News Release

'Microbleeds' may be risk for serious stroke complications

Peer-Reviewed Publication

American Heart Association

American Heart Association journal report

DALLAS, March 1 – Clot-busting therapy is an effective treatment for ischemic stroke, but complications such as bleeding in the brain may occur. Researchers have found a marker that may identify individuals who are more likely to have bleeding complications and who may need to be treated more cautiously, say researchers in the March issue of Stroke: Journal of the American Heart Association.

Cerebral bleeding (CB) can be a devastating complication of ischemic stroke (caused by a blood clot). Between 20 percent and 40 percent of stroke patients have cerebral bleeding within the first week after stroke symptoms occur, says the study’s lead author Norbert Nighoghossian, M.D, professor of neurology of Hospital Neurologique in Lyon France.

The purpose of the study was to detect if previous microbleeds – microscopic bleeding in the brain – are associated with an increased risk of cerebral bleeding after ischemic stroke.

Researchers studied 100 stroke patients, ages 19 to 83, with documented ischemic damage. They analyzed the patients with various imaging technologies to assess the CB and define the presence of mirobleeds.

They found that patients with microbleeds were seven times more likely to develop cerebral bleeding after stroke compared to those without microbleeds.

According to Nighoghossian, old microbleeds often indicate that small blood vessels are diseased. This condition is exacerbated by hypertension, diabetes and the chronic use of drugs to prevent blood clots. Therefore, he urges doctors to manage these post-stroke patients with caution if such injury is detected.

The researchers also found that a new imaging technique called T2*-weighted gradient-echo MRI was best at detecting microbleeds. It offers higher sensitivity than conventional MRI imaging, which often fails to detect CB at an early stage of stroke. The authors say that this is the earliest evaluation of acute CB with T2*-weighted imaging in a large group of ischemic stroke patients.

In the study, early CB, was diagnosed in a total of 26 patients, 18 at the acute stage by T2*-weighted gradient-echo sequence and eight with CT scan performed within the first week. The presence of old microbleeds was significantly related to developing CB. The baseline National Institutes of Health Stroke Scale score (a standardized assessment to determine the neurological impairment-severity of stroke) and diabetes were also significant independent predictors of CB.

The cause of CB is due to many factors. The relationship between acute CB and previous vessel wall damage as revealed by the presence of microbleeds suggests an increased vascular vulnerability, says Nighoghossian. However, a larger number of patients, especially those with microbleeds, are needed to clearly establish this relationship. More research also is needed to determine if benefits outweigh the risks of using antithrombotic therapies in a subgroup at risk for both thrombotic and hemorrhagic events.

"I urge practitioners to carefully manage patients with diabetes and hypertension because they could be at increased risk of microbleeds and for cerebral bleeding,” Nighoghossian says.

###

Co-authors are M. Hermier, M.D.; P. Adeleine, Ph.D.; K. Blanc-Lasserre, M.D.; L. Derex, M.D.; J. Honnorat, M.D.; F. Philippeau, M.D.; J.F. Dugor, M.D.; J.C. Froment, M.D.; and P. Trouillas, M.D.

CONTACT: For journal copies only,
please call: (214) 706-1396
For other information, call:
Carole Bullock: (214) 706-1279
Bridgette McNeill: (214) 706-1135


Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.