Physician's Resources: Neuropathy Treatment

Tarsal Tunnel Syndrome


THE PROBLEM
The numbness and tingling, burning or cramping you are feeling in your toes or your foot or heel is due to nerve compression, and called tarsal tunnel syndrome. A large nerve, the posterior tibial nerve, crosses behind your ankle, on the inside of your foot. Where the nerve crosses behind the ankle there is a tunnel with bone on the deep side and a fibrous roof above. Within this tunnel the large nerve divides into three branches, one to your foot, the plantar nerves. Each of the two plantar nerves, the medial and the lateral plantar nerves, have separate smaller tunnels just under the foot where compression may also occur. Even the smallest branch, the calcaneal to your heel, goes through a very tight fibrous tunnel and can become compressed.

Pressure on these nerves can come from either within the tunnel, such as occurs after a broken or badly sprained ankle, or from swelling within the nerve, such as occurs in association with medical problems like diabetes. Sometimes there may be arthritis of the ankle joint, a cyst or ganglion associated with the toe tendons or the ankle joint that causes the pressure upon the nerve. There are times when it is just not clear what has caused the problem.

When the nerves in these tunnels receive increased pressure, their blood flow decreases. When this happens, the nerve responds with alters sensations such as tingling and numbness. Sometimes this is so severe that it feels as if the foot is asleep. Often the symptoms are worse after standing or walking, when the fluid begins to collect in the foot. The small muscles may give you a cramping feeling as they begin to lose their nerve supply. If just the calcaneal branch is affected, the symptoms may seem much the same as a bone spur on the heel or of the plantar fasciitis, and inflammation along the bottom of the foot.

THE OPERATION
When all that can be done, by either medication or changing your activities or by orthotics, proves to be ineffective in relieving your symptoms, the last possible technique to help you is an operation to relieve the pressure upon the posterior tibial nerve and its branches. The operation requires an incision behind, but not too close to, the ankle bone, the ankle bone, or medial malleolus. The incision will continue down to, but usually not onto, the bottom or plantar aspect of your foot. Very small sensory nerve branches to the skin close to the ankle bone (from the saphenous nerve), and to the skin of the arch /heel (from the calcaneal nerve) need to be protected during surgery to prevent a painful scar.

The posterior tibial nerve is identified above the ankle, separated from its accompanying artery and vein and followed into the tarsal tunnel. Here the varying patterns for the origin of the calcaneal branches are observed and the calcaneal nerve or nerves decompressed. The posterior tibial nerve sometimes has split into the plantar nerves before it enters the tarsal tunnel, in which case the nerves occupy more space than usual in the tunnel and make it more likely for the tarsal tunnel syndrome to occur. The branching pattern of plantar nerves is observed and followed into the bottom of the foot, releasing the medial and lateral plantar tunnels just past the tarsal tunnel.

Any cysts or arthritic problems with the ankle joint may be corrected at this time. If there is scarring within the posterior tibial nerve or its branches, this is relieved by technique of internal neurolysis. During internal neurolysis, the outer layer of the nerve wrapping is opened and the scar tissue is removed from within the nerve. In those patients with symptoms of neuropathy due to multiple sites of nerve compression along multiple peripheral nerves , such as can occur with diabetes , other nerves in the leg may be decompressed at the same time as the posterior tibial nerve and its branches. In those patients with soft tissue ulcers from diabetes or circulation, the soft tissue ulcers may be repaired or the vascular blockages corrected at the same time as the tarsal tunnel release.

The dressing is a large bulky cotton wrapping that is designed to immobilize the ankle joints usually without the use of plaster. This bulky dressing is removed one week after surgery, so the foot can be washed and gentle ankle movements begun. Sutures remain for about three weeks.

COMPLICATIONS
The risk and complications from the operation include a permanent scar. The scar may become painful. Bleeding may occur as well as infection. Wound healing may be unpredictable in the foot and ankle area, especially if you have medical problems such as diabetes or arthritis, or are taking medications such as steroids that slow down the healing process. Even if your stitches have been left in for three weeks, your incision may open up as you begin walking or if your foot swells. This open wound will heal but may take two to eight weeks, during which time you will need dressing changes to prevent infection and dressing changes to promote healing. Rarely the wound may not close, and a skin graft may be required.

