Microbleeds and the risk of recurrent stroke.

BACKGROUND AND PURPOSE: We studied the risk of recurrent cerebrovascular events in patients who had a transient ischemic attack or ischemic stroke and who had evidence of microbleeds on MRI. METHODS: A prospective follow-up study was performed on hospitalized patients who were at least 50 years old with a transient ischemic attack or an ischemic stroke. The presence and number of microbleeds were assessed on gradient echo MRI and the presence of white matter disease on fluid-attenuated inversion recovery imaging using a semiquantitative scale. Patients were followed up by phone every 6 months. End points were intracerebral hemorrhage, ischemic stroke, and unclassified stroke. Cerebral events were adjudicated by 2 independent neurologists blinded to the presence of microbleeds. Cox regression analysis was performed. RESULTS: A total of 487 patients with a mean age of 72 years were followed up for a median of 2.2 years (25th to 75th percentile 1.9 to 2.7 years). Microbleeds were identified in 129 patients (25.6%). Two patients developed intracerebral hemorrhage during follow-up, 32 patients developed recurrent ischemic stroke, and 3 patients had unclassified strokes. Microbleeds were not independent predictors of recurrent stroke (P=0.2) or intracerebral hemorrhage (P=0.43). Lobar microbleeds or combined lobar and deep microbleeds were independently associated with recurrent stroke (P=0.018). CONCLUSIONS: In this European cohort, patients with microbleeds who have had cerebral ischemia have a higher risk of developing new ischemic strokes than of intracerebral hemorrhage. Lobar microbleeds or combined lobar and deep microbleeds might be independent predictors of recurrent stroke.

is leukoaraiosis on CT an accurate surrogate marker for the presence of microbleeds in acute stroke patients?

UNLABELLED: Microbleeds (MB) detected on gradient echo magnetic resonance images (GRE) are a potential risk factor for intracerebral hemorrhage after thrombolysis or oral anticoagulation. We assessed whether the presence of MB could be predicted from the extent of white matter disease (WMD) on computed tomography (CT). METHODS: We studied consecutive TIA or ischemic stroke patients who presented to the ER and who underwent both CT and GRE. WMD was rated on CT using a three point scale by two independent observers. The presence of MB was assessed on GRE. Logistic regression was used to predict the presence of MB on GRE. RESULTS: 199 consecutive patients underwent both CT and GRE. MB were identified on GRE in 56 patients (28.1%). After adjustment for age and sex, MB were more frequent in patients with leukoaraiosis (OR 2.8 per 1-point increase on the Van Swieten scale, p<0.001) and in patients presenting with a lacunar or posterior circulation syndrome (OR 2.0, p=0.048). The area under the ROC-curve derived from the logistic model was 0.70 (95% CI 0.61-0.79). Age, sex, hypertension, diabetes or the presence of left ventricular hypertrophy on ECG were not different in patients with or without MB. CONCLUSION: White matter disease on CT is associated with the presence of microbleeds on GRE. However, leukoaraiosis does not detect the presence of MB accurately enough to be considered a surrogate marker.

Association of apolipoprotein E epsilon2 with white matter disease but not with microbleeds.

BACKGROUND AND PURPOSE: Apolipoprotein E (apoE) alleles (epsilon2 and epsilon4) are associated with cerebral amyloid angiopathy, in which white matter disease and microbleeds are prominent features. The role of apoE in patients with microbleeds or white matter disease but no evidence of cerebral amyloid angiopathy has not been elucidated. We studied apoE alleles in relation to white matter disease and microbleeds in patients with transient ischemic attack or ischemic stroke. METHODS: We obtained brain MRI scans and apoE genotypes in 334 transient ischemic attack or ischemic stroke patients. Microbleeds were scored on a gradient echo MRI and white matter disease was examined on fluid attenuated inversion recovery MRI using a semiquantitative rating scale. RESULTS: Patients with moderate to severe white matter disease more frequently carried apoE epsilon2 alleles (25.2% versus 11.3%, P=0.001), but not apoE epsilon4 (26.6% in apoE epsilon4 carriers versus 25.9%; P=0.98). Adjustment for traditional risk factors did not modify this relationship (odds ratio, 2.9; 95% confidence interval, 1.5 to 5.3). There was no association between the presence of microbleeds and the apoE epsilon4 or apoE epsilon2 alleles. CONCLUSIONS: ApoE alleles do not exert a major influence on the development of microbleeds, but apoE epsilon2 may be associated with development of moderate to severe white matter disease in transient ischemic attack and stroke patients.

Quantitative diffusion tensor imaging in amyotrophic lateral sclerosis.

OBJECTIVE: Aim of present study was to evaluate changes in diffusion tensor imaging (DTI) parameters in the whole brain of 28 patients with amyotrophic lateral sclerosis (ALS) compared to 26 healthy controls. METHODS: In both fibertracking and voxel-based analysis, quantitative comparisons of the diffusion parameters between ALS patients and controls were performed. Correlation analyses of diffusion parameters and disease duration and disease severity were performed. A second DTI examination was acquired, allowing the evaluation of the effect of disease progression on the diffusion parameters. RESULTS: Fibertracking analysis revealed that especially the precentral part of the corticospinal tract (CST) was impaired. In the voxel-based analysis, it was shown that changes of diffusion parameters occurred throughout the brain, including frontal, temporal and parietal lobes. Disease severity was inversely correlated with the fractional anisotropy (FA). In the follow-up examination, a further decline of FA over time could be demonstrated in the CST as well as in the whole brain white matter. INTERPRETATION: This study provides support for the view of ALS as being a multisystem degenerative disease, in which abnormalities of extra-motor areas play an important role in the in vivo physiopathology.