Carpal Tunnel Syndrome

The carpal tunnel is formed by the wrist bones and a tough ligament holding them together called the transverse carpal ligament. The median nerve passes between the carpal bones and the ligament on the way to the hand. The wrist bones are concave, so the carpal tunnel is shaped like a half moon. Some people have a shallow or flat tunnel that predisposes them to get compression of the nerve in the wrist. Repetitive use of the hands and wrists can cause symptoms. Some diseases, such as low thyroid, can also cause it. For a discussion, see: www.medscape.com/features/slideshow/carpal-tunnel-syndrome?src=ptalk&uac=140674AR

Initial treatment is rest and meds by mouth, such as Advil or prednisone. I never inject cortisone for fear of damaging the nerve. For a brief discussion of treatment options, see: http://www.medscape.com/medline/abstract/19782873?cid=med&src=nlbest

Surgery is usually very effective, but has one big risk – damage to the recurrent motor branch to the thumb. That branch allows you to oppose your thumb against the other fingers and grasp objects, which only humans can do. Apes (simians) can’t do that. The motor branch has been called the million dollar nerve, as it allows us to write, sew, play clarinet, do surgery, etc. Without it, we have a simian hand. The motor branch can come off in unusual places, and can even run through the transverse carpal ligament, so the safest operation is “open” exposure to see what is being cut. The minimally invasive methods are more risky. If you look at your palm and stick your thumb out at 90 degrees, the incision would be in the middle of the palm from just past the fleshy part of the thumb to just across the wrist.