Experimental Chronic Subdural Hematoma in Mice: Gross morphology and light microscopic observations

Abstract

A single intraperitoneal injection of 6-aminonicotinamide (25 mg/kg BW) on the 5th postnatal day induced hydrocephalus in mice with almost 100% success. Approximately 60% of the mice spontaneously developed intracranial hemorrhage 20 days after the injection. About 1 week after the hemorrhage, a lens-shaped or spherical subdural hematoma was observed, accompanied by marked dilatation of the lateral ventricles and intraventricular hemorrhage. Histological examination revealed that the hematoma contained well-organized outer and inner membranes. Fresh hemorrhage surrounded by many hemosiderinladen macrophages was seen at the margin of the hematoma adjacent to the organizing outer membrane, in which many fibroblasts and blood vessels were noted. The inner membrane of the hematoma was made up of several tiers of flattened cells with thin-walled blood vessels. The gross morphology and histology of these hematomas closedly resembled those of human chronic subdural hematoma. This is a first experimental animal model of spontaneous subdural hematoma. (J Neurosurg 67: 710–716, 1987)