Carpal Tunnel Syndrome (CTS) is often misunderstood, leading many people to self-diagnose incorrectly. CTS is defined as the compression of the median nerve as it passes through the narrow carpal tunnel in the wrist. This nerve supplies sensation primarily to the thumb, index finger, middle finger, and the thumb-side half of the ring finger. Typical symptoms include pins-and-needles, burning, and pain that frequently worsens at night. Many other conditions mimic this discomfort but originate from different anatomical locations and require different treatment strategies.
Nerve Compression in the Elbow and Forearm
Several conditions involve nerve compression closer to the torso than the wrist, producing similar symptoms in the hand. The body’s three main nerves—median, ulnar, and radial—can be compressed at various points, challenging accurate diagnosis.
Cubital Tunnel Syndrome involves the ulnar nerve (the “funny bone” nerve) as it passes through a groove on the inside of the elbow. Compression causes numbness and tingling in the little finger and the corresponding half of the ring finger, distinct from the median nerve distribution in CTS. Symptoms often include shooting pain from the elbow down to the fingers and worsen when the elbow is bent for long periods, such as while sleeping or driving.
Radial Tunnel Syndrome involves the radial nerve as it passes through a narrow space near the elbow and down the forearm. This typically causes an aching or deep pain in the outer forearm, often mistaken for tennis elbow. Radial tunnel syndrome may not cause the characteristic numbness and tingling of CTS. The pain is the predominant symptom, often lacking the sensory loss associated with other nerve entrapments, and is generally worsened by activities involving twisting the forearm or lifting heavy objects.
Symptoms Referred from the Neck and Upper Torso
Symptoms felt in the hand and wrist can be referred pain, originating where the nerves exit the spinal cord. Cervical Radiculopathy occurs when a nerve root in the neck is irritated or compressed, often due to a herniated disc or degenerative changes. Since the nerves forming the median nerve originate in the neck, root irritation can mimic the numbness and tingling of CTS in the hand and fingers.
A key differentiator is that radiculopathy pain often begins in the neck or shoulder and radiates down the arm, described as a sharp, burning, or electric-like sensation. Neck movement, such as turning or extending the head, often exacerbates the symptoms, which is not true for CTS. The specific pattern of numbness and weakness depends on which cervical nerve root is affected.
Thoracic Outlet Syndrome (TOS) involves the compression of the neurovascular bundle (nerves and blood vessels) as they pass between the collarbone and first rib. The nerve-related form of TOS compresses the brachial plexus, causing numbness and tingling in the hand. This often affects the little finger and ring finger side, similar to cubital tunnel syndrome. TOS symptoms frequently include a general ache, heaviness, or weakness in the entire arm and hand, typically aggravated by activities requiring the arm to be raised overhead.
Conditions Affecting Tendons and Joints
Conditions causing localized inflammation or joint damage in the wrist can present with pain confused with CTS, though they are not neurological. De Quervain’s Tenosynovitis is an inflammatory condition affecting the tendons on the thumb side of the wrist. It involves the sheath surrounding two tendons responsible for moving the thumb, causing localized pain and swelling near the base of the thumb.
The primary symptom is tenderness and pain with movement, particularly when grasping or pinching objects. The pain does not follow the median nerve distribution. While pain may radiate up the forearm, the absence of typical numbness and tingling distinguishes it from CTS.
Wrist Arthritis causes pain and stiffness due to damaged joint cartilage or joint lining inflammation, rather than nerve compression. Arthritic pain is often symmetrical, affecting both hands, and is accompanied by stiffness that is worse in the morning or after inactivity. Unlike CTS, arthritis causes visible joint swelling, tenderness, and a gradual loss of range of motion. Distinguishing these causes requires proper medical evaluation, as treatment for nerve compression is ineffective if the source is an inflamed tendon or an arthritic joint.