Medical management of haemorrhagic stroke

Intracerebral haemorrhage (ICH) is much less common than ischaemic stroke (15% versus 85% in most Western studies), but is associated with a significantly worse prognosis. ICH is much more common in Asian populations, probably reflecting higher rates of small vessel disease, hypertension and genetic factors. Overall, ICH mortality rates approach 50% and there has been little effective treatment to date, except for the overall benefit from stroke unit care. Surgery for supratentorial ICH was not shown to be beneficial in a large recent trial of over 1000 patients, although controversies remain. For example, it still has an important role in selected patients with cerebellar ICH. Medical therapies to reduce brain edema and intracranial pressure, including glycerol and mannitol, are not of proven value. It is accepted that corticosteroids should not be used in ICH and may worsen outcomes. The management of acute hypertension is controversial and guidelines are based on little direct evidence.

Results of a Multicentre, Randomised Controlled Trial of Intra-Arterial Urokinase in the Treatment of Acute Posterior Circulation Ischaemic Stroke

BACKGROUND

Patients with ischaemic stroke due to occlusion of the basilar or vertebral arteries may develop a rapid deterioration in neurological status leading to coma and often to death. While intra-arterial thrombolysis may be used in this context, no randomised controlled data exist to support its safety or efficacy.

METHODS

Randomised controlled trial of intra-arterial urokinase within 24 h of symptom onset in patients with stroke and angiographic evidence of posterior circulation vascular occlusion.

RESULTS

Sixteen patients were randomised, and there was some imbalance between groups, with more severe strokes occurring in the treatment arm. A good outcome was observed in 4 of 8 patients who received intra-arterial urokinase compared with 1 of 8 patients in the control group.

CONCLUSIONS

These results support the need for a large-scale study to establish the efficacy of intra-arterial thrombolysis for acute basilar artery occlusion.

Cooling for Acute Ischemic Brain Damage (COOL AID): a feasibility trial of endovascular cooling

OBJECTIVE

To report results of a randomized pilot clinical feasibility trial of endovascular cooling in patients with ischemic stroke.

METHODS

Forty patients with ischemic stroke presenting within 12 hours of symptom onset were enrolled in the study. An endovascular cooling device was inserted into the inferior vena cava of those randomized to hypothermia. A core body temperature of 33 degrees C was targeted for 24 hours. All patients underwent clinical assessment and MRI initially, at days 3 to 5 and days 30 to 37.

RESULTS

Eighteen patients were randomized to hypothermia and 22 to receive standard medical management. Thirteen patients reached target temperature in a mean of 77 +/- 44 minutes. Most tolerated hypothermia well. Clinical outcomes were similar in both groups. Mean diffusion-weighted imaging (DWI) lesion growth in the hypothermia group (n = 12) was 90.0 +/- 83.5% compared with 108.4 +/- 142.4% in the control group (n = 11) (NS). Mean DWI lesion growth in patients who cooled well (n = 8) was 72.9 +/- 95.2% (NS).

CONCLUSIONS

Induced moderate hypothermia is feasible using an endovascular cooling device in most patients with acute ischemic stroke. Further studies are needed to determine if hypothermia improves outcome.

Magnetic resonance imaging criteria for thrombolysis in acute cerebral infarct

BACKGROUND AND PURPOSE

Magnetic resonance imaging (MRI) selection of stroke patients eligible for thrombolytic therapy is an emerging application. Although the efficacy of therapy within 3 hours after onset of symptoms with intravenous (IV) tissue plasminogen activator (tPA) has been proven for patients selected with computed tomography (CT), no randomized, double-blinded MRI trial has been published yet.

SUMMARY OF REVIEW

MRI screening of acute stroke patients before thrombolytic therapy is performed in some cerebrovascular centers. In contrast to the CT trials, MRI pilot studies demonstrate benefit of therapy up to 6 hours after onset of symptoms. This article reviews the literature that has lead to current controlled MRI-based thrombolysis trials. We examined the MRI criteria applied in 5 stroke centers. Along with the personal views of clinicians at these centers, the survey reveals a variety of clinical and MRI technical aspects that must be further investigated: the therapeutic consequence of microbleeds, the use of magnetic resonance angiography, dynamic time windows, and others.

