The brain can heal.
Just slitting one of those arteries probably wouldn't affect much of your cognitive abilities, or your personalities/memories
Lol. Do you even neuroscience bro? I'm bout to learns you and see how much I remember for medic pre-entrance test the 27th by writing a novel.
Brain cells do not regenerate, nor can they be replaced. When they go without oxygen for 4-10 minutes, they die and do not come back. After a cerebral vascular issue, most patients do not come back mentally. Most end up with severe neurological damage. One patient I had only knew her name, and would ask every 2 minutes where her husband was. When a clot blocks a vessel, you have 3 hours for drugs to dissolve the clot. If one bursts, you pretty much better hope you are on the surgery table or in a hospital already. A bursting one is mostly described as "worst headache I've ever had." Where as an Ischemic stroke is normally presented with an altered mental status. Which may be assessed with the Cincinnati Pre-Hospital Stroke Scale which assess facial droop by smiling with teeth, arm drift by eyes closed palms up hold level, and slurred speech by saying a tough sentence. Do not confuse a stroke with a simple case of hypoglycemia or low blood sugar, and be sure to get a dexi blood glucose check on every patient with altered mental status.
Although "leaking into skull", or Increased Cranial Pressure is serious. It depends on the location. Above the thick leathery shit you see being held back in the pic called the "dura" is more dangerous because it's arterial and bleeds faster. Below that and it could take weeks before you realize it because slow venous flow. Older people have more room in the skull from brain shrinking, and a simple fall can tear those veins causing this often.
The reason ICP is dangerous is because the pressure can build up so much it starts to force the brain stem down into the neck, which can cause a serious case of being dead from not being able to breathe. The medulla oblongata and pons sense the Co2 levels in the brain stem and it sends a stimulus for the diaphragm to contract and lungs to inhale through the C3-C5 phrenic nerve. Negative pressure causes you to exhale. 2% of COPD patients do not have this and breathe on the hypoxic drive, which rides of sensors of o2 in the carotid arteries. I want to say barroreceptors.
When you see decerebrate posturing, or a pulse below 60 beats a minute, a blood pressure below 100, and an irregular breathing pattern, shit is getting real. You may also see a yellow "ring" or halo if you push a napskin slightly into a bloody ear or nose. This is because the cerebral spinal fluid is in the third ventricle in the center of the brain, and the pressure forces it out the ear canals.
I give up now. Too much writing. Just going to go read some study guides. I could probably go way over the 10,000 character limit just on neurological alone.