Science today isn't the same as the science 2000 years ago was but some principles remain the same. The human knowledge constantly grows but with more knowledge there comes even more mysteries and unsolved questions, so science is always going forward.
Causes. The most common cause of a cervical herniated nucleus pulposus is gradual degeneration of the disc, attenuation (weakening) of the posterior annulus fibrosis, and subsequent protrusion of the nucleus pulposus into the spinal canal causing compression of the nerve root.
herniation of nucleus pulposus. Prolapse of the nucleus pulposus of a ruptured intervertebral disk into the spinal canal. This often results in pressure on a spinal nerve, which causes lower back pain that may radiate down the leg, a condition known as sciatica. illustration;