0.87; 95% confidence interval [CI], 0.79 to 0.96) and at 3 months (RR, 0.91; 95% CI, 0.85 to 0.98). A greater proportion of patients cared for in an SU could be discharged home (RR, 1.06; 95% CI, 1.03 to 1.10), and fewer were in long-term institutional care 3 months after the stroke (RR, 0.94; 95% CI, 0.89 to 0.99). No difference was seen in outcome in patients cared for in SUs or GWs if they had impaired consciousness on admission. CONCLUSIONS: The improvement in outcomes after stroke care in SUs compared with care in GWs can be reproduced in the routine clinical setting, but the magnitude of the benefit appears smaller than that reported from meta-analyses.

Activities of Daily Living↗
PubMed1999

Radiological diagnosis of acute stroke. Comparison of conventional MR imaging, echo-planar diffusion-weighted imaging, and spin-echo diffusion-weighted imaging.

PURPOSE: To compare conventional MR imaging, echo-planar diffusion-weighted imaging (EP-DWI) and spin-echo diffusion-weighted imaging (SE)-DWI at radiological diagnosis of acute stroke. MATERIAL AND METHODS: Twenty-seven patients (30-85 years old) were examined. Clinical examination was performed before MR imaging. All MR examinations were assessed by an experienced neuroradiologist blinded to clinical findings. RESULTS: In EP-DWI, every patient had a lesion corresponding to the clinical findings. EP-DWI was used as the gold standard. In conventional PD+T2 imaging, 23/59 focal lesions were interpreted as acute, which was false in 11 lesions, and 36/59 lesions were considered to be old, 6 were in fact acute. Nine acute lesions were only detected retrospectively and 12 acute lesions were not detected at all on PD+T2. SE-DWI including the apparent diffusion coefficient correlated fairly well with EP-DWI but the procedure was impractical. CONCLUSION: EP-DWI is reliable for diagnosis of early ischemic stroke, while SE-DWI performs reasonably well. Conventional PD+T2 imaging is not reliable for diagnosis of early ischemia.

Acute Disease↗
PubMed1998

[Thrombolysis changes the care of stroke].

Thrombolysis using tissue plasminogen activator (tPA) is not the leading strategy in the development of pharmacological treatments for acute ischaemic stroke. The prospect of tPA becoming routine treatment in ischaemic stroke raises several issues the magnitude of the treatment load, the requisite neurological and neuroradiological diagnostic qualifications, identification of local reperfusion effects in the brain, and the pre-hospital and hospital management of acute stroke patients. The results of large randomised trials of intravenous tPA treatment are reviewed in the article, and the current state of our knowledge about interventional thrombolysis is reported. Recruitment for the second European intravenous tPA trail, ECASS II, has recently been completed, and the study findings will be available during the latter half of 1988. In the USA, tPA is already recommended treatment for acute ischaemic stroke within three hours after the onset of symptoms. In Europe, the formulation of guidelines awaits the results of ECASS II.

Cerebral Infarction↗
PubMed1998

Sensorimotor stroke; clinical features, MRI findings, and cardiac and vascular concomitants in 32 patients.

BACKGROUND AND PURPOSE: Sensorimotor stroke (SMS) is often included among the lacunar syndromes, although the underlying cause of this stroke-subtype is less well documented. To this end we analysed 32 patients presenting with a sensorimotor syndrome. METHODS: The study protocol included vascular risk factors, echocardiography, Doppler sonography of carotid arteries, CT scan and MRI of the brain. RESULTS: There were 23 men and 9 women, mean age 65.7 years. Hypertension was present in 28% and diabetes in 19%. In all, 63% had sensorimotor deficit of faciobrachiocrural areas and 37% had faciobrachial or brachiocrural deficits. MRI disclosed a presumably relevant infarct in 26 patients (81%); 20 patients (62%) localized to the territory of small perforating arteries, 3 patients (9.5%) in the internal borderzone, and 3 patients (9.5%) in cortical territories. Eight of 20 deep infarcts were larger than 15 mm. No hemorrhage or non-vascular lesion was found. A potential cardioembolic source was present in 5 patients (16%), whereas 2 patients (6%) had an ipsilateral carotid stenosis >50%. CONCLUSIONS: Small vessel disease was the most likely cause in 69% of our patients with SMS, whereas 31% had a potential cardioembolic source, large artery disease or infarcts not compatible with perforating artery disease.

