Over the years, diagnosing Complex Regional Pain Syndrome (CRPS) has changed quite a bit. These days, the Budapest criteria are often used to diagnose CRPS. These categories are most widely used and were developed by pain clinics to differentiate between CRPS and other neuropathic conditions (Harden et al., 2010). These look at four main categories of symptoms as shown below:
There are different tests that CRPS patients may have to endure in order to arrive at a final diagnosis of CRPS. Although, the current diagnostic tools are mere guides.
Few Doctors Truly Understand CRPS
In general, few doctors truly understand RSD/CRPS. Before patients are first diagnosed, they must navigate an endless maze of specialists, often painful tests, and misdiagnoses. If you are lucky enough to have been diagnosed relatively quickly, your options are few and limited. A lot of medical professionals have never heard of RSD/CRPS. Even if they have heard about it, they still misunderstand it (e.g., thinking that RSD/CRPS can’t spread).
Diagnosis of CRPS is based on a physical exam and your medical history. Again, there’s no single test that can definitively diagnose CRPS, but the following procedures may provide important clues:
The Three-Phase Bone Scan is a medical imaging technique used to help diagnose CRPS in which an intravenous(IV) injection of a particular radiolabelled substance that has a special tendency to concentrate in the bones is administered and a technician takes images of the body part in question. The images measure three phases:
Although the three-phase bone scan is a useful diagnostic tool, it is not definitive on its own It can support a diagnosis of CRPS but should be considered alongside other clinical presentations and diagnostic tests.
X-rays are often used to diagnose complex regional pain syndrome (CRPS). X-rays may be used to identify signs of CRPS in the bone, such as loss of bone minerals, common in CRPS. X-rays may also be used to rule out other conditions which may potentially contribute to the patient’s symptoms. As with several other diagnostic tools, x-rays typically cannot act as a stand-alone tool in the diagnosis for CRPS.
CRPS Bone Loss Assessment through X-Rays
It is common for patients with CRPS to experience a decrease in bone mineral density. This bone loss typically occurs in the later stages of CRPS, three to twelve months after the onset of the condition. X-rays will typically appear normal during the first three months of CRPS. When CRPS affects the patient’s bone, osteopenia occurs. Osteopenia is a condition that causes lower-than-normal bone density. In many cases, osteopenia is considered a precursor to osteoporosis.
A thermogram is a noninvasive means of measuring heat emission from the body surface using a special infrared video camera. It is one of the most widely used tests in suspected cases of CRPS. As noted, detecting an abnormal change in skin temperature in CRPS depends on many factors. A normal thermogram does not necessarily mean the patient does not have CRPS. An abnormal thermogram may, however, be helpful when there are minimal objective findings for a diagnosis of CRPS documented in the medical record. Furthermore, certain patterns of abnormal heat emission from the body (e.g. circumferential versus dermatomal changes) are more indicative of the existence of CRPS than others. The thermogram should be performed at a reputable medical facility. The quality of the test may vary among providers.
The typical neurologic tests used to diagnose nerve injuries involve electromyography (EMG) and nerve conduction techniques that measure major motor or sensory nerve changes. A nerve conduction study (NCS), also called a nerve conduction velocity (NCV) test–is a measurement of the speed of conduction of an electrical impulse through a nerve. NCS can determine nerve damage and destruction.
In my opinion, anything that involves insult to the sensory nervous system of a CRPS patient, such as a needle entering the body, should be avoided except for in life threatening situations. Unfortunately, the small-fiber nerve injuries in CRPS are not detected by these standard tools, which only measures large-fiber function.
The value of a thorough physical exam by a doctor who knows what to look at cannot be overestimated. The typical CRPS patients will often give off physical clues that may seem small, but, in fact, may be crucial in obtaining the best diagnosis. A good exam starts with a thorough history taken by someone who really listens to the patient. Patients will report and demonstrate sensitivity to light touch, deep touch, pain, vibration, circumferential pressure, cold, heat, and increased pain when bad weather comes in. They will often report that the touch of clothes, shoes, carpet underneath bare feet, showers, etc. There are some clues that can be seen by visual observation alone, such as soft tissue edema and enhancement, skin thickening, color changes, changes to the nails and/or hair, skin rashes and wounds and muscle atrophy in later stages. In addition, patients who suffer from CRPS will show abnormalities of the III, VII, IX and X (parasympathetic) cranial nerves.
For additional information, see How is CRPS Diagnosed?
“Just because you can’t find the exact source of someone’s pain doesn’t mean they don’t feel it,” says John F. Dombrowski, MD, a Washington, D.C. pain specialist. “No test can measure the intensity of pain, no imaging device can show pain, and no instrument can locate pain precisely. This doesn’t mean pain can’t be treated. We don’t need to know the exact cause of the pain to try to make it feel better.”
– RSDHope.org
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