Small chronic hemorrhages and ischemic lesions in association with spontaneous intracerebral hematomas

It has been speculated that the same type of hypertensive small-artery disease can cause either intracerebral hemorrhages or ischemic lesions, depending on the circumstances.

To test this hypothesis, we examined the association between spontaneous intracerebral hematomas and both small chronic hemorrhages and ischemic lesions using echo planar and T2-weighted MRI. We considered a hypointense area to represent a hemorrhage and a hyperintense area to represent an ischemic lesion.

We identified small hypointense lesions in 56.7% of 30 patients with intracerebral hematomas (mean age, 62.2 years; total number of lesions, 108) and in 25.4% of 59 patients without hematomas (mean age, 67.6 years; total lesions, 28). The incidence of hypertension was 88.3% in patients with intracerebral hematomas and 42.3% in those without. The hypointense lesions were found in 56.0% of 50 patients with hypertension, whereas they were found only in 10.3% of 39 patients without hypertension. The hypointense lesions were most common in the subcortex, followed by the putamen, pons, thalamus, and cerebellum. The hyperintense lesions were of a higher grade in patients with intracerebral hematomas than in those without. The hypointense lesions were commonly surrounded by hyperintense areas. Additionally, in 3 of 3 autopsied brains, we found hemosiderin deposits around arteriosclerotic microvessels and a surrounding small infarction in areas that had appeared as small hypointense lesions surrounded by hyperintensity on MRI. One specimen also had an organized miliary pseudoaneurysm.

Our findings indicate that spontaneous intracerebral hematomas are frequently associated with small chronic hemorrhages, ischemic lesions, and hypertension. We speculate that hypertensive intracerebral hemorrhage may have the same microangiopathic basis as cerebral infarction.