@56tburd That is interesting and something I haven't read about yet. My father had a couple of episodes of feeling dizzy recently, but has not had any of the other symptoms. He's actually cold all the time, probably because he has no body fat left on him. I will certainly keep this in mind, though, so thank you for mentioning it!

@56tburd
I had radiation and chemotherapy for SCC base of tongue about 16 years ago. The radiation resulted in a series of side effects which have compromised my quality of life. Aside from the short term side effects of mouth sores, loss of taste and trismus, I had long term side effects that were detrimental. I experienced loss of bone due to osteoradionecrosis of the jaw and loss of a few teeth, xerostomia (dry mouth), esophageal stenosis from scar tissue resulting in dysphagia and a feeding tube dependency for nutrition and hydration, Radiation Induced Brachial Plexopathy (RIBP) and significant loss of function, strength and increasing numbness of my left side hand, arm, shoulder and neck. More recently an episode of Bell's Palsy treated by administration of prednisone, resulted in atrial flutter which eventually was relieved by electroversion and ablation. However, nagging symptoms of dizziness and syncope continued especially with postural changes (orthostatic hypotension) from sitting or lying to standing. After experiencing frequent falls and extraordinarily low blood pressure and sometimes very high blood pressure, I was able to see a neurologist at Mayo Clinic and after 4 days of testing the diagnosis was Baroreflex Failure. It was the first time I heard of this problem, but it is the most debilitating because it is challenging to treat and almost impossible to normalize my blood pressure. I take a small dose of medication to raise my blood pressure in the morning along with another short acting medication as needed, but usually just once in the morning as that is when my symptoms of low blood pressure, dizziness and fatigue are most common. You are the first person that I have heard of who has this side effect but if I had not gone to Mayo for a diagnosis, I would be struggling more than I am now. My new "normal" isn't great but it is comforting to at least know the cause of my symptoms and get partial relief. These things that appear many years after radiation therapy like Radiation Induced Brachial Plexopathy (RINB) and Baroreflex Failure can be difficult to diagnose as their onset is so far from the cause. Orthopedic specialists were convinced that my problem with my arm and hand numbness was related to a C6 nerve problem or carpal tunnel problem. Even though there is no cure, the diagnosis is important to prevent going through unnecessary surgeries or treatments. Thank you for your post. All good wishes.