Investigation of patients with stroke and transient ischaemic attacks

Reduced Retinal Microvascular Perfusion in Patients With Stroke Detected by Optical Coherence Tomography Angiography

Currently there is a shortage of biomarkers for stroke, one of the leading causes of death and disability in aging populations. Retinal vessels offer a unique and accessible “window” to study the microvasculature in vivo. However, the relationship between the retinal microvasculature and stroke is not entirely clear. To investigate the retinal microvascular characteristics in stroke, we recruited patients with stroke and age-matched control subjects from a tertiary hospital in China. The macular vessel density (VD) in the superficial capillary plexus (SCP) and deep capillary plexus (DCP), foveal avascular zone (FAZ) metrics, and optical coherence tomography angiography (OCTA) measured optic disc VD were recorded for analysis. A total of 189 patients with stroke and 195 control subjects were included. After adjusting for sex, visual acuity, systolic and diastolic blood pressure, a history of smoking, levels of hemoglobulin (HbA1c), cholesterol, and high-density lipoprotein (HDL), the macular VD of SCP and DCP in all sectors was decreased in patients with stroke. In the stroke group, the VD around the FAZ and the VD of the optic disk were lower. Logistic regression found the parafovea-superior-hemi VD of DCP > 54.53% [odds ratio (OR): 0.169] as a protective factor of stroke. Using the integration of all OCTA parameters and traditional risk factors, the area under the receiver operating characteristic (AUC) curve of distinguishing patients with stroke was 0.962, with a sensitivity of 0.944 and a specificity of 0.871. Our study demonstrates that the retinal VD is decreased in patients with stroke independently of the traditional risk factors of stroke, which may shed light on the monitoring of stroke using the retinal microvascular parameters.

Seizures in pregnancy: epilepsy, eclampsia, and stroke

Seizures during pregnancy complicate <1% of all gestations; however, they are associated with increased adverse maternal and perinatal outcomes (acute and long term). The differential diagnosis of seizures in pregnancy is extensive. Determining the underlying etiology is crucial in the management of these patients. Medical providers caring for pregnant women should be educated about possible etiologies of seizures during pregnancy and the importance of prompt management of these women in a timely fashion. Evaluation and management should be performed in a stepwise fashion and may require a multidisciplinary approach with other specialties such as neurology. The objective of this review is to increase awareness and to provide a stepwise approach toward the diagnosis and management of pregnancies complicated by seizures.

Diagnosis and management of women with stroke during pregnancy/postpartum

Although the incidence of stroke is extremely low, the complications are serious. Maternal mortality has been reported to be as high as 26%. It is important for doctors to be aware of the causes, diagnostic techniques, and management strategies for stroke in order to achieve the best outcome for the mother and fetus. Recurrence risk appears extremely low, so women should feel confident in future positive pregnancy outcomes.

Neuroimaging, the ischaemic penumbra, and selection of patients for acute stroke therapy

Advances in neuroimaging have been central to the expansion of knowledge in the neurosciences over the past 20 years. One of the most important roles of brain imaging is in the selection of patients for acute stroke therapy. Currently, computed tomography (CT) is commonly used to select patients who have had strokes for thrombolytic therapy on the basis of the absence of haemorrhage and, more controversially, the presence of early CT changes of ischaemia. Since patients with ischaemic penumbra are more likely than those without to respond to therapy, identification of patients with this feature will become increasingly important. Although several imaging modalities can identify the penumbra, the most practical is magnetic resonance imaging (MRI) showing perfusion-weighted and diffusion-weighted imaging mismatch. Although uncertainties in image interpretation remain, surrogate MRI outcome measures are becoming an important component of translational research. Future developments in imaging technologies may provide other opportunities for surrogate outcome studies.

