Carpal tunnel syndrome (CTS) causes pain and/or numbness into the hand and because it’s so common, CTS is often the first and the last diagnosis a doctor makes when a patient presents with these symptoms. The purpose of this article is to consider other conditions that present in a similar way and if not treated correctly, may result in a poor post-treatment result.
In order to understand what CTS is, it’s important to learn about where the nerves originates. The nerves to the hand start in the neck and merge together like 5 lanes of traffic (C5 to T1 nerve roots exiting the spine) into 3 primary lanes (called "cords") that give rise to smaller roads and eventually continue into the arm as 3 primary nerves (the ulnar, median, and radial nerves).
In their journey into the arm, they travel through tight openings (some of which are called tunnels) at various places which include: the neck (the anterior scalene triangle made up of muscles); the thoracic outlet (in the shoulder where the collar bone, first rib, and shoulder blade come together with multiple muscle attachments); the elbow which has 3 tunnels -- the cubital tunnel located on the inner side (palm facing forwards) often referred to as the "funny bone," where the ulnar nerve travels (which brings strength and sensations to the pinky side of the forearm, hand and 4th and 5th fingers), the pronator tunnel located in the middle of the elbow where the median nerve travels (bringing strength and sensations to the middle 3 fingers – digits 2, 3, and thumb side of digit 4); and the radial tunnel located on the thumb side outer elbow where the radial nerve travels (which strength and sensations to the thumb and back half of the index finger); and finally the wrist, which also has 3 tunnels for the same 3 nerves: tunnel of Guyon on the pinky side (ulnar nerve), the carpal tunnel in the middle of the wrist (median nerve), and the radial tunnel at the "anatomical snuff box" for the radial nerve for thumb and back side of digit 2/index finger).
Therefore, when we consider all the places where nerves can get pinched, it’s no wonder why the entire area MUST BE thoroughly evaluated BEFORE agreeing to a surgical procedure for CTS or any other peripheral neuropathy. A nerve can get pinched anywhere if a fracture or blunt trauma occurs. The challenge occurs when there isn’t an obvious injury like a fracture and we have to systematically check each of the many "tunnels" that exist in the neck, shoulder, elbow and wrist as described above.
The "take home message" here is don’t rely on a quick exam where the healthcare provider barely touches you and quickly diagnoses CTS based on your history of numb hands. Because it’s the most common of the upper extremity peripheral neuropathies, this is frequently assumed and is probably the explanation for those who fail post-surgically. To complicate matters, diabetes and other conditions can create similar symptoms and more than one area may become compressed, requiring treatment in multiple areas.
