The sleep issues those of us with high NE have interests me, and I was thinking about yours today. I don’t sleep walk, but I have about 1/4 the REM sleep most folks have. NE inhibits REM. Sleep walking has to have an alertness/arousal component, which is a function of NE, to it just for the motor action if nothing else. Anyway, when you have time, you might want to use Dr Google and look at high NE symptoms and NE and sleep.
Good luck.