Disk Herniation

The spine has vertebral bones that are spaced apart by disks at each level. The disk is a ring structure of tough fibrous tissue (annulus) that surrounds a gelatinous substance called the nucleus. The annulus fibers may tear, allowing the dusk to bulge under pressure. The fibers may eventually tear, allowing leakage of the gel through the tear where it may contact the nearby nerve and cause irritation, pressure, and swelling. Disc herniations (prolapse) can occur from general wear and tear, repetitive sitting and lifting, and from specific trauma. Often it is difficult to determine a specific event that led to the onset of pain.

Symptoms of a herniated disc can vary depending on the location of the herniation and the types of soft tissue that become involved. They can range from little or no pain if the disc is the only tissue injured, to severe and unrelenting neck or low back pain that will radiate into the regions served by affected nerve roots that are irritated or impinged by the herniated material. Often, herniated discs are not diagnosed immediately, as the patients come with undefined pains in the thighs, knees or feet. Other symptoms may include sensory changes such as numbness, tingling, weakness, paralysis, and paresthesia. If the herniated disc is in the low back (lumbar) region the patient may also experience sciatica (pain down the leg), or in the case of a disk herniation in the neck, arm pain. Pain from a herniated disc is often continuous and provoked by specific positions of the body.

It is possible to have a herniated disc without any pain or noticeable symptoms, depending on its location. If the extruded nucleus pulposus material doesn't press on soft tissues or nerves, it may not cause any symptoms. Some studies have shown focal disc protrusions in 50% of participants not presenting with spine pain, demonstrating that a considerable portion of the population can have focal herniated discs that do not cause noticeable symptoms.

Typically, symptoms are experienced only on one side of the body. If the prolapse is very large and presses on the spinal cord or the cauda equina in the lumbar region, both legs may be affected, as well as the nerves supplying the bowel and bladder, which may have serious consequences, including permanent weakness and bowel or bladder incontinence, if the diagnosis and treatment are prolonged.

"Chemical radiculitis” is important in the generation of back pain. A primary focus of surgery is to remove mechanical compression on a nerve or the spinal cord. Back, neck, leg and arm pain, rather than being solely due to compression, may also be due to chemical inflammation. This may cause the nerve root to adhere to the canal, leading to nerve root traction with movement. The "hydraulic effect" of a fluid being placed directly within the adherent tissue causes the tissue to separate and allows the nerve to slide in it's channel more easily. For these reasons, epidural steroid injections often result in substantial pain relief, reduction of scar tissue, and return to functional activity. An advanced form of epidural, the transforaminal epidural or nerve root injection, provides the components of the "hydraulic effect" to separate the adherent tissue, proximity to the irritated nerve root and disk tear, and an anti-inflammatory delivered directly to the nerve, all helpful benefits resulting in pronounced and lasting effects in many patients.