Hi and welcome,
I am so very sorry this is happening to your friend or loved one.....an air embolism, is gas trapped within the blood vessels, the bubbles will cut off the blood supply to a particular area of the body and once the arterial gas embolism reaches the brain, it is referred to as a cerebral embolism and can cause a major stroke.....it's actually quite rare and unfortunately what she's going through will not resolve with out surgical intervention, to do nothing would more likely result in very serious consequences and as frightening as brain surgery ever is, this will be her best preventative option!
Thinking of you and yours.......JJ