At ANA, we take advantage of a wide variety of diagnostic tools, working with patients to combine test results with their symptoms to come up with solutions for their care.
In addition to a medical history, at ANA we also perform a physical exam to evaluate spinal conditions. The physical exam is a means by which our doctor will learn about the pain and condition to provide an assessment. In this examination, he will feel the spine, check how well the joints move, and solicit information from the patient on pain and other symptoms. Specifically, an element of the physical exam is a neurological exam, which tests the reflexes, as well as muscle strength and other nerve changes. This is especially important in degenerative disc disease since that condition can affect the nerves or even the spinal cord.
The doctor will examine the areas in which a patient is experiencing pain or other symptoms. In a standard exam, a patient may be checked for:
Typically traditional x-rays are the first imaging test done to evaluate a condition. This test provides information on the bones in the spine. An x-ray is often used to check for spinal instability (such as spondylolisthesis), tumors, fractures, osteoarthritis, bone spurs and narrowed spinal canals (spinal stenosis). Although not effective for showing much of the soft tissue, x-rays do show bones, and thus are used for evaluation of suspected fractures, infections, or tumors (tumors, which are denser than soft tissue, appear white on the x-ray).
An MRI is able to show any abnormality of soft tissues, such as nerves and ligaments, cartilage of the joints, muscles and spinal cord. This test can be used to evaluate disc height and hydration, enlargement of facet joints (hypertrophy), spinal stenosis, or a herniated disc. It can also show spinal cord or nerve root compression, and pinched or inflamed nerves. It can reveal any abnormalities in the spine or spinal cord that may be causing spinal pain.
An MRI does not use radiation (unlike x-ray and CT scans), but rather produces images through magnetic forces which act on the atoms that comprise the body’s tissues and organs by penetrating multiple layers of the spine.
Because it shows both bones and soft tissue, the CT scan is an x-ray image that is similar to both the MRI and a regular x-ray. CT scans are able to produce x-ray “slices” taken of the spine (slices refer to horizontal, or axial, images). This facilitates separate examination of each section of the spine.
The x-ray beam moves in a circle around the body in CT scans. This allows many different views of the same organ or structure. The x-ray information is sent to a computer that interprets the data and displays it in a two-dimensional (2D) form on a monitor.
This scan provides details about the bones in the spine and is effective at showing such conditions as degeneration of bones. It may also be used to check for specific conditions, and like an MRI, can show conditions such as a herniated disc or spinal stenosis.
A CT (or MRI) scan is more effective than x-rays at showing the soft tissues in the spine. With a CT scan, it is easier to see the bones and nerves, and a CT scan more easily reveals problematic structures, such as a bone spur pressing on a nerve.
A myelogram, also called myelography, may be performed to assess any abnormalities in the spinal cord, subarachnoid space (the space between the arachnoid membrane and pia mater), nerve roots and other tissues. It is often indicated when other imaging tests are inconclusive. It is used to check for a spinal canal or a spinal cord disorder, such as nerve compression causing pain and weakness, tumors or infections. In this test, a special dye is injected into the area around the spinal cord and nerves. Administration of the dye is followed by an x-ray or a CT scan. The contrast dye appears on an x-ray screen, allowing for a clearer view of the structures the doctor is seeking to evaluate and assess.
The purpose of a nerve conduction study is to help diagnose nerve disorders and pinpoint the location of abnormal sensations, such as numbness, tingling or pain. It is done to find and assess damage to the nerve that leads away from the brain and spinal cord to the smaller nerves that branch out from them. In this test, electrodes are placed over the nerve to be studied. Brief electrical pulses are sent to the nerve. This is done to measure the electrical pulse in order to show whether the nerves are transmitting electrical impulses to the muscles, or through the sensory nerves, in normal fashion.
A nerve conduction study is usually done in conjunction with an electromyogram (EMG). An EMG evaluates 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. If the EMG machine finds that the muscles are not working properly, the doctor can assume there is impingement (pinched) somewhere along the nerve or nerves in question. In addition, if the doctor suspects nerve damage from degenerative changes in the spine, this test will also measure the speed at which the nerves respond, and aid in this diagnosis.
When an MRI fails to confirm the source of lower back pain and there is a suspicion of disc malfunction, a discogram may be ordered. Discography entails inserting a thin needle into the back muscles directly into the intervertebral disc. The needle placement is then verified by an x-ray. A small amount of contrast dye is then injected into the disc. If there is a problem with the disc, such as herniation, the dye will leak out of the disc. The doctor will be able to see that on an x-ray, which is taken as part of the process. A discogram is also an anatomical test, the result of which depends on a patient’s response. If injecting the dye recreates the pain the patient has been experiencing, it indicates to the doctor that the specific disc being tested is the source of that pain. If the pain is unlike the patient’s normal pain, however, although it may be determined that the disc appears to be degenerative, that disc may not be the cause of the patient’s pain.