Dos and Don'ts for the Physician Evaluating Patients with Carpal Tunnel Syndrome
As a patient with symptoms of hand and arm pain, numbness and tingling, and muscle weakness, you should expect to get the same exam and diagnosis no matter what physician examines you. That's the reason the American Academy of Orthopaedic Surgeons (AAOS) published these guidelines for the diagnosis of carpal tunnel syndrome (CTS).

Carpal tunnel syndrome (CTS) is a common problem affecting the hand and wrist. Symptoms begin when the median nerve gets squeezed inside the carpal tunnel of the wrist. This is a medical condition known as nerve entrapment or compressive neuropathy. Any condition that decreases the size of the carpal tunnel or enlarges the tissues inside the tunnel can produce the symptoms of CTS.

It's easy for anyone to develop their own opinions and biases that might influence outcomes and results in the diagnosis and treatment of CTS. To combat this and to ensure similar results for all patients with carpal tunnel syndrome, groups like the AAOS put together committees of experts to review the current published studies on topics like carpal tunnel syndrome. Then they develop guidelines for all to use. This helps produce an accurate diagnosis early on. An early and accurate diagnosis usually means better results from treatment.

As a result of reviewing 224 full articles (24 of which were chosen as acceptable), five key guidelines have been developed for the diagnosis of carpal tunnel syndrome. Briefly, these are:
  • Physicians start by getting an accurate patient history.
  • Physicians then examine the patient. Specifics about what to include in the exam are presented.
  • Electrodiagnostic tests should be ordered for certain patients.
  • Details are provided about who to order tests for and when to order them.
  • Advanced imaging such as MRIs, CT scans, or pressure-specified sensorimotor devices are not needed to make the diagnosis of carpal tunnel syndrome.

    The full details of each recommendation are published in this guideline. The authors provide a grading system for each guideline to show what level of evidence the guideline was based on. The grades include A for good evidence, B for fair evidence, C for poor-quality evidence, and I for insufficient evidence.

    Knowing how strong the evidence is for each guideline helps physicians decide how closely to follow each guideline. Some patient circumstances or factors may require a different approach to treatment. In cases where the evidence is lacking, the physician can make changes to the treatment protocol based on those individual differences rather than follow the guidelines exactly.

    The recommendations begin with the importance of an accurate patient history. Questions must be asked about the symptoms (e.g., duration, severity, location). Previous treatment, lifestyle and activities, and any limitations in function due to symptoms are also recorded. Most of the material in this section is based on expert opinion rather than actual evidence. In other words, physicians agree that the patient history is very important but studies to prove which pieces of data have the most value haven't been done.

    The physical exam should include age, gender, weight and height, and range-of-motion and strength of the wrist and hand. Special tests for sensation, vibration, nerve irritation can be performed. Any obvious muscle atrophy (wasting) or other deformities should be noted. There are a variety of tests physicians already use to help identify the presence of carpal tunnel syndrome (e.g., Phalen's, Tinel's, reverse Phalen). But the authors say that there really isn't strong evidence to support the use of one test over another. This is an area where future research could be very helpful.

    Studies show that when the physician takes the clinical picture (signs and symptoms reported by the patient) and adds it to the results of clinical tests and electrodiagnostic tests, the diagnosis is more likely to be accurate. The combination of this data also makes it easier to formulate a plan of care. Again, more research is needed to find out which tests give the most accurate information and can be relied on to make the diagnosis.

    When it comes to electrodiagnostic testing, patients with numbness that doesn't go away and/or who have muscle wasting of the thumbpad should have nerve conduction velocity (NCV) and electromyography (EMG) done. Both of those symptoms suggest severe nerve injury. Once this has been confirmed, then treatment can be determined. NCV and EMG have been able to sort out carpal tunnel from other nerve problems. But this isn't true for all cases. Evidence in this area is graded C for poor-quality.

    Some people may find it surprising that the committee recommended against routinely ordering MRIs or CT scans. But there just wasn't any evidence to show that advanced imaging provides anything more than the history and exam could obtain. Likewise, the routine use of pressure-specified sensorimotor devices (PSSDs) couldn't be justified either.

    The authors conclude by making note of the fact that high quality evidence for the diagnosis of carpal tunnel syndrome is lacking at this time. These guidelines should be used with that in mind. Researchers thinking about conducting future studies are encouraged to think about ways to design a study that avoids bias based on physicians' opinions and preconceived ideas about the diagnosis and treatment of carpal tunnel syndrome. Blinded controlled trials are preferred over case-control studies.

    There is a need to compare the costs of carpal tunnel syndrome diagnosis and treatment. With the recent focus on health care reform and rising costs of health care, attention to direct and indirect costs of care for all conditions (including carpal tunnel syndrome) is important. Future studies with a sound design will include cost analysis to help determine the cost burden of carpal tunnel syndrome.
    References
    Michael Warren Keith, MD, et al. AAOS Clinical Practice Guideline Summary. Diagnosis of Carpal Tunnel Syndrome. June 2009. Vol. 17. No. 6. Pp. 389-396.