Can radiation cause dizzy or fainting spells (vasovagal syncope)?
Let’s start by reviewing some anatomy. Then, I will address the problem some patients have when they turn their heads and get a little dizzy and light headed. On either side of your neck is the carotid arteries which are the main suppliers of blood to the head and more specifically, the brain. This artery comes into the neck from the chest as a single large artery, the common carotid artery, then splits in the upper neck to become the external carotid artery supplying blood to the face and head outside of the skull and the internal carotid artery supplying blood to the brain. Where this artery splits is called the carotid bulb and you can usually feel it as a pulsating mass in the upper neck. The carotid artery and especially the carotid bulb are enervated by some specialized nerve fibers that are sensitive to the chemical content of the blood and also to the pressure of the blood inside of them. Now, lets say you have had surgery on the neck or radiation to neck. Remember that either
