BlackMD - TRANSIENT ISCHEMIC

What is a transient ischemic attack (TIA)?

The primary role of the brain is to send signals to the body for motor function and through the five senses (sight, hearing, touch, smell, and taste), to receive signals and return the appropriate response. The brain processes information through conscious thought and unconsciously through nerve systems that control basic bodily functions, like heart rate, temperature control and balance.

For the most part, the brain is arranged so that the right side of the brain controls the left side of the body and the left side of the brain controls the right of the body. Vision is located in the back of the brain (occiput) and balance and coordination is located at the bottom of the brain (cerebellum). Blood supply to the brain comes from the carotid arteries that are located in the front of the neck and the vertebral arteries that run in the back of neck through small canals in the bony spine (vertebrae) of the neck.

n of the brain loses its blood supply, it becomes oxygen deficient and can become damaged. The part of the body that the brain controls stops functioning. This is called a stroke or a cerebro-vascular accident (CVA). If the brain is able to regain its blood supply quickly, then the CVA symptoms may resolve; this is known as a transient ischemic attack (TIA).

What are the causes of transient ischemic attack (TIA)?

Loss of blood supply to portions of the brain can occur for a variety of reasons. A blood vessel can get blocked and blood supply to a part of the brain is lost, or a blood vessel leaks blood into the brain (brain hemorrhage). Most commonly, the blood vessel is blocked. The blockage can be caused by a blood clot that forms in the blood vessel (thrombosis) or it can be caused by a clot or debris that floats downstream (embolus).

Atherosclerosis or "hardening of the arteries" can cause fatty plaque formations in he blood vessel wall. The plaque can rupture and causes a small blood clot to form and occlude the blood vessel. Blockage can also occur when debris from narrowing of a carotid artery breaks off, and floats downstream to cause the occlusion. Sometimes, in people with an irregular heart beat called atrial fibrillation, small blood clots can be formed and travel to the brain to cause the obstruction.

Aneurysm (Brain) »

What is a brain aneurysm and what causes a brain aneurysm?

The brain gets its blood supply from arteries known as the Circle of Willis. It is located at the base of the brain and is a loop of arteries that join in a circle then send branches out to all parts of the brain. These arteries deliver nutrition (glucose and oxygen) to the brain cells.

The junctions where these arteries come together can form weak spots. These weak spots can balloon out and fill with blood, creating the outpouchings of blood vessels known as aneurysms. These sac-like areas may leak or rupture spilling blood into surrounding tissues. While the prevailing thought has been that aneurysms are congenital (meaning that people are born with them), it is now thought that they are due to microscopic damage to the artery walls caused by abnormal flow at the junction points where the arteries come together.