I'm an Australan DAME. Iwill hazard a guess that as a CPL I dont like your like your chances. As a PPL some juristictions might look at the particulars of the case and give you some indication. Get your medical done early so you dont waste too much training money. Both the pain and the medication pose some limitations for flying. If its ananatomical neve root pain causedby impingement a surgical option with cessation of gabapentin might work out.