CONCLUSION

MRI is an established application in acute evaluation of stroke patients and may suit as a brain clock, replacing the currently used epidemiological time clock when deciding whether to initiate thrombolytic therapy. MRI criteria for thrombolytic therapy are applied in some cerebrovascular centers, but the results of ongoing clinical trials must be awaited before it is possible to reach consensus.

Is Doppler ultrasound sufficient as the sole investigation before carotid endarterectomy?

BACKGROUND AND AIMS

Doppler ultrasound (DU) of the extracranial carotid arteries has been advocated as the sole imaging modality in carotid endarterectomy (CE) candidates. However this approach fails to identify patients with potentially significant intracranial disease, at high risk of stroke and death. Therefore, many stroke clinicians recommend angiography after screening DU. We aimed to identify the proportion of cases referred for CE in whom the identification of intracranial disease could have altered management.

METHODS

Two neuroradiologists, blinded to the clinical history, reviewed the films of 111 CE candidates, predominantly of Caucasian background, who had undergone carotid angiography after screening DU. Intracranial stenoses >50% luminal diameter, incidental aneurysms and non-atherosclerotic lesions were documented. Demographic and epidemiological data were collected.

RESULTS

Of the 111 patients, 87 had >50% extracranial stenoses although two thirds were asymptomatic. Intracranial stenotic lesions were recorded in 29% of patients. Over half of these were tandem lesions, distal to an extracranial stenosis. Aneurysms were found in 4.5% of patients.

CONCLUSIONS

DU alone would have failed to detect significant intracranial disease in nearly a third of cases. These patients are at high risk of stroke. The identification of this group allows more aggressive stroke prevention therapy.

Self-care management for neuropathy in HIV disease

Peripheral neuropathy is the most common neurological complication in HIV and is often associated with antiretroviral therapy. As part of a larger study on self-care for symptoms in HIV disease, this study analyzed the prevalence and characteristics of peripheral neuropathy in HIV disease, the self-care strategies, and sources of information for self-care utilized by the sample. A convenience sample of 422 respondents was recruited from an Internet web-based site developed by the University of California, San Francisco International HIV/AIDS Research Network and from five geographic data collection sites (Boston, New York City, San Francisco and Paterson in the USA, and Oslo, Norway). Results of the study indicated that respondents with peripheral neuropathy identified 77 self-care behaviours including complementary therapies, use of medications, exercise and rest and/or elevation of extremities. Sources of information included health care providers, informal networks and media sources.

Baseline blood pressure but not early computed tomography changes predicts major hemorrhage after streptokinase in acute ischemic stroke

BACKGROUND AND PURPOSE

Intracerebral hemorrhage is the most serious complication of thrombolytic therapy for stroke. We explored factors associated with this complication in the Australian Streptokinase Trial.

METHODS

The initial CT scans (< or =4 hours after stroke) of 270 patients were reviewed retrospectively by an expert panel for early signs of ischemia and classified into the following 3 categories: no signs or < or =1/3 or >1/3 of the vascular territory. Hemorrhage on late CT scans was categorized as major or minor on the basis of location and mass effect. Stepwise, backward elimination, multivariate logistic regression analysis was used to identify risk factors for each hemorrhage category.

RESULTS

Major hemorrhage occurred in 21% of streptokinase (SK) and 4% of placebo patients. Predictors of major hemorrhage were SK treatment (odds ratio [OR], 6.40; 95% CI, 2.50 to 16.36) and elevated systolic blood pressure before therapy (OR, 1.03; 95% CI, 1.01 to 1.05). Baseline systolic blood pressure >165 mm Hg in SK-treated patients resulted in a >25% risk of major secondary hemorrhage. Early ischemic CT changes, either < or =1/3 or >1/3, were not associated with major hemorrhage (OR, 1.58; 95% CI, 0.65 to 3.83; and OR, 1.11; 95% CI, 0.45 to 2.76, respectively). Minor hemorrhage occurred in 30% of the SK and 26% of the placebo group. Predictors of minor hemorrhage were male sex, severe stroke, early CT changes, and SK treatment. Ninety-one percent of patients with major hemorrhage deteriorated clinically compared with 23% with minor hemorrhage.

