Spinal Cord Compression Health Article

Description

In order to understand spinal cord compression, it is useful to understand the structure of the spinal cord and to understand the difference between the spinal cord and the vertebral column. The vertebral column includes the bony structure surrounding the spinal cord and the spinal cord itself. Also an important part of the vertebral column, the intervertebral disks, are found between verte-brae. They act as shock absorbers. The spinal cord, however, is the series of nerves that runs down the hollow part of the vertebrae. Thus, the bony vertebrae and shock-absorbing disks protect the spinal cord from physical damage and compression.

Spinal cord compression occurs when something presses down with sufficient force on the nerves within the spinal cord so that they lose their ability to function properly. Although trauma, degenerative back disease, and genetic disorders can cause pressure on the spinal cord, the term spinal cord compression is usually reserved for cases in which the presence of a tumor results in pressure on the spinal cord. The tumor may originate in a number of areas and either directly or indirectly put pressure on the cord.

The spinal cord is a series of nerves bundled together that are responsible for most functions of the body, including, but not limited to, the "fight or flight" response, the movement of arms and legs, and feeling below the neck. Each nerve is responsible for different functions, such as movement, and each has a different position within the structure of the spinal cord. Thus, depending on which angle the spinal cord is compressed from, a person could experience numbness versus a loss of the ability to control muscles (often seen as an odd limp), depending on which area is compressed.

Not only do the different nerve clusters of the spinal cord have different functions, but each has nerves branching off from the spinal cord at many levels. Each of these branches controls different parts of the body. For example, nerves branching off the spinal cord in the low back control movement of the legs, and nerves branching off the spinal cord at the level of the neck are responsible for most of the movements of the arm. Thus, compression of the spinal cord at different levels can result in very different symptoms.

Vertebrae are, in order, divided into cervical, thoracic, lumbar, and sacral sections. The cervical vertebrae correspond to the neck, the thoracic vertebrae correspond to most of the torso, the lumbar vertebrae are found in the low back, and the sacral vertebrae correspond to the area of the buttocks. There are seven cervical, twelve thoracic, five lumbar, and five sacral vertebrae (although the sacrum is one bony structure and contains no inter-vertebral disks). The level of compression is indicated by using the first letter of the type of vertebra and then the number of the vertebra within the group. The topmost vertebrae are numbered lowest, so the first cervical vertebra is the vertebra closest to the head, and is known as C1. C7 is the cervical vertebra furthest down the spine. Compression of the spinal cord in this region would be known as compression at C7. The closer the compression is to the head, the more symptoms the patient is likely to have, since compression of the spinal cord affects all the levels of nerves below the area of compression that are part of the same nerve branch. For example, if movement were affected at C2 and below, a person would have difficulty using both arms and legs, whereas compression at T12 might result in just difficulty using the legs.

Importantly, the first symptom patients usually display prior to actual spinal cord compression is pain, especially pain that is not relieved by lying down, and which has lasted one month or more. This kind of pain should be sufficient to suspect imminent spinal cord compression due to cancerous causes. Also, there may be damage to nerve roots at the level of compression that can lead to symptoms in other parts of the body. For example, if the cord compression is in the lower part of the spine, then parts of the legs may be affected with numbness, tingling and loss of power and movement. Similarly, if the problem lies in the upper part of the spinal column, there may be a loss of power and sensation in parts of the arms or hands. If the cord compression becomes more severe, it can affect lower muscle functions such as bowel and bladder.