A Patient's Guide to Carpal Tunnel Syndrome
This guide will help you understand
AnatomyWhere is the carpal tunnel, and what does it do?The carpal tunnel is an opening through the wrist to the hand that is formed by the bones of the wrist on the bottom and the transverse carpal ligament on the top. (Ligaments connect bones together.) This opening forms the carpal tunnel. View other anatomy features of the carpal tunnel. The median nerve passes through the carpal tunnel into the hand. It gives sensation to the thumb, index finger, long finger, and half of the ring finger. View area of hand supplied by median nerve. The median nerve also sends a nerve branch to control the thenar muscles of the thumb. The thenar muscles help move the thumb and let you touch the pad of the thumb to the tips each of each finger on the same hand, a motion called opposition. The median nerve and flexor tendons pass through the carpal tunnel. The median nerve rests on top of the tendons, just below the transverse carpal ligament. View median nerve in relationship to the transverse carpal ligament. The flexor tendons are important because they allow movement of the fingers and hand, such as when grasping. The tendons are covered by a material called tenosynovium. The tenosynovium is a slippery covering that allows the tendons to glide next to each other as they are worked. View flexor tendons and tenosynovium. CausesWhat causes carpal tunnel syndrome?Any condition that makes the area inside the carpal tunnel smaller or increases the size of the tissues within the tunnel can lead to symptoms of carpal tunnel syndrome (CTS). For example, a traumatic wrist injury may cause swelling and extra pressure within the carpal tunnel. The area inside the tunnel can also be reduced after a wrist fracture or dislocation if the bone pushes into the tunnel. Other conditions in the body can produce symptoms of CTS. Pregnancy can cause fluid to be retained, leading to extra pressure in the carpal tunnel. Diabetics may report symptoms of CTS, which may be from a problem in the nerve (called a neuropathy) or from actual pressure on the median nerve. People with low thyroid function, called hypothyroidism, are more prone to problems of CTS. The way people do their tasks can put them at more risk for problems of CTS. Some of these risks include:
One of these risks alone may not cause a problem. But doing a task that involves several factors may pose a greater risk. And the longer a person is exposed to one or more risks, the greater the possibility of having a problem with CTS. However, scientists believe that other factors such as smoking, obesity, and caffeine intake may actually be more important in determining whether a person is more likely to develop CTS. In other instances, CTS can start when the tenosynovium thickens from irritation or inflammation. This thickening causes pressure to build inside the carpal tunnel. But the tunnel can't stretch any larger in response to the added swelling, so the median nerve starts to squeeze against the transverse carpal ligament. If the pressure continues to build up, the nerve is eventually unable to function normally. View inflamed and swollen tenosynovium, leading to pressure on the median nerve. Any condition that causes abnormal pressure in the tunnel can produce symptoms of CTS. Various types of arthritis can cause swelling and pressure in the carpal tunnel. Fractured wrist bones may later cause CTS if the healed fragments result in abnormal irritation on the flexor tendons. When pressure builds on the median nerve, the blood supply to the outer covering of the nerve slows down and may even be cut off. The medical term for this is ischemia. At first, only the outside covering of the nerve is affected. But if the pressure keeps building up, the inside of the nerve will start to become thickened. New cells, called fibroblasts, form within the nerve and create scar tissue. This is thought to produce the feelings of pain and numbness in the hand. If pressure is taken off right away, the symptoms will go away quickly. Pressure that isn't eased right away can slow or even stop the chances for recovery. SymptomsWhat does CTS feel like?One of the first symptoms of CTS is gradual numbness in the areas supplied by the median nerve. This is quickly followed by pain where the nerve gives sensation in the hand. The hand may begin to feel like it's "asleep," especially in the early morning hours after a night's rest. Pain may spread up the arm to the shoulder and even to the side of the neck. If the condition progresses, the thenar muscles of the thumb can weaken and atrophy, causing the hand to be clumsy when picking up a glass or cup. If the pressure keeps building in the carpal tunnel, the thenar muscles may begin to shrink (atrophy). Touching the pad of the thumb to the tips of the other fingers becomes difficult, making it hard to grasp items such as a steering wheel, newspaper, or telephone. DiagnosisHow do doctors identify the condition?Your doctor begins the evaluation by obtaining a history of the problem, followed by a thorough physical examination. Your description of the symptoms and the physical examination are the most important parts in the diagnosis of CTS. Commonly, patients will complain first of waking in the middle of the night with pain and a feeling that the whole hand is asleep. Careful investigation usually shows that the little finger is unaffected. This can be a key piece of information to make the diagnosis. If you awaken with your hand asleep, pinch your little finger to see if it is numb also, and be sure to tell your doctor if it is or isn't. Other complaints include numbness while using the hand for gripping activities, such as sweeping, hammering, or driving. If your symptoms started after a traumatic wrist injury, X-rays may be needed to check for a fractured bone. If more information is needed to make the diagnosis, electrical studies of the nerves in the wrist may be requested by your doctor. Several tests are available to see how well the median nerve is functioning, including the nerve conduction velocity (NCV) test. This test measures how fast nerve impulses move through the nerve. Treatment OptionsWhat can be done for CTS?Conservative TreatmentActivities that are causing your symptoms need to be changed or stopped if at all possible. Avoid repetitive hand motions, heavy grasping, holding onto vibrating tools, and positioning or working with your wrist bent down and out. If you smoke, talk to your doctor about ways to help you quit. Lose weight if you are overweight. Reduce your caffeine intake. Wrist BraceA wrist brace will sometimes decrease the symptoms in the early stages of CTS. A brace keeps the wrist in a resting position (not bent back nor bent down too far). When the wrist is in this position, the carpal tunnel is as big as it can be--so the nerve has as much room as possible inside the carpal tunnel. A brace