CONCLUSIONS

SK increased the risk of both minor and major hemorrhage. Major hemorrhage was also more likely in patients with elevated baseline systolic blood pressure. However, early CT changes did not predict major hemorrhage. Results from this study highlight the importance of baseline systolic blood pressure as a potential cause of hemorrhage in patients undergoing thrombolysis.

Patterns of physical activity among American Indian children: an assessment of barriers and support

Estimates indicate that 10% to 50% of American Indian and non-Indian children in the U.S. are obese, defined as a body mass index > or = 95th percentile of the NHANES II reference data. Pathways is a two-phase, multi-site study to develop and test a school-based obesity prevention program in American Indian schoolchildren in grades three through five. During Phase I feasibility prior to initiation of the Pathways trial, data were collected related to physical activity patterns, and the supports of, and barriers to, physical activity. Nine schools from communities representing six different tribal groups participated in this study. Multiple measures were used for data collection including direct observation, paired child interviews, and in-depth interviews and focus groups with adults. Students completed the self-administered Knowledge, Attitudes, and Behaviors (KAB) survey, and a Physical Activity Questionnaire (PAQ). Barriers to physical activity at schools included a lack of facilities, equipment, and trained staff persons for PE. Adults were not consistently active with their children, but they were highly supportive of their children's activity level. Children reported a strong enjoyment of physical activity and strong peer support to be physically active. Weather conditions, safety concerns, and homework/chores were common barriers to physical activity reported by children and adult caregivers. The information was used to design culturally and age-appropriate, practical interventions including the five physical activity programs for schoolchildren in the Pathways study.

The value of apparent diffusion coefficient maps in early cerebral ischemia

BACKGROUND AND PURPOSE

Prediction of the regions of the ischemic penumbra that are likely to progress to infarction is of great clinical interest. Whether lowered apparent diffusion coefficient (ADC) values were present in the ischemic penumbra of patients presenting with acute ischemic stroke and were specific to regions of the penumbra that proceeded to infarction was investigated.

METHODS

Nineteen patients with hemispheric stroke of less than 6 hours' onset and with acute scans showing a perfusion lesion greater than a diffusion lesion (ischemic penumbra) were studied. Scans also were performed subacutely (days 3 to 5) and at outcome (day 90). The outcome scan was used to identify regions of the penumbra that proceeded to infarction.

RESULTS

The ADC ratios were significantly reduced (P <.00001) in regions of the penumbra that progressed to infarction on the outcome scan compared with those that remained normal. In regions that showed transition to infarction, the mean ADC ratios were typically 0.75 to 0.90.

CONCLUSION

Intermediate ADC values are present in the ischemic penumbra and are indicative of tissue at risk of infarction.

Perfusion magnetic resonance imaging maps in hyperacute stroke: relative cerebral blood flow most accurately identifies tissue destined to infarct

BACKGROUND AND PURPOSE

In ischemic stroke, perfusion-weighted imaging (PWI) and diffusion-weighted imaging (DWI) provide important pathophysiological information. A PWI>DWI mismatch pattern suggests the presence of salvageable tissue. However, improved methods for distinguishing PWI>DWI mismatch tissue that is critically hypoperfused from benign oligemia are required.

METHODS

We investigated the usefulness of maps of relative cerebral blood flow (rCBF), volume (rCBV), and mean transit time (rMTT) to predict transition to infarction in hyperacute (<6 hours) stroke patients with PWI>DWI mismatch patterns. Semiquantitative color-thresholded analysis was used to measure hypoperfusion volumes, including increasing color signal intensity thresholds of rMTT delay, which were compared with infarct expansion, outcome infarct size, and clinical status.

