One thing my journey in looking after someone with PSP has taught me is that you have to educate people on the nature of PSP because it is so rare. If you think your Mum is not getting the correct care for her condition. SHOUT!. There is literature available from the PSP Association specially for care homes, GPs etc. Ask for it and give it to a senior person at the home. I did this in my sister's case at her nursing home and the staff were pleased because it gave them a greater understanding of the condition and how to deal with her . Both parties benefitted. My sister, because her carer and nurses understood her needs and carers/nurses recognised signs/symptons in the progression of this awful disease.
Hope this helps you on this journey. Best of luck - keep blogging