Well... I'm certainly no expert with regard to this. But my thinking would be the common connection may be anxiety. I would guess it may be what caused your son to have night terrors as well. The question, I suppose, may be what caused the anxiety to begin with. Some people are simply highly sensitive. But it is also possible there were some experiences in your son's young life that either caused his anxiety & night terrors to begin with or exacerbated an innate highly sensitive nature. (I don't really know. I'm just guessing here.)

Anyway... here are links to some articles, from PsychCentral's archives that touch upon these concerns:

https://psychcentral.com/disorders/s...rror-symptoms/

https://psychcentral.com/lib/things-...-in-the-night/

https://psychcentral.com/news/2015/0...ems/84353.html

https://blogs.psychcentral.com/nlp/2...dium=popular17

https://psychcentral.com/lib/how-to-...-with-anxiety/

https://psychcentral.com/lib/how-to-...sed-loved-one/

https://psychcentral.com/lib/underst...ders-part-one/

https://psychcentral.com/lib/underst...orders-part-2/

https://psychcentral.com/news/2011/0...ess/27102.html

I wish you well...