I don't think this is what is meant. I'm guessing of course because I've never heard such an expression before but I think that نخاع العمود refers to his own spine (العمود الفقري وليس عمودا من الحديد أو الألومنيوم). I also think that كهربا here does not refer to the A/C current running in electrical wires, rather a metaphor for a quiver or a similar human physical reaction. I believe that he's saying something like "I got high by a quiver from inside my spine".
I personally didn't like the song, the words were not the easiest to get, but I think this makes more sense in the overall feel of the song.