Other Nerve Compression Syndromes
As well as carpal tunnel syndrome there are a number of other areas of nerve compression in the arm. These all occur at points where there is compression of nerve against unyielding structures or excessive movement of nerves through normal structures. Each of these conditions will cause symptoms similar to carpal tunnel syndrome, with pain, numbness and tingling in the hand and fingers, which can progress to permanent muscle weakness and loss of feeling. Many of these syndromes must be differentiated from carpal tunnel syndrome by their clinical features – and this is where it’s essential to be diagnosed by an experienced hand surgery specialist such as Dr. Hamilton. They include:
Pronator Syndrome (Median Nerve)
Here the median nerve is compressed between muscles and a fibrous band in the forearm causing symptoms similar but not identical to Carpal Tunnel Syndrome.
Cubital Tunnel Syndrome (Ulnar Nerve)
Cubital Tunnel Syndrome is a nerve compression syndrome affecting the ulnar nerve at the elbow. Its symptoms are tingling and numbness mainly of the little finger and inner side of the hand. Initially the symptoms are intermittent but with progression there is weakness of the small muscles of the hand resulting in clumsiness and reduced hand dexterity. The symptoms are usually caused by overuse with cumulative trauma resulting in scarring around the nerve, a reduction of natural nerve glide on elbow movement, and eventually to nerve compression, due to inflammation and swelling of the nerve, often called ‘ulnar nerve neuritis’. (It should also be noted that the ulnar nerve can also be compressed in the wrist beside the carpal tunnel. The presentation in this situation is of an ulnar nerve palsy, with the characteristic claw hand and sensory loss in little and ring fingers and the inner side of the hand.)
Treatment of severe ulnar neuritis at the elbow caused by repetitive injury is by surgical decompression of the ulnar nerve in the cubital tunnel. Dr Hamilton’s favoured technique is to decompress the ulnar nerve by opening the sheath over the nerve and removing the prominent ‘funny’ bone, rather than transposition of the inflamed nerve, which is a more radical approach.
Radial Nerve Compression Conditions
Radial Nerve Entrapment Syndromes occur from compression of this nerve in the proximal forearm.
Superficial radial nerve syndrome occurs where the nerve passes between two extensor muscles in the forearm, and results in pain and numbness over the first web of the hand. It is aggravated by rotation of the hand and can be difficult to distinguish from DeQuervain’s disease. Surgical treatment involves surgical release of the nerve.
Posterior interosseous nerve compression PIN occurs when this branch of the nerve is trapped in the radial tunnel (between the two heads of supinator muscle and a fibrous band), just below the elbow on the outer side. It is aggravated by resisted rotation of the arm and hand and is presents with tenderness over the nerve just below the elbow, pain in the forearm and eventually weakness of finger extension. It can be difficult to distinguish from tennis elbow. Again treatment revolves surgical decompression of the nerve, one of Dr Hamilton’s special procedures.
Muscle-Tendon Overuse Syndromes
Under normal circumstances, the friction produced by a healthy tendon gliding through normal tissues is minimal, as synovial fluid lubricates the tendon and the pulley systems. However, injury to the tendon and abnormal repetitive stress can cause permanent damage resulting in triggering or locking of the digit. Treatment of the many types of tendonitis may be conservative, but hand surgery is necessary to release constrictions or inflamed muscular insertions in certain circumstances.
Trigger Finger and Trigger Thumb (stenosing tenosynovitis of flexor tendons)
Trigger Finger, or Trigger Thumb, is the most common tendonitis involving the flexor tendon as it passes through the fibrous sheath pulley in the palm to enter the digit. Inflammatory swelling of the tendon and pulley causes restriction of the digit movement resulting in triggering, or even locking, so that the finger can no longer be straightened. Trigger Finger is usually best treated by surgical release under local or sedation anaesthetic at Hamilton House Day Surgery.
DeQuervain’s Disease (stenosing tenovaginitis of extensor tendons)
DeQuervain’s Disease is a tenosynovitis of the extensor and abductor tendons of the thumb in the first dorsal compartment of the wrist. The inflammation and compression is due to repetitive movement of the thumb, and is seen most frequently in mothers nursing young babies. Excessive gliding of the tendons causes stress and inflammation resulting in a tenosynovitis that restricts motion and causes intense pain. Diagnosis is confirmed by tenderness over the first dorsal compartment and a positive von Finkelstein’s test. Dr. Hamilton can reduce pressure on the thumb’s tendon by opening and releasing the sheath at the base of the thumb, followed by 9 days splinting. This can be performed as a small local or sedation anaesthetic day case procedure at Hamilton House.
Tennis Elbow (Lateral Epicondylitis)
Tennis Elbow involves a degenerative tendonitis of the extensor muscle attachment on the lateral bony prominence of the elbow. The condition is caused by repetitive elbow and wrist movement producing stress around tendons in the forearm, classically affecting tennis players, but also many repetitive workers. Treatment is initially nonsurgical involving rest, splinting and cortisone injections. Hand surgery is usually reserved for the more resistant situations and involves detaching the tendon from the bony epicondyle under general anaesthetic at Hamilton House Day Surgery.