Experimental intracerebral hematoma in the rat

Current models of intracerebral hematoma are difficult to use for neurotransplantation studies because of high mortality and important variations of morphology, size and location of blood deposits. We propose a modification of the autologous blood infusion technique in rats to reduce these limitations.

The modification consisted in a mechanical microlesion preceding blood infusion. A canula was stereotactically introduced into the striatum of adult rats. Subsequently, a parenchyma lesion was created by a rotating microcatheter coaxially inserted through the canula, followed by slow infusion of 30 mul autologous blood during 5 minutes. Controls included canula insertion only and canula + microlesion. Hematoma volume/morphology were quantified and the animals behaviorally analysed using standardized tests.

Surgical mortality was 0/54 rats. One animal died during follow-up. Hematoma volume was constant and significantly higher (15.20 +/- 0.60 mm;3) than control lesions (canula: 0.11 +/- 0.01 mm;3; canula + trauma: 0.51 +/- 0.01 mm;3). Hematoma edges were sharply delineated and the perihematomal region histologically preserved. Rats with hematoma showed initially a reduced spontaneous rotational behaviour. They also showed persisting deficits of forelimb placing ability.

The advantages of this model include a systematic control of all steps of hematoma production, high reproducibility of volume, size, and location of blood deposits, preservation of perihematomal brain tissue, and quantifiable neurological deficits.