It is possible to experience Carpal Tunnel Syndrome (CTS) and Cubital Tunnel Syndrome (CuTS) at the same time. This concurrent diagnosis involves two common nerve entrapment conditions affecting the upper limb. CTS involves the median nerve at the wrist, while CuTS involves the ulnar nerve at the elbow.
Understanding Carpal Tunnel Syndrome and Cubital Tunnel Syndrome
Carpal Tunnel Syndrome results from the compression of the median nerve as it passes through the carpal tunnel in the wrist. This compression causes symptoms in the thumb, index, middle, and the thumb-side half of the ring finger. Symptoms often include numbness, tingling, and pain that frequently worsens at night or during repetitive wrist motion.
Cubital Tunnel Syndrome involves the ulnar nerve, which travels through the cubital tunnel on the inside of the elbow. Compression or irritation of this nerve leads to symptoms in the little finger and the little finger-side half of the ring finger. Complaints include numbness, tingling, and pain on the inner side of the elbow that can radiate down the forearm and hand. If severe, both conditions can eventually lead to weakness in hand grip and muscle atrophy.
The Mechanism of Coexisting Nerve Compression
The simultaneous occurrence of these two distinct nerve compressions is often explained by “Double Crush Syndrome.” This theory suggests that a nerve compressed at one location becomes more vulnerable to compression at a second, more distant site. The initial compression compromises the overall health of the nerve, making it more susceptible to damage elsewhere.
This increased vulnerability is due to the impairment of axonal transport. Axonal transport moves essential nutrients and materials up and down the length of the nerve cell’s axon. When a nerve is compressed, this system is disrupted, weakening the nerve’s ability to repair itself and maintain function at distal sites.
While the “double crush” concept originally described compression of the same nerve at two points, the principle applies to multiple peripheral nerves in the same limb. A generalized susceptibility, often due to systemic conditions like diabetes or inflammation, can predispose both the median and ulnar nerves to entrapment at their respective common sites. Underlying systemic or mechanical factors can make both nerves prone to compression in the same individual.
Diagnosing Concurrent Nerve Issues
Identifying both Carpal Tunnel and Cubital Tunnel Syndromes is challenging because their symptoms can overlap or mimic other conditions. A medical professional begins with a thorough physical examination designed to isolate the function of each nerve. This includes provocative maneuvers like Phalen’s maneuver, which involves holding the wrists in a flexed position to reproduce median nerve symptoms.
The examination also includes checking for Tinel’s sign, which involves lightly tapping over the nerve at the site of potential compression (wrist for the median nerve or elbow for the ulnar nerve). To distinguish between the two, the physician tests the strength of specific hand muscles innervated by either nerve. For example, the strength of the muscle that pulls the thumb away from the palm indicates median nerve function.
Electrodiagnostic testing is the definitive tool for confirming the diagnosis and determining the severity of compression. This testing includes nerve conduction velocity (NCV) studies and electromyography (EMG). NCV studies measure how quickly electrical signals travel down the median and ulnar nerves, while EMG assesses the electrical activity in the muscles supplied by those nerves. These tests pinpoint the exact location and degree of entrapment for both the median nerve at the wrist and the ulnar nerve at the elbow simultaneously.
Management of Dual Nerve Compression
The initial approach to managing concurrent Carpal Tunnel and Cubital Tunnel Syndromes involves conservative, non-surgical treatments aimed at reducing pressure and inflammation on both nerves. Activity modification is recommended, including avoiding prolonged elbow flexion and repetitive wrist movements. Night splinting is a common measure, utilizing a wrist splint for the median nerve and an elbow brace to prevent excessive bending of the ulnar nerve.
Anti-inflammatory medications, such as non-steroidal anti-inflammatory drugs (NSAIDs), may reduce swelling around the compressed nerves. Corticosteroid injections can be administered directly into the carpal tunnel or around the ulnar nerve at the elbow for focused relief from inflammation. When symptoms are severe, progressive, or fail to improve after non-surgical management, surgical intervention becomes necessary.
The surgical strategy for dual compression often involves a simultaneous approach, releasing both the median and ulnar nerves in the same operation. This dual procedure typically includes a Carpal Tunnel Release and a Cubital Tunnel Release, or ulnar nerve transposition. Studies show that a combined release is a safe and effective option, resulting in significant improvement in pain and numbness for patients.