Hopefully GCA won't be an issue for you. I keep seeing the statistic that roughly 10-20 percent of people with PMR will develop GCA. There are at least 2 subtypes of GCA. The cranial subtype involves the blood vessels in the head. I had most of the symptoms for this subtype: headache, fatigue in the jaw muscles while chewing, tenderness around the ears and scalp, and pain in the cheekbones. The other subtype is extracranial GCA. I'm not personally familiar with that one, but it affects the large blood vessels outside of the head, like the aorta. I googled it, and it says these are the symptoms:

"May include vague symptoms like fatigue, fever, muscle pain, and sometimes more specific vascular symptoms like arm pain when exercising (claudication), decreased pulses in the arms, or abdominal pain depending on the affected arteries."

I see a rheumatologist and an ophthalmologist on a regular basis. The ophthalmologist can see the damage caused by GCA, and can also monitor for problems caused by prednisone. The rheumatologist can check your pulses to monitor for problems with your large blood vessels.

Having lived with it, I can say GCA is scary too.