Abstract & Commentary
Source: Greenberg S, et al. Hemorrhage burden predicts recurrent intracerebral hemorrhage after lobar hemorrhage. Stroke. 2004;35:1415-1420.
This paper carried out a clinical study to use gradient-echo MRI to determine prior evidence of microhemorrhages relating to cerebral amyloid angiopathy after patients had presented initially with lobar intracranial hemorrhage. Greenberg and colleagues attempted to determine whether microhemorrhages, detected at the time of lobar intracranial hemorrhage, predicted recurrent intracranial hemorrhage or declines in cognition and function. The authors studied 94 consecutive survivors of primary lobar intracranial hemorrhage with gradient-echo MRI at presentation. They were studied prospectively for 32.9 ± 24.0 months. A subset of 34 patients had a second MRI after a stroke-free interval of 15.8 ± 6.5 end points. Greenberg et al found that the number of hemorrhages at baseline predicted the risk of future symptomatic intracranial hemorrhage. The 3-year cumulative risks were 14%, 17%, 38%, and 51% for subjects with 1, 2, 3 to 5, or > 6 baseline hemorrhages. These were significant differences. The higher numbers of hemorrhages at baseline also predicted increased risks for subsequent cognitive impairment, loss of independence, or death. These were in subjects who were not previously demented or dependent. In the subjects who were followed after the second MRI, new microhemorrhages appeared in 17 of 34 and predicted increased risk of subsequent symptomatic intracranial hemorrhage. The increased risk was similar to that observed in the initial part of the study. The 3-year cumulative risks were 19%, 42%, and 67% for subjects with 0, 1 to 3, or > 4 new microhemorrhages.
These findings are of interest. They suggest that it may be possible to predict the risk of recurrent intracranial hemorrhage. Patients who have cerebral amyloid angiopathy are at high risk for this. It is clinically important to identify them to make sure that they are not receiving antiplatelet or other anticoagulating drugs, since this can worsen the risk. Interestingly, patients with either ApoE2 or E4 genotypes are at higher risk of developing cerebral amyloid angiopathy. Eventually, clinical trials are going to be designed to try and prevent these cerebral amyloid angiopathy and, therefore, knowing the risk of subsequent intracranial hemorrhage is important in designing these studies as well as in assessing risk benefit calculations in specific clinical situations. — M. Flint Beal
Dr. Beal, Professor and Chairman, Department of Neurology, Cornell University Medical College, New York, NY, is Editor of Neurology Alert.