Adult↗
PubMed1997

Cardiac changes in stroke patients and controls evaluated with transoesophageal echocardiography.

In stroke patients several cardiac changes associated with embolism can be detected with transoesophageal echocardiography. Potential major cardiac embolic sources (e.g. atrial fibrillation, thrombi of left ventricle/atrium, vegetation, myxoma, dilated cardiomyopathy) have a causal relationship to embolism. Other changes with no certain causal relationship are regarded as potential minor cardiac embolic sources (e.g. atrial septal aneurysm, patent foramen ovale, mitral annular calcification, mitral valve prolapse, protruding atheroma of the aorta). We compared the prevalences of major and minor potential cardiac embolic sources in a stroke population with that in controls. One hundred and twenty-one patients with first-ever stroke were compared with 68 randomly selected controls. All subjects underwent magnetic resonance imaging of the brain, carotid ultrasound and transthoracic/transoesophageal echocardiography. The patients were slightly older (mean age 70.7 +/- 10.3 years) than the controls (65.5 +/- 15.5 years) (p < 0.05). Potential major cardiac embolic sources were found in 27% of the patients and in 4% of the controls (p < 0.001). The most common major potential embolic source was atrial fibrillation, detected in 22/121 patients. Fifteen of these also had spontaneous echocontrast in the left atrium. Eleven left atrial thrombi were found (four of these patients had atrial fibrillation and seven had sinus rhythm). A history of heart disease was more common in patients with a potential major cardiac embolic source or a carotid artery stenosis (77%) than in those patients without (44%) (p < 0.01). After excluding subjects with a major potential cardiac embolic source and/or carotid artery stenosis, no differences in the prevalence of minor potential cardiac embolic sources were found between patients (55%) and control subjects (47%) (p = NS). Even when subjects without a major potential cardiac embolic source or a carotid artery stenosis were categorized into three age groups (35-54, 55-74 and > 74 years) the prevalence of potential minor cardiac embolic sources did not differ between patients and controls. To conclude, major potential cardiac embolic sources are more common in an older population with first-ever stroke than in a comparable control group. However, potential minor cardiac embolic sources did not differ in prevalence in the patients compared with controls. Certain changes (e.g. atrial septal aneurysm) might have a potential embolic role in younger stroke patients but in our study no difference was found between older stroke patients and controls.

Acute Disease↗
PubMed1996

Tissue plasminogen activator and plasminogen activator inhibitor-1 in stroke patients.

BACKGROUND AND PURPOSE: Abnormal endogenous fibrinolytic activity may be a risk factor for stroke. Since the possible variation of tissue-type plasminogen activator (TPA) antigen and plasminogen activator inhibitor-1 (PAI-1) antigen concentrations over time after stroke has been rarely studied, it was examined in plasma from stroke patients in the acute and convalescent phases of the disease and in a control group. METHODS: Plasma concentrations of TPA and PAI-1 were determined in 135 stroke patients and in 77 control subjects. All but 4 patients were examined within 7 days after stroke onset, and 32 patients and 18 control subjects were reexamined 2 to 4 years later. RESULTS: In the acute phase, stroke patients had significantly higher TPA (median, 10 micrograms/L) and PAI-1 (median, 14 micrograms/L) antigen concentrations, compared with control subjects (median values, 6 micrograms/L [P = .0001] and 8 micrograms/L [P < .01], respectively); TPA levels were higher in both the cerebral infarction (n = 122) and cerebral hemorrhage (n = 12) subgroups, whereas PAI-1 levels were higher in the cerebral infarction subgroup only. Stepwise logistic regression analysis (with correction for age, sex, history of hypertension, diabetes mellitus, and heart disease) showed TPA antigen level to be an independent discriminator between the cerebral infarction subgroup and control subjects (P = .0001), whereas the corresponding difference for PAI-1 antigen levels just failed to reach significance (P = .05). TPA antigen levels were correlated with concentrations of serum cholesterol (Spearman's rho = 0.15; P < .05), serum triglyceride (rho = 0.33; P = .0001), and plasma homocysteine (rho = 0.19; P < .01). PAI-1 antigen levels were correlated with serum triglyceride levels only (rho = 0.41; P = .0001). At reexamination after 2 to 4 years, neither TPA nor PAI-1 levels had changed significantly from the baseline values. CONCLUSIONS: In stroke patients, high TPA antigen concentrations may indicate an activation of the fibrinolytic system or may be due to a delayed clearance of TPA complexed with inhibitors. High PAI-1 antigen concentrations in patients with cerebral infarction represent increased fibrinolytic inhibition. The findings in this longitudinal study suggest that TPA and PAI-1 antigen concentrations both differ little between the acute and convalescent phases after stroke.

