Definitely experienced this with my father, after two cardiac surgery (cardiac ablation), he became much more radicalized. Politically, he went from someone who was left wing closer to the center to being very much anarcho-left wing, repeating that the poors are exploited and getting very angry whenever someone disagreed with his new views. The change was rather startling. He did also experience some cognitive decline (lower working memory), had a hard time reading (he was a voracious reader before that) and experienced wider mood swings.

It was rather scary how much he changed in so little time.