Usually insulin has nothing to do with high blood pressure and the possibility of a brain stroke. High blood pressure can cause a brain stroke if an arterial blood vessel in the brain can’t handle the pressure and ruptures because of it. Then, a brain hemorrhage occurs. The opposite event is also possible. A brain stroke (from whatever cause) can increase intracranial pressure in the head due to a bleeding/infarct and the surrounding brain tissue edema. Increased intracranial pressure causes high blood pressure by a reflex mechanism. A CT-scan is necessary to conclude or exclude a brain insult.