You awaken at night with a numb hand that you shake to wake up. You are sitting at your desk, trying to ignore the tingling in the hand when you suddenly have a sharp pain. Are these just normal signs of aging, or do you have carpal tunnel syndrome?
Carpal tunnel syndrome is compression of the median nerve at the wrist. Nerves control movement and feeling. The median nerve is one of the major nerves in the hand. The median nerve innervates the thumb, index and middle fingers as well as half of the ring finger. Typically with carpal tunnel syndrome the symptoms are in some or all of these fingers. However, it can also feel as if the entire hand is involved.
Most people believe that carpal tunnel syndrome has to be work related. That a person has to do typing or some type of repetitive activity, such as working on an assembly line, to develop carpal tunnel syndrome. This is not true. Carpal tunnel syndrome is the most common pinched nerve in the general population. In most patients it is a general health issue and is not work related. Common risk factors include being female, age over 40, pregnancy, rheumatoid arthritis, prior wrist fracture, diabetes or hypothyroidism.
The typical first symptom of carpal tunnel syndrome is numbness or tingling in the hand at night. People will shake their hand to awaken it, and not think that anything serious is occurring. As time goes on the numbness becomes more frequent and intense at night, and can also occur during the day with activity such as driving or styling hair. This can progress to pain, constant numbness, electric shocks, weakness and loss of dexterity and function in the hand. Most commonly this occurs in the dominant hand.
However, carpal tunnel syndrome does not always do what is expected or follow the rules. The symptoms can be worse in the non-dominant hand or can be in both hands. I also have had a number of patients who were right handed, and the first sign of carpal tunnel syndrome was that they woke up in the middle of the night with left arm pain and numbness extending up to the shoulder, and go to the emergency room thinking that they are having a heart attack or a stroke.
The carpal tunnel is a narrow tunnel at the wrist that is designed to protect the median nerve. Inside the tunnel are the median nerve and the tendons that flex our fingers. Anything that thickens the tendon sheath inside the tunnel can pinch on the nerve. Anything that narrows the tunnel such as a prior wrist fracture or arthritis, can pinch on the nerve.
Testing for carpal tunnel syndrome is done by clinical examination and by an EMG (electromyography) test. There are other nerves in the arm that can be pinched, and a pinched nerve in the neck can also cause hand numbness. Sometimes people have a combination of nerve issues present at the same time. Therefore EMG studies are very important to help with accurate diagnosis.
Nonsurgical treatment for carpal tunnel syndrome includes wearing a wrist splint at nighttime or a cortisone injection. The carpal tunnel has the most room for the median nerve when the wrist is straight. If the wrist is flexed or extended, the pressure on the nerve increases. Sleeping in a wrist splint allows the nerve to rest in the optimal position, and for mild carpal tunnel symptoms can be very helpful. Cortisone injections may be temporary. NSAIDS and stretching exercises are not effective.
Surgery is the definitive treatment for carpal tunnel syndrome. Surgery is indicated if there is constant numbness, pain, muscle weakness, loss of hand function, or if the EMG demonstrates moderate or severe carpal tunnel. Failure to pursue surgery, or waiting too long to do the surgery, can result in permanent nerve damage.
Numb hands are not normal and can occur from a variety of causes, some of them are quite serious. It is important to seek medical evaluation to avoid permanent nerve injury.
Dr. Katharine Leppard is with Medical Rehabilitation Specialists and may be reached at 719-575-1800