Thursday, August 15, 2013

Disc Desiccation and Spinal Back Treatment


The individual bones that comprise the spine are called vertebrae. Each vertebrae except the top two in the neck are separated by a cushion, an intervertebral disc. The outside of the disc is surrounded by fibrous, ligamentous tissue called the annular fibers named as such from the same root word from which we get annual or year round. In some ways discs resemble automobile tires for they both absorb shock and allow the spine to bend and move, but instead of being full of air like a tire the inside or nucleus of a spinal disc is filled with a jelly-like protein substance that is designed to absorb shock. Desiccation is a scientific word meaning "dry" which means that the inside of the disc is drying out. In time the annular fibers also begin to dry out, lose their elasticity and are subject to cracks or tears that result in a bulging out or herniation of the disc tissue.

Dry

Disc desiccation is the first step in degenerative disc disease and is diagnosed via MRI (Magnetic Resonance Imaging), a noninvasive diagnostic technique that produces computerized images of internal body tissues and is based on nuclear magnetic resonance of atoms within the body. This technique is often imagined as a sort of advanced x-ray but is instead induced by the application of radio waves, not x-rays. Similar in some ways to sonar on a submarine the body is "pinged" by these radio waves. The signals that bounce back are different dependent upon how wet or dry the tissue is and with the magic of computers the data is collected and the computer assigns color to the pixels. Very wet tissue such as body fat is rendered white and completely dry tissue is rendered black with many, many shades of grey in between. Therefore, a healthy hydrated disc will appear white whereas a dry disc will appear very grey or black.

Thin

As a disc loses water content it begins to lose height and the vertebra get closer together. This is easily seen on both x-ray and MRI, and creates the appearance of the disc "wearing away" but in fact no tissue has actually disappeared - it has simply shrunk in size exactly in the same way that a plump plum when dried becomes a shriveled prune. This is the second stage of disc degeneration.

A dry, thin disc is unable to do its job of absorbing shock and as the degenerative changes progress can eventually reach the point where the ordinary jolt of the heel striking the ground which occurs during everyday walking causes pain. More substantial impacts such as dropping the body weight from step to step while descending stairs and an infinite variety of other everyday activities can result in sudden sharp, shooting pains in what many patients describe as "bone on bone" and while, perhaps, not technically correct never-the-less results in mechanical stress to the joints of the spine and the supporting ligaments. This stress results in osteoarthritis, the third step in degenerative disc disease.

Arthritis

It is easy to suppose that if the bones are "catching" or "rubbing wrong" or any of the mishmash of other phrases that patients use to describe this phenomena that eventually the bone would wear down but, in fact, the exact opposite occurs. Remember that bone is living tissue and like other living tissue such as the skin on the palm of a hand, for instance, it will build up when stressed, and this we call a callous. Abnormal or excessive mechanical stress to bone causes it to respond in the same way as does skin and results in a buildup of deposits of calcium. The bone and/or supporting ligaments become denser as these calcium molecules accumulate, and eventually become numerous enough to form visible spurs or osteophytes. There are a variety of medical terms used to describe this buildup of calcium dependent upon the location and severity, but in the end they all spell osteoarthritis.

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