can be especially helpful for easing the numbness and pain felt at night and can keep your hand from curling under as you sleep. The wrist brace can also be worn during the day to calm symptoms and rest the tissues in the carpal tunnel. MedicationAnti-inflammatory medications may also help control the swelling and reduce symptoms of CTS. These include common over-the-counter medications such as ibuprofen and aspirin. In some studies, high doses of vitamin B-6 have been shown to help in decreasing CTS symptoms. Some types of exercises have also shown to help prevent or at least control the symptoms of CTS. If these simple measures fail to control your symptoms an injection of cortisone into the carpal tunnel may be suggested. This medication is used to reduce the swelling in the tunnel and may give temporary relief of symptoms. View injection into carpal tunnel. Cortisone can help ease symptoms and also aids your doctor in making a diagnosis. If you don't get even temporary relief from the injection, it could indicate that some other problem is causing your symptoms. When your symptoms do go away after the injection, it's likely they are coming from within the carpal tunnel. Some doctors feel this is a signal that a surgical release of the transverse carpal ligament would have a positive result. Physical TherapyYour doctor may suggest that you work with a physical or occupational therapist. The main focus of treatment is to reduce or eliminate the cause of pressure in the carpal tunnel. Your therapist may check your workstation and the way you do your work tasks. Suggestions may be given about the use of healthy body alignment and wrist positions, helpful exercises, and tips on how to prevent future problems. Surgical TreatmentIf all attempts to control your symptoms fail, surgery may be suggested to reduce the pressure on the median nerve. Several different surgical procedures have been designed to relieve pressure on the median nerve. By releasing the pressure on the nerve, the blood supply to the nerve improves, and most people get relief of their symptoms. However, if the nerve pressure has been going on a long time, the nerve may have thickened and scarred to the point that recovery after surgery is much slower. The most common procedure is an open-incision technique, but some surgeons are using a newer procedure called endoscopic carpal tunnel release. Using a smaller incision and a fiber-optic TV camera, the doctor is able to see inside the carpal tunnel and release the transverse carpal ligament. Document link: A Patient's Guide to Endoscopic Release for Carpal Tunnel Syndrome ProcedureThe open-incision surgery can be done using a general anesthetic (one that puts you to sleep) or a regional anesthetic. A regional anesthetic blocks the nerves going to only a portion of the body. Injection of medications similar to novocaine are used to block the nerves for several hours. This type of anesthesia could be an axillary block (only the arm is asleep) or a wrist block (only the hand is asleep). The surgery can also be performed by simply injecting novocaine around the area of the incision. Once you have anesthesia, your surgeon will make sure the skin of your palm is free of infection by cleaning the skin with a germ killing solution. A small incision is made in the palm of the hand, usually less than two inches long. In some severe cases, a slightly longer incision is extended into the forearm. The incision makes the palmar fascia visible. This is a sheet of connective tissue in the palm right under the skin. The doctor makes an incision through this material and exposes the transverse carpal ligament. Once in view, the transverse carpal ligament is released using a scalpel or scissors. Care is taken to make sure that the median nerve is out of the way and protected. By cutting the transverse carpal ligament, pressure is taken off the median nerve. Upon releasing the transverse carpal ligament, the surgeon stitches just the skin together and leaves the loose ends of the transverse carpal ligament separated. The loose ends are left apart to keep pressure off the median nerve. Eventually, the gap between the two ends of the ligament fills in with scar tissue. After the skin is stitched together, your hand will be wrapped in a bulky dressing. This surgery can usually be done as an outpatient procedure, meaning you can leave the hospital the same day. RehabilitationWhat should I expect after treatment?If conservative treatment is successful, you may see improvement in four to six weeks. You may need to continue wearing your wrist splint at night to control symptoms and keep your wrist from curling under as you sleep. Try to do your activities using healthy body and wrist alignment. Limit activities that require repeated motions, heavy grasping, and vibration in the hand. If you have surgery, it will take you longer to recover. Pain and symptoms generally begin to improve after surgery, but you may have tenderness in the area of the incision for several months. At first, take time during the day to support your healing arm with your hand elevated above the level of your heart. Move your fingers and thumb occasionally during the day. Keep the dressing on your hand until you return to the doctor. Avoid getting the stitches wet. Your stitches will be removed ten to fourteen days after surgery. Heavy gripping and pinching should be avoided for up to six weeks. These actions need to be avoided to keep the tendons from pushing out against the healing transverse ligament. After six weeks, you should be safe to resume gripping and pinching without irritating the wrist. You will probably need to attend occupational or physical therapy sessions for six to eight weeks, and you should expect full recovery to take several months. You'll begin doing active hand movements and range of motion exercises. Therapists use ice packs, soft-tissue massage, and hands-on stretching to help with the range of motion. When the stitches are removed, you may start carefully strengthening your hand by squeezing and stretching special putty. Therapists also use a series of "fist" positions to encourage the finger tendons to slide within the carpal tunnel. As you progress, your therapist will give you exercises to help strengthen and stabilize the muscles and joints in the hand. Other exercises are used to improve fine motor control and dexterity. Some of the exercises you'll do are designed to get your hand working in ways that are similar to your work tasks and sport activities. Your therapist will help you find ways to do your tasks that don't put too much stress on your hand and wrist. Before your therapy sessions end, your therapist will teach you a number of ways to avoid future problems. |
About Hand University | Hand School
| Expert Advice
Hand News | Other
Resources
Please click here to review our Privacy Policy
© Copyright 2001 Hand University, All Rights Reserved
