Diagnosis

The most common area for back pain is the lower back and this is due to the fact that it carries the majority of your weight. Diagnosing back pain is sometimes a difficult process. The physician will require a detailed history and a physical examination. The doctor may ask specific questions regarding the type of pain you are experiencing, where it radiates, what factors make the pain worse or what factors typically alleviate the pain. The physical examination concentrates on motor and sensory function.

Diagnostic testing will help the doctor in determining a diagnosis and to define its location and configuration. The first step is usually a set of x-rays. Based on the findings of the x-ray reports your doctor may want to perform additional scans or tests. Typically they may want you to have a CT scan (computed tomography), a MRI (magnetic resonance imaging) or perhaps a Myelogram and a CT scan. Generally, a MRI is the preferred diagnostic tool because it is non-invasive and provides excellent detail. However, in Canada it is extremely expensive and the waiting list is long. The CT scan is inferior in soft tissue detail to the MRI but is superior in bony detail. They are less expensive and faster to obtain. Myelography with CT gives excellent definition of the spaces around the nerve roots but its disadvantage is that it requires an injection of contrast dye through a lumbar puncture.

The evaluation of back pain requires a Health Care Professional experienced in this problem. The workup begins with a detailed history and physical examination. Your Health Care Professional will ask about the quality of the pain, where it radiates, factors which worsen or alleviate the pain and other questions. The physical examination concentrates on motor and sensory function.

X-RAYS only show the bones of the body. Most of the soft tissue structures of the spine do not show up, however, much can be learned from the X-rays. X-rays are a first step in looking into any back problem and will help in deciding which other tests, if any, will be required.

CAT SCAN (Computer Assisted Tomography) is an X-ray test that is very similar to the MRI Scan. X-Ray slices can be taken across the spine, giving a cross sectional view. The CAT Scan shows the bones of the spine much better than the MRI Scan and is useful when conditions that affect the bones of the spine are suspected. The CAT Scan is commonly combined with a Myelogram to give a better picture of the spinal nerves and help determine if there is pressure from Spinal Stenosis or a Herniated Disc.

MRI (Magnetic Resonance Imaging) scan is the most common test used to evaluate the spine. The MRI scanner uses magnetic waves instead of x-ray radiation. Imagine if you could slice through the spine layer by layer and take pictures of each slice. Thatís exactly what the MRI scanner allows us to do. Multiple pictures of the spine are taken by the MRI scanner. This allows us to view not only the bones of the spine, but also the nerves and discs. Slices can also be taken across the spine, giving a cross sectional view. The MRI scanner allows us to see the nerves and disc quite clearly. No special dyes or needles are necessary. Here we see a MRI cross section showing a fairly typical herniated disc side view and cross section view image. The scan is painless and there are no known harmful effects.

MYELOGRAM is a test that involves placing dye into the spinal sac that shows up on X-Ray. Any abnormal indentation on the spinal sac may indicate that there is pressure on the nerves of the spine, such as that caused by a herniated disc.

DISCOGRAM is a special test where dye is injected directly into the disc in the area of the Nucleus Pulposus. If the injection causes you to experience the same low back pain you have been complaining of, this suggests that the disc being tested is causing your pain. Plain X-rays and a CAT Scan can also be used to look at the disc and may show whether or not the disc is ruptured.

ELECTROMYOGRAM (EMG) is a test that looks at the function of the nerve roots leaving the spine. The test is done by inserting tiny electrodes into the muscles of the lower extremity. By looking for abnormal electrical signals in the muscles, the EMG can show if a nerve is being irritated or pinched as it leaves the spine. Think of how you test the wiring on a lamp. If you place a working bulb into the lamp and the bulb lights up, you assume that the wiring is OK. But what if the bulb doesnít light up? You can

safely assume that something is probably wrong with the wiring , like the lamp is unplugged or a short circuit has occurred. By using the leg muscles like the light bulb in the lamp, the EMG is able to determine the condition of the nerves that supply those muscles, like the wiring on the lamp. If the EMG machine finds that the muscles (the light bulb) are not working properly, we can assume that the nerves (the wiring) must be getting pinched somewhere.

ELECTROMYOGRAM (EMG) is a test that looks at the function of the nerve roots leaving the spine. Tiny electrodes are inserted into the muscles of the lower extremity. Any abnormal electrical signals in the muscles are observed. This may indicate an irritated or pinched nerve as it leaves the spine.

BONE SCAN is used to help locate the affected area of the spine. In order to perform a Bone Scan, a radioactive chemical is injected into the bloodstream. The radioactive chemical attaches itself to areas of bone that are undergoing rapid changes for any reason. Areas of the skeleton that are undergoing rapid changes appear as dark areas on the film. Once the affected area is identified, other tests, such as the MRI Scan are done to look more closely at the specific area. There are many possible causes of low back pain. Some of these causes are not related to degeneration of the spine. Blood tests to look for infection or arthritis may be necessary. Problems originating in areas other than the spine may also cause back pain. These can include: aortic aneurysm, kidney problems and stomach ulcers. These problems are just a few of the possibilities. Specific tests to rule out these possibilities may be suggested if your doctor feels that they are necessary.

BONE SCAN In order to perform a bone scan, a radioactive chemical is injected into the bloodstream. The radioactive chemical attaches itself to area of bone that is undergoing rapid changes for any reason. These rapidly changing bony areas appear as dark areas on the film. Once the affected area is identified, other tests such as MRI are performed to have a closer look.

There are several causes of low back pain. Some of which may not be related to degeneration of the spine. If the physician suspects an infection or arthritis, a blood test may be required. Some back pain can be caused by problems in other areas of the body. Problems such as aortic aneurysm, kidney problems and stomach ulcers, to name a few. Your doctor may feel it is necessary to perform specific tests to rule out these possibilities.