Clinical Diagnosis of Chronic Pain

One of the most important precursors to effective chronic pain management is the establishment of an accurate diagnosis. Now that you’re done with your self-evaluation, the next step is a thorough history and physical examination by a qualified physician. This is usually followed by appropriate testing to confirm the working diagnosis and to further shed light upon your pain.

History

During the history-taking portion of the evaluation, the doctor listens to the patient’s report of subjective symptoms. The doctor will ask many questions including, but not limited to the following: Did the pain come on suddenly or gradually? Was the onset associated with trauma? What was the mechanism of injury? The doctor will also ask how frequently the pain occurs. Is it constant or does it come and go? Your pain diary will greatly assist your physician in understanding what you’re experiencing.

Physical examination

The doctor will look, listen, and feel as he or she examines the individual for objective signs that are consistent with the subjective symptoms. Sensation, reflexes, muscle strength, bulk and tone, joint stability, range of motion and coordination will be assessed.

Lab work

Analysis of blood and urine samples may render critically important information that can either nail down or rule out a diagnosis. The following table lists some of the more common laboratory tests that may be ordered by a physician to evaluate a patient with pain.

TEST	DESCRIPTION
Alkaline Phosphatase	Elevated in fractures, paget’s disease, bony metastasis, and osteomalacia.
Amylase	Elevated in pancreatitis which can cause both abdominal and back pain.
ANA (antinuclear antibody)	Abnormal in SLE (systemic lupus erythematosis) and various other painful connective tissue diseases.
B12	May be low in peripheral neuropathy and myofascial pain.
Calcium	Elevated in some metabolic disorders such as parathyroidism and certain malignancies such as multiple myeloma.
ESR or Erythrocyte sedimentation rate	Nonspecific lab value that is elevated in inflammation, malignancy, or temporal arteritis (a serious cause of headache associated with visual blurring which can lead to blindness).
Folate	May be low in peripheral neuropathy and myofascial pain.
Hemaglobin	May be low in malignancies such as multiple myeloma. May be low in rheumatological diseases that cause chronic inflammation.;
HLA-B27	Positive in ankylosing spondylitis.
Lipase	Elevated in pancreatitis, which can cause both abdominal and back pain.
Magnesium	May be low in myofascial pain.
Rheumatoid factor	Elevated in rheumatoid arthritis and a wide spectrum of autoimmune disorders and chronic infectious diseases.
Serum acid phosphatase	Elevated in cancer of the prostate, which can metastasize to the spine and pelvis.
Serum protein electrophoresis	Abnormal in multiple myeloma.
Thyroid function studies	May be abnormal in muscular disorders that present with pain, weakness, and reflex changes.
Uric acid	Elevated in gouty arthritis.
Urinalysis	Used to rule out kidney infections.
White blood cell count	May be elevated in infection and malignancies.

X-rays

X-rays provide good resolution of the bony structures and alignment but are ineffective in providing a clear image of soft tissues such as muscles, ligaments, and the intervertebral discs.

The following diagnoses can be made by X-rays

Fractures and dislocations
Arthritis
Abnormal curvatures of the spine
Spondylosis
Spondylolisthesis
Degenerative disc disease
Abnormal straightening of the normal curvatures of the neck and lower back spine due to muscle spasms such as occur with whiplash injuries

CAT scan

It is a method of choice for evaluating bony processes such as spinal stenosis. Unlike the X-ray, CT shows, in addition to bony structures, soft tissues such as ligaments, nerve roots, and the intervertebral disc. The spinal cord and disc fragments may also be visualized by this method.

Magnetic resonance imaging

MRI is an excellent technique for visualizing bones, nerves and nerve roots, muscles, ligaments, discs, and the brain and spinal cord. It is the procedure of choice for diagnosing joint problems, including meniscal and cruciate ligament injuries of the knee and rotator cuff abnormalities of the shoulder.

An MRI of the head or neck may be ordered to evaluate individuals with headaches. It is also the best test available for diagnosing multiple sclerosis.

Myelography

Myelography is performed by first doing a lumbar puncture and then introducing contrast medium into the subarachnoid space. By this means, the spinal cord and nerve roots can be visualized. CT is often done in conjunction with the myelogram to improve diagnostic accuracy. Since the development of CT and MRI, myelography is ordered less frequently.

Electromyography and nerve conduction studies

EMG NCS is performed to determine if there is nerve or muscle damage. It is usually ordered to evaluate patients with objective motor signs, such as weakness or atrophy, and/or subjective sensory symptoms, such as numbness, tingling, or shooting pain.

Nerve conduction studies

Nerve conduction studies test how well signals travel along a nerve. The test is performed by applying a brief electrical stimulus to one portion of a nerve while recording at another place along the same nerve.

Evoked potentials

Evoked potentials evaluate the function of nerve pathways that carry signals through the vision, hearing, and spinal cord pathways. Signals are produced in the nerves by applying pulses of light to the eyes, clicking sounds to the ears, or small, brief electrical stimuli to the nerves of the arms or legs. These tests may be performed to evaluate headache associated with neurological conditions.

Electroencephalography

EEG is an electrophysiological test that evaluates the function of the cerebral cortex (part of the brain responsible for higher mental functions).

EEG is the key test for the diagnosis and management of seizure disorders. It is also frequently ordered to evaluate a patient who presents with headaches, in particular if they are associated with altered mental states such as confusion, memory impairment, or personality change.

Bone densitometry

Bone densitometry assesses the bone density of an individual and compares it to the average value for others of the same age, race, and gender. Osteoporosis is best diagnosed by bone densitometry.

Bone scan

A bone scan is a painless nuclear imaging study for the early detection of a variety of bone lesions. A radioactive “tracer” is injected intravenously into the bloodstream. Bones that are undergoing rapid cell growth have increased uptake of this tracer substance, which shows up as a black area called a “hot spot.”

Discogram

Discogram is very helpful in resolving difficult cases. It is an invasive procedure in which a fine-gauge needle is placed into the disc space, followed by the injection of radiopaque dye. The normal disc accepts about one milliliter of dye, whereas an abnormal disc will accept three milliliters. In the case of an intact disc, no dye will escape and an oval will be seen on X-ray. If the disc is ruptured, however, the dye will be seen leaking out of the disc into the adjoining area.

Ultrasound

Ultrasound is a noninvasive test that evaluates tissues according to their ability to reflect sound waves. By this method, fluid can be easily distinguished from solid tissue in the thyroid gland, kidney, and liver, allowing for the differentiation of cysts from tumors. Gallbladder disease can also be evaluated by ultrasound.

References

Dillard, James N. The Chronic Pain Solution: Your Personal Path to Pain Relief. New York, NY:Bantam Book, 2002.

Schneider, Jennifer. Living with Chronic Pain: The Complete Health Guide to the Causes and Treatment of Chronic Pain. Long Island City, NY. Hatherleigh Press, 2004

This page was first published on May, 15th, 2008 and was last updated on May, 15th, 2008