I60-I69: Cerebrovascular diseases

I65: Occlusion and stenosis of precerebral arteries, not resulting in cerebral infarction

Occlusion and stenosis of precerebral arteries refer to conditions where there is a blockage or narrowing in the arteries supplying blood to the brain, but this has not led to a cerebral infarction (stroke). These conditions are often caused by a buildup of plaque, a substance mainly made of fat, cholesterol, and cellular waste products, which can gradually harden and narrow the arteries, a condition known as atherosclerosis. These changes can slow or block blood flow, reducing the supply of oxygen and nutrients to the brain. Common symptoms include headache, facial pain, confusion, and difficulty with speech and/or movement, but symptoms can vary greatly depending on the specific artery affected. Without adequate blood flow, parts of the brain can start to deteriorate and this may lead to serious neurological problems over time.