After the surgery as the sensation returns, there may be pain in the arch of the foot and the toes. This may last just a few days but may continue for up to three months. Especially if the nerve had degenerated (died), the regenerating nerve fibers may create shooting pains, hot or cold sensations all of which may feel worse than the condition for which you were treated. These disturbing regenerative phenomena are to be expected, may require additional or special medication, but are signs of healing within the nerve. As the regeneration returns to the small muscles of the foot, you may experience cramps, which, although disturbing, is also a good sign, and will stop in time.

These are not the only complications. Rarely the main nerves or their branches may be injured, and pain, swelling and stiffness may persist in your foot.

POST-OPERATIVE MANAGEMENT
For the first two weeks, at least, after surgery you will be using a walker or crutches. The majority of the time you will be seated or lying with your foot elevated to minimize swelling. If you need to stand or bear weight on your foot, you may. It is excessive ankle movement which will cause the sutures to tear through the skin, causing the wound to open and increase the risk of infection. At one week after surgery the large bulky dressing is removed and you can begin daily washing of your foot with soap and water. Usually at about three weeks the sutures are removed. You will begin weight bearing by standing in one place for increasing lengths of time. Attempt to walk by lifting your leg at the hip rather than by bending your ankle. You can wear slippers or large sneakers. At about three to six weeks if the healing is going smoothly but the scar is either thickening or becoming painful, you may begin to massage a steroid containing cream into your scar.

If you have persistent swelling in your foot you may be asked to wear support stockings or panty hose. If your foot remains swollen, it will be necessary for you to resume your activities more slowly.

RECOVERY PHASE
The recovery process occurs generally in two stages. The operation causes release of pressure on the nerve and blood flow improves in the nerve. Therefore, by the time the sutures are removed you may already have had relief of your symptoms. The parts of your symptoms that were due to scarring inside the nerve, such as persistent numbness in the toes or muscle wasting, will recover much more slowly. The nerve fibers must regenerate or grow into the muscle and into the tips of the toes. The nerves grow at about one inch per month. This process may be associated with some pain, as described under complications. You will continue to improve for at least one year.

This information should be reviewed with your doctor and any information not understood brought up discussed with him/her. It is hoped that this information may make you better aware of the operation, its potential benefits, risks, and complications, and help you in the recovery period following surgery.

Restore Sensation and Strength to you Hands and Feet

Optimism for Diabetic Neuropathy

INTRODUCTION
If you are diabetic, then almost certainly one of your doctors has told you about the complications of diabetes. Among the most common complication of diabetes is neuropath. Unfortunately, even with your blood sugar in good control, neuropathy may occur. In fact, over time, this will occur in up to 50% of diabetics. Once diabetic neuropathy occurs, it almost always gets worse. Currently, there is no agreement o why it occurs, and there is no medical treatment to prevent it.

While there are several different types of neuropathy that may occur in diabetics, the most common one affects the feet first, and then the hands. Usually, you will have begun to notice sensory changes, such as numbness or tingling in your fingers or toes. At first, these symptoms will come and go, but then they will be constant. These unpleasant symptoms may interfere with your going to sleep, or cause you to awaken fro sleep. Over a long period of time, these sensory disturbances may cause such a loss of sensibility that you will not feel how tight your shoes are, or know whether the bath water is hot or cold. Changes in muscles strength also occur. In the feet, the weakness may cause you to fall and the arches in your feet to collapse. In your hands, you will notice a problem opening jars, turning a key in a lock, loss of coordination and dropping objects

Neuropathy is the leading cause of the ulcerations or holes that occur in the feet. Neuropathy is the leading cause of infections in the feet. Neuropath is the leading cause of the loss of toes and, with advanced cases, amputation

The purpose of this is to provide you with information that is a new source of optimism for patients with diabetes. By having a yearly measurement made of the sensibility in your hands and fee, the earliest stages of neuropathy can be identified and appropriate changes I your diabetes management can be made. In certain circumstances, it may be found that areas are present in both your arms and legs that cause compression of your nerves. These sites of pressure on your nerves can be treated with surgery in order t restore sensation to your hands and feet.