RESULTS

Acute rCBF lesion volume had the strongest correlation with final infarct size (r=0.91, P<0.001) and clinical outcome (r=0.67, P<0.01). There was a trend for acute rCBF>DWI mismatch volume to overestimate infarct expansion between the acute and outcome study (P=0.06). Infarct expansion was underestimated by acute rCBV>DWI mismatch (P<0.001). When rMTT lesions included tissue with moderately prolonged transit times (mean delay 4.3 seconds, signal intensity values 50% to 70%), infarct expansion was overestimated. In contrast, when rMTT lesions were restricted to more severely prolonged transit times (mean delay 6.1 seconds, signal intensity >70%), these regions progressed to infarction in all except 1 patient, but infarct expansion was underestimated (P<0.001).

CONCLUSIONS

The acute rCBF lesion most accurately identified tissue in the PWI>DWI mismatch region at risk of infarction. Color-thresholded PWI maps show potential for use in an acute clinical setting to prospectively predict tissue outcome.

Q methodology: a new way of assessing employee satisfaction

As yet another nursing shortage faces the country, the issue of the satisfaction of nurses again becomes of critical concern to nursing managers in the interest of staff retention. The authors describe the use of the statistical technique Q methodology to assess the needs of nurses and other medical staff at a level one, tertiary care emergency department in the United States. Using the Q method, the authors were able to identify different, unique viewpoints concerning employee needs among the study population, as well as commonly shared views. This level of detail, not obtainable using more traditional statistical techniques, can aid in the design of more effective strategies aimed at fulfilling the needs of an organization's staff to increase their satisfaction.

Prediction of the final infarct volume within 6 h of stroke using single photon emission computed tomography with technetium-99m hexamethylpropylene amine oxime

BACKGROUND

A simple method to predict the final infarct volume within 6 h of onset of hemispheric ischemic stroke based on the measurement of cerebral blood flow (CBF) using single photon emission computed tomography (SPECT) with techneticum-99m hexamethylpropylene amine oxime ((99m)Tc-HMPAO) was investigated in a clinical model involving patients without definite early reperfusion or clinical recovery.

METHODS

A group of 16 patients (group 1) was used to establish the methodology, which was then validated in a second group of 14 patients (group 2). The final infarct volume was defined using computed tomography (CT) performed at least 7 days after stroke. The relative CBF threshold value, expressed as a percentage of the mean contralateral hemispheric value, which most closely estimated the final infarct size on coregistered CT was established for each patient.

RESULTS

The mean threshold CBF value for group 1 was 63.7%. When this value was used to predict infarct size in group 2, a close correlation was observed between the actual and the estimated sizes (r = 0.973, p < 0.0001). This value was not time dependent.

CONCLUSIONS

If no significant early reperfusion or clinical recovery occurs, a CBF threshold value of 63.7% on (99m)Tc-HMPAO SPECT performed within 6 h of stroke onset will reliably predict the final infarct size.

Comparison of MRI perfusion imaging and single photon emission computed tomography in chronic stroke

There have been few direct comparisons between MR perfusion-weighted imaging (PWI) and established perfusion imaging techniques, and none in chronic stroke. We therefore studied 17 chronic hemispheric infarction patients (mean, 90 days) and compared hypoperfusion volumes determined from PWI maps of relative cerebral blood flow (rCBF) and volume (rCBV), and mean transit time (rMTT) with those measured with (99)Tc-HMPAO single photon emission computed tomography (SPECT). Comparisons were also made between infarct size (T(2)-WI) and clinical scales. Correlations were found between lesion location and volume in all three PWI hemodynamic parameter maps with clinical state and lesions on SPECT and T(2)-WI. In 3 patients, rCBF and rCBV lesions extended well beyond the borders of moderate-sized infarctions. We conclude that in chronic stroke, PWI can delineate regions of abnormal perfusion that reflect the degree of functional impairment and structural damage. The finding of peri-infarct hypoperfusion suggests that PWI may have the potential to provide a rapid and non-invasive template against which interventional strategies aimed at promoting functional recovery may be investigated.

