Tuesday, May 31, 2011

My 50-year-old father has numbness in his left small finger. My friends believe he has carpal tunnel syndrome. Is that accurate?

Hand Surgeon, Ryan Calfee, MD:
There are actually several common nerve compression syndromes in the upper extremity. Family and friends of individuals with numbness and tingling in the hand, often suggest carpal tunnel syndrome. However, your father's symptoms are more likely related to compression of the ulnar nerve.

Carpal tunnel syndrome, the most common upper extremity nerve compression syndrome, is produced when the median nerve is compressed at the wrist. Patients with carpal tunnel syndrome may note that the thumb, index, and middle fingers feel "asleep." They may drop small items, and awaken at night feeling the need to shake out the hand to regain feeling.

In contrast, the ulnar nerve provides the sensation to half of the ring finger and the small finger. It also controls many of the small muscles within the hand. The ulnar nerve can be compressed at the elbow (most common) and at the wrist. The ulnar nerve courses around the back of the elbow where, when struck, it is responsible for the common complaint that, "I hit my funny bone." Ulnar nerve compression at the elbow is termed cubital tunnel syndrome. Numbness and tingling in the small and ring fingers is characteristic of ulnar nerve compresion. Individuals may also note atrophy of the hand muscles and difficulty bringing the small finger together against the other digits.

The diagnosis of cubital tunnel syndrome is based upon patient history, physical examination, and electrodiagnostic studies, which test the nerves ability to transmit sensory and motor signals.

Once diagnosed, treatment is dictated by the severity of compression. Mild nerve irritation can be effectively managed with bracing designed to avoid full bending of the elbow and activity modification. As the nerve becomes more involved, surgery can be performed to release the tissues that are compressing the nerve or even to move the nerve to a more protected location in the front of the elbow. Current medical literature indicates that such surgery is largely successful although severe cases may realize only a halting of disease progression as opposed to a complete reversal of symptoms.