The brain scan will also show what type of stroke it is â whether it was caused by a blockage or by bleeding. In the case of an SAH, a lumbar puncture is usually carried out as well as a brain scan. This is a procedure to remove a sample of the cerebrospinal fluid that bathes the brain and spinal cord.
This can cause a blood clot that can partially or totally block the flow of blood in the artery.  Atherosclerosis is the hardening and narrowing of the arteries. It is caused by the slow buildup of plaque on the inside of walls of the arteries.Neila Rockson.his is a morbid condition. The hardening of arteries within the brain is a form of arteriosclerosis, which in most cases is atherosclerosis. The buildup of hardened scar tissue within the brain can also be caused by the demyelinating autoimmune disease multiple sclerosis.
When plaque builds up in the body's arteries, the condition is called atherosclerosis (ATH-er-o-skler-O-sis). Over time, plaque can harden and narrow the arteries. This limits the flow of oxygen-rich blood to your organs and other parts of your body.hen plaque builds up in the body's arteries, the condition is called atherosclerosis (ATH-er-o-skler-O-sis). Over time, plaque can harden and narrow the arteries. This limits the flow of oxygen-rich blood to your organs and other parts of your body.