October 01, 2018

Carpal tunnel syndrome

Protecting hand nerves

Carpal tunnel syndrome can cause numbness, burning or tingling in the hand, and in the thumb, index, middle and half of the ring finger. Symptoms may occur in both hands, but are usually worse in one.

Carpal tunnel

In the past few months, waking up in the morning has required waking your hand up too. There's numbness and tingling and you need to shake your hand to make it subside. Now you're getting the sensation during the day — such as when reading the paper, holding your cellphone or even during driving — and your hand sometimes aches. Just last night, the discomfort woke you from sleep.

Symptoms such as these are typical of carpal tunnel syndrome, a common disorder in which one of the main nerves (the median nerve) providing sensation to much of the hand is compressed in the wrist.

No wiggle room

The wrist has eight bones, called carpal bones. These form the bottom and sides of a narrow passageway on the palm side of the wrist. The palm side of the passageway is created by a strong band of connective tissue (transverse carpal ligament).

The median nerve originates from a combination of nerves in the neck region and passes down the arm, through the carpal "tunnel" and into the hand. Also passing through the carpal tunnel — which is about an inch wide — are nine tendons that control finger movement. A lubricating membrane (synovium) covers these tendons.

The nerve branches out in the hand, providing sensation to part of the palm and to every finger but the small (pinkie) finger and half of the ring finger.

Compression risk

Carpal tunnel syndrome is caused by compression of the median nerve as it passes through the...