Neff makes a good point about the relationship of brain size to perfusion. On the other hand, middle cerebral artery occlusion in baboons reduces cerebral blood flow to only 20% to 25% of baseline even in the most affected areas,1 suggesting an important role for collateral blood flow in primates.In a human stroke, the situation is even more complex; blockages may be incomplete, spontaneous thrombolysis may occur, and collaterals may reduce the initially threatened areas. By the same token, blood pressure can drop and the temperature and the blood glucose level can rise, adversely affecting the outcome.Clinical stroke is manifestly more complex than any animal model. Positive experimental results under strictly controlled conditions are essential first steps in evaluating stroke therapy, but they are only the beginning.
Hachinski V. Rodent Models of Stroke-Reply. Arch Neurol. 1997;54(4):351. doi:10.1001/archneur.1997.00550160005003