Gold Medal Software 3/Gold Medal Software - Volume 3 (Gold Medal) (1994).iso/tutor/bkache56.arj/PART1.EXE/DISC.TXT

Text File | 1992-12-04 | 13KB | 216 lines

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                              THE "SLIPPED" DISC
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       It seems frightening and sinister. A "slipped disc" sounds like
       what could be causing the nagging pain in your back. Somewhere
       you've heard that a friend needed extensive back surgery or
       manipulation to restore or reposition a slipped disc into proper
       position. A tidy explanation. However, as with most matters of a
       medical nature, a little science, history and anatomy often
       reveal a more accurate mixture of facts.

       In 1764 a malady named sciatica was described in the medical
       literature of the time. It referred to a sharp pain radiating
       downwards into the legs, frequently originating from the region
       of the lower back. By 1864 the terms sciatica and lumbago were
       associated in medical journals.

       The intervertebral disc was described in detail by the German
       pathologist Virchow in about 1855 who noted briefly a specimen
       which displayed a "tumor" or "swelling" he had observed
       protruding into the spinal canal from one of the intervertebral
       discs. Later the German physician Ribbert demonstrated that
       these protrusions were not tumors but were extrusions of the
       intervertebral disc tissue itself.

       By 1861 the French physician Sicard proposed a theory that
       sciatica might be due to pressure upon the nerve roots in the
       region now named the sciatic nerve. The Italian doctor Putti
       advanced the theory further by suggesting that the pressure or
       irritation might be due to intervertebral disc abnormalities or
       malformations.

       The chain of cause and effect was almost complete, but it was
       not until 1933 that a single cause was attributed directly to
       the afflictions of sciatica and lumbago. Doctors Mixter and
       Barr, American physicians practicing at Massachusetts General
       Hospital, finally drew the threads of information into a single
       coherent strand by linking the protrusion of intervertebral disc
       tissue with pressure on the sciatic nerve as the cause of the
       intense pain of sciatica.

       A word of caution. Not every manifestation of sciatica is caused
       by protruding or damaged disc tissue. However this is the most
       common source of severe back pain which radiates or "shoots"
       into the legs.

       Let's turn back a few pages and glance at the anatomy of the
       disc.

       The intervertebral disc is actually constructed of several
       tissues. Roughly oval in shape, it is composed of 1) top and
       bottom plates of gristle-like cartilage which are joined to the
       bony vertebrae, 2) the sides of the disc which are rounded and
       quite elastic. These layers of tissue are present in a radial
       layered arrangement like the belts of a tire. This makes them
       extremely tough. These layers comprise the annulus fibrous.
       Inside this disc "containment wall" is 3) the inner core of the
       disc, the nucleus pulposus, which is a white flexible gel-like
       tissue. Its function is to act as a shock absorber and force
       distribution mechanism. Technically only this pulpy core is the
       disc.

       If you hear that a disc has been removed during surgery, it is
       normally the inner nucleus pulposus which is extracted. As an
       aside, about 22% of the average height or length of the spinal
       column is due to the discs which provide both support and
       lateral side-to-side movement. Their design allows a fair degree
       of movement, but remember that the disc can only stretch so far
       before it ruptures. The outer walls of the disc are bonded
       directly to the vertebra and restrict their movement beyond
       certain limits.

       To understand the nature of a disc rupture you need to
       understand that the pulpy inner core of a disc acts like all
       hydraulic fluids. It can move, change shape and absorb shock but
       it CANNOT be compressed to occupy a smaller volume (at least at
       pressures normally present in the human body.) If the pressure
       becomes too great, the fluid will bulge outwards at a point
       opposite the compression. If a weak spot has been created in the
       outer containment of the disc, a rupture can take place.
       Sometimes the wall of the annulus merely bulges without actual
       escape of the nucleus pulposis. Other times the nucleus can also
       rupture.

       Once this happens the disc loses its value as a shock absorber
       because the pulpy core is no longer contained. It is important
       to note that the shock absorbing nature of the discs sometimes
       causes the bones of the vertebra to fracture first in cases of
       severe impact! Surprisingly some victims of car accidents or
       falls have fractured vertebra and scarcely damaged their discs -
       a testament to their excellent design and load bearing
       characteristics!

       A slipped disc, then, is not slipped at all but actually a
       rupture of the inner pulp of the disc either outwards away from
       the spinal canal or inwards into the spinal canal. In most cases
       the deterioration of the protective capsule of the disc is a
       gradual process which frequently begins at the rear portion of
       the disc. This is due to the fact that the wall of the disc is
       thinner there than the front of the capsule. A gradual softening
       or wearing down takes place in this outer disc wall.