Acute Disease↗
PubMed1995

Isolated acute vertigo in the elderly; vestibular or vascular disease?

INTRODUCTION: Elderly patients with isolated acute vertigo are commonly encountered in clinical practice, but little is known about the underlying cause of the symptoms. MATERIAL & METHODS: We prospectively studied 24 patients aged 50-75 years with the acute onset of isolated vertigo lasting > 48 h and no abnormality on neurological examination other than nystagmus. The study protocol included neuro-imaging (MRI 22 patients, CT 2 patients), Doppler sonography, and electro-oculography. RESULTS: MRI/CT showed the presence of an infarction of the caudal cerebellum in six patients (25%), 3 of whom had a potential cardioembolic source and normal Doppler sonography findings, whereas 3 patients had ipsilateral vertebral artery occlusion and normal cardiac findings. MRI of the posterior fossa was normal in 18 patients. On electro-oculography, ataxic pursuit eye movements was a characteristic finding in patients with cerebellar infarction, whereas caloric test findings were not discriminative. CONCLUSION: A caudal cerebellar infarction may easily be misdiagnosed clinically as a labyrinthine disorder, and was found to be the cause in one fourth of patients presenting with isolated acute vertigo.

Acute Disease↗
PubMed1995

Plasma homocysteine in the acute and convalescent phases after stroke.

BACKGROUND AND PURPOSE: Stroke patients frequently manifest moderate hyperhomocysteinemia. In most published studies, plasma homocysteine was measured at least 1 month after stroke (or the interval was not reported). To determine whether plasma homocysteine concentrations change in the acute phase, we compared acute-phase values with both convalescent-phase and control values. METHODS: Plasma homocysteine concentrations were measured in the acute phase (mean, 2 days after stroke onset) in 162 first-ever stroke patients aged 50 years or more (median, 75 years) and again at a median interval of 583 days (range, 460 to 645 days) after stroke onset in a subgroup of 17 patients, with values for 60 age-matched subjects serving as controls. Twenty of the control subjects were reexamined 2 to 3 years after their initial examination. RESULTS: The median plasma homocysteine concentration was 13.4 mumol/L in the patient group compared with 13.8 mumol/L for control subjects (NS, Mann-Whitney U test) and increased from 11.4 mumol/L in the acute phase to 14.5 mumol/L in the convalescent phase in the subgroup of patients examined twice (P < .01, Wilcoxon signed rank test). In the 20 reexamined control subjects, no significant change over time in plasma homocysteine concentration was found. CONCLUSIONS: The post-acute-phase increase in plasma homocysteine may explain why higher values were obtained for stroke patients than for control subjects in previous studies. Possible reasons for the variation in plasma homocysteine concentrations over time are (1) an acute-phase reduction secondary to a decrease in plasma albumin and (2) an increase in plasma homocysteine during the convalescent phase due to modified vitamin intake and/or lifestyle. The timing of plasma homocysteine measurements relative to stroke onset is a factor to be considered in the interpretation of results.

Aged↗
PubMed1994

Carotid artery and heart disease in subtypes of cerebral infarction.

