Carpal Tunnel Syndrome is a debilitating condition that affects over 8 million Americans, but often similar symptoms mistaken for CTS are attributed to an incomplete examination of the additional structures that may compress the median nerve. An incorrect diagnosis can leave sufferers to face an unnecessary surgery, only to be provided with no relief.
The Carpal Tunnel is a structural canal in the wrist formed by the 8 carpal bones and the transverse carpal ligament, permitting the passage of 9 flexor tendons, blood vessels, and the Median Nerve, which allows function, circulation and sensation to the palm and fingers . True Carpal Tunnel Syndrome involves a compression of the Median Nerve inside of the Carpal Tunnel caused by a narrowing of the space inside the canal. This can be caused by inflammation of the tendons, fluid retention, wrist injuries, bone spurs, pregnancy, and repetitive wrist motions.
The Median Nerve is one of the 5 main nerves stemming from the brachial plexus. It is responsible for both sensory and motor function; therefore a compression anywhere along the nerve may cause a deficit in sensation, movement, or both, down the length of the nerve. Median Nerve Entrapment is often misdiagnosed as Carpal Tunnel Syndrome. They share the same symptoms; numbness, tingling and weakness of the wrist, hand, thumb and first 3 fingers. The difference between the two is the location of the compression.
There are 8 sites along the median nerve's pathway, including the carpal tunnel, where an impingement can take place:
1. Beginning at the spinal cord, the Median Nerve may become impinging at the cervical spine at the level of C5-T1. Bone spurs, small growths or tumors, and vertebral misalignments are responsible for pressing on the on the nerve. In this case, a realignment of the vertebrae will take the pressure off the nerve root.
2.4. Following the Median Nerve's pathway, compression may take place between the middle and anterior scalene, between the clavicle and the first rib, or under the pectoralis minor tendon against the coracoid process. These three compression areas may have a complication of something more accurately called Thoracic Outlet Syndrome. TOS may also present with reduced circulation in the arms and hands, neck or shoulder pain, or paresthesia in the neck, shoulder, arms and hands. Poor posture, trauma, or repetitive motions could have been the cause of this condition. After a detailed evaluation, the TOS can be treated with chiropractic adjustments, soft tissue manipulation, physical therapy and stretching exercises.
5. The next area where the Median Nerve can become impinged is just proximal to the elbow along the medial epicondyle and humeral shaft. Although uncommon, a purposeless structure called the Ligament of Struthers found in less than 3% of the population may be the source of compression in this area. Surgical release of the ligament has been proven effective in this case.
6. The bicipital aponeurosis, or lacertus fibrosis, is a fibrous tissue that connects a small portion of the biceps brachii to the ulna. The Median Nerve could become compressed here, more likely while the biceps are contracted. Surgically releasing the thickened fibrous tissue can relieve pressure on the nerve.
7. Moving distally from the elbow, as the Median Nerve runs between the two heads of the pronator teres it may become compressed here in a painful condition called Pronator Teres Syndrome. Pressure on the nerve is caused by repetitive movement of the pronator teres or trauma to the elbow.
A similar condition called Anterior Interosseous Syndrome shares a similar presentation to Pronator Teres Syndrome. The Anterior Interosseous Nerve is a branch of the Median Nerve, and controls motor function to the flexor pollicus longus, pronator quadratus, and the lateral portion of the flexor digitorum profundus. As a result, a weakness in the first 3 fingers will present when compromised. Performing the Pinch-Grip Test should confirm both of these assessments.
Courses of action for Pronator Teres Syndrome and Anterior Interosseous Syndrome include massage therapy and bodywork, ultrasound therapy, corticosteroid injections, and non-steroidal anti-inflammatories.
8. The final compression site of the Median Nerve, as indicated earlier, is the carpal tunnel. Performing Phalen's Test will confirm that the nerve impingement is coming from the carpal tunnel. Manual circulation of the area can reduce water retention in the area, and immobilization splints to keep the wrist from flexing are helpful in keeping pressure off the nerve. Corticosteroid injections and NSAIDs can effectively provide relief by reducing inflammation in the area. In several cases, a surgical procedure is indicated.
A thorough examination by your health care provider should narrow down the cause of this intolerable neuropathy. Several tests, including Phalen's Test, the Pinch-Grip Test, and Tinnel's Test, as well as X-rays and MRI's, can be implemented to find the focal point of the Median Nerve Entrapment, allowing the compression to be properly trated.