John was reliving some of his distressing past experiences through seeing visions of Japanese soldiers. After writing the blog I was later contacted by several people who had a diagnosis of PTSD who were anxious that their eventual fate might be to develop dementia and be forced to relive their worst nightmares over and over again. I certainly needed to do some desk top research on any potential links before I could offer insight as once case history like John's might raise questions but it was by no means certain there was a definitive link between PTSD and dementia.
I knew there was some evidence to suggest links between stress and dementia but then again dementia is not just one condition and PTSD is a manifestation of extreme trauma and not necessarily a culmination of on going day to day stresses.
So I will start with dementia. It seems John in all likelihood has quite a rare form of dementia called dementia with Lewy Body which accounts for only 4 per cent of all dementia diagnosis and how it presents very much depends on where the Lewy Bodies are in the brain. It tends to present in part as visual hallucinations but is more prevalent in people who already have visual problem (such as John who is almost blind).