Vertebrobasilar insufficiency is a condition characterized by poor blood flow to the posterior (back) portion of the brain, which is fed by two vertebral arteries that join to become the basilar artery. Blockage of these arteries occurs over time through a process called atherosclerosis, or the build-up of plaque.
No, Portugal is not a Mediterranean country. It does, however, have a mediterranean climate, but it is not considered a mediterranean country because the south does not have the Mediterranean Sea as a coast.
The Tyrrhenian Sea portion of the Mediterranean Sea is directly to the east of Sardinia between the Sardinian east coast and the west coast of the Italian mainland peninsula. The Strait of Bonifacio is directly north of Sardinia and separates Sardinia from the French island of Corsica.