How Carpal Tunnel Syndrome Is Diagnosed

carpal tunnel diagnosis
© Verywell, 2018 

If you have carpal tunnel syndrome (CTS), then you may understand how the symptoms can affect your everyday work and recreational activities. The pain, tingling, and weakness in your hand or fingers may keep you from typing on your computer, writing, or holding items. And one of the most challenging characteristics of carpal tunnel syndrome: getting an accurate diagnosis.

Getting an accurate diagnosis of your hand pain and tingling can ensure that you get the proper treatment for your specific condition. So how is carpal tunnel syndrome diagnosed, and how do you know that the diagnosis you get is the right one?

Self-Checks/At-Home Testing

The symptoms of CTS are caused by compression of your median nerve as it crosses from your forearm into your wrist. This area, called the carpal tunnel, contains several tendons and vascular structures along with the median nerve. (Carpals are wrist bones, and they form the roof of the tunnel.)

One of the simplest self-tests for CTS involves analyzing and understanding your symptoms. Symptoms of carpal tunnel syndrome may include:

  • Pain in your wrist and forearm
  • Pain in your thumb, index finger, and middle finger
  • Tingling in your thumb, index, and middle finger
  • Weakness in your hand

Carpal tunnel syndrome is considered a repetitive stress injury. That means that it is caused by some motion or motions that are repeated over and over again. For this reason, symptoms tend to come on gradually and with no specific injury. Symptoms are usually worsened by excessive computer work that involves using the mouse and typing. Other repetitive tasks like writing may cause CTS.

So your first inkling that you may have CTS is the nature and behavior of your symptoms. Pain, tingling, and weakness in your thumb and first two fingers that is worsened with repetitive hand use is a sign that CTS may be the culprit. If that is the case, it may be time for you to visit your doctor.

Clinical Tests

If you suspect you have CTS, checking in with your doctor is a good idea. After listening to your history and recording your symptoms, he or she may perform specific clinical tests to confirm (or rule out) carpal tunnel syndrome.

Measuring Range of Motion

Your doctor may measure hand and wrist range of motion. Many people with CTS exhibit decreased motion in their wrist. This is due to the swelling of the nerve and tendons that course through the carpal tunnel. This swelling prevents the normal motion from occurring, and a loss of wrist flexion and extension motion may be present.

Tinel's Sign

Tinel's sign involves gently tapping on a nerve to elicit symptoms. Tinel's sign for CTS is done by having your doctor tap over your median nerve near your wrist just above your palm. If this tapping causes pain or tingling in your thumb or fingers, carpal tunnel syndrome may be suspected.

Phalen's Test

Phalen's test involves placing the back of your hands together in front of you with your wrists in extreme positions of flexion. This flexion compresses the carpal tunnel and may cause your symptoms to occur.

Grip Strength

Sometimes, CTS causes loss of strength in your hand or fingers. Your doctor may use a special instrument called a grip dynamometer to measure your strength. Decreased strength in your hand may be a sign of CTS, especially if you are having other symptoms such as pain and tingling in your hand.

EMG

Electromyographical (EMG) testing involves inserting small needles into your arm along the course of your median nerve. These needles may run from your neck and upper arm and into your hand. Once the needles are placed, a small electrical shock will be sent down your arm and into your hand. Specialized instruments will measure the velocity of this electricity. If there is compression of your median nerve, the electrical signal will be slowed as it crosses your wrist, indicating carpal tunnel syndrome.

Getting Your Diagnosis

Sometimes performing these special tests and measures is enough to confirm a diagnosis of carpal tunnel syndrome. Your doctor may then prescribe treatments to help decrease your symptoms and improve your overall function. This may include a referral to physical therapy or occupational therapy.

If your symptoms are severe or if they continue even after actively participating in conservative treatment, more advanced imaging may be performed.

Imaging

Carpal tunnel syndrome is largely diagnosed by examination of your wrist and hand and by the description of your clinical symptoms. Sometimes, more advanced imaging is used to completely diagnose your condition. These images may include:

X-Ray

An x-ray can show your doctor the bones in your forearm, wrist, and hand, and a fracture here may cause some of your symptoms. (Keep in mind a wrist fracture is typically caused by a traumatic event, and CTS usually comes on gradually.)

MRI

Magnetic resonance imaging (MRI) allows your doctor to visualize the soft tissue structures of your wrist and hand. This includes a detailed image of your median nerve, tendons in your wrist, and the ligaments that support your wrist and hand.

CT Scan

A  computed tomography (CT) scan is a three-dimensional image of the bones of your wrist and hand and it may be obtained by your doctor to rule out arthritis or a fracture.

The results of your images, combined with your history and clinical examination, can lead your doctor to definitively diagnose you with carpal tunnel syndrome.

Differential Diagnosis

There are other conditions that may present with similar symptoms to CTS. These may include:

Cervical Radiculopathy

Cervical radiculopathy occurs when a nerve in your neck is compressed by a herniated disc, arthritis, or facet joint problems. This condition may cause pain to travel from your neck and into your arm and hand, mimicking some symptoms of carpal tunnel syndrome.

Ulnar Nerve Compression

Your ulnar nerve travels down your arm and into your hand on the pinky side. (If you have ever baned your elbow on your funny bone, this is really your ulnar nerve.) Your ulnar nerve can be compressed in your elbow and cause tingling and numbness in your hand and ring and pinky fingers. While these symptoms are slightly different from median nerve compression in the wrist, they may be confused with CTS.

Thumb Arthritis

Arthritis may affect your carpometacarpal (CMC) joint of your thumb. This may cause weakness and pain in your thumb and hand, leading you to believe you have CTS.

Wrist Arthritis

Arthritis of your wrist may also cause hand, thumb, and finger pain, which may be confused with CTS.

If you suspect you have carpal tunnel syndrome, it is important that you see your doctor. He or she can perform a thorough clinical examination and order the correct tests to ensure a proper diagnosis. By getting an accurate diagnosis, you can get started on the best treatment for your specific condition.

View Article Sources
  • Hultman, C. S. (2014). The carpal-tunnel syndrome. Seventeen years’ experience in diagnosis and treatment of six hundred fifty-four hands. In 50 Studies Every Plastic Surgeon Should Know (pp. 59-65). CRC Press.