What is Paracentral inferior extrusion type disc hernation and vacuum phenomenom?

Answer 1

Paracentral means backwards next to the middle. The longitudinal posterior ligament blocks the direct backwards path, so the disc extrudes next to the center, or paracentrally. Extrusion means that the gooey disc nucleus has pushed all the way outwards of the annular fibers so that it is no longer contained. Similar to when a pimple pops and the gooey stuff comes out of the bump. Inferior means it moved downward in the spinal canal towards the feet. Vacuum phenomenon means that where the gooey disc nucleus used to be in the middle of the annular fibers of the disc is empty and appears "vacuumed" out. So the disc has completely popped towards the back and a little off the center, squirting downwards in the spinal canal leaving an empty space where it came from. Since it is no longer contained by the tough annular fibers, macrophages and such can now get to the material and clean it up. It should disappear over the next few to several months. If it is causing severe pain or progressive nerve damage, it can be surgically removed which provides quicker relief, but possibly more long term issues from scar tissue which results from the surgery. The empty disc will likely degenerate over time no matter which option is taken.