One of the hallmarks of a covert narcissist is an acute sensitivity to criticism. They might not express their displeasure openly, but look for signs of passive aggression or withdrawal when faced with feedback.

NeuroVISION was the study that put perioperative covert strokes on the map in 2019. That report found a 7% rate of these silent strokes in people ages 65 and older undergoing elective, non-cardiac surgery; it tied these strokes to a near doubling of risk of cognitive decline within a year.