WHY SHOULD NERVES IN THE DIABETIC BE Compressed?
Nerves begin in the spinal cord and extend into the fingers and toes. These exist in everyone and many are already known to you, such as your funny bone at the elbow and the carpal tunnel at the wrist. In the leg, there are similar tight places at the outside of your knee and the inside of your ankle, called the tarsal tunnel. Although some people may have been born with structures that would make the tunnels more narrow and the nerves more likely to become pinched, like a smaller wrist or extra muscles that go through one of these tunnels, the diabetic has two unique reasons to make nerves susceptible to compression.

The first reason that a diabetics nerves are susceptible to compression is that the nerves in a diabetic are swollen. Sugar from the blood enters into the nerve to give the nerve energy. This sugar, glucose, is converted into another sugar, called sorbitol. Sorbitolss chemical formula makes it attract water molecules, and so water is drawn into the nerve, causing the nerves in a diabetic to be swollen. This information has been known since 1978. It is my hypothesis that if a nerve swells in a place that is already tight, like those anatomic areas described above, then the nerve becomes pinched or compressed, causing symptoms.

The second reason is related to the transport systems within the diabetic nerve. The nerve is filled with a substance that lets important chemical messengers move along the nerve, carrying messages that let the nerves central part know what is happening at its other end. If the nerve becomes damaged, by compression, for example, and its cell membranes need to be rebuilt, these building proteins are transported downstream inside the cell along tracks called tubulin. This mechanism, called the slow anterograde component of axoplasmic transport, does not work normally in diabetics. This information has been known since 1979. It is my hypothesis that the decrease in axoplasmic transport means that the nerve cannot repair itself well, rendering it more likely to remain in trouble from compression, and therefore produce symptoms.

WHAT ARE THE SYMPTOMS OF NERVE COMPRESSION?
If someone were squeezing your neck, choking you, you would be yelling and screaming, struggling to get air into your lungs. If your nerve gets choked, or pinched, it also does not get enough oxygen. The nerve makes you aware of this lack of oxygen by sending you a warning message. You will feel buzzing, tingling or numbness in the areas that are supplied by that nerve. Therefore, if the median nerve in your wrist becomes compressed in the carpal tunnel and with the knowledge that the median mere supplies sensation to your thumb, index, middle and ring fingers, you can predict that compression of the median nerve at the wrist, called carpal tunnel syndrome, you cause symptoms in these fingers. Because your wrist bends at night when you sleep, these symptoms often begin at nighttime, or, if they are already present during the day, they will become worse at night. Because the median nerve goes to very few muscles, the only weakness that you may notice from compression of the median nerve at the wrist is related to a few thumb movements. A method to treat this nerve compression without surgery is to wear a splint that keeps the wrist from bending, minimizing pressure upon the median nerve.

The little finger is supplied by a nerve called the ulnar nerve, which can be compressed at either the elbow or in a small tunnel at the wrist next to the carpal tunnel. So if the little finger also has numbness and tingling, compression of the ulnar nerve must be considered. Because the ulnar nerve supplies many important muscles, compression of the ulnar nerve at the wrist level results problems pinching and controlling finger movements. Compression of the ulnar nerve at the elbow, called cubital tunnel syndrome, results in weakness of grip and pinch and loss of coordination. The ulnar nerve compression problem is made worse when the elbow is bent and therefore attempting to keep the elbow straight, perhaps with some type of splinting device as a reminder, is the most important non-surgical treatment available.

