Carpal Tunnel Syndrome

Question 1

Provide a brief description of Carpal Tunnel Syndrome (including complaints, findings and treatment options)

Answer 1

Carpal Tunnel Syndrome (CTS) is an entrapment neuropathy due to compression of the median nerve as it passes through the carpal tunnel. The tunnel is at the base of the palm, right above the wrist. It has four sides: 3 of which are carpal bones and the 4th side/top of structure being the transverse carpal ligament.

The key clinical point is based on the anatomy: the signs and symptoms must be in the median nerve only; and they need to be related to targets of the median nerve distal to the tunnel itself. That is, objective median nerve function in the forearm should not be affected.

Carpal Tunnel Syndrome occurs most commonly in patients between 30-60 years of age; more common in females.

Risk/causative factors: POSITIONAL (this may be why typing a lot causes symptoms); increases in contents of canal ( fractures synovitis); neuropathic conditions (DM); inflammatory conditions (RA, gout); alterations of fluid balance (pregnancy, menopause, , thyroid disorders); and external forces (jackhammer?).

The chief complaints are numbness and paresthesias in the anatomic distribution of the median nerve: radial 3 ½ fingers (thumb, index, middle, and radial side of ring). Patients may experience pain radiation proximally into the forearm.

A common early complaint is awakening in the night due to numbness or pain in these fingers (night-time worsening). Patients may also complain of swelling in the hands, dry skin, and cold hands (less common symptoms).

Later, patients may report constant numbness, motor disturbances, and decreased strength (tendency to drop objects)

Exam findings: the exam may show: Nothing; Weakness of the thenar intrinsic muscles (clinically tested by abduction of thumb against resistance); Diminished sensation to pin prick in the median nerve distribution; a Positive Phalen test or Tinel’s test (not “sign”); or any combination thereof.

EMG would likely show focal slowing of conduction velocity in median nerve across carpal tunnel.
There are many treatment options for individuals with CTS, and the treatment choice depends on the severity of the nerve dysfunction, patient preference, and availability. Non-operative treatment options include: rest, wrist splinting, NSAISDs, and oral steroids or corticosteroid injections.

In patients who do not respond to more conservative treatment modalities or in patients with signs of atrophy or muscle weakness, carpal tunnel release–cutting the transverse carpal ligament –can be considered. This surgery is performed to decrease pressure on the median nerve.

Obviously if there is a precipitating cause (like a wrist fracture) that cause should be addressed expeditiously

Question 2

Cervical radiculopathy is certainly on the differential diagnosis in a patient with suspected Carpal Tunnel Syndrome. Think of some other entries on that list as well. What complaints would make you think that a patient has one of these, and not Carpal Tunnel Syndrome?

Answer 2

The differential diagnosis for carpal tunnel syndrome includes:

C6 or C7 radiculopathy. (With radiculopathy expect to see neck pain and pain proximal to the wrist)

Osteoarthritis. This may exist concurrently occur with CTS, but would see tenderness and crepitus on exam (and EMG would also be normal unless CTS co-exists)

Ulnar neuropathy Just like CTS but wrong nerve! The sensory symptoms are on the medial aspect of the hand, distal forearm and 4th and 5th fingers (instead of radial 3 ½ finders). No thumb weakness.

De Quervain tenosynovitis: Extensor tendinitis of the thumb. With this, tend to see pain with movement of thumb along with tenderness near the radial styloid. EMG is normal (unless CTS co-exists)

Question 3

Tinnel’s sign is not a true sign—in what way? Why might that be significant?

Answer 3

Tinel’s test is performed by tapping over the median nerve as it passes through the carpal tunnel in the wrist. A positive response is a sensation of tingling in the median nerve distribution over the hand.

This is not a sign because it reports a subjective sensation. Signs are objective. The response to a Tinel’s test might better be termed a “wign”, defined as a subjective reaction to a provocative examination maneuver deemed to have some valid relationship to the underlying pathology.

This word is pronounced “whine” to remind us it is a spoken response, and its spelling echoes that of sign, reminding us likewise a wign might be more specific that than a complaint.

The distinctions between sign, symptom, and wign are worthy of preservation: treatments offered on the basis of signs can be said to be most rigorously indicated, as symptoms, unlike signs, pass through (and are affected by) the prism of patients’ perceptions.

Remaining skeptical about the value of information provided by our patients is in the interest of these patients, as our skepticism might save them from unnecessary treatments and procedures.