BACKGROUND AND PURPOSE: The aim of the study was to determine the prevalences of carotid artery disease and major and minor potential cardioembolic sources (1) in patients with cerebral infarction and age-matched control subjects and (2) in different clinical subtypes of cerebral infarction. METHODS: A series of 166 consecutive patients with cerebral infarction and 59 control subjects was examined. The study protocol included clinical subtyping of the cerebral infarctions, ultrasonography of the carotid arteries, transthoracic echocardiography (TTE), transesophageal echocardiography (TEE), ECG, and examination of the brain with computed tomography, magnetic resonance imaging, or autopsy. RESULTS: Carotid artery stenosis > or = 80% or occlusion was present in 35 (21%) patients but in no control subjects (P < .001; chi 2 test). A major potential cardioembolic source was detected in 65 (39%) patients and 3 (5%) control subjects. Atrial fibrillation was present in 35 (21%) patients and 3 (5%) control subjects at initial ECG (P < .01) and in 47 (28%) patients at repeat examination; 17 patients had paroxysmal atrial fibrillation. Sinus rhythm and a major potential cardioembolic source were detected in 18 (11%) patients but in no control subjects (P < .01) at TTE (all patients and control subjects examined) or TEE (118 patients and 52 control subjects examined). The frequency of a minor potential cardioembolic source detectable at TTE or TEE was similar in the patient and control groups (51% and 53%, respectively [NS]) and increased significantly with age. A finding of carotid artery stenosis > or = 80% or occlusion, atrial fibrillation, or a major cardioembolic source detected at TTE or TEE was more frequent among patients with cortical symptoms from anterior or middle cerebral artery territories than among those with lacunar syndromes (66% versus 22%, respectively). The probable source of cerebral infarction was identified in most of the 166 patients: cardiac embolism in 28% of cases (n = 46), carotid artery disease in 8% (n = 14), both cardiac embolism and carotid artery disease in 7% (n = 11), and lacunar infarction in 23% (n = 38). In 57 (34%) of the patients no unequivocal cause of the cerebral infarction was found. CONCLUSIONS: The prevalences of carotid artery and heart disease differ significantly between clinical subtypes of cerebral infarction. The cause of cerebral infarction remains uncertain in one third of patients. Because a minor potential cardioembolic source occurs in about 50% of both patients and control subjects, this finding is of questionable value as a risk factor for stroke in the elderly.

Adult↗
PubMed1994

Costs of stroke in Sweden. A national perspective.

BACKGROUND AND PURPOSE: Cost-effectiveness analyses of stroke management are hampered by paucity of economic data. We made an update of the direct and indirect costs of stroke in Sweden (population, 8.5 million). METHODS: Direct costs (ie, the costs for hospital and outpatient care and social services) were estimated on the basis of two prospective population-based studies of stroke and of two nationwide cross-sectional inventories of bed-days and diagnoses. Indirect costs (ie, the costs for loss of productivity and early retirement) were based on official statistics. RESULTS: The direct annual costs of care for stroke patients in 1991 equaled 7836 million Swedish krona (SKr) ($1306 million in US dollars), and the indirect costs, 2430 million SKr ($405 million). The cost of stroke care was 1208 SKr ($201) per inhabitant in Sweden. The expected direct costs per patient from first stroke to death were 440,000 SKr ($73,333). When prestroke costs for other diseases and advanced age were subtracted, the sum was reduced to 180,000 SKr ($30,000). CONCLUSIONS: Costs for hospital and outpatient care and social services accounted for 76% of Swedish stroke costs and for 24% of costs for loss of production and early retirement. Only 41% of direct costs were stroke-related.

Aged↗
PubMed1994

Cerebral lesions on magnetic resonance imaging, heart disease, and vascular risk factors in subjects without stroke. A population-based study.

BACKGROUND AND PURPOSE: To assess the prevalence of asymptomatic abnormalities on magnetic resonance imaging of the brain and their possible relation to hypertension, heart disease, and carotid artery disease, we studied 77 randomly selected subjects (mean age, 65.1 years; range, 36 to 95 years) with no history of focal brain lesions. METHODS: The study protocol included magnetic resonance imaging of the brain, transthoracic and transesophageal echocardiography, ultrasonography of the carotid arteries, and electrocardiographic recording. Deep and periventricular white matter hyperintensities on magnetic resonance imaging were assessed both separately and together. RESULTS: On magnetic resonance imaging of the brain 62.3% (95% confidence interval [CI], 51.5% to 73.2%) of the subjects had white matter hyperintensities. These abnormalities increased significantly with age (chi 2 test; P = .0001), from 13.6% (95% CI, 0% to 28.0%) of subjects aged younger than 55 years to 85.2% (95% CI, 71.8% to 98.6%) of subjects aged 75 years or older. Six subjects had deep gray matter hyperintensities localized in the basal ganglia, and one had a cerebellar infarction. Stepwise logistic regression analysis identified age and a history of heart disease (but not echocardiographic findings) to be independently associated with deep and periventricular white matter hyperintensities. Hypertension was only independently associated with periventricular white matter hyperintensities. Of the 68 subjects examined with both transthoracic and transesophageal echocardiography, potential cardioembolic sources were detected in 38.2% (95% CI, 26.7% to 49.8%) of the subjects with transthoracic echocardiography and in 47.1% (95% CI, 35.2% to 58.9%) of those with transthoracic and transesophageal echocardiography combined. In subjects aged 75 years or older, a possible cardiac embolic source was detected in 64.0% on transthoracic echocardiography and in 72.0% on transthoracic and transesophageal echocardiography combined, compared with 5.3% and 15.8%, respectively, in subjects aged younger than 55 years. CONCLUSIONS: White matter hyperintensities and potential cardioembolic sources are frequently present in asymptomatic individuals, stressing the need for age-matched control subjects in studies of patients with stroke or dementia.