Stroke: pathogenesis, investigations, and prognosis--Part II of III

The aim of this review is to present the current knowledge regarding stroke. It will appear in three parts (in part I the epidemiology, clinical picture, and risk factors were discussed, while part III will consist of the management and rehabilitation). In the present part (II) the pathogenetic and pathophysiologic aspects of stroke are described. Regarding the investigations apart from the history and clinical examination and general investigations, the following specialized investigations and their role are discussed in detail: Computed tomography (CT), magnetic resonance imaging (MRI), xenon-blood-flow, positron emission tomography (PET), cerebral angiography, magnetic resonance angiography (MRA), ultrasonography, transcranial Doppler (TCD), echocardiography, Holter monitoring, and biopsies. In addition, taking into account the information from the above-cited modalities a prognosis for the final outcome is presented.

Early management and outcome of acute stroke in Auckland

BACKGROUND

Studies of acute stroke management in stroke units and tertiary referral hospitals may not accurately reflect practice within the population. Reliable information on the management of stroke within a population is sparse.

AIMS

To compare clinical practice in acute stroke management in Auckland with guidelines for the management and treatment of stroke in other countries; to provide a baseline measure against which future changes in management can be evaluated.

METHODS

All new stroke events in Auckland residents in 12 months were traced through multiple case finding sources. For each patient, a record of investigations and treatment during the first week of hospital admission was kept.

RESULTS

One thousand eight hundred and three stroke events (including subarachnoid haemorrhages) occurred in 1761 patients in one year. Twenty-seven per cent of all events were managed outside hospital and 73% of the stroke events were treated in an acute hospital. Of the 1242 stroke events admitted to an acute hospital in the first week, only 6% were managed on the neurology and neurosurgery ward, 83% were managed by a general physician or geriatrician and 42% had computed tomography (CT). Of 376 validated ischaemic strokes, 44% were treated with aspirin and 12% with intravenous heparin. Of the 690 unspecified strokes (no CT or autopsy), 38% received aspirin and 0.5% heparin. The 28 day in-hospital case fatality for all stroke events admitted to an acute hospital during the first week was 25%.

CONCLUSIONS

In Auckland, management of acute stroke differed from clinical guidelines in the high proportion of patients managed in the community, the low rate of neurological consultation, and the low frequency of CT scanning. Despite these deficiencies in management, the 28 day hospital case fatality in Auckland was similar to other comparable studies which had a high proportion of cases evaluated by a neurologist and CT.

Computed tomographic brain scans and antiplatelet therapy after stroke: a study of the quality of care in Dutch hospitals

BACKGROUND AND PURPOSE

We sought to develop a measure ("quality weight" that indicates the severity of a deviation from optimal care with respect to secondary prevention with antiplatelet treatment after stroke. We also sought to estimate the effects that efforts to improve the quality of secondary prevention may have on health outcome and healthcare costs in the Netherlands.

METHODS

First, we developed quality weights with decision analysis techniques. These quality weights express the excess risk of vascular events in the first 2 years after stroke compared with the optimal strategy (CT brain scan in all patients and aspirin in case of cerebral infarction). Second, these weights were applied in a follow-up study of 738 stroke patients older than 45 years. The number of stroke patients admitted to a hospital in 1991 in the Netherlands was used to estimate nationwide effects. We used data from 23 neurological departments and from the Information Center for Health Care in the Netherlands.

RESULTS

The 2-year excess risk of fatal and nonfatal vascular events caused by omitting CT brain scan and giving aspirin to all patients is rather small (on average, 0.6%). The 2-year excess risk caused by not giving aspirin to a patient with cerebral infarction is much higher (4.1%). The follow-up study indicated that only 6% of the admitted patients had not been evaluated with a CT brain scan and that 14% of the patients with cerebral infarction proven by CT scan did not get antiplatelet treatment at discharge. Efforts to improve the quality of secondary prevention after stroke may prevent 74 vascular events annually in the Netherlands at an expense of 6200 Dutch guilders per prevented event (1 Dutch guilder=0.53 US dollar, 1991).

CONCLUSIONS

Efforts to improve the quality of secondary prevention with antiplatelet treatment might reduce the number of new vascular events within the first 2 years after stoke by approximately 3%. The total costs related to the extra diagnostic and therapeutic activities are approximately 0.2% of the total annual hospital costs for acute stroke patients in teh Netherlands (250 million Dutch guilders).

