Good morning, Strike ~
Did you have this MRI with contrast (usually an injection of gadolinium) that helps to set off certain things in the imaging?
The way I understand this sentence is that there is minimal scar tissue abutting the Sacral 1 nerve. (enhancing is referring to the way the epidural fibrosis is visualized, not describing the nerve.)
The word "enhancing" (or enhance) usually refers to the increase of the signal of certain types of lesions. It has to do with how well something shows up on the image...and to explain the technicalities of this is beyond my pay grade.