CHICAGO—Magnetic resonance imaging (MRI) may be as accurate as computed tomography (CT) in detecting acute bleeding in the brain in patients showing signs of stroke, and more accurate than CT in revealing chronic bleeding in the brain, according to a study in the October 20 issue of JAMA.

Noncontrast computed tomography (CT) has been the standard brain imaging technique used for the initial evaluation of patients with acute stroke symptoms, greatly due to its capacity to rule out the presence of hemorrhage (bleeding), according to background information in the article. Magnetic resonance imaging (MRI) has been suggested as an alternative to CT in an emergency department setting because of its ability to outline the presence, size, location and extent of hyperacute ischemia (blocked blood vessel).

Chelsea S. Kidwell, M.D., from the UCLA Medical Center, Los Angeles, and colleagues examined MRIs and CT scans in 200 patients showing signs of stroke, in order to compare their accuracy in detecting acute bleeding in the brain. The Hemorrhage and Early MRI Evaluation (HEME) study was performed at the UCLA Medical Center and the Suburban Hospital in Bethesda, Md., between October 2000 and February 2003. The average age of patients was 75 years; fifty-five percent of study participants were women. MRI and CT scans were performed within six hours of the patients' onset of stroke symptoms.

Researchers stopped the HEME study early after an unplanned interim analysis revealed that MRI was detecting acute bleeding not detected by CT. In diagnosing any type of bleeding, MRI identified 71 positive patients, while CT identified 29 positive patients. Acute bleeding was diagnosed in 25 participants on both MRI and CT, with four additional patients identified in MRI scans not found in corresponding CT. Chronic bleeding, most often microbleeds, was visualized on 49 patient MRIs, although not on their CT scans.

The authors write: "… MRI may be able to detect regions of hemorrhagic transformation of an acute ischemic stroke not evident on CT. Our study confirms the superiority of MRI for detection of chronic hemorrhage, particularly microbleeds. The role of these findings in the decision-making process for treatment of patients who are candidates for thrombolytic [clot-dissolving] therapy is currently unknown."

CHICAGO—Stroke patients who were older and had disturbances of their consciousness had a greater risk of death in the hospital following thrombolytic (clot-dissolving) therapy, according to an article in the October 20 issue of JAMA.

Intravenous clot-dissolving treatment with tissue plasminogen activator (tPA) is currently the only approved treatment for patients with acute ischemic stroke and is recommended in the guidelines of several national and international stroke associations, according to background information in the article. Clarification of clinical factors associated with early death in patients treated with tPA could help identify subgroups of patients with increased risks and thereby allow clinicians to give special attention to these patients after tPA treatment.

Peter U. Heuschmann, M.D., M.P.H., of the University of Muenster, Germany, and colleagues conducted a study to identify predictors of in-hospital death in patients with ischemic stroke treated with tPA outside of clinical trials. The study was conducted at 225 community and academic hospitals throughout Germany cooperating within the German Stroke Registers Study Group. The study included 1,658 patients with acute ischemic stroke who were admitted to study hospitals between 2000 and 2002 and were treated with tPA.

The researchers found that 166 patients (10 percent) who received tPA died during hospitalization, with 67.5 percent of these deaths occurring within 7 days. Factors predicting in-hospital death after tPA use were older age (for each 10-year increment in age, a 60 percent greater risk) and altered level of consciousness (3.4 times increased risk). One or more serious complications was observed in 27.2 percent of all patients and in 83.9 percent of patients who died after tPA treatment. Risk of in-hospital death after thrombolysis decreased with increasing experience of the treating hospital in tPA administration, indicating an inverse relation.

CHICAGO—Stroke patients who show little improvement in the first 24 hours after receiving thrombolytic (clot-dissolving) therapy are more likely to have poor outcomes or death at three months, according to a study in the October 20 issue of JAMA. Several factors, including elevated blood glucose levels and time to treatment were predictors of lack of improvement.

According to background information in the article, the focus of thrombolytic therapy in acute stroke has been on favorable outcome at 3 months. Few studies have analyzed outcome at 24 hours. Identifying predictors of lack of improvement could improve understanding of the clinical factors that influence the recovery and clinical response to alteplase (clot-dissolving drug). This could help predict poor outcome earlier (24 hours after receiving alteplase) than at 3 months and would have important implications for clinical management and for discharge planning.

Gustavo Saposnik, M.D., of the University of Western Ontario, London, Ontario, Canada and colleagues examined predictors of lack of improvement at 24 hours after receiving alteplase and their relationship with poor outcome at 3 months. The study included 216 acute stroke patients who received alteplase and were admitted to a university hospital from January 1999 to March 2003. Participants were recruited from two academic centers in a major city in Ontario and 33 affiliated hospitals from 7 counties.

The researchers found that 111 (51.4 percent) of the patients had a lack of improvement at 24 hours. After adjusting for age, sex, and stroke severity, independent predictors of lack of improvement included elevated glucose level on admission (nearly 3 times greater risk); cerebral cortex involvement (2.6 times increased risk), and time to treatment. At three months, 43 patients (20.2 percent) had died; of the 170 survivors, 75 patients (44 percent) had poor outcomes. After adjusting for age, sex, and stroke severity, lack of improvement at 24 hours was an independent predictor of poor outcome (nearly 13 times more likely) and death (7.5 times more likely). Patients with a lack of improvement had longer lengths of hospitalization (14.5 vs. 9.6 days).

MRI SUPERIOR TO CT SCAN IN DIAGNOSING STROKE - FINDINGS COULD CHANGE THE WAY EMERGENCY DEPARTMENTS DIAGNOSE STROKE