Ipsilateral simultaneous multiple hypertensive intracerebral hemorrhages: Analysis of hematoma formation and comparison with distribution of hypertensive mixed-type hematoma.

A 55-year-old Japanese woman with a history of hypertension and right putaminal hemorrhage developed simultaneous hemorrhages in the left thalamus and putamen and died 24 h later. There were no vascular anomalies in the brain. Synaptophysin immunostaining combined with eosin azure 50 (EA50) staining clearly identified the hematoma and the surrounding brain structures. In the right cerebral hemisphere, a cystic lesion as a sequela of the usual type of hypertensive putaminal hematoma was evident. In the left cerebral hemisphere, two fresh hematomas were evident. One was a thalamic hematoma, which had destroyed the dorsal and medial structures of the thalamus, and the other was an unusual putaminal hematoma, which had destroyed the entire putamen and crossed the internal capsule and caudate nucleus. α-Smooth muscle actin immunostaining combined with EA50 and Victoria bleu staining demonstrated three ruptured arteries associated with fibrin aggregates in the anterior thalamic nucleus and anterior putamen. Some circular structures composed of fibrin, suggesting the presence of ruptured arteries in the neighborhood, were evident in the thalamus and putamen. In the putamen, ruptured arteries and circular structures were present in the lateral to medial areas. Fibrin aggregates in the anterior thalamic nucleus were more numerous than those in the putamen. On the basis of these findings, we concluded that: (i) the artery with numerous fibrin aggregates in the anterior thalamic nucleus had ruptured first, followed by the arteries distributed in other parts of the thalamus and putamen; (ii) the unusual putaminal hematoma was attributable to rupture of the arteries around the center of the putamen, which are not responsible for the usual type of hypertensive putaminal hematoma; and (iii) it is suggested that even if hypertensive hemorrhage occurs simultaneously in the ipsilateral putamen and thalamus, the usual type of hypertensive mixed-type hematoma does not form.