2. How Does Acute Carpal Tunnel Syndrome Cause Nerve Damage?
The wrist is injured more often than is reported in many car accident claims. This is often due to the delay in diagnosis. The wrist is also called the “carpus” in latin, hence the name Carpal Tunnel or wrist tunnel. The carpal tunnel syndrome can be an insidious and progressive injury. Delays in early detection of the injury, and then immediate treatment can lead to median nerve damage. It can take months after an accident before people begin to experience any hand, wrist, and finger symptoms. If the carpal tunnel syndrome goes undiscovered, and is never connected (related) to the auto claim then these car accident victims will never receive any help for their pain, suffering, medical bills, and loss of wages due to their injuries.
In order to understand how carpal tunnel syndrome leads to nerve damage it is important to understand the basic anatomy of the carpal tunnel area.
Anatomy of Carpal Tunnel Syndrome
The carpal tunnel is located on the palm side of the wrist, a little bit off of center towards the thumb. The outer border of the small tunnel is the radius bone. The radius bone goes from the bend of the elbow to bottom of the thumb. The inside border of the tunnel is the ulna bone. This bone goes from the bend of the elbow to the bottom of the pinky side of the wrist. The bottom of the carpal tunnel or floor contains the wrist (carpal) bones. The top of the carpal tunnel is band of ligament.
A number of things go through the carpal tunnel. These things are the median (middle) nerve, some blood vessels and nine muscle flexor tendons. These tendons attach muscles to bones. These tendons control the muscles that flex (bend) the four fingers, and one goes to the thumb.
Car Accident Carpal Tunnel Syndrome (Also Known As Acute CTS) is an injury to the median nerve. This is often due to the wrist being bent, stretched, hit, and/or braced during impact. This in turn causes the inner tendons within the tunnel to become inflamed, swell, and expand which causes a number of symptoms. Inflammation of a tendon is called tendon-itis. Any inflamed area that is swollen is called an “itis” medically. This is a SPACE problem, NOT enough space TOO much pressure.
Following a car accident, injury to any of the inner structures of the tunnel can slowly progress so that it causes increasing pressure upon the median nerve from the swelling of the tendons or surrounding structures. The term “syndrome” merely means a combination of symptoms. In Acute Accident Related CTS the two most common symptoms are pain and numbness in the fingers and hand, particularly in the thumb and first two fingers.
Unfortunately, the first symptoms of Acute CTS may go unnoticed, and thereby undiagnosed. There may only be only occasional numbness and/or a tingling sensation. This tingling may progress to intermittent pain. The consequences of continued pressure and swelling upon the wrist nerve can be permanent damage to the muscles of the hand and wrist. This is because the median (middle) nerve supplies life to the hand (by electrical impulses) and any compression of this area can compromise (block) the flow of life current from the brain to the muscles. In the long term this compression of the median nerve will lead to the muscles of the hand, wrist, and fingers to hypotrophy (shrink and weaken).
3. How Acute Carpal Tunnel Syndrome Gets Discovered?
The most common symptom of Acute CTS is numbness and tingling in the hands. These sensations follow the median (middle) nerve distribution (where the nerve travels) pattern. Symptoms will usually begin in the palm, the thumb, and the first two fingers. Quite often people will be woken up in the middle of the night with their hand or hands asleep months after their accident. Numbness, tingling, or pain in the hands, wrist, or fingers may not start immediately after an accident. When symptoms begin some people may not even think to link it to that event. When people are in car accidents they experience an adrenaline rush which can last for hours. This flood of the body’s numbing chemicals can mask and cover up some of their pain areas. Most paramedics, emergency room staff, and primary care doctors will focus their exams on areas of acute and obvious injury. Injuries to the wrist and hands are commonly overlooked. Unless doctors and/or healthcare providers do a thorough exam and evaluation to specifically to these areas carpal tunnel syndrome may never be diagnosed. In fact, doctors may tell their patients many other reasons for numbness, tingling, or pain in the hands, such as neck or shoulder injury when in fact the person is suffering with undiagnosed CTS. Two main orthopedic tests are used to start a primary diagnosis of Acute CTS. They are Tinel’s Test, and Phalen’s test. In Tinel’s test the median nerve is struck with a doctor hammer (those funny looking triangles) at the base of the wrist. If the test is positive the median nerve should tingle in the areas it goes to. In Phalen’s test, the hands are both brought together (face to face) in hyperextension. This test is positive if it recreates numbness, tingling, or pain along the median nerve distribution. The reason for a positve Phalen’s test is that the carpal tunnel is made smaller (increased compression) when the wrist is hyperextended. Confirmation of the diagnosis of Acute CTS is made using electrical nerve tests such as the NCV/NCS (nerve conduction velocity), and/or EMG (electromyography).