Hello @valerie6062, Welcome to Connect. I haven't read any conclusive evidence on prednisone causing neuropathy but I definitely agree with you that eyesight is of key importance when it comes to treating giant cell arteritis. Here is some information that might be helpful on the treatment strategies:

--- Treat-to-target recommendations in giant cell arteritis and polymyalgia rheumatica: https://ard.bmj.com/content/early/2023/02/23/ard-2022-223429.

I haven't had GCA but my rheumatologist and doctor were always asking me to let them know if I had any symptoms of GCA like scalp or temple tenderness/pain or vision problems. In my first round with PMR, I had some pain flares due to tapering off of prednisone too quickly or too big of a drop too fast.

Do you think the flare ups causing the roller coaster ride with the treatment is due to tapering too fast?

I have peripheral neuropathy too. It was confirmed by an EMG and a nerve conduction study (NCS). A neurologist called my peripheral neuropathy "idiopathic" meaning the cause of it was unknown. It started as a vague numbness in my feet which gradually worked its way up to well above my knees. The neuropathy was also called "diffuse" because my arms were also affected. My hands never feel numb but they sometimes feel like they are freezing even in the summer. My hands are warm --- they only feel like they are freezing.

A vitamin B-12 supplement was "recommended" by the neurologist but not prescribed. When I first felt the vague sense of numbness in my feet, I told my GP that it was the least of my problems.

After PMR and other autoimmune problems were effectively treated with a biologic rather than prednisone, I was saying peripheral neuropathy was higher than PMR on on my list of problems. Pain from PMR held first place on my problem list for more than 12 years.

In my opinion, there are several possibilities about what caused my peripheral neuropathy. I'm taking into account that it seems to be improving since I tapered off prednisone.

1) Prednisone is known to cause a loss of potassium and vitamins B-6, B-12 and folic acid. Prednisone also interferes with vitamin D, which affects calcium metabolism. Because of taking prednisone, I was also taking Zantac to "protect" my stomach. Zantac and other acid-suppressing drugs can make it difficult to absorb vitamin B-12.

2) I might have what is called Chronic Inflammatory Demyelinating Polyneuropathy (CIDP).
https://medlineplus.gov/ency/article/000777.htm#:~:text=Polyneuropathy%20means%20several%20nerves%20are,to%20be%20an%20autoimmune%20disease.
I once asked my rheumatologist if my immune system could be attacking my nerves. My rheumatologist said he "wouldn't be surprised" based on my having a "full range" of rheumatology problems.

3) PMR might have played a role because of interfering with the blood supply to my nerves. PMR is thought to be a type of vasculitis.

I have been off prednisone for 3 years. I take a multivitamin twice per day to cover any and all vitamin deficiencies. Subjectively, I would say my peripheral neuropathy is improving. I would need another NCS to know for sure.