A disc protrusion is similar to a disc bulge in that it is caused by weakening of the outside layer of the spinal disc (called the annulus), causing the disc to flatten and balloon into the spinal canal (figure 1). A disc protrusion is less severe than a disc herniation, where the outer layer (annulus) breaks causing the gel filled center (nucleus) spill into the canal. Paracentral means the protrusion is affecting the sides of the spinal canal.
