Carpal Tunnel Syndrome - Diagnosis

Diagnosis

Carpal tunnel syndrome (CTS) is most accurately diagnosed using the patients' descriptions of symptoms, and electrodiagnostic tests that measure nerve conduction through the hand. If electrodiagnostic testing is not available, then symptom descriptions and a series of physical tests are useful.

Diagnosing CTS, however, is not straightforward. Only a small fraction of patients exhibit all three factors necessary for a clear diagnosis:

• Classic CTS symptoms
• Specific physical findings
• Abnormal electrodiagnostic test results

Many people have abnormal electrodiagnostic test results without classic symptoms or any symptoms at all. Furthermore, about 15% of the population has symptoms consistent with CTS, but most do not show test results indicating the disorder. In fact, in a 2001 study, some patients who had symptoms, but whose nerve and physical tests were normal, still experienced relief after CTS surgery.

Symptom Description and Severity

Many cases of CTS are a combination of a medical problem exacerbated by repetitive stress factors at work. The patient should give the doctor a detailed history and description of any complaints, in any part of the body. The patient should report in detail any daily activities that require repetitive hand or wrist actions, abnormal postures, or other regular situations that could affect the nerves in the neck, shoulders, and hands. The patient should report whether the symptoms are more likely to appear at night, or after particular tasks.

Questionnaires. The use of specific questionnaires that score results are quite accurate in assessing the severity of the condition.

Hand Diagram. A diagram of the hand and wrist, usually divided into six regions, is a very useful diagnostic tool. Patients are asked to indicate where their symptoms are, including pain, numbness, or tingling, by locating the affected areas on the diagram. They may also be asked to rate the severity of their symptoms. A diagnosis is probable if at least two of fingers 1, 2, or 3 have these symptoms, and if there is pain in or near the wrist. CTS is possible if at least one of these fingers has symptoms. It is unlikely if there are no symptoms in these fingers, the palm, or the wrist.