Body image and weight concerns among Southwestern American Indian preadolescent schoolchildren

This study was undertaken to determine whether perceptions about body image and size vary by body mass index (BMI) and demographic factors among American Indian children in the Southwestern United States. We surveyed 1,996 American Indian schoolchildren in the fifth grade (mean age 10.5 +/- 0.7 years) at eleven rural elementary schools. Heights and weights were measured using standard protocol. Multiple linear regression models were developed for preferred body shape, desired body shape, and body satisfaction to determine association with demographic and physical factors. Results from multiple linear regression modeling indicated that BMI and gender influence body satisfaction, with heavier children and girls being less satisfied with their bodies (P<.001 and P<.05, respectively). Geographic isolation and lack of amenities in the home did not appear to affect body satisfaction or messages from others about being too fat or thin; however, geographically isolated students were more likely to choose a larger body shape as best looking. Girls of appropriate weight were 2.2 times more likely than boys to have been told they were too fat. Sixty-one percent of all students surveyed had tried to lose weight. These findings, although similar to those for non-Hispanic Whites of the same age, are contrary to prevailing ideas that American Indians value obesity. In fact, we observed a high level of body dissatisfaction among children of appropriate weight, particularly girls, and prevalent dieting across all weight categories and both genders.

Divergent roles of SHP-2 in ERK activation by leptin receptors

The protein tyrosine phosphatase SHP-2 has been proposed to serve as a regulator of leptin signaling, but its specific roles are not fully examined. To directly investigate the role of SHP-2, we employed dominant negative strategies in transfected cells. We show that a catalytically inactive mutant of SHP-2 blocks leptin-stimulated ERK phosphorylation by the long leptin receptor, ObRb. SHP-2, lacking two C-terminal tyrosine residues, partially inhibits ERK phosphorylation. We find similar effects of the SHP-2 mutants after examining stimulation of an ERK-dependent egr-1 promoter-construct by leptin. We also demonstrate ERK phosphorylation and egr-1 mRNA expression in the hypothalamus by leptin. Analysis of signaling by ObRb lacking intracellular tyrosine residues or by the short leptin receptor, ObRa, enabled us to conclude that two pathways are critical for ERK activation. One pathway does not require the intracellular domain of ObRb, whereas the other pathway requires tyrosine residue 985 of ObRb. The phosphatase activity of SHP-2 is required for both pathways, whereas activation of ERK via Tyr-985 of ObRb also requires tyrosine phosphorylation of SHP-2. SHP-2 is thus a positive regulator of ERK by leptin receptors, and both the adaptor function and the phosphatase activity of SHP-2 are critical for this regulation.

Using Q methodology to assess the needs of emergency medicine support staff employees

The support staff members of any Department of Emergency Medicine perform a plethora of tasks that are crucial to the productivity of both individual physicians and the department as a whole. It is important to ensure that the personal and professional needs of the support staff are being met. This report describes the use of a relatively new statistical technique, Q methodology, to elucidate the needs of the support staff. This method allowed the investigators to quantitatively reveal the presence of two distinct viewpoints on employee needs among the support staff. Additionally, opinions that were held by the employees concerning their needs were identified. These results allowed for strategies to be tailored to both the individual and the group. The results indicate that Q methodology can have widespread application in the relatively new area of health care quality research.

Newer antiplatelet therapies in stroke prevention

BACKGROUND

Aspirin has been the mainstay of antiplatelet therapy in stroke prevention for 30 years. In the past decade, a number of new antiplatelet strategies have been shown in clinical trials to provide some benefits over aspirin therapy. These new compounds include ticlopidine, clopidogrel and the combination of aspirin with dipyridamole.

OBJECTIVES

To review the efficacy and dosage of aspirin in stroke prevention, and to review the benefits and risks of the newer strategies, compared with aspirin. Based on the evidence from randomised, controlled clinical trials and systematic overviews, to present practical clinical guidelines for the use of aspirin and the newer antiplatelet drugs.

