I was told that it was definitely cause buy a herniated disc surgery that went bad. It was well herniated and they had to go very deep which caused the arachnoiditis membrane to break and right after that I developed a leak where I had a bulge on the base of my spine that looked like a grapefruit. Had 3 surgeries to calm it down within a 8 week period. Then months later that had to go back in and do a Fusion and we operate which I think that is when the arachnoiditis came about. It's hard to say but there are certain injections that were done years ago using different medications that they say caused spinal leaks. You just don't want anybody putting needles into your spinal fluids canal.