An Attempt of a Staining Method to Clarify the Localization of Hematomas in Autopsy Cases of Intracerebral Hemorrhage: Application of Double Staining With Immunohistochemistry for Anti‐Synaptophysin Antibody Using <scp>DAB</scp> ‐ <scp> CoCl <sub>2</

In order to prepare specimens to clarify the anatomical localization of intracerebral hematomas (ICHs), we examined 18 autopsy cases ranging from 1 day to 2.5 months after onset: Five cases of hypertensive ICH (two cases of putaminal hematoma, one case of thalamic hematoma, one case of mixed-type hematoma, and one case of cerebellar hematoma), two cases of subarachnoid hemorrhage with ICH, three cases of cerebral amyloid angiopathy-related hemorrhage, two cases of ICH associated with blood coagulation abnormalities, and six cases of brain death with ICH (brain death period: 10 h to 13 days). Paraffin blocks containing hematomas that have hardened and have poor formalin penetration can be easily sectioned at 6 μm thickness by using Histoheme, an ammonia-based softening reagent. By mounting the sections on MAS-coated glass slides or New Silan III-coated glass slides, we were able to minimize the peeling of hematomas from the slides. Conventional staining (Klüver-Barrera staining, Elastica-Masson Goldner staining) showed decreased staining of the brain tissue surrounding the hematoma due to the effects of edema, making the localization of the hematoma unclear. Synaptophysin (SYP) immunostaining was visualized with 3,3'-diaminobenzidine tetrahydrochloride (DAB)-CoCl₂ and double stained with eosin azur 50 (EA50) (DAB-CoCl₂ SYP + EA50). This method revealed gray matter as black and fresh to relatively recent hematoma as red, and clearly demonstrated the anatomical localization of the hematoma without any reduction in staining due to edema. In contrast, hematomas in cases more than 29 days after onset showed heterogeneous staining in red or green, and the boundary between the brain tissue and the hematoma was unclear. However, with double staining using DAB-CoCl₂ SYP and Masson Goldner staining, the hematoma stained dark red, and the boundary with the brain tissue was more clearly visible than with DAB-CoCl₂ SYP + EA50.