Thanks Cotswold - it has been a complete nightmare. I don't think either condition is taken seriously enough.
I went to see my DM at Christmas a year ago, I hadn't seen her for a few months and just thought something is really really wrong here, you can barely move. And then the whole story can out, she was in agony, she could hardly brush her hair. She'd seen the doctor - told fibromyalgia 
I am a doctor, I thought she had PMR, she then told me she had visual symptoms and I really panicked. She got a blood test out of her GP who still told her diagnosis was unlikely and well, next day she was on high dose steroids. We now know she had all the classic features of both PMR and GCA and had all the risk factors.
She's lost most of the use of her arm since the break, developed diabetes, been in hospital twice with sepsis as she is immuno-supressed, hasn't responded to steroids and needed to go on to methotrexate and the latest is that she has toxicity to methotrexate... We just feel lucky she didn't go blind.
I think as it is largely a disease of old ladies it doesn't attract the interest of other illnesses and isn't taken that seriously.