Steroids, Cortisone, Corticosteroids and Glucocorticoids
SpU: If the proper terms are corticosteroid or glucocorticoid, why do people refer to cortisone as steroids?
Confusion has arisen because physicians and laypersons alike commonly use the slang term steroids when referring to cortisone and synthetically manufactured cortisone-like medications. People also use the term steroids to refer to anabolic steroids, such as male testosterone or growth hormones. Anabolic steroids have limited medical use and have earned a bad reputation because they have been widely abused by competitive athletes to increase their own muscle and bone mass.
So, to sum it up - cortisone and cortisone-like steroids are powerful anti-inflammatory medications. They are very similar to naturally occurring anti-stress hormones made by the adrenal glands. Technically speaking, the correct term is either corticosteroids or glucocorticoids.
SpU: But how do cortisone injections help relieve chronic low back and neck pain?
To help you understand the answer, you need to understand what can cause low back and neck pain. I will use the diagnosis of sciatica as an example. Sciatica (sometimes called lumbar radiculopathy) is commonly caused by nerve root compression or nerve root inflammation in the lumbosacral spine (low back). The cause is often a herniated disc or narrowing of the spinal canal. Sometimes narrowing of the spinal canal includes the foramina; the pathways through which the nerve roots exit the spinal column. Narrowing of the spinal canal or foramen (singular of foramina, or neuroforamen) is called spinal stenosis. The term stenosis means narrowing.
Lumbar spinal stenosis; spinal canal
Although the term sciatica refers to the pain felt in the lumbosacral spine and legs, an analogous condition exists in the cervical spine and is felt as neck pain radiating into the shoulder and down one, or both, upper extremities when a cervical nerve root is compressed or inflamed. Clinically, such neck symptoms are termed cervical radiculopathy. Sciatica and cervical radiculopathy tend to be caused mostly by disc herniation and occurs in people in the 25 to 50 age range. Low back and leg pain caused by spinal stenosis is, on the other hand, more of a bony arthritic disorder. Therefore, it has a later onset in life and affects people more commonly in their 60s, 70s, 80s, and beyond.
Disc disorders including those of a degenerative nature.
Regardless of the disease entity causing sciatica or radiculopathy, the pain and paresthesias (numbness, pins and needles) associated with these diseases comes about because nerve roots are trapped and inflamed. Spinal nerve roots are living tissue. Nerve roots need a healthy environment and a regular blood supply for nourishment. When nerves become inflamed, compressed or trapped, their blood supply is restricted. In response, nerve fibers fire abnormally causing a combination of pain, electric-like or stabbing sensations, and paresthesias. Because the motor portion of the spinal nerves is more deeply protected than the sensory portion, neurological findings, other than pain and abnormal sensations, are usually delayed until the underlying disease process becomes severe.
Now we can move on to the role of corticosteroids in relieving back and neck pain. Remember the five stages of the inflammatory response discussed above? Nerve tissue is quite vulnerable to the effects of the inflammatory response and it has been a principle of medical therapeutics for decades that corticosteroids have a beneficial effect on inflamed and compressed nerve tissue. Therefore, corticosteroids are correctly used in the early treatment of sciatica or cervical radiculopathy to revive ailing nerve tissue. The pain relief that accompanies corticosteroid treatment for sciatica or cervical radiculopathy is a fortunate by-product. Corticosteroids seem not to be analgesics, per se. They do not exert their beneficial effect by covering up unpleasant sensations as do narcotics for example. Rather, they relieve pain due to the modulation of the inflammatory response itself and pain relief that is experienced by the herniated disc or spinal stenosis patient is a favorable by-product of recuperating, injured nerve tissue.