I am sure the reason he wants to keep everyone away is to keep things as they are, with him controlling the situation. The house belongs to her and he is reliant on it for somewhere to live. He has quite a nice set up financially, and doesn't want it threatened. He has lived there all his life, did used to work until he had go give up a physical job through an injury. He has always been a loner and has always been spoiled by mum. When she was able to she did absolutely everything for him. I do know it's not easy for anyone to care for someone 24 hours a day but his attitude is that he knows absolutely everything about life (despite never having had a relationship, children, moved house, etc etc), and also he thinks he is totally heroic for what he's doing. His favourite phrase: "It's the hardest thing I've ever had to do". Well, I always think of course, because you've always been shielded from life til now.I wonder whether brother is terrified that if Mum goes into a home he will lose his own home, as well as the carer's allowance and what she gives him (and she pays all the bills too). Depends whether it's rented, if so whose name on tenancy, or owned, again by whom, and on his age and any other factors I think. It may also be that he's scared to let too many other outsiders see her in case they think that she needs to be in a home.
Has he got problems of his own? Did he work before starting to be her carer, and give up a job, or has he always been dependent on her?
It really sounds as if the current setup is not in her best interests - no visitors, no tv, kept in her room, and verging onto financial abuse. (When we moved in to look after Mother we still had our own house 2 hours away which we scarcely saw but were paying bills for, so it seemed reasonable for her to carry on paying the bills on her house, but we carefully kept track of grocery shopping etc and charged her 1/3; as soon as she moved into care home we took over all the bills for the house). Is he hoping that if he runs down her capital she'll be eligible for state funding for her care, perhaps? If she's paying all the bills for a jointly-occupied house, and giving him an allowance, it might be claimed by the council that she's voluntarily depriving herself of capital?
Please talk to your dementia adviser. Aside from the money, she needs a more stimulating life. Would he let her go out to a day centre, perhaps? More stimulation, company, etc, but without anyone venturing into his territory? Though it would cost, and he'd be reluctant to let her spend her money?
Good luck.
Thank you for your help, I will ring Dementia adviser next week.