The carotid arteries are the large arteries on each side of your neck which supply the majority of blood to your brain. The arteries are subject to atherosclerosis (plaque formation and hardening) leading to narrowing of the artery we call stenosis. These arteries supply small sense organs which detect changes in blood oxygen levels.
If these arteries develop plaques and harden, these organs malfunction and create problems for us. One of the problems that can arise from carotid stenosis is disruption in our sleep. The specific disruption is called central sleep apnea.
There are two sleep apnea conditions, obstructive sleep apnea (OSA) and central sleep apnea (CSA). Central sleep apnea is caused by impairment in the blood supply to the brain such as carotid stenosis. Here is where it gets complicated. Central sleep apnea is associated with a high degree of carotid stenosis and, therefore, stroke occurrence. Obstructive sleep apnea, because of the periodic lowering of the body’s oxygen levels during sleep, tends to promote hardening of the arteries and particularly the carotid arteries. Studies have shown that as many as 76% of the patients with severe carotid stenosis have sleep apnea.
The treatment of central and obstructive sleep apnea is essentially the same, but patients with sleep apnea should be considered for a study of their carotids since many of the patients do not have other symptoms. This study is easy and non-invasive. The latest data on this sleep apnea/carotid artery disease association may change how we work up patients in the future.