Sequential Histological Changes in Tissue Surrounding Experimental Intracerebral Hematoma (I) : Light Microscopic Studies

In an attempt to investigate the sequential histological changes in the tissue surrounding intracerebral hematoma, an experimental model of intracerebral hematoma was made by an injection of 0.7ml of autologous whole blood, with the stereotaxic frame, into the right basal ganglia of the anesthetized rabbit. The total of 60 adult rabbits weighing 1.6 to 2.5kg were divided into 10 groups and sacrified in 0.5, 3, 6, 9 and 12 hours, and 1, 2, 3, 4 and 7 days after the formation of intracerebral hematomas. The sequential microscopical changes in the brain tissue surrounding hematoma were observed. The results obtained were as follows : 1) At the earlier stages, in 0.5 to 24 hours after hematoma formation, edema, migration of RBCs, perivascular hemorrhage and infiltration of neutrophils were observed in the surrounding brain tissues. These changes began to appear in 3 to 6 hours and were aggravated rapidly in 12 to 24 hours. At the later stages, in 2 to 7 days after hematoma formation, infiltration of macrophage, proliferation of vessels and fibrin were observed in the surrounding brain tissue. These changes in the process of tissue repair seemed to begin in 2 days and promote in 3 to 7 days after hematoma formation. 2) The experimental data suggested that in the clinical practice the removal of intracerebral hematoma might as well be carried out in the early stage of hemorrhage, particularly within 12 hours, before the degree and extent of necrosis in the surrounding brain tissue would be marked.

Sequential Histological Changes in Tissued Surrounding Experimental Intracerebral Hematoma (II) : Electron Microscopic Studies

In an attempt to investigate the sequential histological changes in the tissue surrounding intracerebral hematoma, and experimental model of intracerebral hematoma was made by an injection of 0.7ml of autologous whole blood, with the stereotaxic frame, into the right basal ganglia of the anesthetized adult rabbit. The total of 33 adult rabbits weighing 2.5 to 3.5kg were divided into 7 groups and sacrificed in 0.5, 3, 6, 9 and 12 hours, and 1 and 3 days after the formation of intracerebral hematomas. The sequential electron microscopical changes in the brain tissue surrounding hematoma were observed. The results obtained were as follows. 1) Degeneration of axon and glial cell were observed. 2) Degeneration of glial cell began to appear in 3 hours and was aggravated in 12 hours, and glial cell necrosis occurred in 1 day. Degeneration of axon began to appear in 6 hours and was aggravated in 12 hours to 1 day, and phagocytosis of degenerating axon was observed in 3 days. 3) This experimental data suggested that the removal of intracerebral hematoma might be carried out as quickly as possible, and must be done within 12 hours whenever possible.