Diagnosis:

Although most episodes of new back pain, as well as exacerbations of chronic back pain, clear up or return to a previous level of discomfort, a medical history and a brief physical examination is always necessary. Depending on the severity of the symptoms, how long they have been present, and any associated medical problems, history and physical exam alone may or may not be sufficient.

The goal is to classify patients into one of three categories

• Nonspecific back pain (back pain that is not due to a specific condition or abnormality of the spine)
• Back pain associated with nerve roots problems or spinal stenosis
• Back pain associated with another specific cause, which may or may not be of a serious nature

A medical history and physical examination can usually clarify the classification.

Medical History

The patient should be able to describe the back pain and its history in the following manner:

• Frequency, duration, and nature of the pain
• When the pain occurs
• What triggered the pain (such as lifting a heavy object)
• Conditions that make the pain worse, such as coughing
• Other relevant symptoms, such as morning stiffness, weakness, or numbness in the legs
• Previous episodes of back pain
• Severity of the pain and how it affects the person's ability to perform everyday activities or work activities
• Any situation that relieves the pain
• Any history of injuries or accidents involving the neck, back, or hips
• Other medical conditions, such as arthritis or osteoporosis

A patient should report any serious health problems, symptoms, and concerns that may raise a red flag for a more serious condition. These include:

• HIV infection or AIDS
• Pain that is persistently increasing in intensity and cannot be relieved
• Fever that is associated with the back pain
• Any new or worsening neurological symptoms, such as weakness in a specific part of the legs or feet
• History of cancer, or currently being treated for cancer
• Problems emptying the bowels or bladder, including incontinence
• Unexplained weight loss

Physical Examination

The main goal of a physical exam is to try and determine the source of the pain and the limits of movement.

• Patients are asked to sit, stand, and walk in different ways (flat-footed, on the toes, and on their heels).
• In some cases they are asked to walk on a treadmill to test for weakness in toe or heel walking (which may indicate stenosis).
• Patients will be requested to bend forward, backward, and sideways and to twist.
• Patients will be asked to lift their leg straight up while lying down. The health care provider will also move the patient's legs in different positions and bend and straighten the knees. (Pain caused by sciatica can be intensified by lifting the affected leg straight in the air. It is usually sharp, localized, and accompanied by numbness or tingling. Pain caused by inflammation is duller and more generalized and not affected by lifting a straight leg.)
• The health care provider may measure the circumference of the calves and thighs to look for muscle deterioration.
• To test nerve function and reflexes, the health care provider will tap the knees and ankles with a rubber hammer. The health care provider may also touch parts of the body lightly with a pin, cotton swab, or feather to test for numbness and nerve sensitivity.
• The health care provider will assess strength in different muscle groups of the legs.

Imaging Techniques

Imaging tests used to evaluate back pain range from a simple x-ray to a CT scan or MRI of the spine. Depending on medical diagnoses that are identified by the history, the patient may need such tests as a Dual energy X-ray absorptiometry (DEXA) scan for osteoporosis or a nuclear scan for suspected arthritis, cancer, or infection.

Because most patients with back pain are on the mend or completely recovered within 6 weeks, imaging techniques such as x-rays or scans are rarely recommended in the first month unless the health care provider suspects a tumor, fracture, infection, cauda equina syndrome, or progressive neurological disease.

Even when symptoms last longer, unless a potentially serious diagnosis is suspected, MRI or CT scans can often be delayed until the time when surgery or epidural steroid injections come into consideration as treatment options.

X-Rays. Many patients with acute and uncomplicated low back pain believe that plain x-rays of the spinal column are important in a diagnosis. However, they are not very helpful in most patients with nonspecific back pain.

Patients who have the following symptoms or experience certain events may need more sophisticated imaging studies:

• Significant pain that lasts more than 1 - 2 months
• Symptoms such as pain, numbness, or tingling extending from the buttocks down the leg that are very severe or get worse
• Muscle weakness that is significant, persistent, or getting worse
• A previous accident or injury that might have affected the disks or vertebra
• A history of cancer
• Indications of an underlying disease such as fever or unexplained weight loss
• Pain that occurs in patients over 65 years of age

Magnetic Resonance Imaging (MRI). Magnetic resonance imaging (MRI) can provide very well-defined images of soft tissue and bone. It is not painful, but some people may feel claustrophobic in scanners that are fully enclosed. MRIs can detect annular tears, or disk fragments, and non-spinal causes of back pain, including infection and cancer. Some medical evidence suggests that relying on MRI images of disk abnormalities to determine treatment has resulted in many unnecessary surgeries. At least 40% of all adults have bulging or protruding vertebral disks, and most have no back pain. The degree of disk abnormalities revealed by MRIs often have very little to do with the severity of the pain or the need for surgery. Disk abnormalities in people who have back pain may simply be a coincidence rather than an indication for treatment.

CT stands for computerized tomography. In this procedure, a thin x-ray beam is rotated around the area of the body to be visualized. Using very complicated mathematical processes called algorithms the computer is able to generate a 3-D image of a section through the body. CT scans are very detailed and provide excellent information for the doctor.

Bone Scintigraphy and SPECT Imaging. In rare cases, doctors may use bone scintigraphy (bone scanning) to determine abnormalities in the bones. The technique may be useful for early detection of spinal fractures, cancer that has spread to the bone, or certain inflammatory arthritic conditions. During this exam, a small amount of radioactive material is injected into a vein. It circulates through the body, and is absorbed by the bones. The bones can then be seen using x-rays or single photon emission computed tomography (SPECT).

An x-ray myelogram is an x-ray of the spine that requires a spinal injection of a special dye and the need to lie still for several hours to avoid a very painful headache. It has value only for select patients with pain on moving and standing. It has largely been replaced by CT and MRI scans.

Electrodiagnostic Tests

Tests that analyze the electric waveforms of nerves and muscles may be useful for detecting nerve abnormalities that may be causing back pain, and identifying possible injuries. They are also useful to determine if any abnormal structural findings on an MRI or other imaging tests have real significance as a cause of back pain. It should be noted that any nerve injuries that affect these tests may not be present for 2 - 4 weeks after symptoms begin.

Nerve conduction studies and electromyography are the electrodiagnostic tests most commonly performed. These tests are not used often in the evaluation and management of patients with low back pain.

Other Tests

Diskography is an x-ray of the disk. Since many people have evidence of disk degeneration on their MRI scans, it is not always easy to tell if the finding on this MRI scan explains pain the patient may be experiencing. Diskography is a test that is used to help determine whether an abnormal disk seen on MRI explains someone's pain. When performed, it is generally reserved for patients who did not experience relief from other therapies, including surgery. This procedure requires injections into disks suspected of being the source of pain and disks nearby. It can be painful. There is controversy among physicians who take care of the spine regarding the usefulness of diskography for making decisions about care, particularly surgery

Blood and urine samples may be used to test for infections, arthritis, or other conditions.

Injecting a drug that blocks pain into the nerves in the back helps locate the level in the spine where problems occur.

A procedure called a facet block is also useful in locating areas of specific damage.