Out of all the organs in the human body we know the least about the brain. Every other organ in the body and we know to the cellular, if not the molecular level.
But the brain... You've heard the clichés, I'm sure; given the interdependence of neurons, the human brain is the most complex structure in the known galaxy, including the galaxy itself. The estimate of planets in the galaxy is upwards of 1 trillion. The most conservative estimate of the number of synaptic connections in the human brain is 1000 trillion!
"But," you may think, "I can't even figure out which socks match my shoes." That maybe true, but remember: while you're trying to figure that out, your brain is keeping every one of the trillions of cells in your body in relative harmony.
Here's a place to start... Below is a video of the surgery for a subdural hematoma. This type of stroke is the least common (about 7%), but the most deadly.
Warning: this video is graphic. Frankly, I had a hard time sitting through it.I would suggest watching just one portion – a few seconds, from 1:32 to 1:39. This is the good part, where the surgeon rids the brain of this sort of cap of blood that has accumulated between the skull and the brain. If this sort of surgery is not done, the brain will continue to compress, furthering damage.