DISCUSSION

For most patients aspirin monotherapy is still recommended as the first line antiplatelet strategy. However, some stroke clinicians are now recommending the combination of aspirin plus dipyridamole as a first line approach. For patients who are allergic to aspirin, clopidogrel is the drug of first choice and has largely replaced ticlopidine. For aspirin failures, either combined aspirin plus dipyridamole, or clopidogrel, are recommended. The combination of aspirin plus clopidogrel has theoretical appeal, is valuable in prevention of coronary stent thrombosis and is undergoing clinical trial in stroke prevention. Other novel approaches, such as oral platelet Gp IIb/IIIa antagonists are also being evaluated.

Self-reported symptom experience of critically ill cancer patients receiving intensive care

OBJECTIVE

To characterize the symptom experience of a cohort of intensive care unit (ICU) patients at high risk for hospital death.

DESIGN

Prospective analysis of patients with a present or past diagnosis of cancer who were consecutively admitted to a medical ICU during an 8-month period.

SETTING

Academic, university-affiliated, tertiary-care, urban medical center.

PATIENTS

One hundred cancer patients treated in a medical ICU.

INTERVENTION

Assessment of symptoms.

MEASUREMENTS

Patients' self-reports of symptoms using the Edmonton Symptom Assessment Scale (ESAS), and ratings of pain or discomfort associated with ICU diagnostic/therapeutic procedures and of stress associated with conditions in the ICU.

MAIN RESULTS

Hospital mortality for the group was 56%. Fifty patients had the capacity to respond to the ESAS, among whom 100% provided symptom reports. Between 55% and 75% of ESAS responders reported experiencing pain, discomfort, anxiety, sleep disturbance, or unsatisfied hunger or thirst that they rated as moderate or severe, whereas depression and dyspnea at these levels were reported by approximately 40% and 33% of responders, respectively. Significant pain, discomfort, or both were associated with common ICU procedures, but most procedure-related symptoms were controlled adequately for a majority of patients. Inability to communicate, sleep disruption, and limitations on visiting were particularly stressful among ICU conditions studied.

CONCLUSIONS

Among critically ill cancer patients, multiple distressing symptoms were common in the ICU, often at significant levels of severity. Symptom assessment may suggest more effective strategies for symptom control and may direct decisions about appropriate use of ICU therapies.

SOCS3 mediates feedback inhibition of the leptin receptor via Tyr985

During leptin signaling, each of the phosphorylated tyrosine residues on the long form of the leptin receptor (LRb) mediates distinct signals. Phosphorylated Tyr(1138) binds STAT3 to mediate its tyrosine phosphorylation and transcriptional activation, while phosphorylated Tyr(985) binds the tyrosine phosphatase SHP-2 and reportedly mediates both activation of ERK kinases and inhibition of LRb-mediated STAT3 activation. We show here that although mutation of Tyr(985) does not alter STAT3 signaling by erythropoietin receptor-LRb (ELR) chimeras in transfected 293 cells at short times of stimulation, this mutation enhances STAT3 signaling at longer times of stimulation (>6 h). These data suggest that Tyr(985) may mediate feedback inhibition of LRb signaling by an LRb-induced LRb inhibitor, such as SOCS3. Indeed, SOCS3 binds specifically to phosphorylated Tyr(985) of LRb, and SOCS3 fails to inhibit transcription by ELR following mutation of Tyr(985), suggesting that SOCS3 inhibits LRb signaling by binding to phosphorylated Tyr(985). Additionally, overexpression of SOCS3, but not SHP-2, impairs ELR signaling, and the overexpression of SHP-2 blunts SOCS3-mediated inhibition of ELR signaling. Thus, our data suggest that in addition to mediating SHP-2 binding and ERK activation during acute stimulation, Tyr(985) of LRb mediates feedback inhibition of LRb signaling by binding to LRb-induced SOCS3.