The value of magnetic resonance imaging in the detection of type II hemorrhagic lacunes.

Lacunar infarcts (lacunes) are small necrotic/cystic lesions of the brain associated with hypertension. Many are clinically silent, but some are associated with localizing symptoms and signs. Lacunes recently were classified into three types, namely, those resulting from small infarcts (type I), those arising as small hemorrhages (type II), and those due to dilatation of perivascular spaces (type III). The type II lacunes are thought to be much less common than those of type I. Type II lacunes have not previously been reported during life. We report a case of subacute type II lacune in the pontine tegmentum that was detected by magnetic resonance imaging and later verified by histopathologic examination. The patient was hypertensive and had numerous other type I lacunes. This case shows that the magnetic resonance imaging features of hemorrhagic lacunes are identical to those of small hemorrhages or small hemorrhagic infarcts and that magnetic resonance imaging is a useful tool in the detection of lacunes and their correlation with clinical neurologic symptoms and signs.