In the foot, the problem similar to carpal tunnel syndrome is called tarsal tunnel syndrome. It involves compression of the posterior tibial nerve in the bony tunnel on the inside of the ankle. This nerve supplies the entire bottom of the foot, including the heel. Compression of the posterior tibial nerve can result in numbness or tingling of the hell, the arch, the arch, the ball of the foot, and the bottom and tips of the toes, the loss of sensation in the feet can cause a loss of balance, a felling of unsteadiness, and can cause you to fall. Special inserts, called orthotics, may be placed into your shoes to relieve pressure on the tarsal tunnel. Special education for the care of the foot with poor will be required to teach you to minimize the dangers that can come from this impaired sensibility. A cane may be needed

THAT IS THE RELATIONSHIP BETWEEN NEUROPATHYAND NERVE COMPRESSION?
The most common form of nerve problem in the diabetic, diabetic neuropathy is a change in sensation in a stocking and glove distribution. This means that for your hand, the entire hand is affected, both the top and bottom, and all of the toes. These changes can be present up to the knee. The pattern of a neuropathy is usually the same for both the left and right hand and the left and right foot. The problem usually begins in your feet first. In contrast, nerve compression usually is thought of as one nerve in one arm or in one leg, and this suggests that with nerve compression, just part of one arm or of one leg would have the numbness pattern. This difference in the pattern if numbness associated with a nerve compression is one of the main reasons that doctors in the past have not considered that the symptoms of diabetic neuropathy as due to nerve compression.

The symptoms of diabetic neuropathy, of the sensorimotor polyneuropathy type, the most common type that we have been discussing thus far, are numbness and tingling, and weakness and are essentially the same as those of nerve compression.

But what if there is more than one nerve compression the arm or leg at the same time? Knowing that diabetes makes nerves susceptible to nerve compression and knowing that diabetes makes nerves susceptible to nerve compression and knowing that there are many areas of tightness that occur normally in everyone, it is possible that the diabetic could have more than one nerve compressed in each arm. If this were to be true, then multiple sites of nerve compression along the path of the nerves would give a stocking and glove pattern to the symptoms of numbness and tingling.

Another way to think about the relationship pf neuropathy according and nerve compression is that diabetes creates the neuropathy according to some metabolic process. This neuropathy then creates circumstances that allow nerve compression to occur. It is well-known and accepted that nerve compression can cause the symptoms of numbness, tingling and weakness. It is possible, then, to think that the nerve compressions are superimposed upon the underlying neuropathy. This means that at some point in time, both may be due to the sites of compression.

WHAT TYPE OF SURGERY CAN BE DONE?
Surgery that is well-known to restore sensation and strength to people with nerve compression, like carpal tunnel syndrome, can be done in patients with diabetes. Surgery to decompress the carpal tunnel is among the most common operations done in the United States. You probably know someone who has had this surgery. This type of surgery can be done in the arm, the hand, the leg and the foot. The surgery opens the tight area through which the nerve passes by dividing a ligament or fibrous hand that crosses the nerve. This gives the nerve more room, allows blood to flow better in the nerve and permits the nerve to glide with movements of nearby joints. If the diabetic has other complication of diabetes, retinopathy, with vision loss, then restoring sensation to the finger tips is essential for not only daily activity, but for reading braille.

HOW DOES THIS TYPE OF SURGERY HELP THE NERVE?
Decompression of a peripheral nerve in a person with diabetes can alter the natural course or history of diabetic neuropathy by removing the tight areas along the length of the nerve that are the symptomproducing regions of friction.

The surgery to decompress the nerve does not change the basic, underlying metabolic (diabetic) neuropathy that made the nerve susceptible to compression in the first place. When the surgical decompression is done early in the course of nerve compression, restoration of blood flow to the nerve will stop the numbness and tingling, and permit strength to recover. When the decompression is done late r in the course of nerve compression, and nerve fibers have begun to die, decompression of the nerve will permit the diabetic nerve to regenerate.

Of course, if you wait too long to decompress the nerve, recovery may not be possible. If you already have ulcerations on your feet, or have lost toes, then very little sensation may be recovered because the damage to the nerve has become irreversible.