Hi, my husband had the same symptoms for months after his treatments. His dr said the effects of radiation and in his case chemo can last months and months after you are done. It was worse for him after he exercised or walked or actually did anything that took exertion, he would look down or put his head down and have that feeling.
Dr also said you can feel that as your nerves and muscles repair themselves. Does that make sense?
He doesn't get it very often anymore.