A herniated disc occurs when the annulus (the outer fibers) of your intervertebral disc is damaged and the soft inner material of the nucleus pulposus ruptures out of its normal space. If the annulus tears near the spinal canal, the nucleus pulposus material can push into the spinal canal. There is very little extra space around your spinal cord, especially in the thoracic area. So when a herniated disc occurs in the mid back it can be extremely serious. In severe cases, the pressure on the spinal cord can lead to paralysis below the waist. Fortunately, herniated discs are not nearly as common in the thoracic spine as in the low back or lumbar spine.
Herniated discs can occur in children, although it is rare. A true herniated nucleus pulposus is most common in young and middle-aged adults and generally occurs in the low back. Disc herniations in the thoracic spine mostly affect people between age 40 and 60. In older folks, the degenerative changes that occur in the spine with aging make it less likely for them to suffer a true herniated disc.
Discs can rupture suddenly because of too much pressure all at once. For example, falling from a ladder and landing in a sitting position can cause a great amount of force through your spine. If the force is strong enough, either a vertebra can break or a disc can rupture. Bending places high forces on the discs between each vertebra in your spine. If you bend and try to lift something that is too heavy, the force can cause a disc to rupture.
Discs can also rupture from a small amount of force, usually because the annulus has been weakened from repeated injuries that add up over time. As the annulus becomes weaker, at some point lifting or bending can cause too much pressure across the disc. The weakened disc may rupture while you are doing something that five years earlier would not have caused a problem. This is due to the effects of aging on your spine, which is the most common reason for a herniated disc in the thoracic spine.
The material that has ruptured into the spinal canal from the nucleus pulposus can cause pressure on the nerves in your spinal canal. There is also some evidence that the nucleus pulposus material causes a chemical irritation of the nerve roots. Both the pressure on the nerve root and the chemical irritation can lead to problems with how your nerve root functions. The combination of the two can cause pain, weakness, and numbness in the area of your body to which the affected nerve supplies sensation.
In the thoracic spine, the pressure can also affect your spinal cord. This is due to the fact that there is little extra space within the spinal canal of your thoracic spine. Too much pressure on the spinal cord can lead to paralysis from the waist down.
The first symptom of a herniated disc is usually pain. The pain is most often felt in the back, directly over the sore disc. Pain may also radiate around to the front of your body. Pressure or irritation on the nerves can also cause symptoms. Depending on which nerves are affected, a herniated disc can include pain that feels like it is coming from another part of your body, such as your heart, abdomen, or kidneys.
Herniated discs sometimes press against your spinal cord. When this happens, symptoms may include:
- Herniated disc in your thoracic spine:
- Muscle weakness, numbness, or tingling in one or both legs
- Increased reflexes in one or both legs that can cause spasticity
- Changes in bladder or bowel function
- Paralysis from the waist down
- Herniated disc in your cervical spine:
- Pain moving your neck
- Deep pain near or over your shoulder blade
- Radiating pain in your upper arm, forearm, and possibly your fingers
Pain from a herniated disc may start slowly and get worse over time or during certain activities. The symptoms of herniated disc often get better within a few weeks or months.
Diagnosing a herniated disc begins with a complete history of the problem and a physical exam. Your doctor may ask whether you are aware when you have to urinate or have a bowel movement. If there is a problem, it could indicate that a herniated disc in your thoracic spine is pushing against your spinal cord. Your doctor may also want to perform certain diagnostic tests including an X-ray, MRI, or CT scan.
Your doctor may suggest taking X-rays of your spine. Although an X-ray can't show a herniated disc, it can give your doctor an idea of how much wear and tear is present in your spine. X-rays can also show a disc that has become calcified. If part of the calcified disc appears to be pointing into your spinal cord, it's a good indication the disc is herniated.
The most common test to diagnose a herniated disc is the MRI scan. This test is painless and very accurate. It is usually the preferred test to do (after X-rays) if a herniated disc is suspected.
Myelogram with CT Scan
Sometimes, the X-ray and MRI do not tell the whole story. Other tests may be suggested. A myelogram, usually combined with a CT scan, may be necessary to give as much information as possible.
A herniated disc does not necessarily mean that you will need to undergo surgery. The treatment of a herniated disc depends on your symptoms. If your symptoms are getting better, your doctor may suggest conservative treatment such as watching and waiting to see whether your symptoms go away, pain medications, and physical therapy. Many patients who initially have problems due to a herniated disc find their symptoms completely resolve over several weeks or months.
If your symptoms are getting steadily worse, your doctor may be more likely to suggest surgery.
The traditional way to surgically treat a herniated disc used to be to perform a laminotomy and discectomy. The term laminotomy means "make an opening in the lamina", and the term discectomy means "remove the disc." The purpose of taking out a herniated disc was to decompress the spinal cord or spinal nerves. But nerve problems that occurred with this traditional method of decompression have led many doctors to discontinue this form of surgery for herniated disc.
If the herniated disc is in your thoracic spine and surgery is needed, your doctor may perform transthoracic decompression, which is a way to decompress your spinal cord or spinal nerves by removing a small amount of the vertebral body and problem disc through a small opening in the side of your chest. If a large section of vertebra has to be taken out, you may also need spinal fusion.
A herniated disc in the thoracic spine may also be treated surgically with a costotransversectomy, in which a section of the transverse process (the small bone on the side of the vertebra) is taken off, which helps the doctor to see and then treat the injured disc through an incision through the back of the spine.
Video Assisted Thoracoscopy Surgery (VATS) is a new way to perform thoracic surgery in which the doctor can see and treat the herniated disc using a small TV camera that is passed through your chest cavity. Because the incisions are small, most patients have an easier time recovering from the VATS procedure.
If surgery on a herniated disc requires removal of a large section of bone and disc material, the section of spine may become loose or unstable. When this happens it may be necessary to fuse the bones right above and below the unstable section. Bone graft material is used to get the unstable bones to grow together. Rods, plates, and screws are commonly used to hold the bones in place so the bone graft heals.