Introduction
Discography is a diagnostic procedure designed to identify the specific source of back or neck pain. Discs, the cushioning structures between the vertebrae of the spine, serve as shock absorbers, protecting the bones from impact. However, aging or trauma can lead to the deterioration of these discs, resulting in pain. Various treatment methods exist for alleviating disc-related discomfort; however, if these treatments fail after a certain period, a discogram may be recommended to pinpoint the problematic disc, enabling the formulation of a tailored treatment plan.
Anatomy
The spine consists of a series of small bones known as vertebrae. Each vertebra contains an opening that forms the spinal canal, which houses the spinal cord—a crucial component of the nervous system extending from the brain. The spinal cord does not occupy the entire spinal canal space; instead, it is surrounded by the epidural space, which contains fluid, nerves, and blood vessels. Spinal nerves emanate from the spinal cord and exit through openings in the vertebrae called foramina, facilitating communication between the brain and various body parts.
Intervertebral discs, made of resilient connective tissue, are situated between each vertebra. The tough outer layer of the disc is known as the annulus fibrosus, composed of multiple layers, with the outermost containing nerves. The gel-like center of the disc is referred to as the nucleus pulposus. Together with two small joints, the discs connect adjacent vertebrae, providing support and stability while allowing for movement. Additionally, these discs act as shock-absorbing cushions that protect the vertebrae.
Causes
Discography is primarily a diagnostic tool rather than a treatment modality, aimed at identifying the specific disc responsible for pain. Several factors can lead to disc pain, including heavy lifting, repetitive strenuous activities, and improper lifting techniques, which can cause tears in the annulus fibrosus. Sudden trauma can also result in a disc rupture.
As people age, intervertebral discs lose their water content, leading to decreased flexibility and height, making them less effective as cushions between the vertebrae. Conditions such as obesity and smoking can exacerbate these issues. Consequently, herniated discs are most commonly observed in middle-aged individuals.
When a disc deteriorates, its outer layer may weaken and tear, leading to a herniated disc where the inner fluid leaks out. Disc healing is a slow process, and as new nerve endings form in the damaged areas, the leaking fluid can irritate these nerves. This irritation, combined with the chemical composition of the disc fluid, can result in pain. If the herniated disc protrudes into the spinal canal, it may compress the spinal cord or spinal nerves, further contributing to discomfort.
Symptoms
Disc-related issues can manifest as neck or back pain localized to the affected disc area. Individuals may experience symptoms such as burning or tingling sensations, numbness, weakness, or shooting pain. Depending on the location of the herniated disc, these symptoms may radiate to the arms or legs.
Diagnosis
A discogram is a diagnostic procedure typically performed after conservative treatments have proven ineffective. It is common for individuals to attempt multiple pain relief strategies, and if pain persists for several months, a discogram may be warranted to identify the exact disc causing the problem, enabling the development of a new treatment plan that may include surgical options.
On the day of the procedure, patients will be advised against taking pain medication and will wear a gown. They will be positioned to allow access to the affected spinal area, usually lying face down. The doctor will begin by sterilizing and numbing the area with an anesthetic, and patients may receive relaxation medication and antibiotics prior to the procedure.
Using live X-ray imaging (fluoroscopy), the doctor will carefully insert and guide a needle to the outer layer of the suspected disc. A second needle is then advanced through the first to reach the center of the disc. If multiple discs are suspected, this process may be repeated as necessary.
Once the needle is positioned in the disc center, contrast dye is injected, which may cause temporary discomfort. Patients will be asked to rate their pain and indicate if it resembles their typical symptoms. This step is repeated for each disc under examination if applicable. After evaluating the pain response, the needles are removed.
The second phase of the discogram involves taking X-ray images to assess the spread of the contrast dye. The pattern of dye distribution within the disc can reveal abnormalities, and a computed tomography (CT) scan may be employed to provide detailed information regarding the rupture or tear patterns, as well as the size and shape of the disc.
After the procedure, patients will be monitored for approximately 45 minutes before being allowed to go home. If relaxation medication was administered, it is essential to have someone else drive them. Doctors will prescribe pain relief for any temporary discomfort resulting from the procedure and will discuss the results with the patient, presenting options for future treatment.