Comparing the use of diagnostic tests in Canadian and US hospitals

Although Americans pay much more for a day in the hospital than Canadians, we know little about whether inpatient physician practice patterns might explain some of this difference. The authors compared the utilization of all diagnostic imaging (plain radiographs, computed tomography (CT) and magnetic resonance imaging (MRI) scanning, ultrasound, nuclear medicine and vascular studies) and selected laboratory tests (hematology, basic biochemistry, and advanced biochemistry) for all patients discharged with selected medical and surgical diagnoses in 1990 and 1991 from four university hospitals and four community hospitals in Canada (n = 6,491) and the United States (n = 7,980). Overall, US medical patients received 22% more diagnostic tests than their Canadian counterparts (544.2 relative value units [RVUs] vs. 446.5 RVUs in Canada, P < 0.001), which was mainly the result of higher radiology use. Although mean radiology use was 40% higher in the United States (370.0 vs. 264.5 RVUs in Canada, P < 0.05), there was little difference in the use of laboratory tests between countries (174.2 vs. 182.4 RVUs in Canada, P = 0.3). Within radiology, only CT and MRI use differed significantly between countries (US patients received 119% more tests than Canadians). These findings were consistent after adjustments for age, gender, diagnosis-related group, and university status. Differences in test use between countries were mainly the result of more testing among the US elderly than counterparts in Canada. Among surgical patients, there was little difference between countries for radiology (76.3 vs. 67.3 RVUs in Canada, P < 0.05) and laboratory (83.6 vs. 91.4 RVUs in Canada, P < 0.05). Comparable inpatients admitted to US hospitals received more diagnostic tests than their Canadian counterparts even in hospitals with similar availability of technology. Differences between countries were larger for high-cost tests than for lower-cost tests. Much of the difference in test use is explained by more intensive use for the elderly in the United States.

Transient ischaemic attacks due to meningioma--report of 4 cases

Computed tomography of patients diagnosed as having transient ischaemic attacks has revealed a heterogenous group whose symptoms may be due to completed infarcts or space-occupying lesions (such as neoplasia). Four such cases due to meningioma are presented including one which atypically simulated an infarct on an unenhanced scan. A sign to differentiate this from a true infarct is discussed.

Classification of subtype of acute ischemic stroke. Definitions for use in a multicenter clinical trial. TOAST. Trial of Org 10172 in Acute Stroke Treatment

BACKGROUND AND PURPOSE

The etiology of ischemic stroke affects prognosis, outcome, and management. Trials of therapies for patients with acute stroke should include measurements of responses as influenced by subtype of ischemic stroke. A system for categorization of subtypes of ischemic stroke mainly based on etiology has been developed for the Trial of Org 10172 in Acute Stroke Treatment (TOAST).

METHODS

A classification of subtypes was prepared using clinical features and the results of ancillary diagnostic studies. "Possible" and "probable" diagnoses can be made based on the physician's certainty of diagnosis. The usefulness and interrater agreement of the classification were tested by two neurologists who had not participated in the writing of the criteria. The neurologists independently used the TOAST classification system in their bedside evaluation of 20 patients, first based only on clinical features and then after reviewing the results of diagnostic tests.

RESULTS

The TOAST classification denotes five subtypes of ischemic stroke: 1) large-artery atherosclerosis, 2) cardioembolism, 3) small-vessel occlusion, 4) stroke of other determined etiology, and 5) stroke of undetermined etiology. Using this rating system, interphysician agreement was very high. The two physicians disagreed in only one patient. They were both able to reach a specific etiologic diagnosis in 11 patients, whereas the cause of stroke was not determined in nine.

CONCLUSIONS

The TOAST stroke subtype classification system is easy to use and has good interobserver agreement. This system should allow investigators to report responses to treatment among important subgroups of patients with ischemic stroke. Clinical trials testing treatments for acute ischemic stroke should include similar methods to diagnose subtypes of stroke.