I have been having dizzy spells, especially when tilting my head to look down and to the right. At first high blood pressure was treated ( it was extremely high, now good as long as I keep taking the tablets).
I had treatment three weeks ago for BPPV. The specialist used the Epley manoeuvre (other treatments are possible, apparently America and Europe have different choices).
It involved having my head put into different positions, therefore not suitable for anyone with neck or back problems. For the following three days I had to keep my head still, no looking up or down or turning suddenly, and sleep sat up in a chair- not painful but very awkward.
The consultant said the success rate is about eighty percent. It does seem to have eased the problem when I tilt my head, but one of the P's stands for paroxymal, which means it comes and goes, so I might get the problem back again.
I also still get occasional dizziness, which seems linked to delays in getting something to eat, and stress from work.
Something you could check into is the Cawthorne-Cooksley exercises, that are meant to build up tolerance of the dizziness. These are probably not suitable for an elderly person unless they are still fairly fit. I didn't find they had much success for me.

Hope this helps

Alan J.