Acid leaks from
the herniated
nucleus pulposus
causing nerve
irritationActivity, stress or a mechanical problem in the spine can cause one of the discs to bulge
and become misshapen just as a rubber tyre might with pressure on it. When this
happens, the disc may pinch or put pressure on a nerve root and the patient experiences
pain. Occasionally, the disc will bulge to the point where it herniates or ruptures and
puts even greater pressure on the nerve root.
Most of the pain of nerve root irritation is not solely due to disc protrusion. The nucleus
pulposus in the intervertebral disc contains an acid – hyaluronic acid. When there is a
break or rupture of the annulus fibrosus, the nucleus pulposus is exposed and its acidic
chemical contents come in contact with the nerve roots. Acid irritates and thereby
stimulates free nerve endings to send electrical impulses that are perceived as pain by
higher centres. Hence pain due to disc herniation is not necessarily due only to
mechanical pressure of the disc on the nerve roots.
To correct this abnormal acidity, one needs to enhance
hydration and fluid exchange in the intervertebral disc. Since
the intervertebral disc is not supplied by blood vessels, the only
way this can be accomplished is by the physical pumping action
of spine motion i.e. physical activity in the form of exercises.
Progressive physical activity also pumps out the fluid accumulated
due to inflammation from the tissues. Therefore, injured tissues should be mobilized
early by continued physical activity as long as no further injury is produced.
A word of caution here: Degenerative changes of the disc seem to occur in everyone
as a consequence of the aging process but this is not an inevitable cause of back pain.
You may find evidence of damage to an intervertebral disc on X-ray or MRI but the
actual pain may be due to a muscle spasm or ligament tear. Treating the patient for his
or disc prolapse, when the actual problem lies elsewhere, not only does not resolve the
pain but may actually make it worse.