       Then perhaps a sudden twist of the spine, a load improperly
       lifted or a fall causes a rupture to take place. This can
       produce the classic protruded disc. Frequently the bulge
       enlarges through the posterior longitudinal ligament of the
       spine and begins to press on either the spinal cord or the nerve
       roots which descend from it. Usually the protrusion will be
       slightly to the left or right side of the midline of the spinal
       canal which causes painful symptoms on only one side of the
       body. This single-sidedness of the pain is sometimes a
       diagnostic clue in cases of disc damage.

       Two separate types of pain are frequently reported by patients
       suffering from disc damage. If sensory nerves of the skin are
       irritated by the pressure of the ruptured or protruding disc,
       then the patient may report burning or tingling of the skin. If
       motor nerves supplying muscles are pressed by the protruding
       disc, muscles of the leg or back may go into uncontrollable
       painful spasm - classic sciatica.

       It is important to note that for all practical purposes the disc
       does not "slip" back into place and only rarely heals itself.
       The damage is permanent and does not heal completely. Eventually
       tissue scarring will begin to take place in the area of the
       protrusion which may further inflame nerve roots. If the
       pressure of the protruding disc becomes too great, nerves of the
       bladder and bowel may also be affected which almost always
       indicates surgical intervention.

       Lumbago is a different type of pain in which the back "suddenly
       seizes up." The muscles of the lumbar region go into rigid spasm
       and refuse to relax. The spasm may fade in a few hours or days.
       By lying perfectly still, the pain may be minimized and finally
       disappear as quickly as it began.

       Disc related pain may also produce another manifestation. Lack
       of activity of a disc-damaged back may cause recurring stiffness
       unless the back is kept supple with motion and exercise. The
       pain seems to be worse with inactivity and will diminish when
       the person moves around a bit. This may also reflect both true
       arthritis as well as a form of arthritis caused directly by long
       term disc degeneration.

       Treatment for mild disc protrusion is relatively specific.
       Initially some physicians may prescribe bed rest, since standing
       increases the pressure on the damaged disc. Pelvic traction may
       be initiated while a patient lies in bed. The function of the
       traction is not to pull or stretch the spine, but to tilt the
       pelvis and reduce the curve of the spine which relieves some
       pressure and produces comfort. Pain medications and some muscle
       relaxants might be prescribed by a physician. X rays would be
       taken along with some blood tests. After one or more weeks of
       bed rest or traction some standing might be permitted with no
       sitting allowed. Back strengthening exercises would gradually be
       added to build muscle tone. This course assumes surgical
       intervention is not attempted.

       In more severe cases, a myelogram or NMR scan would be done to
       confirm substantial disc protrusion and probable need for
       surgery to remove the inner core of the disc. After surgery the
       space within the disc gradually fills with scar tissue. In time,
       and with some patients, the space between the two vertebrae may
       gradually grow together in a type of spontaneous bone to bone
       fusion which lessons mobility and further damage at that area of
       the spine. After disc surgery, rehabilitative exercises are
       prescribed to build up the muscles of the back so that proper
       support is maintained.

       The topic of surgical fusion, the deliberate joining of two or
       more vertebrae after disc surgery, is controversial. Some
       physicians routinely fuse vertebrae after a disc operation,
       others fuse on a more selective basis. Usually small pieces of
       bone from the hip or other area of the body are grafted directly
       between vertebral bodies to limit their motion and provide
       support. This technique is generally the most severe course of
       action and is usually reserved for the extreme cases of disc
       degeneration. It also performed for other diseases such as
       spinal bifida, a birth defect.

       So far we have discussed problems usually seen in the lower
       lumbar region of the back. However, the cervical discs of the
       neck region can occasionally be affected. Arthritis is a common
       culprit here. Symptoms can involve radiating pain into the
       shoulders, arms and hands. In severe cases of cervical disc
       rupture or degeneration weakness of the arm and hand muscles
       will be seen and "tingling" or even complete loss of sensation
       in the skin of the hands and arms. Again this is caused by
       pressure on sensory or motor nerves in the area of the cervical
       region of the spine. Cervical disc problems are more frequently
       seen in older people since these complains are more commonly
       arthritic in origin. Cervical disc protrusion can be more
       serious than lumbar disc problems since a large section (more
       nerves) of the spinal cord is present at this level of the
       spine. Bed rest, traction and neck braces or cervical collars
       are usually attempted in milder forms of this disc problem.

       The bottom line, however, in dealing with disc disease is that a
       weak back is unstable and prone to disc disease and injury.
       Proper exercise and posture can go a long way to preventing disc
       disease in the first place and minimizing its impacts.

       This tutorial is merely a starting point! For further
       information on back care and back pain, be sure to register this
       software ($25.00) which brings by prompt postal delivery a
       printed, illustrated guide to back pain written by a physician
       plus two software disks. From the main menu select "Print
       Registration Form." Or from the DOS prompt type the command
       ORDER. Mail to Seattle Scientific Photography (Dept. BRN), PO
       Box 1506, Mercer Island, WA 98040. If you cannot print the order
       form, send $25.00 to the above address and a short letter
       requesting these materials. End of chapter.