Hi Sag,
I think the memory clinic can vary depending on which area you are in, but in our case it was merely a fancy word for a meeting with the consultant. He carried out an MMSE (mini mental state examination) and gve us a slightly different diagnosis to the one we had been given previously.
The other things which could happen, as I understand it, is that your mum may be referred for scans and other tests; you may be referred to Social Services for a care assessment; and be assigned a CPN (Community Psychiatric Nurse).
From our experience none of this may happen unless you ask for it. So if you and your Mum need help you may need to shout (loudly) for it. Don't feel you are being a nuisance, these services are there for a reason.
I hope it goes well, please let us know how you get on.