Recently, someone very close to me suffered what is called a hemorrhagic stroke. It's similar to an ischemic stroke, which is what most of us are familiar with, the main difference between the two being that a hemorrhagic stroke involves the leakage of blood from a vein or artery, while an ischemic stroke involves the blockage inside an vein or an artery. This is a very general analysis of the two, if you want more information about strokes, you can go here. In this case, she suffered the stroke during brain surgery to replace a shunt. I visited almost every day after the stroke, and I had the chance to witness the amazing elasticity of the brain, first hand.
The first day I visited, her speech was very garbled, and she had lost the use of her entire right side. After reading Chapter 3, I realized that these symptoms were a sign that her frontal lobe had been affected, especially her motor cortex. The fact that her speech was incoherent at first, as well as a noticeable decrease in short term memory led me to believe that it was the frontal lobe that had been affected. The loss of motion in her right side was quite obviously due to the motor cortex, a part of the frontal lobe. Because the doctors were not aware when the stroke occurred, these symptoms helped them to realize what had happened. Once it was identified that it was in fact a stroke (this was done by a CT scan), they were able to stop the bleed.
The brains' ability to recover from such an incident is incredible. Improvements were literally seen by the hour, as the swelling in her brain went down. Her brain had repaired itself so quickly that she was close to normal a week after she suffered the stroke. The speed at which the brain repaired itself in this situation makes me wonder what, if any, role stem cells played in making repairs. It seems to me that the loss of motion in her right side was due more to the pressure caused by a portion of her brain swelling than any sort of actual damage to the nerves. One can still see the effects of the stroke on her, she walks with a slight limp and she still has a bit of trouble with short term memory. Could this be because of actual damage that is being repaired by stem cells at a slower rate? Or does she still have some residual swelling (she only left the hospital last Tuesday, September 27th) that is still decreasing?