Might be interesting to find out, at night, do the staff wear usual uniforms (we think uniforms set Mummy off) or do they wear nightwear. Some homes do this to reinforce to the residents that it is night time and therefore time to sleep.Thanks @Helly68, the problems with mum are at night and she has been very aggressive if she needs intervention (help). The EMI unit is more geared up for this kind of behaviour so hopefully they will be able to cope with this when it happens.
With Mummy, they are changing her drug regimen but also thinking about trying personal care from staff not in uniform, to see if this makes any difference. We noticed she's a lot less ASBO with the managers, who don't wear a uniform. I am not convinced this is going to work, but it will be interesting to see.
You may find that in a better home, with more experienced staff, there is less agitation as staff understand how to approach people in late stage dementia and also look beyond the behaviour itself to try and find what triggers it. it's a big ask though.....