Yeah, I did some research and it’s really weird. The majority of sites that talk about it are Australian and it’s barely, if at all acknowledged anywhere else in the world. I found some sites that seems legit:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3943077/

https://www.adelaide.edu.au/newsroom/news/list/2023/09/18/devastating-causes-of-childhood-dementia-revealed

https://www.alzint.org/news-events/news/shining-a-light-on-childhood-dementia/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10486052/

https://www.dzne.de/en/news/background/childhood-dementia/

https://rareportal.org.au/rare-disease/childhood-dementia-disorders/

https://rarediseases.org/organizations/childhood-dementia-initiative/

I think that maybe it wasn’t recognized before due to how rare and weird it is, like ptsd was, but I can’t say for sure if it’s not a scam.