Over the last few days I've had dialogues with both my brothers - and they are related in a way (the dialogues, that is, not just the brothers).

Greg and I were discussing other people's reactions to the TV programs I've posted about in the last week or so. One of his colleagues had used words like 'scary' and 'tragic' to describe the predicament of dementia. Neither Greg nor I were in tune with these adjectives - at least not in relation to mum and dad. Greg said something like:

'Eighty good years, followed by a death you have time to prepare for...' and left the obvious conclusion unsaid.

'I'm sure it's a deal most parents back in the 1920s would've jumped at if it'd been offered to them at the birth of their child,' I added.

Greg then told me that the daughter of one of his colleagues was killed in a car accident last week, aged 21. Now that is scary and tragic, if you like, but not what is happening to mum and dad.

With Derek, it was a perfectly useless but intellectually interesting attempt to work out exactly when our grandfather started showing signs of dementia. We have an end point (his death at the age of 91), and a start point, when we can recall that he was compos mentis (aged 82). Somewhere during the interval he lost all his marbles.

Derek had written:

Last night, Janet and I were trying to establish at what age Granddad started to deteriorate. We both had the feeling that he was well into his 80s, but casual analysis (without any data) suggested that it could have been in his early 80s, say around 81 or 82. As I remember, he moved to live with Bob and Jane when Mum joined Dad in China and it was from there that he moved into the nursing home. The dementia had started much earlier and he was certainly confused at the time of the Falklands war as he was convinced that the MOD was after him as a deserter. He also expected to be called up into the army. I remember Dad reporting that Granddad talked of two men who had come to the house asking about his whereabouts. As you can imagine Dad’s explanation was a model of sensitivity and Granddad is supposed to have said something along the lines of ‘I understand that you are right, but you must understand that it is very real to me’.

As the Falklands war was in 1982 when he was 88 and, at that time, he was still able to hold conversations which were partially comprehensible, my guess is his dementia started to become noticeable when he was in his mid 80s. There was no real point to this and we were merely comparing Mum with her father, but I wondered if you had any thoughts.

Well I did, as it happened. I couched them as follows:

Granddad was definitely demented before leaving Derby, but when it started, it's hard for me to say. He amazed me once. He had read about a flower show in the Derby Evening Telegraph. It was being staged somewhere the other side of Derby. On his own initiative he found out which buses he should take to get there, visited it, and got back home later that day, all on his own. Some months later he intended to go into town, put on his jacket and cap, and then found he couldn't remember where the bus stop was (Darwin Rd if my memory holds). This is a clear case of comparable events showing the decline in his competence while in Derby. They both happened after I left for Liverpool, which was at the end of September 1976, but before I left the UK in May 1982.

I'd say he was fairly competent when he arrived in Derby; his gardening was a great success at first. He would have been 82 at the time of that move.

At one stage mum and dad took him to Germany or Switzerland for a holiday. He didn't know he was in a foreign country, and was convinced they were on a train when they were on a coach. That experience convinced mum and dad that there was no longer any point taking him on trips - once something that he really loved and took to rather well.

On a slightly different issue - I can never remember Granddad being inarticulate, only vague. I have recently come to suspect that mum has some other neurological problem, as her speech is particularly bad - even by Alzheimer's standards. Only three people (Greg, Rachel and I) have a decent idea of what she is on about and, as you know, most of the time it is inspired guesswork based on lifelong familiarity. This is one of the things that concerns me greatly about her being put in a home. She won't be able to make herself understood to anyone.

If mum has something like Wernicke's Aphasia then, in addition to her obvious speech production problems, she would also be suffering from an inability to properly understand spoken speech. This would explain a lot, including why she appears to be so far gone while her brain shows only minor atrophy. All the above is amateur speculation, of course - but I'll copy Rebecca just for information.

So granddad had a good long innings, losing his wicket with his century in sight. He was active until his late eighties, out turning the sod every day with his worn old spade. Perhaps that continuous physical activity was instrumental in keeping him fit and alive. The other point I raise - that of mum's aphasia (or dysphasia, as I prefer to call it) - is something that has been bothering me ever since looking at her brain scans.