Adult↗
PubMed1994

Comparison of clinical and neuroradiological findings in first-ever stroke. A population-based study.

BACKGROUND AND PURPOSE: To determine how a recently proposed clinical stroke subclassification corresponds to specific findings on computed tomography (CT) and magnetic resonance imaging (MRI) of the brain. METHODS: Two hundred twenty-eight patients with first-ever stroke were divided into four clinical subgroups: (1) total anterior circulation syndrome: both cortical and subcortical symptoms from anterior and middle cerebral artery territory; (2) partial anterior circulation syndrome: more restricted and predominantly cortical symptoms from the same arterial territories; (3) lacunar syndrome; and (4) posterior circulation syndrome: vertebrobasilar or posterior cerebral artery symptoms. The imaging protocol included CT of the brain on day 0 through 15 and a second CT and an MRI of the brain on day 16 through 180 after acute stroke onset. RESULTS: There were 200 patients with cerebral infarction and 28 patients with intracerebral hemorrhage. Intracerebral hemorrhage was found in 19% of patients with total anterior circulation syndrome and in no patients with lacunar syndrome (chi 2 test; P < .01 for the difference between the four clinical subgroups). Of the 200 patients with cerebral infarction, 27% had total anterior circulation, 30% partial anterior circulation, 26% lacunar, and 16% posterior circulation syndromes. CT within 2 days revealed a visible lesion in about two thirds of patients with infarctions of total or partial anterior circulation syndrome type, compared with only 22% of patients with lacunar infarction (chi 2 test; P = .02 for the difference between the four subgroups). The mean volume of the symptomatic infarction on CT within 15 days was 95 mL for total anterior circulation, 20 mL for partial anterior circulation, and 2.5 mL for lacunar syndrome (one-factor ANOVA; P = .0001). A cortical involvement of the infarction on CT day 16 through 180 was seen in 81% of patients with total anterior circulation syndrome and 58% of those with partial anterior circulation syndrome, compared with only 8% of patients with lacunar syndrome (chi 2 test; P = .0001). MRI more often than CT showed a cortical involvement of lacunar infarctions and also revealed more silent lesions. CONCLUSIONS: The described clinical subgroups significantly differed in frequencies of intracerebral hemorrhage, cortical involvement, and lesion volume on CT and MRI.

Adult↗
PubMed1993

Cerebellar infarction. Clinical and anatomic observations in 66 cases.

BACKGROUND AND PURPOSE: Cerebellar infarction displays different clinical features, depending on the vascular territory involved. We studied patients with infarcts in the territories of the posterior inferior cerebellar artery or the superior cerebellar artery to compare their clinical presentation, course, and prognosis. METHODS: We retrospectively analyzed the clinical features, laboratory data, and imaging studies of 66 patients with cerebellar infarction collected consecutively at five institutions. All the cerebellar infarcts were documented on computed tomographic scan or magnetic resonance imaging. RESULTS: Two distinct profiles emerged, depending on the vascular territory involved. In 36 patients with posterior inferior cerebellar artery territory infarcts, a triad of vertigo, headache, and gait imbalance predominated at stroke onset. Computed tomography showed severe cerebellar mass effect in 11 cases (30%), with associated hydrocephalus in seven. In these seven patients (19%), postinfarct swelling led to brain stem compression that resulted in four deaths. In 30 patients with superior cerebellar artery infarcts, gait disturbance predominated at onset; vertigo and headache were significantly less common. The clinical course was usually benign. Computed tomography showed marked cerebellar mass effect, hydrocephalus, and brain stem compression in only two instances (7%). Presumed cerebral embolism was the predominant stroke mechanism in patients with superior cerebellar artery distribution infarcts, whereas in those with posterior inferior cerebellar artery distribution infarcts, the stroke mechanism was equally divided between cardiogenic embolism and posterior circulation arterial disease. CONCLUSIONS: Cerebellar infarcts in the posterior inferior cerebellar artery and superior cerebellar artery distribution have distinct differences in clinical presentation, course, and prognosis. These differences should help in the selection of appropriate monitoring and treatment strategies.

Adolescent↗