What Are The Signs Of Subclavian Steal Syndrome?

Double Vision

Double vision may manifest in subclavian steal syndrome patients. Double vision is best described as when an individual sees two images of the same object when they should only be seeing one. The images the individual is seeing can be on top of one another, side by side, or both. Double vision in patients with subclavian steal syndrome typically occurs in both eyes or is binocular. The reduced blood supply to the brain can cause tissues located in the parietal lobe and the occipital lobe to shut down or begin to die. The occipital lobe is responsible for taking visual information from nerve signals and creating an image in the brain.

The parietal lobe controls many functions, including that of perception, which can alter the way the eyes work. Oxygen deprivation from poor blood supply may also adversely affect the motor area of the brain and the brain stem, resulting in vision disturbances like double vision. Less commonly, the actual nerves that communicate between the tissues of the eye and the brain can become impaired from a lack of oxygen supply due to subclavian steal syndrome. If the eyes fall out of coordination with each other because of problems with nerves or muscle movement in the brain, double vision may occur.

Issues With Memory

Two subclavian arteries branch from the aorta to supply blood to each one of the arms. Each subclavian artery branches into a vertebral artery that carries blood to the base of the brain. An obstruction can occur in one of the subclavian arteries before the branching off of the vertebral artery as a complication of atherosclerosis. This obstruction causes blood flow to the subclavian and vertebral artery to halt. The blood in the brain at the end of the vertebral arteries enters into a structure named the circle of Willis.

During this type of blockage in the subclavian artery, the circle of Willis initiates the reverse of blood flow from the brain back to the arm to help supply the tissues of the limb. This redistribution of blood from the brain to the arm can cause a decrease in the amount of oxygen and nutrients received by some brain tissues, causing them to shut down. Issues with memory occur when certain parts of the brain do not receive enough oxygen due to the blood being stolen from the brain by the subclavian artery.